From ???@??? Mon Nov 03 12:38:24 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA14631; Sun, 2 Nov 1997 19:59:50 -0600 (CST) Date: Sun, 2 Nov 1997 19:59:50 -0600 (CST) Message-Id: <01BCE7D1.0ADD7D00@rick.cnssys.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Richard M. Hambly" To: tacgps@tapr.org Subject: [TACGPS:810] TAC32 Version 1.0.16 is available X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BCE7D1.0AF76DA0" MIME-Version: 1.0 All TAC32 testers, Here is another release of the TAC32 software. There are quite a few changes that you should find interesting. I am working my way up to the point where every feature from Showtime is reflected in TAC32 so I can get to work on additional features that are not in Showtime. This release gets me another step of the way to that goal. Complete information and downloading directions are on the TAC32 Web page at http://www.cnssys.com/tac32/ As always, I look forward to your comments and suggestions. Rick WB2TNL Summary of the changes - BUG Fixes: Makes sure Motorola receivers are not left in idle mode. Corrected an error in the Set Serial Port/Search command which caused the result to always return "Mot NMEA". Corrected an error which sometimes prevented successful initialization, especially with Garmin receivers. New Features: Added GPS Week to the GPS Time window. Improved the raw data display for Motorola binary messages to show messages received but not decoded. Provide a full set of DOP information in Motorola binary mode. Display Average and Reference position data in the Navigation window. Permit the user to update the reference location from either the Current or the Average positions (go to the Data menu item). From ???@??? Mon Nov 03 12:38:53 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA21405; Sun, 2 Nov 1997 21:06:39 -0600 (CST) Date: Sun, 2 Nov 1997 21:06:39 -0600 (CST) Message-Id: <199711030258.VAA18598@aus-e.mp.campus.mci.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Donald E. Haselwood" To: tacgps@tapr.org Subject: [TACGPS:811] DOS Display program for GPS-30 X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" X-Mailer: Windows Eudora Light Version 1.5.2 Is there a DOS program around that will pick off the data from the GPS-30 (*without* the TAC board) and display the lat/long, etc.? A terminal program of course displays the raw "sentences" but it would be handy to have it displayed in fixed position screen format. I looked on the TAPR FTP, but didn't find one. It wouldn't take much effort to cobble up a program (but it takes even less to download one & I expect there are many that do this). 73's Don, W4DH From ???@??? Mon Nov 03 12:39:34 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA26512; Sun, 2 Nov 1997 22:23:35 -0600 (CST) Date: Sun, 2 Nov 1997 22:23:35 -0600 (CST) Message-Id: <01BCE7E5.990FAE40@rick.cnssys.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Richard M. Hambly" To: tacgps@tapr.org Subject: [TACGPS:812] RE: TAC32 and Motorola firmware update X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BCE7E5.99207720" MIME-Version: 1.0 Kohjin, I looked into your problem again. Are you running Windows NT or Windows 95. I found that for Windows NT you must make the change from the Administrator's account even if the user has the privilege which allows him to set the system clock. Also, the change must be made from the Control Panel's Date/Time program or from the system clock in the lowe right corner of the screen, not from the "Regional Settings" program. When I changed to UTC+9 and restarted TAC32 the time zone reported "Tokyo Standard Time" I noticed that TAC32 had to be restarted. That may be a bug, I'll have to check. In any case, the string describing the time zone is retrieved directly from the operating system. I do not keep the strings in TAC32. I doubt that the Japanese version would return the wrong string. Rick WB2TNL -----Original Message----- From: Kohjin Yamada [SMTP:kohjin@cosmos.marina.prug.or.jp] Sent: Friday, October 31, 1997 11:46 PM To: rick@cnssys.com Subject: Re: [TACGPS:806] RE: TAC32 and Motorola firmware update Hi Rick, Thanks for your response. I'm going to send this direct to you because I can't read the attached file at the end. I have tried all available programs but it were all failed. Seems you are you are using Microsoft mail, aren't you, mine is Eudora. Sorry but could you please send it again in an other file type? Before I send my comment to the tacgps mailing list, here's for you; At 16:10 97/10/31 -0600, you wrote: > Kohjin, > > Sorry for the delay. I've been out of town on business. > > TAC32 gets the time zone setting from the operating system. All Windows products ship with PST because that's where Microsoft is located. For Win95 open the Control panel and double click on Date/Time or just double click on the little clock in the lower right of your screen on the status bar. Select the Time Zone tab and set the time zone to whatever you like. TAC32 will follow these instructions, including daylight savings time offsets. It's only selectable from (GMT+09:00) for my QTH. Our Japanese version of Win95 seems to be different! No i.e; JST PST EST etc etc :-< So it's definitely true we need that option for all over the world! 73 & thanks, Kohjin JR1EDE From ???@??? Mon Nov 03 13:28:00 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA13801; Mon, 3 Nov 1997 12:49:42 -0600 (CST) Date: Mon, 3 Nov 1997 12:49:42 -0600 (CST) Message-Id: <345E1AD2.2EF8@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Dr Thomas A Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:814] Re: TAC32 Version 1.0.16 is available X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) Richard M. Hambly wrote: > > All TAC32 testers, > > Here is another release of the TAC32 software. There are quite a few changes that you should find interesting. I am working my way up to the point where every feature from Showtime is reflected in TAC32 so I can get to work on additional features that are not in Showtime. This release gets me another step of the way to that goal. > > Complete information and downloading directions are on the TAC32 Web page at http://www.cnssys.com/tac32/ > > As always, I look forward to your comments and suggestions. > > Rick > WB2TNL Since Rick's cnsys.com host has a fairly slow internet connection, I have mirrored his files (but not the "Install from Web") at ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/tac32/ The current files on aleph have a date/time stamp Nov.3 @ approx 13:30 and correspond to Rick's files of Nov.3 @ 01:45 73, Tom From ???@??? Mon Nov 03 20:56:22 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id UAA27812; Mon, 3 Nov 1997 20:43:54 -0600 (CST) Date: Mon, 3 Nov 1997 20:43:54 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: wb5kcm@juno.com (by way of Greg Jones, WD5IVD) To: tacgps@tapr.org Subject: [TACGPS:816] [MIC-E:1401] TAPR/Garmen GPS-30. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" I recently obtained one of the Garmen GPS-30 units from TPRS. It did not work in the original configuration. It was not receiving the satellites. I was watching the NMEA data from the DB9 connector using a nmea reader program and small interface unit. The plastic case was removed exposing the GPS-30PC engine and antenna. Removed the antenna connection from the GPS-30 engine and checked for the 5 volt supply for an active antenna. There was no 5 volts. Opened the metal cover near the antenna connection, this is where the RF components are enclosed. Traced along the PC Board from the center pin back and noticed a small solder pad near where the antenna line terminates. Found the 5 volts on this pad. Jumpered this over to the antenna side solder pad using a very small wire. Possibly the factory did not connect this wire in some of the units. Now reconnected the antenna and the GPS-30 immediately started receiving satellites and took a good fix. Replaced the metal cover on the RF box. If anyone else has purchased one of these units and its not working, may want to try this fix. DO THIS AT YOUR OWN RISK!...good luck... Randy Perkins (WB5KCM) wb5kcm@juno.com From ???@??? Mon Nov 03 21:28:21 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA29853; Mon, 3 Nov 1997 21:20:11 -0600 (CST) Date: Mon, 3 Nov 1997 21:20:11 -0600 (CST) Message-Id: <199711040240.LAA11848@cosmos.marina.prug.or.jp> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Kohjin Yamada To: tacgps@tapr.org Subject: [TACGPS:817] RE: TAC32 and Motorola firmware update X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="ISO-2022-JP" X-Mailer: Windows Eudora Pro Version 3.0-J (32) Demo Hi Rick, I'm running Windows 95 Japanese version. I'm sure it uses Japanese *fonts* for many applications including Date/Time. This must be same as many others like Germany, France, Asia etc using not ascii. So I think I can agree with you 'sending the wrong string' to TAC32. If these are found true, why don't you go for edit feature for local timezone. 73 and thanks for version 1.0.16 Kohjin, JR1EDE At 22:23 97/11/02 -0600, you wrote: > Kohjin, > > I looked into your problem again. Are you running Windows NT or Windows 95. I found that for Windows NT you must make the change from the Administrator's account even if the user has the privilege which allows him to set the system clock. Also, the change must be made from the Control Panel's Date/Time program or from the system clock in the lowe right corner of the screen, not from the "Regional Settings" program. > > When I changed to UTC+9 and restarted TAC32 the time zone reported "Tokyo Standard Time" I noticed that TAC32 had to be restarted. That may be a bug, I'll have to check. In any case, the string describing the time zone is retrieved directly from the operating system. I do not keep the strings in TAC32. I doubt that the Japanese version would return the wrong string. > > Rick > WB2TNL > > -----Original Message----- > From: Kohjin Yamada [SMTP:kohjin@cosmos.marina.prug.or.jp] > Sent: Friday, October 31, 1997 11:46 PM > To: rick@cnssys.com > Subject: Re: [TACGPS:806] RE: TAC32 and Motorola firmware update > > Hi Rick, > > Thanks for your response. > > I'm going to send this direct to you because I can't read the attached file > at the end. I have tried all available programs but it were all failed. > Seems you are you are using Microsoft mail, aren't you, mine is Eudora. > Sorry but could you please send it again in an other file type? > Before I send my comment to the tacgps mailing list, here's for you; > > At 16:10 97/10/31 -0600, you wrote: > > Kohjin, > > > > Sorry for the delay. I've been out of town on business. > > > > TAC32 gets the time zone setting from the operating system. All Windows > products ship with PST because that's where Microsoft is located. For Win95 > open the Control panel and double click on Date/Time or just double click on > the little clock in the lower right of your screen on the status bar. Select > the Time Zone tab and set the time zone to whatever you like. TAC32 will follow > these instructions, including daylight savings time offsets. > > It's only selectable from (GMT+09:00) for my QTH. > Our Japanese version of Win95 seems to be different! > No i.e; JST PST EST etc etc :-< > So it's definitely true we need that option for all over the world! > > 73 & thanks, Kohjin JR1EDE From ???@??? Tue Nov 04 01:42:33 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id BAA26171; Tue, 4 Nov 1997 01:13:45 -0600 (CST) Date: Tue, 4 Nov 1997 01:13:45 -0600 (CST) Message-Id: <345EC74D.7FD27CE4@deltanet.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Ray Grace To: tacgps@tapr.org Subject: [TACGPS:818] Re: [MIC-E:1401] TAPR/Garmen GPS-30. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 X-Mailer: Mozilla 4.02 [en]C-DIAL (Win95; U) I guess I was lucky, mine worked right out of the box. RX performance was poor in the Radio Shack, so I did mount the unit outdoors at about 20 feet. Now I can copy 7 to 8 satellites with SNR of 20-40dB. I have tested the unit using Street Atlas 5.0 and WAPRS205. Works great. Good luck with your repaired unit Ray - WA6OWM wa6owm@deltanet.com ===== by way of Greg Jones, WD5IVD wrote: > I recently obtained one of the Garmen GPS-30 units from TPRS. It did not > work in the original configuration. It was not receiving the satellites. > I was watching the NMEA data from the DB9 connector using a nmea reader > program and small interface unit. The plastic case was removed exposing > the GPS-30PC engine and antenna. Removed the antenna connection from the > GPS-30 engine and checked for the 5 volt supply for an active antenna. > There was no 5 volts. Opened the metal cover near the antenna connection, > this is where the RF components are enclosed. Traced along the PC Board > from the center pin back and noticed a small solder pad near where the > antenna line terminates. Found the 5 volts on this pad. Jumpered this > over to the antenna side solder pad using a very small wire. Possibly the > factory did not connect this wire in some of the units. Now reconnected > the antenna and the GPS-30 immediately started receiving satellites and > took a good fix. Replaced the metal cover on the RF box. If anyone else > has purchased one of these units and its not working, may want to try > this fix. DO THIS AT YOUR OWN RISK!...good luck... > > Randy Perkins (WB5KCM) > wb5kcm@juno.com From ???@??? Tue Nov 04 13:40:17 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA24698; Tue, 4 Nov 1997 12:44:00 -0600 (CST) Date: Tue, 4 Nov 1997 12:44:00 -0600 (CST) Message-Id: <199711041842.KAA14966@saiph.hpl.hp.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "James L. Johnson" To: tacgps@tapr.org Subject: [TACGPS:819] Re: [MIC-E:1401] TAPR/Garmen GPS-30. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII MIME-Version: 1.0 X-Mailer: ELM [version 2.4 PL21] In-Reply-To: from "by way of Greg Jones, WD5IVD" at Nov 3, 97 08:43:54 pm > antenna line terminates. Found the 5 volts on this pad. Jumpered this > over to the antenna side solder pad using a very small wire. Possibly the > factory did not connect this wire in some of the units. Now reconnected > the antenna and the GPS-30 immediately started receiving satellites and > took a good fix. Replaced the metal cover on the RF box. If anyone else > has purchased one of these units and its not working, may want to try > this fix. DO THIS AT YOUR OWN RISK!...good luck... > > Randy Perkins (WB5KCM) > wb5kcm@juno.com > > > Randy, Sounds like they didn't test this one before they shipped it out the door. Maybe they only sample-test ... maybe they don't final test at all. Risky business. Thanks for passing it on to others who may suffer the same problem or other problems that might have been caught by adequate testing. Jim W6SC jjohnson@hpl.hp.com From ???@??? Tue Nov 04 13:40:23 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id NAA01981; Tue, 4 Nov 1997 13:19:27 -0600 (CST) Date: Tue, 4 Nov 1997 13:19:27 -0600 (CST) Message-Id: <42639@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: clark@tomcat.gsfc.nasa.gov (Tom Clark -- W3IWI) To: tacgps@tapr.org Subject: [TACGPS:820] Re: [MIC-E:1401] TAPR/Garmen GPS-30. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Here is my gut feelining: The GPS30 has an internal non-amplified patch antenna. They may have omitted the antenna bias jumper because it isn't needed unless you use an external amplified antenna. Your finding that the jumper is needed is a useful contribution! You might want to make the jumper be a real RF Choke. Here is a hint -- take a pre-stripped 1" long piece of #30 wire-wrap wire (this makes the total length be ~3"). Wind the insulated portion of the wire on a small nail or drill-bit (like ~1/16" diameter) to make a coil. Then use this instead of a simple jumper wire. I've used such simple home-made RF chokes a lot of times for L/S-band applications. 73, Tom From ???@??? Wed Nov 05 13:36:13 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id NAA04644; Wed, 5 Nov 1997 13:04:52 -0600 (CST) Date: Wed, 5 Nov 1997 13:04:52 -0600 (CST) Message-Id: <3.0.3.32.19971105140055.008a0bd0@pop700.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Pat Kilroy To: tacgps@tapr.org Subject: [TACGPS:821] GPS30PC Simple Test & Preliminary Results X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) I connected my GPS30PC to a MIM module (obtained from http://www.agrelo.com/clement.html) and connected the MIM to a low-output transmitter. I saw no output from the little packet system on the system in my shack. In fact, the GPS30PC froze all MIM operations. Unplugging the GPS unit brought the MIM back to life, sans GPS telemetry. Substituting a GPS-45XL receiver, all worked dandy together. The next day I again set up on the picnic table in my backyard with a beautiful view of the Maryland sky. I connected the GPS30PC directly to a laptop PC and received kilobytes of NMEA 0183 sentences saved to disk using a simple terminal program. Appeared to be nominal operation. Example excerpt: $GPRMC,131922,A,3855.5527,N,07644.1954,W,0.0,000.0,301097,010.5,W*72 $GPGGA,131922,3855.5527,N,07644.1954,W,1,06,1.3,77.4,M,-34.1,M,,*47 $GPGSA,A,3,06,10,17,23,24,26,,,,,,,2.3,1.3,2.0*31 $GPGSV,2,1,07,06,51,241,44,10,34,060,44,17,38,312,44,23,21,264,41*72 $GPGSV,2,2,07,24,20,119,41,26,69,163,47,27,14,057,,,,,*48 $PGRME,59.1,M,92.8,M,110.0,M*20 $GPVTG,000.0,T,010.5,M,00.0,N,00.0,K*4A $GPRMC,131923,A,3855.5526,N,07644.1954,W,0.0,000.0,301097,010.5,W*72 $GPGGA,131923,3855.5526,N,07644.1954,W,1,06,1.3,77.3,M,-34.1,M,,*40 $GPGSA,A,3,06,10,17,23,24,26,,,,,,,2.3,1.3,2.0*31 $GPGSV,2,1,07,06,51,241,44,10,34,060,44,17,38,312,44,23,21,264,41*72 $GPGSV,2,2,07,24,20,119,41,26,69,163,47,27,14,057,,,,,*48 $PGRME,59.1,M,92.8,M,110.0,M*20 $GPVTG,000.0,T,010.5,M,00.0,N,00.0,K*4A $GPRMC,131924,A,3855.5527,N,07644.1948,W,0.0,000.0,301097,010.5,W*79 $GPGGA,131924,3855.5527,N,07644.1948,W,1,06,1.3,77.7,M,-34.1,M,,*4F $GPGSA,A,3,06,10,17,23,24,26,,,,,,,2.3,1.3,2.0*31 $GPGSV,2,1,07,06,51,241,44,10,34,060,44,17,38,312,44,23,21,264,41*72 $GPGSV,2,2,07,24,20,119,41,26,69,163,47,27,14,057,,,,,*48 $PGRME,59.1,M,92.8,M,110.0,M*20 $GPVTG,000.0,T,010.5,M,00.0,N,00.0,K*4A I disconnected the GPS30PC power for about 30 seconds. I was pleased to see that, after reconnection, it took less than 25 seconds to churn out meaningful data again. Well, that was a few days ago and now it's time to go back and check further to see why the GPS30PC won't talk to the MIM module. Any comments and suggestions accepted. More later. 73, Pat WD8LAQ From ???@??? Thu Nov 06 10:31:43 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id JAA14620; Thu, 6 Nov 1997 09:47:04 -0600 (CST) Date: Thu, 6 Nov 1997 09:47:04 -0600 (CST) Message-Id: <199711061543.HAA26772@grieg.holmsjoen.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Randolph Bentson To: tacgps@tapr.org Subject: [TACGPS:823] Re: Archive of TACGPS-list messages? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio There are lists for July, Aug & Sep in ftp://ftp.tapr.org/tapr/tac2/mail_archives/ I'm told the Oct list will appear soon, but it depends on a manual process. I don't know if there is/will be a current month list. Randolph Bentson bentson@grieg.seaslug.org http://www.ssc.com/ssc/insidelinux From ???@??? Fri Nov 07 11:45:21 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA17126; Fri, 7 Nov 1997 11:36:28 -0600 (CST) Date: Fri, 7 Nov 1997 11:36:28 -0600 (CST) Message-Id: <34634F60.61BACD7B@amsat.org> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Ronald G. Parsons" To: tacgps@tapr.org Subject: [TACGPS:824] [Fwd: TAC2] X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 X-Mailer: Mozilla 4.03 (Macintosh; I; PPC) Can someone help this person. Ron Josi Carlos de Andrade wrote: > > Dear Ron, > > I am mounting the KIT TAC2 as Dr. Trivedi had said yours. > First, thanks for your prompt answer. Well, I did mount all parts of kit > and i did all tests in hardware as explained in manual. Ok it's working > very well but when I connect it in a computer and run the software > SHOWTIME.bat included with the kit, happens the follow: > 1. The software can't find the signal DCD (1PPS) > 2. The software can't establish communications with the unit in any of > RS232 ports or speeds. > > I'm using an antenna with 40 cm of length and BNC connector without > polarization. > > Looking to a scope , I see a permanent signal (words) coming out in TX > of port RS232 (#1 or #2). > > For any answer please use my correct e-mail address: > andrade@yabae.cptec.inpe.br or andrade@coma.cptec.inpe.br > > JCA -- Ron W5RKN also: rparsons@bga.com From ???@??? Fri Nov 07 17:02:04 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA23905; Fri, 7 Nov 1997 12:32:29 -0600 (CST) Date: Fri, 7 Nov 1997 12:32:29 -0600 (CST) Message-Id: <34635E16.3DBA@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Dr Thomas A Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:825] Re: [Fwd: TAC2] X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) Ronald G. Parsons wrote: > > Can someone help this person. > > Ron > > Josi Carlos de Andrade wrote: > > > > Dear Ron, > > > > I am mounting the KIT TAC2 as Dr. Trivedi had said yours. > > First, thanks for your prompt answer. Well, I did mount all parts of kit > > and i did all tests in hardware as explained in manual. Ok it's working > > very well but when I connect it in a computer and run the software > > SHOWTIME.bat included with the kit, happens the follow: > > 1. The software can't find the signal DCD (1PPS) > > 2. The software can't establish communications with the unit in any of > > RS232 ports or speeds. Josi: Sounds to me like you do not have SHOWTIME pointing to the correct COM port on the computer. The search for the 1PPS on DCD happens outside of any serial port routines and involves looking for a change of state on the hardware pin, which is read with the absolute I/O port address associated with COM1/2. You didn't say what computer software you are using. If it is raw MessDOS, then it should read fine. If it is W95, then have you done any I/O port re-mapping? If it is NT, then SHOWTIME doesn't run at all since NT runs all I/O in protected mode. For either Windows 95 or NT, I recommend you get a copy of the new TAC32 software -- use the web and go to http://www.cnssys.com/tac32 and either use the "Install from the Web" option or fetch the file tac32s.exe by ftp. The tac32s.exe installation software is also available from ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/tac32/ You also did not state which GPS receiver you are using -- the Motorola ONCORE or the Garmin GPS-20. You probably want to join the tacgps Email group. Go to http://www.tapr.org and then click in the "SIGS" button -- near the bottom of the list you will see the TAC group's address. > > I'm using an antenna with 40 cm of length and BNC connector without > > polarization. 40 cm is waaaaaaaay too long -- for GPS a quarter-wave is 5 cm. A real GPS antenna is most recommended. > > Looking to a scope , I see a permanent signal (words) coming out in TX > > of port RS232 (#1 or #2). The ports #1 and #2 should be identical. > > For any answer please use my correct e-mail address: > > andrade@yabae.cptec.inpe.br or andrade@coma.cptec.inpe.br > > > > JCA > > -- > Ron W5RKN > > also: > rparsons@bga.com I wonder what group at INPE Josi is in. My original TACs are running at the radio telescopes (partially sponsored by INPE) at Fortaleza and Itapetinga (Atiabia) -- I visited both locations about 2 months ago. Tom Clark From ???@??? Fri Nov 07 20:44:34 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA22597; Fri, 7 Nov 1997 19:32:24 -0600 (CST) Date: Fri, 7 Nov 1997 19:32:24 -0600 (CST) Message-Id: <3463C14D.60190708@mindspring.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Thomas Mahaney To: tacgps@tapr.org Subject: [TACGPS:826] Motorola Oncore X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 X-Mailer: Mozilla 4.02 [en]C-DIAL (Win95; U) I wonder if someone could help me with a little problem the Oncore. It bought at the tapr booth in Dayton, and only recently got around to working with it. I bought one of the Rs232 bds and it seems to be working(oncore sees sats, I do test of the software on bd.) and I some exprience because I do have an pvt-6(rx is not working at this time.) My Main problem with Oncore is that it will not go into nmea(either informat command) or dosaprs(qbasic nmea) . Any thought on the matter Thanks Tom Kd4dKw From ???@??? Fri Nov 07 20:49:19 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id UAA27606; Fri, 7 Nov 1997 20:47:28 -0600 (CST) Date: Fri, 7 Nov 1997 20:47:28 -0600 (CST) Message-Id: <3463D12D.4659@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Tom Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:827] Re: Motorola Oncore X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) Thomas Mahaney wrote: > > I wonder if someone could help me with a little problem the Oncore. It > bought at the tapr booth in Dayton, and only recently got around to > working with it. I bought one of the Rs232 bds and it seems to be > working(oncore sees sats, I do test of the software on bd.) and I some > exprience because I do have an pvt-6(rx is not working at this time.) My > Main problem with Oncore is that it will not go into nmea(either > informat command) or dosaprs(qbasic nmea) . > Any thought on the matter > > Thanks > > Tom > Kd4dKw I presume the interface board you got is the "McKinney" board. It would be easiest to walk you thru the operation if you make it into a TAC clone, which involves adding one wire from pin 10 on the ONCORE 10-pin header (1PPS Out) to Pin 5 on the RS232 connector (DCD in). Then (assuming your computer can be "tricked" by feeding 0/+5 v into the DCD line and thinking it is RS232 -- this works on about 99% of the machines around) you will have a functional TAC and any of the TAC software will run on it. What you will have is shown in the "How to emulate a TAC" on my aleph file server: ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/emulate.zip (you will find both a PostScript and GIF drawing in emulate.zip -- the wire I said to add is shown in the lower left corner of the drawing). The problem may you are having comparing the ONCORE VP with the PVT-6 is probably due to the fact that Motorola added a new set of 8-channel binary commands to the original 6-channel set. You didn't say what computer you are using. In dumb old MessDOS, my SHOWTIME software will handle both the 6- and 8-channel versions. Go to ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/ and pick up the file success.tac for a pretty simple cookbook. Then go to ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/distribution/ and look at README, then fetch the showtime_v334.zip file. When you do what README tells you, you will have both my SHOWTIME code and also Motorola's latest 6- or 8-channel controller software (in \tac\zip\motorola.zip). If you are running in W95/NT, fetch Rick (WB2TNL) TAC32 code at http://www.cnssys.com/tac32 If you have trouble reaching Rick's host, you should fetch ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/tac32/tac32s.exe which is mirrored from ftp.cnssys.com Hope this helped -- 73, Tom From ???@??? Fri Nov 07 23:55:53 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA05442; Fri, 7 Nov 1997 22:25:11 -0600 (CST) Date: Fri, 7 Nov 1997 22:25:11 -0600 (CST) Message-Id: <199711080530.VAA27232@mail.redshift.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Doug McKinney" To: tacgps@tapr.org Subject: [TACGPS:828] Re: Motorola Oncore X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: multipart/mixed; boundary="----=_NextPart_000_01BCEBBA.4CFFACC0" MIME-Version: 1.0 X-Mailer: Microsoft Internet Mail 4.70.1161 ---------- > From: Thomas Mahaney > To: tacgps@tapr.org > Subject: [TACGPS:826] Motorola Oncore > Date: Friday, November 07, 1997 5:32 PM > > I wonder if someone could help me with a little problem the Oncore. It > bought at the tapr booth in Dayton, and only recently got around to > working with it. I bought one of the Rs232 bds and it seems to be > working(oncore sees sats, I do test of the software on bd.) and I some > exprience because I do have an pvt-6(rx is not working at this time.) My > Main problem with Oncore is that it will not go into nmea(either > informat command) or dosaprs(qbasic nmea) . > Any thought on the matter > > Thanks > > Tom > Kd4dKw Tom, Attached is an applications note I wrote for NMEA ops. This should get you going. What I don't know is if you have the PC Controller software, if you do, then you can enter on the command line ioformat nmea. At that point the PC Controller is not useable and you need to type quit, at the command line. The ioformat nmea commands the ONCORE from 9600 8N1 to 4800 8N1. You now can use ProComm to talk to the ONCORE. PC Controller doesn't work in NMEA mode. Tom Clark's TAC2 software has a GPS.BAT, which executes the latest Motorola PC Controller software under the Directory BIN. Good luck. Doug Content-Type: application/octet-stream; name="NMEA ops.doc" Content-Description: NMEA ops.doc (WordPad Document) Content-Disposition: attachment; filename="NMEA ops.doc" Attachment converted: Power Mac:NMEA ops.doc 2 (WDBN/MSWD) (0002ACB9) From ???@??? Fri Nov 07 23:56:05 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id WAA05876; Fri, 7 Nov 1997 22:32:59 -0600 (CST) Date: Fri, 7 Nov 1997 22:32:59 -0600 (CST) Message-Id: <3463E9B3.11A3@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Tom Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:829] Re: [Fwd: TAC2] X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) Jose -- after reading another Email from you, I see that you are using Garmin GPS-20 receivers. The GPS-20 will not produce a 1PPS output signal until after it has locked onto GPS satellite signals. The GPS-20 does not have very high sensitivity. Since you said that your antenna was a 40 cm (2 wavelength) piece of wire, I now believe that your problem is that your antenna is so poor that it is not seeing any satellites! If you look at the RS232 NMEA messages with a terminal program like PROCOMM, you should see a message beginning with $GPGSA. The format of this message is like $GPGSA,am,N,x,x,x,x,x,x,x,x,p,h,v am=either A or M for automatic or manual mode N = 1 if not tracking, 2 if 2-D tracking or 3 if 3-D tracking x,x,x... are the PRN satellite numbers being tracked (up to 8) by the receiver. If less than 8 satellites are being tracked, some of the x values are replaced by a , so you will see a sting of commas (like ,,,,,,,). At the end of the of the message, p,h,& v are the PDOP, HDOP and VDOP values for the satellites being tracked. If you see here it again says that you are not trqacking enough satellites. After you connect a real antenna, let the receiver observe the sky for a while, until you see a $GPGSA message that does not have long strings of ,,,,,,,, -- Then (only after it is tracking GPS satellites) will the GPS-20 start generating 1PPS output signals. When it is generating 1PPS signals, then SHOWTIME will allow the initial test to pass. Sorry that I was confused about which type of receiver you are using. Tom Clark From ???@??? Fri Nov 07 23:56:07 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id XAA08700; Fri, 7 Nov 1997 23:12:01 -0600 (CST) Date: Fri, 7 Nov 1997 23:12:01 -0600 (CST) Message-Id: <3463F2B9.15B1@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Tom Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:830] Re: GPS Time vs UTC Time X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) John Palmer wrote: > > Can anyone tell me the reason for the time difference between UTC time > and GPS time? > > GPS time is 11 seconds ahead of UTC as observed by simultaneous > monitoring WWV and the clock on a GPS receiver. > > Thanks, > > John, WA0NTT Stewart Nelson's answer was correct. Let me add a bit more. a. The current offset GPS-UTC is 12 seconds, since Jan 1.0 1997 (not 11 as in your message) b. In doing calculations of position, your receiver internally uses GPS time to guarantee that there aren't any discontimuities. Last New Year's Day there was a one second Leap-second discontinuity. The satellites move at speeds of 7 km/sec and such a discontinuity would have totally screwed up navigation all around the world if the receivers were internally running in UTC! c. But the existence of GPS time can be TOTALLY IGNORED by GPS users. The GPS satellites broadcast the conversion from GPS to UTC time continuously.[A few early receivers ignored this broadcast info and had the GPS-UTC offset hard-coded in ROM. Such receivers did display really screwy timing. But I know of no rcvrs made in the past couple of years that have this flaw]. Your receiver internally knows both GPS and UTC time and displays UTC to you. The display of the time is a low priority task, so the displayed time (and the time in the RS232 NMEA messages) often lags "truth" by a fraction of a second. Your message said "... by monitoring WWV and the clock on a GPS receiver." -- I know of few (if any) user-class GPS receivers that normally display GPS time -- they ALLshow UTC! d. Inside your receiver, time is known to a fraction of a microsecond. Some GPS receivers (OEM boards, not hand-helds) generate accurate 1PPS timing signals. For several years, I've been working on my "Totally Accurate Clock" (TAC) project. With Motorola ONCORE OEM receivers, I'm able to get long-term precision (smoothness) and accuracy (comparing the TAC with the USNO's Master Clock) at levels of 20-30 nanoseconds (remember 1 nsec is the time it take light to travel 1 foot). TAPR has now made the TAC-2 available as a kit. You can see info on the TACs on TAPR's web site at http://www.tapr.org and then click on the "W3IWI/TAC-2" button and on my ftp file server at ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/ where you will see GIF plots showing the performance of the TAC at sites all around the world. e. FYI -- the next phase of the TAPR TAC project is to develop a board that will lock a good crystal to GPS to achieve Rubidium to Cesium performance levels. We expect to achieve accuracy levels better than 1:10e10 -- meaning frequency accuracy at 10 GHz of 1 Hz or better! f. Stewart pointed you to the WECA club web pages, and I didn't see much of relevance to the subject. Instead, you might want to surf the US Naval Observatory's site at http://tycho.usno.navy.mil 73 de Tom, W3IWI From ???@??? Sat Nov 08 00:56:36 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id AAA15107; Sat, 8 Nov 1997 00:04:16 -0600 (CST) Date: Sat, 8 Nov 1997 00:04:16 -0600 (CST) Message-Id: <3463FFF4.6305@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Tom Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:831] Re: Motorola Oncore X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) Doug McKinney wrote: > > Tom, Attached is an applications note I wrote for NMEA ops. This should > get you going. What I don't know is if you have the PC Controller > software, if you do, then you can enter on the command line ioformat nmea. > At that point the PC Controller is not useable and you need to type quit, > at the command line. The ioformat nmea commands the ONCORE from 9600 8N1 > to 4800 8N1. You now can use ProComm to talk to the ONCORE. PC Controller > doesn't work in NMEA mode. Tom Clark's TAC2 software has a GPS.BAT, which > executes the latest Motorola PC Controller software under the Directory > BIN. Good luck. > Doug Good posting, Doug. One small thing -- for the older 6-channel receivers, where your text shows @@Ea, the user should substitute @@Ba. There are several other of the proprietary commands where @@E* translates to @@B*. In SHOWTIME, I send both commands when these cases happen -- the receiver ignores the one that is not applicable. Rick's TAC32 also handles both the old/new 6/8 channels cases. Tom From ???@??? Sat Nov 08 09:55:09 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id JAA11316; Sat, 8 Nov 1997 09:41:51 -0600 (CST) Date: Sat, 8 Nov 1997 09:41:51 -0600 (CST) Message-Id: <3.0.1.32.19971108103616.0081e490@pop.gate.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Steven R. Bible" To: tacgps@tapr.org Subject: [TACGPS:832] Re: DOS Display program for GPS-30 X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <199711030258.VAA18598@aus-e.mp.campus.mci.net> X-Mailer: Windows Eudora Light Version 3.0.1 (32) Don, I didn't see an answer to your post on the TACGPS list. Take a look at Peter Bennett's FTP site at ftp://sundae.triumf.ca/pub/peter/index.html There are dozens of programs to choose from. 73, Steve N7HPR At 09:06 PM 11/2/97 -0600, you wrote: >Is there a DOS program around that will pick off the data from the GPS-30 >(*without* the TAC board) and display the lat/long, etc.? > >A terminal program of course displays the raw "sentences" but it would be >handy to have it displayed in fixed position screen format. I looked on the >TAPR FTP, but didn't find one. It wouldn't take much effort to cobble up a >program (but it takes even less to download one & I expect there are many >that do this). > >73's >Don, W4DH > > - Steve, N7HPR (n7hpr@tapr.org) From ???@??? Sat Nov 08 12:55:05 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA02320; Sat, 8 Nov 1997 12:45:53 -0600 (CST) Date: Sat, 8 Nov 1997 12:45:53 -0600 (CST) Message-Id: <199711081841.NAA24932@aus-d.mp.campus.mci.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Donald E. Haselwood" To: tacgps@tapr.org Subject: [TACGPS:833] Xtal locked to GPS X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" X-Mailer: Windows Eudora Light Version 1.5.2 >e. FYI -- the next phase of the TAPR TAC project is to develop a board > that will lock a good crystal to GPS to achieve Rubidium to Cesium > performance levels. We expect to achieve accuracy levels better > than 1:10e10 -- meaning frequency accuracy at 10 GHz of 1 Hz or > better! >73 de Tom, W3IWI > I noticed the above in Re: [TACGPS:830] Re: GPS Time vs UTC Time. 1. Any rough time frame when the board might be available? (months, years, decades, eons?) I like to keep a rough plan of future projects in mind. The idea of shack freq standard has been a project (very low on the list) for at least 35 years...maybe the time to do it is about to arrive! 2. Could you say something about the scheme and error sources/control? I tinkered with a digital phase-lock of a M6800 micro to WWVB some 15-20 years ago. I concluded that the minimum bandwidth of the phase-locked loop, and hence the deviation from the received WWVB, was set by the rate of frequency change due to temp changes. I haven't analyzed the GPS situation, but seat-of-the-pants suggests that in achieving 1 part in 10e10 things such as xtal freq drift due to temp will be noticeable during the 1 second intervals between xtal & gps comparisons. Very interesting project! Regrads, Don, W4DH From ???@??? Sat Nov 08 21:26:14 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA12133; Sat, 8 Nov 1997 21:10:40 -0600 (CST) Date: Sat, 8 Nov 1997 21:10:40 -0600 (CST) Message-Id: <3.0.2.32.19971108220213.0069292c@rio.atlantic.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Bob Johnson To: tacgps@tapr.org Subject: [TACGPS:834] Re: GPS Time vs UTC Time X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" X-Mailer: QUALCOMM Windows Eudora Light Version 3.0.2 (32) >Subject: Re: GPS Time vs UTC Time >> Can anyone tell me the reason for the time difference between UTC time >> and GPS time? >> >> GPS time is 11 seconds ahead of UTC as observed by simultaneous >> monitoring WWV and the clock on a GPS receiver. >> >> Thanks, >> >> John, WA0NTT > [most of replies omitted...] >c. But the existence of GPS time can be TOTALLY IGNORED by GPS users. > The GPS satellites broadcast the conversion from GPS to UTC time > continuously.[A few early receivers ignored this broadcast info > and had the GPS-UTC offset hard-coded in ROM. Such receivers did > display really screwy timing. But I know of no rcvrs made in the > past couple of years that have this flaw]. Your receiver internally > knows both GPS and UTC time and displays UTC to you.[...] Perhaps his receiver is similar to my (very early) Magellan Trailblazer. On its default "POSITION" display (showing the current fix), it typically displays time that is several seconds behind the correct time (I just went out and got a fix: it was four seconds behind UTC, while on other days I think I've seen up to eight seconds). In another display mode (the AUX/SETUP menu) it displays the correct UTC time. I finally decided (after re-reading the manual) that the time on the "current fix" display is the time at which that fix was valid, which apparently can lag real time by several seconds. Presumably this is due to the algorithm it uses to reconcile data obtained from sequentially-scanned satellites, and I guess it would vary depending on how many satellites are being tracked. -- Bob Johnson WB4JCM@amsat.org -- Bob Johnson Above comments are personal and are not intended to reflect the official position of any other person or corporation. From ???@??? Sun Nov 09 01:25:23 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id BAA14847; Sun, 9 Nov 1997 01:24:04 -0600 (CST) Date: Sun, 9 Nov 1997 01:24:04 -0600 (CST) Message-Id: <346563CC.6ABF@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Tom Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:835] Re: GPS Time vs UTC Time X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) Bob Johnson,WB4JCM wrote: [SNIP] > Perhaps his receiver is similar to my (very early) Magellan Trailblazer. > On its default "POSITION" display (showing the current fix), it typically > displays time that is several seconds behind the correct time (I just went > out and got a fix: it was four seconds behind UTC, while on other days I > think I've seen up to eight seconds). In another display mode (the > AUX/SETUP menu) it displays the correct UTC time. I finally decided (after > re-reading the manual) that the time on the "current fix" display is the > time at which that fix was valid, which apparently can lag real time by > several seconds. Some of the early receivers (circa 1992-3) had a firmware flaw that the GPS-UTC offset (i.e. accumulated leapseconds) was hardcoded (I recall one case when it was fixed at 7 or 8 seconds) rather than taking the current offset (and pending leapsecond status) from the 1500 bit GPS navigation message. I don't recall which brand it was for sure, but I think it began with "M". To my knowledge, all current receivers properly pick up the leapsecond from the nav message. If you do a dump of NMEA messages on either the Motorola or Garmin OEM boards every ~18 months when a leapsecond happens, they properly report the seconds as ...57,58,59,60,00,01... Just to set the record straight, my SHOWTIME code has a simplifying approximation so it will display (not qite correctly) the seconds as ...57,58,59,00,00,01... when a leapsecond happens. I don't know about Rick's TAC32 code but I suspect it will does the same thing. In case you wonder why, the reason is that we read the UTC time from the serial data port (which arrives late, at an indeterminate epoch mid-second), and then increment the time to the next second in the software, and finally act on the incremented value when the hardware 1PPS signal arrives on the RS232 DCD line. 73, Tom From ???@??? Mon Nov 10 01:31:57 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id AAA26046; Mon, 10 Nov 1997 00:44:54 -0600 (CST) Date: Mon, 10 Nov 1997 00:44:54 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:836] Status of GPS30PC Purchase X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" TAPR was able to get another 50 GPS30PC's from Garmin after we closed the purchase to handle the people that where calling wanting an extra unit here or there. This was on top of the 50 we ordered above the group purchase number. So ---- Dorothy has reported that we have an extra 20 or so GPS30PC left over for various reasons. If you want a GPS30PC as part of the $99 group purchase call Dorothy starting Tuesday (940) 383-0000 with Credit information handy. For details can be found on http://www.tapr.org I expect these to go fast! Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Tue Nov 11 14:41:39 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA07215; Tue, 11 Nov 1997 14:36:28 -0600 (CST) Date: Tue, 11 Nov 1997 14:36:28 -0600 (CST) Message-Id: <01BCEEB7.930A8FA0@rick.cnssys.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Richard M. Hambly" To: tacgps@tapr.org Subject: [TACGPS:837] Re: TAC32 Version 1.0.16 is available X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 To all TAC32 testers, I have followed up on Tom's concern about slow download time. Effective immediately, all the files associated with InstallFromTheWeb, PackageFromTheWeb and FTP have been mirrored on one of my ISP's high speed servers. This should improve installation and download performance, especially for those of you with high speed Internet access. This should relieve Tom of the need to mirror the files. You still go to http://www.cnssys.com/tac32 with your browser regardless of which type of installation or download you want. Access to the new server is totally transparent for FTP and PackageForTheWeb. For InstallFromTheWeb you will be asked which server you want to load from. Choose "ClarkNet" to access the new high speed server and avoid the slower and sometimes congested lines to my company's server. Now that I am back from two weeks on the road I will begin work on the remaining new features and the bugs which a couple of you have reported. Thanks, Rick WB2TNL -----Original Message----- From: Dr Thomas A Clark (W3IWI) [SMTP:clark@tomcat.gsfc.nasa.gov] Sent: Monday, November 03, 1997 1:50 PM To: tacgps@tapr.org Subject: [TACGPS:814] Re: TAC32 Version 1.0.16 is available Richard M. Hambly wrote: > > All TAC32 testers, > > Here is another release of the TAC32 software. There are quite a few changes that you should find interesting. I am working my way up to the point where every feature from Showtime is reflected in TAC32 so I can get to work on additional features that are not in Showtime. This release gets me another step of the way to that goal. > > Complete information and downloading directions are on the TAC32 Web page at http://www.cnssys.com/tac32/ > > As always, I look forward to your comments and suggestions. > > Rick > WB2TNL Since Rick's cnsys.com host has a fairly slow internet connection, I have mirrored his files (but not the "Install from Web") at ftp://aleph.gsfc.nasa.gov/GPS/totally.accurate.clock/tac32/ The current files on aleph have a date/time stamp Nov.3 @ approx 13:30 and correspond to Rick's files of Nov.3 @ 01:45 73, Tom From ???@??? Wed Nov 12 10:24:16 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA25195; Wed, 12 Nov 1997 10:13:20 -0600 (CST) Date: Wed, 12 Nov 1997 10:13:20 -0600 (CST) Message-Id: <199711121610.KAA14496@mail.tds.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "tom dennis" To: tacgps@tapr.org Subject: [TACGPS:838] Motorola GPs X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain MIME-Version: 1.0 X-Mailer: Microsoft Internet Mail 4.70.1155 Would anyone know about the Motorola model T5398A. It also has a model # PUT602N323. How about wiring to a computer? Software? It has a nine pin RS232 port and a antenna connection only. Thanks Tom From ???@??? Wed Nov 12 19:37:32 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA06057; Wed, 12 Nov 1997 19:27:16 -0600 (CST) Date: Wed, 12 Nov 1997 19:27:16 -0600 (CST) Message-Id: <3.0.3.32.19971112191413.0099ac20@199.1.11.3> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: mdmiller@onramp.net To: tacgps@tapr.org Subject: [TACGPS:839] Re: Motorola GPs X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <199711121610.KAA14496@mail.tds.net> X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) I am not familiar with that part number, but if it is 19" rackmountable I would bet that there is a Motorla Basic or Oncore in inside of it. Do you know what is was used for? Mark Miller N5RFX At 10:13 AM 11/12/97 -0600, you wrote: >Would anyone know about the Motorola model T5398A. It also has a model # >PUT602N323. How about wiring to a computer? Software? It has a nine pin >RS232 port and a antenna connection only. >Thanks >Tom > > > From ???@??? Wed Nov 12 19:52:31 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id TAA07840; Wed, 12 Nov 1997 19:37:26 -0600 (CST) Date: Wed, 12 Nov 1997 19:37:26 -0600 (CST) Message-Id: <3.0.3.32.19971112193115.009a1860@199.1.11.3> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: mdmiller@onramp.net To: tacgps@tapr.org Subject: [TACGPS:840] TAC32 Problems X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" X-Mailer: QUALCOMM Windows Eudora Pro Version 3.0.3 (32) I have had problems keeping TAC32 running for more than about 12 hours. Most of the time it locks up my computer(after 12 hours), I have had 1 instance of an out of memory message and one message shown below: TAC32 caused an invalid page fault in module MFC42.DLL at 0137:5f40129c. Registers: EAX=00000000 CS=0137 EIP=5f40129c EFLGS=00010246 EBX=5f4cbe38 SS=013f ESP=00e3fa94 EBP=00e3fac8 ECX=00000000 DS=013f ESI=008245f0 FS=25d7 EDX=00000003 ES=013f EDI=005c022c GS=1dbe Bytes at CS:EIP: 8b 71 04 85 f6 57 74 26 8b 7c 24 0c 33 d2 8b c7 Stack dump: 008245f0 5f4119b5 00000ca4 5f4cbe38 005c022c 005c0160 5f41b40d 00000001 005c0160 005c0160 00e3fc40 5f48f6b4 00000000 00e3faec 5f404a5a 005c027c The computer TAC32 runs on is a 486 DX2 50 Windows 95 with 12 MB of ram. The GPS is a VP Oncore connected to a TAC2 kit. The TAC32 version is 1.1.16 Any ideas? 73 Mark Miller N5RFX From ???@??? Thu Nov 13 14:14:29 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA05068; Thu, 13 Nov 1997 14:00:36 -0600 (CST) Date: Thu, 13 Nov 1997 14:00:36 -0600 (CST) Message-Id: <01BCF043.FAF27500@rick.cnssys.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Richard M. Hambly" To: tacgps@tapr.org Subject: [TACGPS:841] RE: TAC32 Problems X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BCF043.FAFA1620" MIME-Version: 1.0 Mark, This is a new one on me. I have had TAC32 running for weeks without a problem. Looks like it is getting swapped out of memory into the swap area on disk but that shouldn't cause this problem. I have an old 486 with 16Mb ram which I will load the software on to test for this condition. Rick WB2TNL -----Original Message----- From: mdmiller@onramp.net [SMTP:mdmiller@onramp.net] Sent: Wednesday, November 12, 1997 8:37 PM To: tacgps@tapr.org Subject: [TACGPS:840] TAC32 Problems I have had problems keeping TAC32 running for more than about 12 hours. Most of the time it locks up my computer(after 12 hours), I have had 1 instance of an out of memory message and one message shown below: TAC32 caused an invalid page fault in module MFC42.DLL at 0137:5f40129c. .. Any ideas? 73 Mark Miller N5RFX From ???@??? Fri Nov 14 16:47:46 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA22292; Fri, 14 Nov 1997 15:36:45 -0600 (CST) Date: Fri, 14 Nov 1997 15:36:45 -0600 (CST) Message-Id: <46c7de66@bilow.bilow.uu.ids.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: mikebw@bilow.bilow.uu.ids.net (Mike Bilow) To: tacgps@tapr.org Subject: [TACGPS:842] TAC32 Problems X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio X-Mailer: uugate 0.34 (OS/2 2.30) mdmiller wrote in a message to Mike Bilow: m> I have had problems keeping TAC32 running for more than m> about 12 hours. Most of the time it locks up my m> computer(after 12 hours), I have had 1 instance of an out of m> memory message and one message shown below: m> TAC32 caused an invalid page fault in m> module MFC42.DLL at 0137:5f40129c. m> Registers: m> EAX=00000000 CS=0137 EIP=5f40129c EFLGS=00010246 m> EBX=5f4cbe38 SS=013f ESP=00e3fa94 EBP=00e3fac8 m> ECX=00000000 DS=013f ESI=008245f0 FS=25d7 m> EDX=00000003 ES=013f EDI=005c022c GS=1dbe m> Bytes at CS:EIP: m> 8b 71 04 85 f6 57 74 26 8b 7c 24 0c 33 d2 8b c7 m> Stack dump: m> 008245f0 5f4119b5 00000ca4 5f4cbe38 005c022c 005c0160 m> 5f41b40d 00000001 005c0160 005c0160 00e3fc40 5f48f6b4 m> 00000000 00e3faec 5f404a5a 005c027c m> The computer TAC32 runs on is a 486 DX2 50 Windows 95 with m> 12 MB of ram. The GPS is a VP Oncore connected to a TAC2 m> kit. The TAC32 version is 1.1.16 Well, I suppose that my first posting on this list should be something I don't really know anything about! I'm no Win32 expert, but what is going on here looks from the dump like copying from the code segment. It is common for Windows compilers to keep constant data in the code segment, for a lot of good reasons. However, code segments are "discardable," meaning that they are never swapped to disk because they are never modified, so Windows will simply reload them as needed from the original file. This is Ring 3 code running -- you can see that immediately from the selector values -- so Windows should have intercepted any attempt to access an invalid page and handled it by reloading the page. If this didn't happen, the most likely cause is that you were out of memory, or at least your process was. Even if the process is not leaking memory, it might be leaking LDT descriptors, especially if it is frequently accessing a device through a driver, and that would cause this sort of fault. Another very slim possibility is that your disk could have a problem, and that Windows is not handling the error very gracefully. For example, if you have power management enabled and you allow your disk to spin down after inactivity, then you could see this kind of fault under certain circumstances. -- Mike, N1BEE From ???@??? Fri Nov 14 16:47:52 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id QAA05649; Fri, 14 Nov 1997 16:33:41 -0600 (CST) Date: Fri, 14 Nov 1997 16:33:41 -0600 (CST) Message-Id: <97Nov14.162625cst.26881@texas.dsatex.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Chandler, Jim" To: tacgps@tapr.org Subject: [TACGPS:843] JAVA GPS Display X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Version 1.0 of a JAVA GPS display program for use with the Garmin GPS30PC in located on the tapr ftp site under software_lib/upload. Run GPSDISP.exe to extract a readme and another executable that will install the program. Even though this is a JAVA application, it currently will only run on a PC (see the readme file). I hope to upgrade and enhance this program soon. Jim, N0VH jchandle@flash.net, n0vh@juno.com From ???@??? Wed Nov 19 09:46:02 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id JAA06507; Wed, 19 Nov 1997 09:28:58 -0600 (CST) Date: Wed, 19 Nov 1997 09:28:58 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Henk Uijterwaal (RIPE-NCC)" To: tacgps@tapr.org Subject: [TACGPS:844] Antenna cables. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: TEXT/PLAIN; charset=US-ASCII I have to install a TAC plus (Motorola) GPS antenna at a remote site. The TAC will be sitting in a computer room and the antenna on the roof of the building. There are already cables running from the computerroom to the roof. The Motorola manual says that the input impedance of the antenna is 50 Ohm, so, with my limited knowledge of these things, I'd expect that I'd have to use 50 Ohm coaxial cable to connect them. However, the impedance of the cables that are running to the computer room is 75 Ohm. Does anybody know if one can just use these cables, if there is any trick to use them or should we run a new cable? Henk ------------------------------------------------------------------------------ Henk Uijterwaal Email: henk.uijterwaal@ripe.net RIPE Network Coordination Centre WWW: http://www.ripe.net/home/henk Singel 258 Phone: +31.20.535-4414, Fax -4445 1016 AB Amsterdam Home: +31.20.6651962 The Netherlands Pager: +6.57626855 ------------------------------------------------------------------------------ %DCL-E-NOCFFE, unable to locate coffee - keyboard input suspended. From ???@??? Wed Nov 19 16:41:47 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA23497; Wed, 19 Nov 1997 15:41:27 -0600 (CST) Date: Wed, 19 Nov 1997 15:41:27 -0600 (CST) Message-Id: <4731e401@bilow.bilow.uu.ids.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk X-UIDL: 879976830.000 From: mikebw@bilow.bilow.uu.ids.net (Mike Bilow) To: tacgps@tapr.org Subject: [TACGPS:845] GPS-30 TAPR special purchase: connectors? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio X-Mailer: uugate 0.34 (OS/2 2.30) Status: U I just received one of the GPS-30 special purchase units from TAPR. This is the GPS-20 board encased in a sealed housing, which I have removed. There is an unusual connector on the GPS-20 which is used to interface it to the rest of the world. However, the TAC-2 documentation just says that, if you ordered the GPS-20 from TAPR, it would come with the necessary connector. On the connector that comes inside the GPS-30, there are no female pins for any of the unwired signals, although there is a plastic shell for the connector. The key issue, obviously, is that I want to attach to 1 PPS. How can I get the connector, or at least some female pins for the shell I have? -- Mike, N1BEE From ???@??? Wed Nov 19 16:41:48 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA23526; Wed, 19 Nov 1997 15:41:56 -0600 (CST) Date: Wed, 19 Nov 1997 15:41:56 -0600 (CST) Message-Id: <4731e400@bilow.bilow.uu.ids.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk X-UIDL: 879976830.001 From: mikebw@bilow.bilow.uu.ids.net (Mike Bilow) To: tacgps@tapr.org Subject: [TACGPS:846] Antenna cables. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio X-Mailer: uugate 0.34 (OS/2 2.30) Status: U RIPE-NCC wrote in a message to Mike Bilow: R> I have to install a TAC plus (Motorola) GPS antenna at a R> remote site. The TAC will be sitting in a computer room and R> the antenna on the roof of the building. There are already R> cables running from the computerroom to the roof. R> The Motorola manual says that the input impedance of the R> antenna is 50 Ohm, so, with my limited knowledge of these R> things, I'd expect that I'd have to use 50 Ohm coaxial cable R> to connect them. However, the impedance of the cables that R> are running to the computer room is 75 Ohm. Does anybody R> know if one can just use these cables, if there is any trick R> to use them or should we run a new cable? First, GPS operates at fairly high frequency where cable losses can be severe. To go more than a few meters, you would have to use high quality and therefore very expensive cable. Second, why would a computer room have 75 ohm coax? The only types of coax you are likely to see in a computer room are 50 ohm, which is used for Ethernet, and 93 ohm, which is used in certain mainframe or ARCnet applications. However, 75 ohm cable is most commonly used for video. So, the answer is that you probably cannot use the cable because of the impedance issue and probably do not want to use it even if was the correct impedance because of the loss issue. -- Mike From ???@??? Wed Nov 19 16:46:57 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id QAA11063; Wed, 19 Nov 1997 16:44:45 -0600 (CST) Date: Wed, 19 Nov 1997 16:44:45 -0600 (CST) Message-Id: <44340@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: clark@tomcat.gsfc.nasa.gov (Tom Clark -- W3IWI) To: tacgps@tapr.org Subject: [TACGPS:847] Re: Antenna cables. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Henk Uitjerwaal asked > I have to install a TAC plus (Motorola) GPS antenna at a remote site. The > TAC will be sitting in a computer room and the antenna on the roof of the > building. There are already cables running from the computerroom to the > roof. > > The Motorola manual says that the input impedance of the antenna is 50 > Ohm, so, with my limited knowledge of these things, I'd expect that I'd > have to use 50 Ohm coaxial cable to connect them. However, the impedance > of the cables that are running to the computer room is 75 Ohm. Does > anybody know if one can just use these cables, if there is any trick to > use them or should we run a new cable? Mike Bilow gave a pretty negative response. Let me be a bit more upbeat. Mike was correct in saying that cable losses can become a problem. Henk -- how long is the cable run. If less than ~20 meters, it shouldn't be much of a problem. If it is more than ~50 meters, you will have difficulty. Now I will run counter to Mike's statement -- you will take a fairly minor "hit" by using 75 ohm cable in a 50 ohm system -- the Voltage Standing Wave Ratio (VSWR) is only 1.5:1, which will lead to ~2 dB of excess loss. Many of the ~7 mm diameter 75 ohm cables (like RG59) have less loss than their 50 ohm counterparts (like RG58) and at about 20 meters or so, the lower losses in RG59 actually WIN over RG58 at the GPS L-band frequency! Some of the 75 ohm coax cable (often incorrectly called "RG-6" here in the USA) is made with a low-loss foam dielectric and it is quite good at the GPS frequency. Such cable is sold here for installation of the small (~50 cm diameter) Ku-band satellite dishes. FYI -- the downconverter in the Ku-band dish systems (located at the dish feed) typically has a 900-1500 MHz IF output. The GPS L1 frequency is at 1575 MHz, at the top end of the DSS IF spectrum. So the cables that work for a DSS dish system will probably work just fine for GPS. My best advice is to try it. If you see that the strongest satellites show SNRs of 30 dB or more (as displayed in SHOWTIME or TAC32, or as seen in the $GPGSV NMEA message) and if you see 5-7 satellites most of the time, then the cable is fine. If you are only getting peak SNRs (like for satellites above ~60 deg elevation) of 20 dB or if you are only locking on 2-4 satellites, then the cable is hurting you and you should try to replace it. If you don't lock up on ANY satellites, then the cable is a total disaster! Regards, Tom From ???@??? Wed Nov 19 17:14:45 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA16717; Wed, 19 Nov 1997 17:02:57 -0600 (CST) Date: Wed, 19 Nov 1997 17:02:57 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:848] Re: GPS-30 TAPR special purchase: connectors? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <4731e401@bilow.bilow.uu.ids.net> It is a JST connector. Anyway, TAPR now has the Garmin GPS-20 and GPS-25 data interface cables. You can call or e-mail Dorothy. We had the JST connectors at one time, but a vast majority of people said they couldn't solder the onto the connectors. Greg >I just received one of the GPS-30 special purchase units from TAPR. This is >the GPS-20 board encased in a sealed housing, which I have removed. There is >an unusual connector on the GPS-20 which is used to interface it to the >rest of >the world. However, the TAC-2 documentation just says that, if you >ordered the >GPS-20 from TAPR, it would come with the necessary connector. > >On the connector that comes inside the GPS-30, there are no female pins >for any >of the unwired signals, although there is a plastic shell for the connector. >The key issue, obviously, is that I want to attach to 1 PPS. How can I >get the >connector, or at least some female pins for the shell I have? > >-- Mike, N1BEE ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Wed Nov 19 17:14:46 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id RAA16849; Wed, 19 Nov 1997 17:03:21 -0600 (CST) Date: Wed, 19 Nov 1997 17:03:21 -0600 (CST) Message-Id: <199711192249.OAA01127@grolsch.cs.ubc.ca> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Dave Martindale To: tacgps@tapr.org Subject: [TACGPS:849] Re: Antenna cables. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio R> I have to install a TAC plus (Motorola) GPS antenna at a R> remote site. The TAC will be sitting in a computer room and R> the antenna on the roof of the building. There are already R> cables running from the computerroom to the roof. R> The Motorola manual says that the input impedance of the R> antenna is 50 Ohm, so, with my limited knowledge of these R> things, I'd expect that I'd have to use 50 Ohm coaxial cable R> to connect them. However, the impedance of the cables that R> are running to the computer room is 75 Ohm. Does anybody R> know if one can just use these cables, if there is any trick R> to use them or should we run a new cable? First, GPS operates at fairly high frequency where cable losses can be severe. To go more than a few meters, you would have to use high quality and therefore very expensive cable. Second, why would a computer room have 75 ohm coax? The only types of coax you are likely to see in a computer room are 50 ohm, which is used for Ethernet, and 93 ohm, which is used in certain mainframe or ARCnet applications. However, 75 ohm cable is most commonly used for video. So, the answer is that you probably cannot use the cable because of the impedance issue and probably do not want to use it even if was the correct impedance because of the loss issue. Well, it's more complex than that. First, you can't expect to put a passive antenna on the roof and get decent signal strength in a room several stories below unless you use some very low-loss (and large) cable. But if you have an active antenna (with internal preamp) this can work quite well. I've used a Lowe active antenna with 50 or 60 additional feet of RG-58 between the GPS and the antenna's own 15-foot cable. There are antennas designed for rooftop mounting which have even more gain, specifically to deal with even longer cable runs. Second, most GPS hardware is designed for 50 ohm cable impedance. If you use 75 ohm cable instead, there will be some power reflected back at the 50-to-75-ohm junctions. You will have two of these in the system. However, the signal loss per unit length of RG-59 (75 ohm) cable is *less* than RG-58 (50 ohm) cable. So by using 75-ohm cable, you take a fixed loss penalty that is independent of length, plus there is a *gain* compared to RG-58 proportional to length. For long runs, you will actually get more signal at the GPS receiver using 75 ohm cable than using 50 ohm cable of similar size. (There can also be problems with signals being reflected twice at impedance mismatches being received at the GPS delayed in time and distorting the desired signal. For long runs of cable, the attenuation caused by two passes along the length of the cable reduces the reflections to a level where they are insignificant). Anyway, in *some* circumstances 75 ohm cable actually works better than 50 ohm. Try it. If it doesn't work well, try using 50 ohm cable instead. Or just use larger cable (lower loss) of either impedance. Or use a different antenna with more gain. Dave From ???@??? Thu Nov 20 06:11:32 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id FAA25776; Thu, 20 Nov 1997 05:33:39 -0600 (CST) Date: Thu, 20 Nov 1997 05:33:39 -0600 (CST) Message-Id: <4740e3b1@bilow.bilow.uu.ids.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk X-UIDL: 880026256.000 From: mikebw@bilow.bilow.uu.ids.net (Mike Bilow) To: tacgps@tapr.org Subject: [TACGPS:850] Re: Antenna cables. X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio X-Mailer: uugate 0.34 (OS/2 2.30) Status: U Tom Clark -- W3IWI wrote in a message to Mike Bilow: TC-W> Mike Bilow gave a pretty negative response. Let me be a bit TC-W> more upbeat. :-) TC-W> Now I will run counter to Mike's statement -- you will take TC-W> a fairly minor "hit" by using 75 ohm cable in a 50 ohm TC-W> system -- the Voltage Standing Wave Ratio (VSWR) is only TC-W> 1.5:1, which will lead to ~2 dB of excess loss. My concern, which I probably should have expressed more clearly, is: what is in the walls? The question concerned using the 75 ohm coax already in the building, which is probably of unknown quality and origin. My guess is that it is standard video coax, the sort of thing that often says "Color TV" on the jacket, as if color needed better cable than black and white. The original post said: > There are already cables running from the computerroom to the roof. I cannot think of any good reason why 75 ohm coax would be run for computer networking purposes, neither for Ethernet (50 ohm) nor ARCnet or SNA (93 ohm). TC-W> The GPS L1 frequency is at 1575 MHz, at the top end of the DSS TC-W> IF spectrum. So the cables that work for a DSS dish system will TC-W> probably work just fine for GPS. Something like Belden 1829A? What are the odds this is what is in the wall? TC-W> My best advice is to try it. No one could argue with that advice, certainly. -- Mike, N1BEE From ???@??? Thu Nov 20 18:22:51 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id SAA04893; Thu, 20 Nov 1997 18:18:52 -0600 (CST) Date: Thu, 20 Nov 1997 18:18:52 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:851] GPS-30PC Units X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" Just as an update. Dorothy found a box of GPS30PC that had been covered up after the return from the DCC ---- thus TAPR has 25 GPS30PC units left. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Sun Nov 23 23:41:30 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id VAA05953; Sun, 23 Nov 1997 21:09:50 -0600 (CST) Date: Sun, 23 Nov 1997 21:09:50 -0600 (CST) Message-Id: <199711240300.WAA11298@aus-f.mp.campus.mci.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Donald E. Haselwood" To: tacgps@tapr.org Subject: [TACGPS:852] Re: JAVA GPS Display X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" X-Mailer: Windows Eudora Light Version 1.5.2 At 04:33 PM 11/14/97 -0600, you wrote: >Version 1.0 of a JAVA GPS display program for use with the Garmin GPS30PC >in located on the tapr ftp site under software_lib/upload. Run >GPSDISP.exe to extract a readme and another executable that will install >the program. Even though this is a JAVA application, it currently will >only run on a PC (see the readme file). I hope to upgrade and enhance >this program soon. > > > >Jim, N0VH > >jchandle@flash.net, n0vh@juno.com > Jim, Sounds interesing. Do you have the full url? I rummaged around and didn't find gpsdisp.exe in: ftp://ftp.tapr.org/tapr/software_lib/upload/" nor other directories. Don, W4DH From ???@??? Mon Nov 24 08:18:35 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id IAA00631; Mon, 24 Nov 1997 08:11:45 -0600 (CST) Date: Mon, 24 Nov 1997 08:11:45 -0600 (CST) Message-Id: <97Nov24.080923cst.26881@texas.dsatex.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Chandler, Jim" To: tacgps@tapr.org Subject: [TACGPS:853] GPS Display X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Donald E. Haselwood wrote: Don, Chech out ftp://ftp.tapr.org/tapr/software_lib/gps. I guess they have moved it since I uploaded it. I hope to have a website this weekend! Let me know how you like it and ways to improve it. Thanks Jim > > At 04:33 PM 11/14/97 -0600, you wrote: > >Version 1.0 of a JAVA GPS display program for use with the Garmin GPS30PC > >in located on the tapr ftp site under software_lib/upload. Run > >GPSDISP.exe to extract a readme and another executable that will install > >the program. Even though this is a JAVA application, it currently will > >only run on a PC (see the readme file). I hope to upgrade and enhance > >this program soon. > > > > > > > >Jim, N0VH > > > >jchandle@flash.net, n0vh@juno.com >> > > Jim, > > Sounds interesing. Do you have the full url? I rummaged around and didn't > find gpsdisp.exe in: > > ftp://ftp.tapr.org/tapr/software_lib/upload/" > > nor other directories. > > Don, W4DH From ???@??? Mon Nov 24 12:18:04 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id MAA12624; Mon, 24 Nov 1997 12:11:24 -0600 (CST) Date: Mon, 24 Nov 1997 12:11:24 -0600 (CST) Message-Id: <3479C215.31DF@sparc.isl.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Gilbert Baron To: tacgps@tapr.org Subject: [TACGPS:854] GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 X-Mailer: Mozilla 3.01 (X11; I; AIX 1) Has there been any thought of changing or adding to the group buy to make the GPS12-XL available. It is a MUCH better unit. It is 12 channel and is MUCH faster and MUCH more accurate. The current unit is really ancient technology. In addition the current price on the current unit is no longer a bargain. -- Gil gbaron@sparc.isl.net Bailar es vivir http://www.geocities.com/Yosemite/Trails/4168 From ???@??? Mon Nov 24 13:18:01 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id NAA25143; Mon, 24 Nov 1997 13:14:31 -0600 (CST) Date: Mon, 24 Nov 1997 13:14:31 -0600 (CST) Message-Id: <45233@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: clark@tomcat.gsfc.nasa.gov (Tom Clark -- W3IWI) To: tacgps@tapr.org Subject: [TACGPS:855] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Gil asked: > Has there been any thought of changing or adding to the group buy to > make the GPS12-XL available. It is a MUCH better unit. It is 12 channel > and is MUCH faster and MUCH more accurate. The current unit is really > ancient technology. > In addition the current price on the current unit is no longer a > bargain. Maybe one of us is confused. TACGPS has focussed on single-board OEM receivers for time/frequency applications. The 12XL is a handheld, standalone unit. I haven't checked on the board inside the 12XL, but I did make some quick tests on the guts of the Garmin GPS-III+ (which I think is the same) and I was unable to locate any signal that looked like a hardware 1PPS that could be tapped, so that it could be incorporated into the TAC activity. The 12-channel parallel OEM rcvr board is the GPS-25. Greg has indicated that he hopes to replace the GPS-20 TAPR offering with the -25. I've asked him to get me a sample so that we can make sure of its timing characteristics, but so far I haven't seen one to "certify". 73, Tom From ???@??? Mon Nov 24 14:12:59 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA27816; Mon, 24 Nov 1997 14:10:25 -0600 (CST) Date: Mon, 24 Nov 1997 14:10:25 -0600 (CST) Message-Id: <3479DE1E.7DE1@sparc.isl.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Gilbert Baron To: tacgps@tapr.org Subject: [TACGPS:856] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii MIME-Version: 1.0 X-Mailer: Mozilla 3.01 (X11; I; AIX 1) Tom Clark -- W3IWI wrote: > > Gil asked: > > > Has there been any thought of changing or adding to the group buy to > > make the GPS12-XL available. It is a MUCH better unit. It is 12 channel > > and is MUCH faster and MUCH more accurate. The current unit is really > > ancient technology. > > In addition the current price on the current unit is no longer a > > bargain. > > Maybe one of us is confused. TACGPS has focussed on single-board OEM receivers > for time/frequency applications. The 12XL is a handheld, standalone unit. I > haven't checked on the board inside the 12XL, but I did make some quick tests > on the guts of the Garmin GPS-III+ (which I think is the same) and I was > unable to locate any signal that looked like a hardware 1PPS that could be > tapped, so that it could be incorporated into the TAC activity. > I am sorry that I did not realize the purpose of the GPS for this group. Nevertheless it would be nice to get a handheld unit for a good price if possible. The unit does have a pc interface connection so I assume it could be used for all that you want but I do not know that. > The 12-channel parallel OEM rcvr board is the GPS-25. Greg has indicated that > he hopes to replace the GPS-20 TAPR offering with the -25. I've asked him I am not so sure of that, maybe maybe not. The 12Xl is VERY new. > to get me a sample so that we can make sure of its timing characteristics, > but so far I haven't seen one to "certify". > I can tell you this unit has been certified as among the best in the field. Navagation is my only interest in GPS so perhaps I am at the wrong place. I was only hoping that I could get my GPS before the summer hiking and conoeing starts at a good price. I see that this is probably not the place and after seeing what activity is here I will probably unsubscribe. Thanks for the information. -- Gil gbaron@sparc.isl.net Bailar es vivir http://www.geocities.com/Yosemite/Trails/4168 From ???@??? Mon Nov 24 14:41:22 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA28086; Mon, 24 Nov 1997 14:17:02 -0600 (CST) Date: Mon, 24 Nov 1997 14:17:02 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:857] Re: GPS Display X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <97Nov24.080923cst.26881@texas.dsatex.com> Hi. Just as an update on how the various software upload areas work. When you upload to a TAPR software area, like upload, it is only readable by whoever is responsible for the area. As the README says, you need to send an e-mail to that person so they no something needs quick attention -- else it might sit a few days. They then move it over to the correct directory once they check the file to make sure it is okay. This resulted last year when TAPR.ORG was hit by a plague of people using the system for swaping stolen and very shady software. Tied up huge amounts of disk space and system throughput. Anyway, we have to maintain this, becuase we still get software that appears and we would be considered at fault if we allowed it to be downloaded. Just the other day some crank uploaded about 20 Megs of @!(#$* about how to use stolen credit cards, how to break into ATM machines, and other stuff. That was fun doing the big rm on. One of the ills of having a good system with big pipes these days. The day of complete openness has long been gone. When you get that new site going, let me know and I'll add a link on the SIG listing. Also, hope to see further updates on the TAPR site, since that is how we keep the yearly CD updated. Cheers - Greg >Donald E. Haselwood wrote: > >Don, > > Chech out ftp://ftp.tapr.org/tapr/software_lib/gps. I guess they have >moved it since I uploaded it. I hope to have a website this weekend! >Let me know how you like it and ways to improve it. Thanks > > > >Jim > >> > >> At 04:33 PM 11/14/97 -0600, you wrote: > >> >Version 1.0 of a JAVA GPS display program for use with the Garmin >GPS30PC > >> >in located on the tapr ftp site under software_lib/upload. Run > >> >GPSDISP.exe to extract a readme and another executable that will >install > >> >the program. Even though this is a JAVA application, it currently >will > >> >only run on a PC (see the readme file). I hope to upgrade and >enhance > >> >this program soon. > >> > > >> > > >> > > >> >Jim, N0VH > >> > > >> >jchandle@flash.net, n0vh@juno.com > >>> > >> > >> Jim, > >> > >> Sounds interesing. Do you have the full url? I rummaged around and >didn't > >> find gpsdisp.exe in: > >> > >> ftp://ftp.tapr.org/tapr/software_lib/upload/" > >> > >> nor other directories. > >> > >> Don, W4DH > > > > ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Mon Nov 24 14:47:25 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA29632; Mon, 24 Nov 1997 14:42:07 -0600 (CST) Date: Mon, 24 Nov 1997 14:42:07 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:858] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <3479C215.31DF@sparc.isl.net> We will be adding the Garmin GPS-25 here in about a few weeks. Probably about $10 more then the current 20's. Cheers - Greg >Has there been any thought of changing or adding to the group buy to >make the GPS12-XL available. It is a MUCH better unit. It is 12 channel >and is MUCH faster and MUCH more accurate. The current unit is really >ancient technology. >In addition the current price on the current unit is no longer a >bargain. >-- >Gil gbaron@sparc.isl.net >Bailar es vivir >http://www.geocities.com/Yosemite/Trails/4168 ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Mon Nov 24 14:47:26 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA29660; Mon, 24 Nov 1997 14:43:37 -0600 (CST) Date: Mon, 24 Nov 1997 14:43:37 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:859] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <45233@tomcat.gsfc.nasa.gov> >The 12-channel parallel OEM rcvr board is the GPS-25. Greg has indicated that >he hopes to replace the GPS-20 TAPR offering with the -25. I've asked him >to get me a sample so that we can make sure of its timing characteristics, >but so far I haven't seen one to "certify". Still working on getting you one Tom. Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Mon Nov 24 14:47:26 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA29716; Mon, 24 Nov 1997 14:45:04 -0600 (CST) Date: Mon, 24 Nov 1997 14:45:04 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Greg Jones, WD5IVD" To: tacgps@tapr.org Subject: [TACGPS:860] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <3479DE1E.7DE1@sparc.isl.net> >I am sorry that I did not realize the purpose of the GPS for this group. >Nevertheless it would be nice to get a handheld unit for a good price if >possible. The unit does have a pc interface connection so I assume it >could be used for all that you want but I do not know that. I have looked into the same thing. The only real source we have for handheld units at a price we could do something with for members would be Garmin. Garmin now has a policy that seems to be against sales over the Internet (like our GPS web page). The problem is that we use the GPS page to give full and detail information over time to our member without having to print it all the time in the PSR....not like we have an Internet store front. I guess we could do it just through the PSR, but that slows down how many units you can get out the door up front and thus the price is back up again. The numbers just don't look right for TAPR to be doing a group deal with respect to Handheld units. REI and other store fronts have to good a deal that we could never meet. The reason TAPR does OEM boards and RIE does handheld units. TAPR can do enough OEM boards to its members to make it look good to the OEM distributors, while the consumer versions we come no where close to the volume. The purpose of group purchases within TAPR is to make a few selected items available to the membership becuase 1) they can not be gotten normally in single qty or 2) we can get them cheaper even after our overhead added in ---- keep in mind that the item still has to be something that advances TAPR's mission statement of Educational and R&D related. I have been amazed how long the window for the GPS OEM boards have been around. Typically one of these group things works for a year at most and then just stops. Anyway, unless something changes in relations to getting handheld units that would benefit APRS or timing, then I probably keep working on other things. Just thought I would throw this in. Cheers - Greg ----- Greg Jones, WD5IVD Austin, Texas wd5ivd@tapr.org http://www.tapr.org/~wd5ivd From ???@??? Mon Nov 24 15:17:20 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA00893; Mon, 24 Nov 1997 15:03:40 -0600 (CST) Date: Mon, 24 Nov 1997 15:03:40 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Dave Martindale To: tacgps@tapr.org Subject: [TACGPS:861] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <3479DE1E.7DE1@sparc.isl.net> >I am sorry that I did not realize the purpose of the GPS for this group. >Nevertheless it would be nice to get a handheld unit for a good price if >possible. The unit does have a pc interface connection so I assume it >could be used for all that you want but I do not know that. The 12XL has NMEA output, so you can use it for APRS position reporting like almost any other GPS. However, the time in the NMEA data is only reported to the nearest second, and the NMEA data bursts are *not* synchronized to the beginning of UTC seconds. There is no way to use a 12XL or other small Garmin handheld for precision timing. In contrast, the GPS 20 (and probably the 25, which has the same receiver as the 12XL) *is* designed for a broader variety of uses, including timing. The NMEA data is synchronized to the beginning of each second, and there is a 1 PPS output which provides a pulse synchronized to the beginning of each second. The 20 is accurate to about 1 us, the 25 might well be better (judging by the improvement in navigation performance between the 1- and 12-channel Garmin receivers). I have Garmin 45XL, 12XL, and 20 receivers and have looked at the NMEA outputs of all of them. >I am not so sure of that, maybe maybe not. The 12Xl is VERY new. I bought my 12XL last February, 9 months ago. That makes the 12XL almost obsolete as consumer GPSes go. I hasn't been replaced in function by anything else, but I wouldn't be surprised if it was. >> to get me a sample so that we can make sure of its timing characteristics, >> but so far I haven't seen one to "certify". >I can tell you this unit has been certified as among the best in the >field. It's a good receiver for navigation, but useless for timing. Dave From ???@??? Mon Nov 24 15:17:20 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA01238; Mon, 24 Nov 1997 15:10:00 -0600 (CST) Date: Mon, 24 Nov 1997 15:10:00 -0600 (CST) Message-Id: <97Nov24.150442cst.26881@texas.dsatex.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Chandler, Jim" To: tacgps@tapr.org Subject: [TACGPS:862] TAPR FTP site X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Thanks Greg, That's what I get for not reading the README!!! I'll let you know when I get the web site populated. Jim >Greg Jones, WD5IVD wrote: > > Hi. > > Just as an update on how the various software upload areas work. When you > upload to a TAPR software area, like upload, it is only readable by whoever > is responsible for the area. As the README says, you need to send an > e-mail to that person so they no something needs quick attention -- else it > might sit a few days. They then move it over to the correct directory once > they check the file to make sure it is okay. From ???@??? Mon Nov 24 15:47:15 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA02544; Mon, 24 Nov 1997 15:34:04 -0600 (CST) Date: Mon, 24 Nov 1997 15:34:04 -0600 (CST) Message-Id: <45244@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: clark@tomcat.gsfc.nasa.gov (Tom Clark -- W3IWI) To: tacgps@tapr.org Subject: [TACGPS:863] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Regarding Garmin hand-held units -- let me recommend one source. One of the "good guys" who has always given me a competitive price is Larry James or James Assoc. in Boulder. Larry happens to be KG0GB and is both an AMSAT & TAPR member. Call him at 303-530-9014. Yes, he will take plastic. He will give you an honest answer on when he will ship to you. Thru the years, I've ordered some 20-30 units from him for colleagues. 73, Tom From ???@??? Tue Nov 25 15:37:09 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA27498; Tue, 25 Nov 1997 11:26:14 -0600 (CST) Date: Tue, 25 Nov 1997 11:26:14 -0600 (CST) Message-Id: <199711251725.JAA13257@saiph.hpl.hp.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "James L. Johnson" To: tacgps@tapr.org Subject: [TACGPS:864] Re: Results on 58503 measurements X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII MIME-Version: 1.0 X-Mailer: ELM [version 2.4 PL21] In-Reply-To: <343E8062.2D4A@veritas.com> from "Tom Van Baak" at Oct 10, 97 02:33:21 pm Tom wrote: > > For another data point, the OCXO in the HP 58503A I've been > using is a 10811-60159. In a conversation with HP last year > I was told this variation of the standard 10811D OCXO has > an extended EFC range specification. It enables the 58503 > to continue to be software disciplined, without maintenance, > in spite of years of oscillator ageing and without requiring > the user to ever turn a coarse adjustment screw. I have specs > on the 10811 OCXO family but not the special -60159 model > so I can't confirm this report but it sounds plausible. > > I also recall them saying that the HP 58503A tracks ambient > temperature and factors that into the control voltage, at > least during hold-over. > > It would be nice, Jim, if you could confirm or elaborate on > any of this. > > Based on my tests, I have to agree with Tom Clark's earlier > comment about the short-term (1 to 1000 s) stability of > the HP 58503A. I found it surprisingly poor compared to a > stand-alone 10811D or other high-end OCXO. > > I once remarked to HP that the 58503A must have at least a > 24-bit DAC and extremely low tempco voltage references in > order to work unattended for years. The answer I got was: > no, because of the software PLL it wasn't necessary to have > extremely precise DACs or voltage references: the control > voltage is adjusted as necessary regardless whether the > phase error is the result of oscillator ageing, poor DAC > or EFC resolution, or ambient temperature effects on the > analog ICs or the OCXO. Interesting. > > I have a number of 10811 or equivalent OCXO's and after > running for months or years many of them have ageing rates > one or two orders of magnitude below their 5e-10 spec. But > a typical tempco for these is 2.5e-9 for 0 to 50 C which > (assuming linear) is 5e-11/C. Since I often see a 10 C > temperature change in my lab (garage), this net 5e-10 daily > temperature-induced error *totally* dominates the medium > term (1000 to 100000 s) stability of these references. > > /tvb ------------------------------------------------------------------ Hi Tom, The -60159 version of the HP 10811 oscillator is one that has had its EFC tuning circuit "enhanced". The factory sets the coarse tuning adjustment for 10 MHz, after which it needs no further adjustment for the life of the product. The improved EFC tuning circuit has the range to tune the oscillator frequency to compensate for crystal aging and environmental effects. The 58503 does indeed track the ambient temperature and apply a correction to the control voltage. This is a first-order, open loop correction used to enhance the performance of the unit under the condition of widely varying ambient temperatures. Our tests of the 58503 found that it does meet its specifications, but it is true that for averaging times longer than a few ten's of seconds, the SA on the GPS signal does cause the 58503's Allan variance to be higher than that of a stand-alone OCXO. But this would be true for any high quality crystal oscillator that is being disciplined in the long-term by a noisy, but stable reference. I'm not sure what I can add to the answer you got from HP about not needing precision DACs or voltage references to work unattended for years. I agree with that answer - if the oscillator is locked up to GPS, then in the long-term it should be disciplined to UTC(USNO) regardless of any oscillator characteristics or environmental conditions that try to steer it off frequency. The control loop will pull it back to UTC(USNO) if it tries to drift off for any reason. You're absolutely right about local environmental effects dominating the medium-term performance of free-running precision (those with low aging and close-in phase noise) oscillators. We see the same problem. Sorry this took so long but I hope it answers some of your questions. 73, Jim W6SC jjohnson@hpl.hp.com From ???@??? Tue Nov 25 15:37:19 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA14216; Tue, 25 Nov 1997 14:18:41 -0600 (CST) Date: Tue, 25 Nov 1997 14:18:41 -0600 (CST) Message-Id: <47aecfe5@bilow.bilow.uu.ids.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: mikebw@bilow.bilow.uu.ids.net (Mike Bilow) To: tacgps@tapr.org Subject: [TACGPS:865] GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio X-Mailer: uugate 0.34 (OS/2 2.30) Gilbert Baron wrote in a message to Mike Bilow: GB> Has there been any thought of changing or adding to the group GB> buy to make the GPS12-XL available. It is a MUCH better unit. GB> It is 12 channel and is MUCH faster and MUCH more accurate. The GB> current unit is really ancient technology. I have recently been using the newer MultiTrac 12 engine, instead of the old PhaseTrac 8 engine. I agree that it is far better. Side by side, my GPS-38 (with the old engine) and my GPS-12 (with the new engine) leave almost no comparison. I will consistently get twice as many satellites, and, what is more important, will tend to add the satellites closest to the horizon which provide the greatest (positioning) accuracy. It is common for the 38 to show EPE of 200-300 feet, while the 12 generally shows EPE of 50-80 feet. Inside a wooden house, the 38 usually sees no satellites, but the 12 sees about as many satellites as the 38 would see outside. Initializing from cold start is also much improved on the new engine. The 38 could take 20-60 minutes to do a cold start and about 5 minutes for a warm start, but the 12 cold starts in about 1-2 minutes and warm starts instantly. I was quite pleasantly surprised. GB> In addition the current price on the current unit is no longer GB> a bargain. I can't speak to that, but certainly complete GPS-12 units with keyboard and LCD display are selling at street prices in the $150-175 range. I know that Garmin typically charges a lot more for their OEM (bare) units, though. Of course, I don't know anything about the innards of the 12, but I assume it must somehow be able to provide the 1 PPS signal. This is not brought out of the case on the 12, but neither is it brought out of the case on the 38, and the 38 uses the same engine as in the TAPR GPS-20 buy. I think the OEM version of the 12 engine is the GPS-25, but I am not sure of that; Tom or Greg will probably have better information. -- Mike From ???@??? Tue Nov 25 15:37:18 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA14229; Tue, 25 Nov 1997 14:19:05 -0600 (CST) Date: Tue, 25 Nov 1997 14:19:05 -0600 (CST) Message-Id: <47aecfe6@bilow.bilow.uu.ids.net> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: mikebw@bilow.bilow.uu.ids.net (Mike Bilow) To: tacgps@tapr.org Subject: [TACGPS:866] Re: GPS group X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio X-Mailer: uugate 0.34 (OS/2 2.30) Gilbert Baron wrote in a message to Mike Bilow: GB> I can tell you this unit has been certified as among the best GB> in the field. Navagation is my only interest in GPS so perhaps GB> I am at the wrong place. I was only hoping that I could get my GB> GPS before the summer hiking and conoeing starts at a good GB> price. I see that this is probably not the place and after GB> seeing what activity is here I will probably unsubscribe. GB> Thanks for the information. This is a fairly low traffic list, and my own opinion is that the technical issues of comparing the equipment are probably appropriate here. However, you have fallen in with a bunch of people whose primary interest is in cutting the units open and experimenting with them! Seriously, I don't think TAPR cares what you do with your unit, but non-navigational issues, especially precise timing, have been the focus of this list. If your main interest is navigation, then you are probably better off buying a unit off the shelf from any of the commercial suppliers. Wal-Mart sells the GPS-12 handheld unit around here for $164. Several mail order dealers who specialize in GPS equipment have Internet sites, including James Associates ("http://www.csn.net/~lwjames/index.html"), which sells the GPS-12 at $160. Note that the GPS-12 is not the same as the more expensive GPS-12XL (although they use the same engine), but I doubt you would notice the difference for hiking and canoeing. -- Mike From ???@??? Tue Nov 25 15:37:24 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id OAA15938; Tue, 25 Nov 1997 14:58:36 -0600 (CST) Date: Tue, 25 Nov 1997 14:58:36 -0600 (CST) Message-Id: Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: John Franke To: tacgps@tapr.org Subject: [TACGPS:867] Searchable file? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="us-ascii" In-Reply-To: <47aecfe6@bilow.bilow.uu.ids.net> Is there a searchable log or file for this SIG? If so, where is it and how does one, or more, access it? John From ???@??? Tue Nov 25 15:37:26 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id PAA16481; Tue, 25 Nov 1997 15:10:37 -0600 (CST) Date: Tue, 25 Nov 1997 15:10:37 -0600 (CST) Message-Id: <199711252108.OAA13811@newreg.lanl.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: Brooks Shera To: tacgps@tapr.org Subject: [TACGPS:868] Re: Results on 58503 measurements X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset="US-ASCII" Hi Jim I found your comments and measurements on the 58503 very interesting, especially the fact the that unit includes a temperature sensor to make first order ambient corrections. However I disagree about one point you raise. > Our tests of the 58503 found that it does meet its specifications, >but it is true that for averaging times longer than a few ten's of >seconds, the SA on the GPS signal does cause the 58503's Allan variance >to be higher than that of a stand-alone OCXO. But this would be true >for any high quality crystal oscillator that is being disciplined in the >long-term by a noisy, but stable reference. I believe this is true only if the disciplining circuit has inappropriate (or no) filtering. For optimum performance the output frequency should be controlled by the OCXO in the short term and GPS in the longer term. An analogy is the calendar and the wristwatch. My calendar, like GPS, is accurate in the long term, but I don't continually reset my wristwatch by it. An appropriately long filter time constant insures that a good wristwatch is not reset when its error is less than the clock used to reset it. Someday, hopefully, the DoD will cause SA to go away and we can use shorter disciplining time constants. Maybe the 58503 design is just anticipating the future. Thanks for your interesting comments. -Brooks From ???@??? Wed Nov 26 12:03:01 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA14380; Wed, 26 Nov 1997 11:34:09 -0600 (CST) Date: Wed, 26 Nov 1997 11:34:09 -0600 (CST) Message-Id: <347C5C62.10C@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Dr Thomas A Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:869] Re: Searchable file? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) John Franke wrote: > > Is there a searchable log or file for this SIG? If so, where is it and how > does one, or more, access it? > John In a sense, the precursor to TACGPS was my gps-timing exploder. It still exists but has been very inactive of late. The old historical archives can be viewed by setting a newsreader to news://aleph.gsfc.nasa.gov and then subscribing to gps-timing. The other news groups on aleph are browsable but uninteresting -- they relate to my VLBI project here in NASA. Of particular interest in the aleph archives are a series of messages involving Dave Mills (Professor xntpd -- the network timing daemon), Louie Makamos, Doug Hogarth (who wrote the TAC-compatible NTP code for Windows NT) et al which discuss things that could/should/might/need to/ be done to properly use GPS for network timing applications. 73, Tom From ???@??? Fri Nov 28 07:47:38 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id HAA29495; Fri, 28 Nov 1997 07:41:05 -0600 (CST) Date: Fri, 28 Nov 1997 07:41:05 -0600 (CST) Message-Id: <199711281401.JAA14007@meow.febo.com.> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: John Ackermann N8UR To: tacgps@tapr.org Subject: [TACGPS:871] One serial line driving two serial ports? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: text/plain; charset=us-ascii X-Mailer: exmh version 1.6.9 8/22/96 This may be a dumb question, but... I'd sometimes like to run two GPS programs on my PC at the same time (for example, TAC32 and SA Watch). I have enough serial ports available to let each program have its own. For logistical reasons, I can't use the second serial output on the TAC to drive the second application -- I need to figure out how to make the Port 1 output drive both applications. Is there a simple kludge to allow a single serial line to be "Y"d into two ports? I don't think that either application talks to the GPS unit after initialization, so all I really need to do is split the GPS output signals in two. Is a passive splitter good enough, or do I need to either isolate the two serial ports from each other, or provide more drive, or both? John N8UR jra@febo.com From ???@??? Fri Nov 28 11:00:05 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id KAA06107; Fri, 28 Nov 1997 10:21:23 -0600 (CST) Date: Fri, 28 Nov 1997 10:21:23 -0600 (CST) Message-Id: <01BCFBEF.49551700@rick.cnssys.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Richard M. Hambly" To: tacgps@tapr.org Subject: [TACGPS:872] RE: One serial line driving two serial ports? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Type: multipart/mixed; boundary="---- =_NextPart_000_01BCFBEF.49551700" MIME-Version: 1.0 John, This is not recommended because programs like TAC32 and ShowTime do send commands to the GPS receiver when it is running. This happens when configuration parameters are changed such as 1pps delay or operating mode. The point of having two serial outputs on the TAC is to allow two serial ports to connect to the same receiver, even if that receiver has only one port. Internally, the TAC-2 board provides an active buffered "Y" connection. Rick WB2TNL -----Original Message----- From: John Ackermann N8UR [SMTP:jra@febo.com] Sent: Friday, November 28, 1997 8:41 AM To: tacgps@tapr.org Subject: [TACGPS:871] One serial line driving two serial ports? This may be a dumb question, but... I'd sometimes like to run two GPS programs on my PC at the same time (for example, TAC32 and SA Watch). I have enough serial ports available to let each program have its own. For logistical reasons, I can't use the second serial output on the TAC to drive the second application -- I need to figure out how to make the Port 1 output drive both applications. Is there a simple kludge to allow a single serial line to be "Y"d into two ports? I don't think that either application talks to the GPS unit after initialization, so all I really need to do is split the GPS output signals in two. Is a passive splitter good enough, or do I need to either isolate the two serial ports from each other, or provide more drive, or both? John N8UR jra@febo.com From ???@??? Fri Nov 28 12:00:15 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA09554; Fri, 28 Nov 1997 11:51:09 -0600 (CST) Date: Fri, 28 Nov 1997 11:51:09 -0600 (CST) Message-Id: <347F0322.194A@tomcat.gsfc.nasa.gov> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Tom Clark (W3IWI)" To: tacgps@tapr.org Subject: [TACGPS:873] Re: One serial line driving two serial ports? X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii X-Mailer: Mozilla 3.01 (Win95; I) John Ackermann N8UR wrote: > > This may be a dumb question, but... > > I'd sometimes like to run two GPS programs on my PC at the same time (for > example, TAC32 and SA Watch). I have enough serial ports available to let > each program have its own. For logistical reasons, I can't use the second > serial output on the TAC to drive the second application -- I need to figure > out how to make the Port 1 output drive both applications. > > Is there a simple kludge to allow a single serial line to be "Y"d into two > ports? I don't think that either application talks to the GPS unit after > initialization, so all I really need to do is split the GPS output signals in > two. Is a passive splitter good enough, or do I need to either isolate the > two serial ports from each other, or provide more drive, or both? John -- this is PRECISELY one of the reasons that the TAC-2 is a bit more complicated than an absolutely minimalist board might have been! The TAC-2 has two independent serial ports #1 & #2 -- Port #1 is dubbed"prime" and #2 is "secondary" (except for the specail case of a dual-port rcvr like the Trimble SK-8). Both ports have the same serial output data and RS232 1PPS signals going from the TAC-2, driven by the MAX232 U2. On the computer-to-TAC2 input side, the ports have independent RS232 receivers (Port #1 = MAX232 and Port #2 = U1A) which are ORed together in U1B. Input into Port #2 is muted (squelched) whenever Port #1 data is present. This "squelch" has a "squelch tail" of about 0.1 seconds set by R1*C1. The original primary intent of this was so that a computer running SHOWTIME or TAC32 connected to Port #1 could have guaranteed control over the receiver for setting up operating conditions, while a lower priority DGPS beacon rcvr connected to Port #2 could be sending DGPS corrections. Since you suggest TAC32 and SAWATCH are the 2 programs you want to use, you need to be sure that they are both running at the same baud rate. Since SAWATCH requires 4800 baud NMEA data (on Port #2), TAC32 must be running in MOT NMEA mode on Port #1. So all you need is an additional 10-pin IDC header to 9-pin RS232 cable to do what you want. 73, Tom From ???@??? Sat Nov 29 11:25:14 1997 Received: from tapr.org (localhost [127.0.0.1]) by tapr.org (8.7.5/8.7.3/1.9) with SMTP id LAA21723; Sat, 29 Nov 1997 11:10:43 -0600 (CST) Date: Sat, 29 Nov 1997 11:10:43 -0600 (CST) Message-Id: <97Nov29.110749cst.26881@texas.dsatex.com> Reply-To: tacgps@tapr.org Originator: tacgps@tapr.org Sender: tacgps@tapr.org Precedence: bulk From: "Chandler, Jim" To: tacgps@tapr.org Subject: [TACGPS:874] GPS display 1.5 web site X-Listprocessor-Version: 6.0 -- ListProcessor by Anastasios Kotsikonas X-Comment: Tucson Amateur Packet Radio I have created a web site for the GPS display program. It is http://www.flash.net/~jchandle You will always be able to download the latest version there. I will send it to the TAPR ftp site shortly. BTW, does anyone else have problems sending email to the tacgps group and it never shows up? Jim, N0VH jchandle@flash.net