From bounce-tacgps-6754@lists.tapr.org Wed Jan 2 15:07:21 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id PAA24925 for ; Wed, 2 Jan 2002 15:07:20 -0600 (CST) Message-ID: Date: Wed, 02 Jan 2002 16:06:58 -0500 From: xaos User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4) Gecko/20011019 Netscape6/6.2 X-Accept-Language: en-us MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] NTP Requirements. References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C337672.2030901@darksmile.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Hello everyone, I am a bit confused about what it takes to get the TAC2 working under Linux and NTP. First, do I need the PPS kit? I have NTP version 4.0.99k23. It seems that if I use the PPSkit I will have to re-compile NTP. What's the difference between ntp and xntp? Can I use NTP and still get the GPS data from TAC2? Can I also communicate (send messages to the TAC2) when I use NTP. Can someone provide me with a valid ntp.conf using tha TAC2? I am just a bit overwhelmed with info right now. Please excuse my stupid questions. Thanks in advance, George Hrysanthopoulos, N2FGX --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Wed Jan 2 15:35:54 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id PAA27015 for ; Wed, 2 Jan 2002 15:35:51 -0600 (CST) From: "Tom Clark \(W3IWI\)" To: "TAPR Special Interest Group" Subject: [tacgps] Change of Address test Date: Wed, 2 Jan 2002 16:35:23 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Importance: Normal List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <000001c193d5$635422e0$0200a8c0@tomcat> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk I switched ISPs -- new Email address is mailto:w3iwi@toad.net. This is a test to verify that TACGPS made the change ok. 73 and Happy New Year de Tom, W3IWI --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Wed Jan 2 17:39:52 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id RAA05035 for ; Wed, 2 Jan 2002 17:39:49 -0600 (CST) From: "Gary J. Myers" Message-Id: Date: Wed, 02 Jan 2002 15:45:14 z (???) To: "TAPR Special Interest Group" Subject: [tacgps] RE NTP Requirements. X-URL: http://www.geekslounge.com/ List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <200201022345.PAA39188@geekslounge.com> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Tell me if I am wrong but I thought you cannot connect a TAC2 to a *NIX box or UNIX flavors. I was thinking of porting a clone of Showtime or TAC32 over to BSD UNIX becuase of this notion. I would much rather run my TAC2 on my FreeBSD box instead of a windoze box. Gary > From: xaos > To: "TAPR Special Interest Group" > Date: Wed, 02 Jan 2002 16:06:58 -0500 > Subject: [tacgps] NTP Requirements. > > > Hello everyone, > > I am a bit confused about what it takes to get > the TAC2 working under Linux and NTP. > > First, do I need the PPS kit? > I have NTP version 4.0.99k23. It seems that if I use the PPSkit > I will have to re-compile NTP. > > What's the difference between ntp and xntp? > > Can I use NTP and still get the GPS data from TAC2? > Can I also communicate (send messages to the TAC2) when > I use NTP. > > Can someone provide me with a valid ntp.conf using tha TAC2? > > I am just a bit overwhelmed with info right now. Please excuse > my stupid questions. > > Thanks in advance, > George Hrysanthopoulos, N2FGX > > > > --- > You are currently subscribed to tacgps as: gary@geekslounge.com > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Wed Jan 2 18:08:12 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id SAA07245 for ; Wed, 2 Jan 2002 18:08:11 -0600 (CST) Date: Wed, 02 Jan 2002 19:07:34 -0500 From: "John R. Ackermann" To: "TAPR Special Interest Group" Subject: [tacgps] Re: RE NTP Requirements. Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <448578081.1009998454@[192.168.1.26]> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk There are at least three ways you can use the TAC-2 with a Linux/BSD/*nix box, at least if you're willing to run the NTP daemon: 1. Use the Oncore reference clock driver built into recent versions of ntpd. This provides very good performance, but talks to the Oncore in Motorola binary format at 9600 bps, and interrogates the GPS once per second, so it doesn't work too well with other simultaneous uses of the TAC-2. 2. Use the NMEA driver, which doesn't (in unpatched mode) provide 1pps accuracy. However, you can use the patched version at my web site (http://www.febo.com/time-freq/ntp) to get 1pps accuracy. This uses the standard 4800 bps NMEA strings, and doesn't talk to the GPS (i.e., it just turns on the necessary sentences and then sits back and listens). 3. You can ignore the serial data entirely, and just use the 1pps signal to determine the second marker, while using another ntp server to provide the actual date/time. Hope this helps. 73, John N8UR jra@febo.com --On Wednesday, January 02, 2002 3:45 PM +0000 "Gary J. Myers" wrote: > Tell me if I am wrong but I thought you cannot connect a TAC2 to a *NIX > box or UNIX flavors. I was thinking of porting a clone of Showtime or > TAC32 over to BSD UNIX becuase of this notion. I would much rather run my > TAC2 on my FreeBSD box instead of a windoze box. > > Gary > >> From: xaos >> To: "TAPR Special Interest Group" >> Date: Wed, 02 Jan 2002 16:06:58 -0500 >> Subject: [tacgps] NTP Requirements. >> >> >> Hello everyone, >> >> I am a bit confused about what it takes to get >> the TAC2 working under Linux and NTP. >> >> First, do I need the PPS kit? >> I have NTP version 4.0.99k23. It seems that if I use the PPSkit >> I will have to re-compile NTP. >> >> What's the difference between ntp and xntp? >> >> Can I use NTP and still get the GPS data from TAC2? >> Can I also communicate (send messages to the TAC2) when >> I use NTP. >> >> Can someone provide me with a valid ntp.conf using tha TAC2? >> >> I am just a bit overwhelmed with info right now. Please excuse >> my stupid questions. >> >> Thanks in advance, >> George Hrysanthopoulos, N2FGX >> >> >> >> --- >> You are currently subscribed to tacgps as: gary@geekslounge.com >> To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org >> >> >> > > --- > You are currently subscribed to tacgps as: JRA@FEBO.COM > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Wed Jan 2 18:10:22 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id SAA07278 for ; Wed, 2 Jan 2002 18:10:17 -0600 (CST) Date: Wed, 02 Jan 2002 19:09:34 -0500 From: "John R. Ackermann" To: "TAPR Special Interest Group" Subject: [tacgps] Re: RE NTP Requirements. Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <448698263.1009998574@[192.168.1.26]> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk See addition below... --On Wednesday, January 02, 2002 7:07 PM -0500 "John R. Ackermann" wrote: > 3. You can ignore the serial data entirely, and just use the 1pps signal > to determine the second marker, while using another ntp server to provide > the actual date/time. I forgot to say that this requires using the "ATOM" reference clock driver in ntpd. John > --On Wednesday, January 02, 2002 3:45 PM +0000 "Gary J. Myers" > wrote: > >> Tell me if I am wrong but I thought you cannot connect a TAC2 to a *NIX >> box or UNIX flavors. I was thinking of porting a clone of Showtime or >> TAC32 over to BSD UNIX becuase of this notion. I would much rather run my >> TAC2 on my FreeBSD box instead of a windoze box. >> >> Gary >> >>> From: xaos >>> To: "TAPR Special Interest Group" >>> Date: Wed, 02 Jan 2002 16:06:58 -0500 >>> Subject: [tacgps] NTP Requirements. >>> >>> >>> Hello everyone, >>> >>> I am a bit confused about what it takes to get >>> the TAC2 working under Linux and NTP. >>> >>> First, do I need the PPS kit? >>> I have NTP version 4.0.99k23. It seems that if I use the PPSkit >>> I will have to re-compile NTP. >>> >>> What's the difference between ntp and xntp? >>> >>> Can I use NTP and still get the GPS data from TAC2? >>> Can I also communicate (send messages to the TAC2) when >>> I use NTP. >>> >>> Can someone provide me with a valid ntp.conf using tha TAC2? >>> >>> I am just a bit overwhelmed with info right now. Please excuse >>> my stupid questions. >>> >>> Thanks in advance, >>> George Hrysanthopoulos, N2FGX >>> >>> >>> >>> --- >>> You are currently subscribed to tacgps as: gary@geekslounge.com >>> To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org >>> >>> >>> >> >> --- >> You are currently subscribed to tacgps as: JRA@FEBO.COM >> To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org >> >> >> > > > > --- > You are currently subscribed to tacgps as: JRA@FEBO.COM > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 3 15:54:04 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id PAA05631 for ; Thu, 3 Jan 2002 15:54:04 -0600 (CST) Sender: bounce-tacgps-6754@lists.tapr.org Message-ID: Date: Thu, 03 Jan 2002 15:56:18 -0600 From: Gerry Creager N5JXS Reply-To: "TAPR Special Interest Group" Organization: AATLT/TAMU X-Accept-Language: en MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] Re: Change of Address test References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio X-Message-Id: <3C34D382.47E2E4C5@cs.tamu.edu> Precedence: bulk Happy New Year, yourself! Are you going to the ION National Meeting? Anyone else from the SIG going? I'm currently planning on a short trip out there. Gerry -- "Tom Clark (W3IWI)" wrote: > > I switched ISPs -- new Email address is mailto:w3iwi@toad.net. > > This is a test to verify that TACGPS made the change ok. > > 73 and Happy New Year de Tom, W3IWI -- Gerry Creager AATLT/Network Engineering Texas A&M University 979.458.4020 (Phone) 979.847.8578 (FAX) --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 3 18:29:29 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id SAA14187 for ; Thu, 3 Jan 2002 18:29:22 -0600 (CST) From: "Tom Clark \(W3IWI\)" To: "TAPR Special Interest Group" Subject: [tacgps] Re: Change of Address test Date: Thu, 3 Jan 2002 19:27:33 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Importance: Normal List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <001c01c194b6$9c548cb0$0200a8c0@tomcat> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Nope -- I won't be there. But I do have some really neat new stuff to spring on y'all! > -----Original Message----- > From: bounce-tacgps-25677@lists.tapr.org > [mailto:bounce-tacgps-25677@lists.tapr.org]On Behalf Of Gerry Creager > N5JXS > Sent: Thu, January 03, 2002 16:56 > To: TAPR Special Interest Group > Subject: [tacgps] Re: Change of Address test > > > Happy New Year, yourself! Are you going to the ION National Meeting? > Anyone else from the SIG going? I'm currently planning on a > short trip > out there. > > Gerry > -- > "Tom Clark (W3IWI)" wrote: > > > > I switched ISPs -- new Email address is mailto:w3iwi@toad.net. > > > > This is a test to verify that TACGPS made the change ok. > > > > 73 and Happy New Year de Tom, W3IWI > -- > Gerry Creager > AATLT/Network Engineering > Texas A&M University > 979.458.4020 (Phone) 979.847.8578 (FAX) > > --- > You are currently subscribed to tacgps as: w3iwi@toad.net > To unsubscribe send a blank email to > leave-tacgps-6754G@lists.tapr.org > > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Wed Jan 9 09:42:24 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA19572 for ; Wed, 9 Jan 2002 09:42:18 -0600 (CST) From: "Steven Bible" To: "TAPR Special Interest Group" Subject: [tacgps] How accurate an Oscillator? Date: Wed, 9 Jan 2002 08:44:52 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Importance: Normal List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk My personal studies have shifted to crystals, oscillators and PLLs. So it was a natural to look at W5OJM's article. I have everything built up and initially I am trying to discipline a low-cost VC-TXO that I bought from Digi-Key (I have a Rb and oven oscillators coming later). It is made by ECS Inc. and their PN is VC-TXO-39SM-100. It is 10 MHz. The data sheet is available from ECS web site. I wanted to investigate this oscillator for my DSP-10. Since Sunday I have been trying to discipline this oscillator. The ASCII data and subsequent graphs show the DAC voltage in a saw-tooth pattern over several hours. This is in Mode 2. Mode one the DAC voltage is steady. Last night I revisited the set-up of R5 and R6. The values now are R5 = 330 ohms and R6 = 220K ohms. S for this oscillator is 1.105 x 10e-5. The change in frequency over 1 volt is 110.5 Hz. I suspect that this is too much for the algorithm that Brooks' has programmed. I read that Rd and Oven Oscillators have a much lesser S with 5 volts changing only 1 Hz. I have not installed a second 4250 counter. I'll surely understand more when the Rd and oven oscillators arrive and I can hook them up and see. But I wanted to post a note to the list and get some ideas from the group as to what is happening here. I am curious as to how low an accuracy, or rather, how large and S can be used to discipline and oscillator? Any ideas? - Steve, N7HPR (n7hpr@tapr.org) --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 10 02:39:08 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id CAA21631 for ; Thu, 10 Jan 2002 02:39:07 -0600 (CST) Message-ID: From: Ian Roberts To: "TAPR Special Interest Group" Subject: [tacgps] RE: How accurate an Oscillator? Date: Thu, 10 Jan 2002 10:37:18 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <963B718939AFD5118ED300902773C3B31B6DA0@SRVEXCH1> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Steve, my experiences with a similar setup may be of interest. The oscillator is a 10 MHz Ovenaire Precision Oscillator TTL output with a 40 second spec'ed stability of around exp-8. In native form the suggested voltage tuning network will not work - the controller bounces from end-stop to end-stop (in voltage terms). The work-around was to place a series resistor of around 18K in series with the 5v tuning voltage, and around 4 Mega Ohm between the wiper of the tuning pot and the voltage tuning pin of the oscillator. This reduces the supply voltage at the tuning pot to below 1v and the total tuning range of the oscillator is then around 40 Hz (from the previous ~300Hz). This is a long way off Brooks' example of 1 Hz/10v with the HP oscillator. R5 and R6 are minimum values - the Analogue Devices DAC I'm using is capable of an indefinite period short on the DAC output, but to keep thermal cycling low maintain about 800-1000 ohms as suggested. A second frequency divider is used to bring the 10 MHz down (to around 78 kHz). The GPS OEM is a Trimble ACE. In N=2 this oscillator provides around 4x exp-10 with my measurement setup, which is pure ham, and is compared to the SABC's on-air rubidium on ch 13 (247.456030 MHz) - I use a harmonic of the osc as I cannot measure to exp-10/11 at 10 MHz. It is interesting to note that a phase error of more than about 10 ns has measurable influence on the frequency of the osc, for this reason I wait until the phase error is 5 ns or less in N=2, then take the frequency which compares well with the rubidium. There has been some debate on this reflector regarding 2nd and 3rd order control loops. In N=3 the average phase error increases and the osc spends much more time way off the required frequency, so in my opinion when using cheap oscillators anyway, the longer constants greatly reduce the system's accuracy. In N=4 the system unlocks. After a power failure my system manages to find its feet again, without intervention. Also, determination of the actual frequency is a problem in the absence of another reference standard. Brooks did not enlarge on how to do this in his article, but in subsequent correspondence told me that each DAC unit = 92 uv. From this it seems one needs to translate the oscillator's tuning curve in volts/Hz to DAC units and transpose these to the 800 ns set point (for the latter software version), then its no-mans land. Cheers, Ian ZS6BTE -----Original Message----- From: Steven Bible [mailto:n7hpr@tapr.org] Sent: 09 January 2002 05:45 To: TAPR Special Interest Group Subject: [tacgps] How accurate an Oscillator? My personal studies have shifted to crystals, oscillators and PLLs. So it was a natural to look at W5OJM's article. I have everything built up and initially I am trying to discipline a low-cost VC-TXO that I bought from Digi-Key (I have a Rb and oven oscillators coming later). It is made by ECS Inc. and their PN is VC-TXO-39SM-100. It is 10 MHz. The data sheet is available from ECS web site. I wanted to investigate this oscillator for my DSP-10. Since Sunday I have been trying to discipline this oscillator. The ASCII data and subsequent graphs show the DAC voltage in a saw-tooth pattern over several hours. This is in Mode 2. Mode one the DAC voltage is steady. Last night I revisited the set-up of R5 and R6. The values now are R5 = 330 ohms and R6 = 220K ohms. S for this oscillator is 1.105 x 10e-5. The change in frequency over 1 volt is 110.5 Hz. I suspect that this is too much for the algorithm that Brooks' has programmed. I read that Rd and Oven Oscillators have a much lesser S with 5 volts changing only 1 Hz. I have not installed a second 4250 counter. I'll surely understand more when the Rd and oven oscillators arrive and I can hook them up and see. But I wanted to post a note to the list and get some ideas from the group as to what is happening here. I am curious as to how low an accuracy, or rather, how large and S can be used to discipline and oscillator? Any ideas? - Steve, N7HPR (n7hpr@tapr.org) --- You are currently subscribed to tacgps as: itr@nanoteq.co.za To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 10 08:03:14 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id IAA16310 for ; Thu, 10 Jan 2002 08:03:10 -0600 (CST) Message-ID: Date: Thu, 10 Jan 2002 07:02:39 -0700 From: Diane Foray and Jeff Vollin X-Accept-Language: en MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] RE: How accurate an Oscillator? References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C3D9EFF.D61C1689@flash.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk My experience with trying to disciple a low cost oscillator indicate it is not worth the effort. I ran a setup using a Rakon 10 MHz TCXO for several months. The DAC output as well as the Phase output from Brooks' controller both looked like sine waves in direct correlation with the average temperature of the room day to night. If I switched on some overhead track lights, the loop would unlock. The only way to get the loop to stay locked was to do something to isolate the crystal from the local thermal environment. If I turned on the air conditioning in the room, the loop would unlock almost immediately after the start of a cooling cycle. My room is in Arizona, in the basement of a brick house. The wall near the workbench is above grade and the sun hits it in the afternoon, so the day-night temperature excursion is about 3-4 deg F without the A/C. I think the controller was successful keeping the crystal frequency on target, when averaged over a long period (say several days) but the short term errors were pretty large. The phase output had about a 300 nS p-p sinewave on it. Eventually, I gave up and switched to an OCXO, an HP 10811 in a 5370 time interval counter. Even this oscillator shows evidence of toom temperature effects if you look at the DAC output. The phase is pretty flat thanks to the controller's loopgain. I plan on finding a double-oven OCXO before I call this project complete. I found N=3 had the lowest phase errors with the Rakon. I don't know the exact shape of the loopgain, but I expect that loop may have higher loopgain for frequencies associated with a 24 hour period, while still maintaining adequate bandwidth to not experience non-linear effects, such as saturation of the control signal. Higher N's were prone to losing lock, and never recovering. Jeff Vollin > > From: Steven Bible [mailto:n7hpr@tapr.org] > Sent: 09 January 2002 05:45 > To: TAPR Special Interest Group > Subject: [tacgps] How accurate an Oscillator? > > My personal studies have shifted to crystals, oscillators and PLLs. So it > was a natural to look at W5OJM's article. > > I have everything built up and initially I am trying to discipline a > low-cost VC-TXO that I bought from Digi-Key (I have a Rb and oven > oscillators coming later). It is made by ECS Inc. and their PN is > VC-TXO-39SM-100. It is 10 MHz. The data sheet is available from ECS web > site. I wanted to investigate this oscillator for my DSP-10. > > Since Sunday I have been trying to discipline this oscillator. The ASCII > data and subsequent graphs show the DAC voltage in a saw-tooth pattern over > several hours. This is in Mode 2. Mode one the DAC voltage is steady. > > Last night I revisited the set-up of R5 and R6. The values now are R5 = 330 > ohms and R6 = 220K ohms. S for this oscillator is 1.105 x 10e-5. The > change in frequency over 1 volt is 110.5 Hz. I suspect that this is too > much for the algorithm that Brooks' has programmed. I read that Rd and Oven > Oscillators have a much lesser S with 5 volts changing only 1 Hz. > > I have not installed a second 4250 counter. > > I'll surely understand more when the Rd and oven oscillators arrive and I > can hook them up and see. But I wanted to post a note to the list and get > some ideas from the group as to what is happening here. I am curious as to > how low an accuracy, or rather, how large and S can be used to discipline > and oscillator? Any ideas? > > - Steve, N7HPR > (n7hpr@tapr.org) > > --- > You are currently subscribed to tacgps as: itr@nanoteq.co.za > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > --- > You are currently subscribed to tacgps as: BARNIE@FLASH.NET > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 10 17:33:31 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id RAA20865 for ; Thu, 10 Jan 2002 17:33:26 -0600 (CST) From: "Kenneth Lerman" To: "TAPR Special Interest Group" Subject: [tacgps] RE: How accurate an Oscillator? Date: Thu, 10 Jan 2002 18:34:08 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="Windows-1252" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 In-Reply-To: List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Years (actually decades) ago, I remember seeing an article that suggested a cheap way to maintain a fairly constant temperature. Take a post hole digger and bury the oscillator as deep in the ground as you can put it. Ken -----Original Message----- From: bounce-tacgps-23240@lists.tapr.org [mailto:bounce-tacgps-23240@lists.tapr.org]On Behalf Of Diane Foray and Jeff Vollin Sent: Thursday, January 10, 2002 9:03 AM To: TAPR Special Interest Group Subject: [tacgps] RE: How accurate an Oscillator? My experience with trying to disciple a low cost oscillator indicate it is not worth the effort. I ran a setup using a Rakon 10 MHz TCXO for several months. The DAC output as well as the Phase output from Brooks' controller both looked like sine waves in direct correlation with the average temperature of the room day to night. If I switched on some overhead track lights, the loop would unlock. The only way to get the loop to stay locked was to do something to isolate the crystal from the local thermal environment. If I turned on the air conditioning in the room, the loop would unlock almost immediately after the start of a cooling cycle. My room is in Arizona, in the basement of a brick house. The wall near the workbench is above grade and the sun hits it in the afternoon, so the day-night temperature excursion is about 3-4 deg F without the A/C. I think the controller was successful keeping the crystal frequency on target, when averaged over a long period (say several days) but the short term errors were pretty large. The phase output had about a 300 nS p-p sinewave on it. Eventually, I gave up and switched to an OCXO, an HP 10811 in a 5370 time interval counter. Even this oscillator shows evidence of toom temperature effects if you look at the DAC output. The phase is pretty flat thanks to the controller's loopgain. I plan on finding a double-oven OCXO before I call this project complete. I found N=3 had the lowest phase errors with the Rakon. I don't know the exact shape of the loopgain, but I expect that loop may have higher loopgain for frequencies associated with a 24 hour period, while still maintaining adequate bandwidth to not experience non-linear effects, such as saturation of the control signal. Higher N's were prone to losing lock, and never recovering. Jeff Vollin > > From: Steven Bible [mailto:n7hpr@tapr.org] > Sent: 09 January 2002 05:45 > To: TAPR Special Interest Group > Subject: [tacgps] How accurate an Oscillator? > > My personal studies have shifted to crystals, oscillators and PLLs. So it > was a natural to look at W5OJM's article. > > I have everything built up and initially I am trying to discipline a > low-cost VC-TXO that I bought from Digi-Key (I have a Rb and oven > oscillators coming later). It is made by ECS Inc. and their PN is > VC-TXO-39SM-100. It is 10 MHz. The data sheet is available from ECS web > site. I wanted to investigate this oscillator for my DSP-10. > > Since Sunday I have been trying to discipline this oscillator. The ASCII > data and subsequent graphs show the DAC voltage in a saw-tooth pattern over > several hours. This is in Mode 2. Mode one the DAC voltage is steady. > > Last night I revisited the set-up of R5 and R6. The values now are R5 = 330 > ohms and R6 = 220K ohms. S for this oscillator is 1.105 x 10e-5. The > change in frequency over 1 volt is 110.5 Hz. I suspect that this is too > much for the algorithm that Brooks' has programmed. I read that Rd and Oven > Oscillators have a much lesser S with 5 volts changing only 1 Hz. > > I have not installed a second 4250 counter. > > I'll surely understand more when the Rd and oven oscillators arrive and I > can hook them up and see. But I wanted to post a note to the list and get > some ideas from the group as to what is happening here. I am curious as to > how low an accuracy, or rather, how large and S can be used to discipline > and oscillator? Any ideas? > > - Steve, N7HPR > (n7hpr@tapr.org) > > --- > You are currently subscribed to tacgps as: itr@nanoteq.co.za > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > --- > You are currently subscribed to tacgps as: BARNIE@FLASH.NET > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org --- You are currently subscribed to tacgps as: Kenneth.Lerman@se-ltd.com To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Sat Jan 12 00:30:23 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id AAA21266 for ; Sat, 12 Jan 2002 00:30:19 -0600 (CST) Message-ID: Date: Fri, 11 Jan 2002 22:29:38 -0800 From: Dan Hinz X-Accept-Language: en MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] How accurate an Oscillator? Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C3FD7D2.905FBB12@ieee.org> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Steve- Symptoms sound like what I suffered from. Mode 1 appeared normal, Mode 2 I got a saw tooth that drove to the rail and then reset to 0. The cycle repeated in 4.13 hours or 10x the filter constant of 1500 seconds. When I went to mode 3, the problem continued with a longer period that I estimated at about 14.5 hours. (I didn't wait for a full cycle to figure it out, merely looked at the slope) The response I got back from Brooks was that I was either picking up a bunch of noise or else "way" off frequency. "way" being a relative term, I was actually off almost 2Hz. I had another stable time base that I used as a "reference" to get to the right frequency. I wrote everything down so that I could get back to where I was if need be. The other OCXO was not locked to GPS, I just kept it powered up. Once I got the disciplined oscillator locked to GPS for several days, I then set my "reference" to the correct frequency. I used the 1.33 PIC software that has the phase difference output available for monitoring via an analog meter. Here is the text of my message to Brooks after I finally locked on... Good luck, Dan Brooks- I installed a 10pF cap on the input, then ran out to an end of the year soccer party for my 6 year old. I collected data for several hours. I still had a random number but the average was around 600 as opposed to ~715 . So I figured I'd check the frequency. As you suspected, I was way off frequency, nearly 2Hz! That was a 1 hour test of patience to get on frequency. I set it, went to mode 2 and then to bed. I analyzed the data this morning and it looks great! Max difference in phase from one reading to the next is 87 (120nS) with an average of 8.5 (11.8nS) The controller is averaging an actual phase number of 795, the stdev is 35. Thanks for all your help. This is a great project! 73, Dan - W6LSN --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Sun Jan 13 19:29:32 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id TAA25855 for ; Sun, 13 Jan 2002 19:29:31 -0600 (CST) From: "Steven Bible" To: "TAPR Special Interest Group" Subject: [tacgps] RE: How accurate an Oscillator? Date: Sun, 13 Jan 2002 18:32:44 -0700 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 Importance: Normal List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Thanks to everyone who replied. All great information which was most helpful. Here's what I have discovered so far. The output of U3 pin 15 was way too jittery. I was trying to do as Brooks instructed to look at the pulse width to get the frequency as close as possible. So there must be some noise somewhere. I found that I did not have a good match between the VC-TXO and the HCT4046 phase detector input. I found this problem by measuring the frequency of the PD output. It was not 10 MHz, it was something less. In fact, it varied. So I made a direct connection from the VC-TXO output to the PD input and now there's a 10 MHz output of the PD. Once I did this the output of U3 pin 15 was much more stable. I was able to adjust the frequency phase. Before, the low/high LEDs would flicker a bunch (no wonder), now they were much more stable and the frequency was easier to adjust. I was able to get the pulse width stable and close to frequency. I then put the device in Mode 2. As I watched, things looked good. That was yesterday and today I found from the ASCII data that there was a close lock for about 3-4 hours. Then the DAC output appeared to hit the top rail and then started saw-toothing (if that's a word :-). A little while ago it appears to found a lock again. I suspect temperature has a role here. The high today was 74 degrees in Phoenix (just had to throw that in there :-). So I suspect I am not in the middle of the EFC range. I'll need to go back and look at values of Ra and Rb again. Plus, since this oscillator is also a TXO, there might an influence not desirable for the loop filter of the W5OJM device. I'll keep an eye on it for the moment. I still need to look at noise on the supply voltage (I am using a wall wart) and try a second 4250 counter to divide down the 10 MHz by 32 instead of 16 as I am now. Me thinks to really assess how low-cost oscillators will perform when disciplined by GPS is to get a more accurate reference up and running to compare with. I have a Rb now that I'll get connected up and use it as my reference. Then I'll compare the accuracy of the ECS VC-TXO that I have now and hopefully other VCXOs that I can try. More to follow... - Steve, N7HPR (n7hpr@tapr.org) --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 07:25:20 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id HAA29627 for ; Thu, 24 Jan 2002 07:25:16 -0600 (CST) Message-ID: Date: Thu, 24 Jan 2002 08:24:35 -0500 From: xaos User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4) Gecko/20011019 Netscape6/6.2 X-Accept-Language: en-us MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] GPS Distribution amplifier References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C500B13.30401@darksmile.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Hello everyone, I need to split the GPS signal from the TAC2 so I can feed a second GPS receiver. Some GPS distribution amplifiers I found, were very expensive ($300-$400 range). I also found a unit on sale at Ebay for ~$150.00. This one is a HP 58535A. Does anybody have info on this unit? I was wondering if there is another way to do this. Basically the problem arises from the fact that GPS receivers provide power to the antenna. I can't just combine the signals since I would damage the units. Has anyone here addressed this problem? Thanks, -George Hrysanthopoulos, N2FGX --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 07:36:57 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id HAA00466 for ; Thu, 24 Jan 2002 07:36:54 -0600 (CST) Date: Thu, 24 Jan 2002 08:36:27 -0500 From: John Ackermann N8UR To: "TAPR Special Interest Group" Subject: [tacgps] Re: GPS Distribution amplifier Message-ID: In-Reply-To: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <2518291.1011861387@WUSJA129861-8HP> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk --On Thursday, January 24, 2002 8:24 AM -0500 xaos wrote: > Hello everyone, > > I need to split the GPS signal from the TAC2 so I can feed a second > GPS receiver. Some GPS distribution amplifiers I found, > were very expensive ($300-$400 range). > > I also found a unit on sale at Ebay for ~$150.00. > This one is a HP 58535A. Does anybody have info on this unit? I bought one of the HP-58535As off eBay for about $100 (lucky I guess). It works fine. It has N connectors all around. You can also build a cheap but effective splitter/amplifier using DSS satellite TV components from Radio Shack; there've been a couple of messages on the list with a pointer to a web site with info on the bits and pieces to use, but I can't find the ##$%#@@#@ URL right now. 73, John ---- John Ackermann N8UR jra@febo.com http://www.febo.com President, TAPR n8ur@tapr.org http://www.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 07:50:50 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id HAA01183 for ; Thu, 24 Jan 2002 07:50:44 -0600 (CST) Message-ID: Date: Thu, 24 Jan 2002 08:50:08 -0500 From: xaos User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4) Gecko/20011019 Netscape6/6.2 X-Accept-Language: en-us MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] Re: GPS Distribution amplifier References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C501110.4070101@darksmile.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk John, That sounds great. I feel much better since you have already tested the HP unit. I just didn't want to take a chance on damaging my TAC2 or my antenna. Your second suggestion on using DSS satellite TV components: I wonder if that splitter supports powered antennas or passive ones. Again I am worried about damaging something. 73, George John Ackermann N8UR wrote: > --On Thursday, January 24, 2002 8:24 AM -0500 xaos > wrote: > >> Hello everyone, >> >> I need to split the GPS signal from the TAC2 so I can feed a second >> GPS receiver. Some GPS distribution amplifiers I found, >> were very expensive ($300-$400 range). >> >> I also found a unit on sale at Ebay for ~$150.00. >> This one is a HP 58535A. Does anybody have info on this unit? > > > I bought one of the HP-58535As off eBay for about $100 (lucky I > guess). It works fine. It has N connectors all around. > > You can also build a cheap but effective splitter/amplifier using DSS > satellite TV components from Radio Shack; there've been a couple of > messages on the list with a pointer to a web site with info on the > bits and pieces to use, but I can't find the ##$%#@@#@ URL right now. > > 73, > John > > > ---- > John Ackermann N8UR jra@febo.com http://www.febo.com > President, TAPR n8ur@tapr.org http://www.tapr.org > > > --- > You are currently subscribed to tacgps as: xaos@darksmile.net > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 08:21:52 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id IAA03374 for ; Thu, 24 Jan 2002 08:21:51 -0600 (CST) Message-Id: X-Sender: ohaprs@pop.oh.verio.com Date: Thu, 24 Jan 2002 09:21:06 -0500 To: "TAPR Special Interest Group" From: Doug Bade Subject: [tacgps] Re: GPS Distribution amplifier In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <4.3.2.7.2.20020124091655.00b3e5b0@pop.oh.verio.com> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk I currently use a 4 way DSS splitter from Radio shack and even use their inline DSS amplifier for long cable runs when testing, and to overcome loss of 4-way splitter. Currently in use with 2 HP 10 Mhz GPS disciplined oscillators, My Oncore DGPS, and a Trimble Svee-Six, with great signal strength, and lock. It does not seem to bother the stability or accuracy of any of them. It was also a lot cheaper than $100.00... DO not use the cable variety, but the DSS versions are rated to 2 GHZ. Doug At 08:50 AM 1/24/02 -0500, you wrote: >John, > >That sounds great. I feel much better since you have already tested the HP >unit. >I just didn't want to take a chance on damaging my TAC2 or my antenna. > >Your second suggestion on using DSS satellite TV components: I wonder if >that splitter >supports powered antennas or passive ones. Again I am worried about >damaging something. > >73, >George > >John Ackermann N8UR wrote: > >>--On Thursday, January 24, 2002 8:24 AM -0500 xaos >>wrote: >> >>>Hello everyone, >>> >>>I need to split the GPS signal from the TAC2 so I can feed a second >>>GPS receiver. Some GPS distribution amplifiers I found, >>>were very expensive ($300-$400 range). >>> >>>I also found a unit on sale at Ebay for ~$150.00. >>>This one is a HP 58535A. Does anybody have info on this unit? >> >> >>I bought one of the HP-58535As off eBay for about $100 (lucky I >>guess). It works fine. It has N connectors all around. >> >>You can also build a cheap but effective splitter/amplifier using DSS >>satellite TV components from Radio Shack; there've been a couple of >>messages on the list with a pointer to a web site with info on the bits >>and pieces to use, but I can't find the ##$%#@@#@ URL right now. >> >>73, >>John >> >> >>---- >>John Ackermann N8UR jra@febo.com http://www.febo.com >>President, TAPR n8ur@tapr.org http://www.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 08:26:12 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id IAA03509 for ; Thu, 24 Jan 2002 08:26:06 -0600 (CST) Message-Id: X-Sender: ohaprs@pop.oh.verio.com Date: Thu, 24 Jan 2002 09:24:59 -0500 To: "TAPR Special Interest Group" From: Doug Bade Subject: [tacgps] Re: GPS Distribution amplifier In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <4.3.2.7.2.20020124092236.00b3b220@pop.oh.verio.com> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk OOPs, I forgot to mention, put DC blocks on all but one of the ports, as you need to pass DC from one GPS to run the preamp in the antenna. That is a standard CATV part on the hooks at R.S... according to the docs with the splitter it is DC isolated port to port, but I have not trusted or tried this yet, as I fried on Oncore a while back, backfeeding DC into antenna port with no power on main VCC.. Have fun, Doug KB8GVQ At 09:21 AM 1/24/02 -0500, you wrote: >I currently use a 4 way DSS splitter from Radio shack and even use their >inline DSS amplifier for long cable runs when testing, and to overcome >loss of 4-way splitter. Currently in use with 2 HP 10 Mhz GPS disciplined >oscillators, My Oncore DGPS, and a Trimble Svee-Six, with great signal >strength, and lock. It does not seem to bother the stability or accuracy >of any of them. It was also a lot cheaper than $100.00... DO not use the >cable variety, but the DSS versions are rated to 2 GHZ. Doug > > > >At 08:50 AM 1/24/02 -0500, you wrote: >>John, >> >>That sounds great. I feel much better since you have already tested the >>HP unit. >>I just didn't want to take a chance on damaging my TAC2 or my antenna. >> >>Your second suggestion on using DSS satellite TV components: I wonder if >>that splitter >>supports powered antennas or passive ones. Again I am worried about >>damaging something. >> >>73, >>George >> >>John Ackermann N8UR wrote: >> >>>--On Thursday, January 24, 2002 8:24 AM -0500 xaos >>>wrote: >>> >>>>Hello everyone, >>>> >>>>I need to split the GPS signal from the TAC2 so I can feed a second >>>>GPS receiver. Some GPS distribution amplifiers I found, >>>>were very expensive ($300-$400 range). >>>> >>>>I also found a unit on sale at Ebay for ~$150.00. >>>>This one is a HP 58535A. Does anybody have info on this unit? >>> >>> >>>I bought one of the HP-58535As off eBay for about $100 (lucky I >>>guess). It works fine. It has N connectors all around. >>> >>>You can also build a cheap but effective splitter/amplifier using DSS >>>satellite TV components from Radio Shack; there've been a couple of >>>messages on the list with a pointer to a web site with info on the bits >>>and pieces to use, but I can't find the ##$%#@@#@ URL right now. >>> >>>73, >>>John >>> >>> >>>---- >>>John Ackermann N8UR jra@febo.com http://www.febo.com >>>President, TAPR n8ur@tapr.org http://www.tapr.org > > >--- >You are currently subscribed to tacgps as: DOUG@CLECOM.COM >To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 09:19:18 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA07290 for ; Thu, 24 Jan 2002 09:19:17 -0600 (CST) Message-ID: Date: Thu, 24 Jan 2002 10:18:44 -0500 From: xaos User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4) Gecko/20011019 Netscape6/6.2 X-Accept-Language: en-us MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] Re: GPS Distribution amplifier References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C5025D4.7080406@darksmile.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Doug, You mentioned the magic word "fried". That's what I am worried about. -GH Doug Bade wrote: > OOPs, I forgot to mention, put DC blocks on all but one of the ports, > as you need to pass DC from one GPS to run the preamp in the antenna. > That is a standard CATV part on the hooks at R.S... according to the > docs with the splitter it is DC isolated port to port, but I have not > trusted or tried this yet, as I fried on Oncore a while back, > backfeeding DC into antenna port with no power on main VCC.. Have fun, > Doug KB8GVQ > > > > At 09:21 AM 1/24/02 -0500, you wrote: > >> I currently use a 4 way DSS splitter from Radio shack and even use >> their inline DSS amplifier for long cable runs when testing, and to >> overcome loss of 4-way splitter. Currently in use with 2 HP 10 Mhz >> GPS disciplined oscillators, My Oncore DGPS, and a Trimble Svee-Six, >> with great signal strength, and lock. It does not seem to bother the >> stability or accuracy of any of them. It was also a lot cheaper than >> $100.00... DO not use the cable variety, but the DSS versions are >> rated to 2 GHZ. Doug >> >> >> >> At 08:50 AM 1/24/02 -0500, you wrote: >> >>> John, >>> >>> That sounds great. I feel much better since you have already tested >>> the HP unit. >>> I just didn't want to take a chance on damaging my TAC2 or my antenna. >>> >>> Your second suggestion on using DSS satellite TV components: I >>> wonder if that splitter >>> supports powered antennas or passive ones. Again I am worried about >>> damaging something. >>> >>> 73, >>> George >>> >>> John Ackermann N8UR wrote: >>> >>>> --On Thursday, January 24, 2002 8:24 AM -0500 xaos >>>> wrote: >>>> >>>>> Hello everyone, >>>>> >>>>> I need to split the GPS signal from the TAC2 so I can feed a second >>>>> GPS receiver. Some GPS distribution amplifiers I found, >>>>> were very expensive ($300-$400 range). >>>>> >>>>> I also found a unit on sale at Ebay for ~$150.00. >>>>> This one is a HP 58535A. Does anybody have info on this unit? >>>> >>>> >>>> >>>> I bought one of the HP-58535As off eBay for about $100 (lucky I >>>> guess). It works fine. It has N connectors all around. >>>> >>>> You can also build a cheap but effective splitter/amplifier using >>>> DSS satellite TV components from Radio Shack; there've been a >>>> couple of messages on the list with a pointer to a web site with >>>> info on the bits and pieces to use, but I can't find the ##$%#@@#@ >>>> URL right now. >>>> >>>> 73, >>>> John >>>> >>>> >>>> ---- >>>> John Ackermann N8UR jra@febo.com http://www.febo.com >>>> President, TAPR n8ur@tapr.org http://www.tapr.org >>> >> >> >> --- >> You are currently subscribed to tacgps as: DOUG@CLECOM.COM >> To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > > > --- > You are currently subscribed to tacgps as: xaos@darksmile.net > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 09:34:30 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id JAA08397 for ; Thu, 24 Jan 2002 09:34:27 -0600 (CST) Message-Id: X-Sender: ohaprs@pop.oh.verio.com Date: Thu, 24 Jan 2002 10:33:14 -0500 To: "TAPR Special Interest Group" From: Doug Bade Subject: [tacgps] Re: GPS Distribution amplifier In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <4.3.2.7.2.20020124102612.00b3a310@pop.oh.verio.com> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk That happened long before the radio shack DSS splitter and dc blocks, I had directly coupled 2 gps's in a 2.4ghz 2 way splitter ( not DC blocked) which I got at the Dayton Hamfest a couple years ago.. The DSS splitter with DC blocks works perfect. I have over 50 feet of feedline to the antenna, and no major issues.. I became a believer real quick. Just hooking up and watching TAC32 and or SA Watch before, during and after ..... With the DSS inline amp in just ahead of the 4 way splitter, it overcomes the splitter losses just fine. The 5 volts from the source GPS feeds the amp enough to make it work for 5-10 db or so... I have no reservations... Doug At 10:18 AM 1/24/02 -0500, you wrote: >Doug, > >You mentioned the magic word "fried". That's what I am worried about. > >-GH > > >Doug Bade wrote: > >>OOPs, I forgot to mention, put DC blocks on all but one of the ports, as >>you need to pass DC from one GPS to run the preamp in the antenna. That >>is a standard CATV part on the hooks at R.S... according to the docs with >>the splitter it is DC isolated port to port, but I have not trusted or >>tried this yet, as I fried on Oncore a while back, backfeeding DC into >>antenna port with no power on main VCC.. Have fun, Doug KB8GVQ >> >> >> >>At 09:21 AM 1/24/02 -0500, you wrote: >> >>>I currently use a 4 way DSS splitter from Radio shack and even use their >>>inline DSS amplifier for long cable runs when testing, and to overcome >>>loss of 4-way splitter. Currently in use with 2 HP 10 Mhz GPS >>>disciplined oscillators, My Oncore DGPS, and a Trimble Svee-Six, with >>>great signal strength, and lock. It does not seem to bother the >>>stability or accuracy of any of them. It was also a lot cheaper than >>>$100.00... DO not use the cable variety, but the DSS versions are rated >>>to 2 GHZ. Doug >>> >>> >>> >>>At 08:50 AM 1/24/02 -0500, you wrote: >>> >>>>John, >>>> >>>>That sounds great. I feel much better since you have already tested the >>>>HP unit. >>>>I just didn't want to take a chance on damaging my TAC2 or my antenna. >>>> >>>>Your second suggestion on using DSS satellite TV components: I wonder >>>>if that splitter >>>>supports powered antennas or passive ones. Again I am worried about >>>>damaging something. >>>> >>>>73, >>>>George >>>> >>>>John Ackermann N8UR wrote: >>>> >>>>>--On Thursday, January 24, 2002 8:24 AM -0500 xaos >>>>> wrote: >>>>> >>>>>>Hello everyone, >>>>>> >>>>>>I need to split the GPS signal from the TAC2 so I can feed a second >>>>>>GPS receiver. Some GPS distribution amplifiers I found, >>>>>>were very expensive ($300-$400 range). >>>>>> >>>>>>I also found a unit on sale at Ebay for ~$150.00. >>>>>>This one is a HP 58535A. Does anybody have info on this unit? >>>>> >>>>> >>>>> >>>>>I bought one of the HP-58535As off eBay for about $100 (lucky I >>>>>guess). It works fine. It has N connectors all around. >>>>> >>>>>You can also build a cheap but effective splitter/amplifier using DSS >>>>>satellite TV components from Radio Shack; there've been a couple of >>>>>messages on the list with a pointer to a web site with info on the >>>>>bits and pieces to use, but I can't find the ##$%#@@#@ URL right now. >>>>> >>>>>73, >>>>>John >>>>> >>>>> >>>>>---- >>>>>John Ackermann N8UR jra@febo.com http://www.febo.com >>>>>President, TAPR n8ur@tapr.org http://www.tapr.org >>> >>> >>>--- >>>You are currently subscribed to tacgps as: DOUG@CLECOM.COM >>>To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org >> >> >> >>--- >>You are currently subscribed to tacgps as: xaos@darksmile.net >>To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org >> > > > >--- >You are currently subscribed to tacgps as: DOUG@CLECOM.COM >To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 11:29:32 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id LAA15914 for ; Thu, 24 Jan 2002 11:29:31 -0600 (CST) Message-Id: To: "TAPR Special Interest Group" From: clemens@dwf.com Subject: [tacgps] Re: GPS Distribution amplifier In-Reply-To: Your message of "Thu, 24 Jan 2002 08:24:35 EST." Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Thu, 24 Jan 2002 10:28:50 -0700 Sender: bounce-tacgps-6754@lists.tapr.org List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <200201241728.g0OHSol8005591@orion.dwf.com> Precedence: bulk You dont mention what the second GPS receiver is, but if it can power the antenna, then all you need to do is put in a splitter and remove the shorting clip on the TAC2 that causes it to supply power to the antenna. Thats how I run a TAC2 (with an Oncore VP) and a M12 here. -- Reg.Clemens reg@dwf.com --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 13:04:41 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA22760 for ; Thu, 24 Jan 2002 13:04:41 -0600 (CST) From: xaos Message-Id: Subject: [tacgps] Re: GPS Distribution amplifier To: "TAPR Special Interest Group" Date: Thu, 24 Jan 2002 14:02:35 -0500 (EST) In-Reply-To: from "clemens@dwf.com" at Jan 24, 2002 10:28:50 AM MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <200201241902.g0OJ2Z102018@darksmile.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk As a matter of fact, the second GPS receiver is a custom Motorola box I got from eBay. The receiver ID looks like a VP (6 channel 1994 date). So, my target configuration would be a TAC2 (UT+) and the Motorola box connected to the Motorola 97 antenna. I checked the voltage on the Custom Motorola box and it provides +5V. I was not aware that the TAC2 could be configured to disable the +5V from the antenna. The antenna connection is direct from the UT+. I don't see how I could disable that. -GH > > You dont mention what the second GPS receiver is, but if it can power > the antenna, then all you need to do is put in a splitter and remove the > shorting clip on the TAC2 that causes it to supply power to the antenna. > Thats how I run a TAC2 (with an Oncore VP) and a M12 here. > -- > Reg.Clemens > reg@dwf.com > > > > --- > You are currently subscribed to tacgps as: xaos@darksmile.net > To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org > --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 13:13:44 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA23559 for ; Thu, 24 Jan 2002 13:13:43 -0600 (CST) Message-Id: X-Sender: jimwatt@connect.gi Date: Thu, 24 Jan 2002 19:56:53 +0100 To: "TAPR Special Interest Group" From: Jim Watt Subject: [tacgps] Re: GPS Distribution amplifier In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" X-MDaemon-Deliver-To: tacgps@lists.tapr.org X-Return-Path: jimwatt@pobox.com List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3.0.1.32.20020124195653.0456f9f8@connect.gi> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Hi, I'm new to this GPS stuff, however have been involved in TVRO for some time. Global make a rather nice and cheap four way active splitter which can accept power on any of its inputs, but protects the inputs from each other. http://www.globalcom.co.uk European Satellite LNB's usually work on 12/14v so the drive from the GPS board may be a bit low otherwise this item would work nicely and provide adequate protection. It uses F connectors - I'm still trying to come to terms with the fiddly little things used on GPS. Jim Watt ZB0D http://www.gibnet.com --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Thu Jan 24 14:30:35 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id OAA00836 for ; Thu, 24 Jan 2002 14:30:34 -0600 (CST) Message-Id: X-Sender: davem@localhost Date: Thu, 24 Jan 2002 12:29:11 -0800 To: "TAPR Special Interest Group" From: Dave Martindale Subject: [tacgps] Re: GPS Distribution amplifier In-Reply-To: References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <5.1.0.14.0.20020124122641.00aac818@localhost> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk >I was not aware that the TAC2 could be configured to disable the >+5V from the antenna. The antenna connection is direct >from the UT+. I don't see how I could disable that. There are different ways to build a TAC2. Some options use a GPS receiver board that internally provides 5 V to the antenna terminals, while others use a 5 V supply provided by the TAC board. If your GPS board provides 5 V, then you need a DC-isolated feed from the splitter. If your 5V power comes from the TAC board, not the GPS receiver, then you can disable it with a jumper. Dave --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Sun Jan 27 13:38:11 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id NAA04182 for ; Sun, 27 Jan 2002 13:38:10 -0600 (CST) Message-ID: Date: Sun, 27 Jan 2002 14:37:46 -0500 From: xaos User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.4) Gecko/20011019 Netscape6/6.2 X-Accept-Language: en-us MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] Unknown Motorola unit. References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C54570A.2030408@darksmile.net> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk Hello everyone, Two weeks ago, I got this unit from Ebay and I've been trying to get some info on it. First, it is a Motorola 19' rack unit (2U). The front panel says: "Time Frequency Reference" There are no other markings anywhere on the unit. The back had some labels: GPS Antenna", "-48V", "Redundancy Control", "remote GPS", "RS232", "1PPS out", and "5Mhz. Out". I opened the unit and inside there was a GPS receiver what looked like a crystal oven and some other stuff. Well, I powered the unit using a Lambda Power supply, and connected it to my computer using the TAC32 software. It turns out that the unit has a Motorola VP receiver (V5.1). I connected it to my GPS antenna and it started working fine and producing the 5Mhz. signal as indicated. There are some DIP switches inside but I need some info about their function. Specifically, there is a DIP switch block that is labeled: 1. 1/3 PPS - Ok this is an easy one. 2. No GPSR - No clue here. 3. Force ON - ?? 4. Force Off - ?? The other problem is, that the unit seems to have the 1PPS signal on the CTS pin not the DCD pin. I am out of luck on the Linux NTP driver here because according to the code, the 1PPS signal must come from the DCD pin. Well, I hope someone here has some info. 73, -George Hrysanthopoulos, N2FGX --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Sun Jan 27 14:45:37 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id OAA09066 for ; Sun, 27 Jan 2002 14:45:34 -0600 (CST) Message-ID: Date: Sun, 27 Jan 2002 15:45:01 -0500 From: GS Organization: bigfoot.com X-Accept-Language: en MIME-Version: 1.0 To: "TAPR Special Interest Group" Subject: [tacgps] Re: Unknown Motorola unit. References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <3C5466CD.7C7089F6@bigfoot.com> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk xaos wrote: > > The other problem is, that the unit seems to have the 1PPS signal on the > CTS pin not the DCD pin. I am out of luck on the Linux NTP driver here > because according to the code, the 1PPS signal must come from the DCD pin. Shouldn't be a real problem.... Two ways to fix it. Since the NTP driver is open source, just recode it to move the signal to CTS Or, if you're like me, and more comfortable with a pound of solder than a compiler, just make up a simple custom RS-232 cable, moving the 1PPS signal wherever you need it. -- Gary Sanders --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org From bounce-tacgps-6754@lists.tapr.org Sun Jan 27 20:38:01 2002 Received: from lists.tapr.org (lists.tapr.org [204.17.217.24]) by tapr.org (8.9.3/8.9.3/1.13) with SMTP id UAA26236 for ; Sun, 27 Jan 2002 20:37:59 -0600 (CST) From: "Tom Clark \(W3IWI\)" To: "TAPR Special Interest Group" Subject: [tacgps] RE: Unknown Motorola unit. Date: Sun, 27 Jan 2002 21:37:36 -0500 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal Importance: Normal In-Reply-To: X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2600.0000 List-Unsubscribe: List-Software: Lyris Server version 3.0 List-Subscribe: List-Owner: X-List-Host: Tucson Amateur Packet Radio Reply-To: "TAPR Special Interest Group" X-Message-Id: <000001c1a7a4$bff1e220$0200a8c0@tomcat> Sender: bounce-tacgps-6754@lists.tapr.org Precedence: bulk The VP 5.1 is most likely one of the original 6-channel rcvrs. 5.1 was the first production release of the firmware that worked pretty nearly correctly. 48v power sez that it came out of a telephone facility, or perhaps an early analog cell-fone site. It would appear this is a GPS disciplined xtal with holdover. Not knowing what xtal unit it is, but being pretty well versed in the old Motorola receiver, my gut feeling is that (now that S/A is off) this unit will work as a frequency standard at the ~1e-9 level. Maybe 1e-10 if you are lucky. The switches and connectors are a mystery to me too. 73 de Tom, W3IWI --- You are currently subscribed to tacgps as: lyris.tacgps@tapr.org To unsubscribe send a blank email to leave-tacgps-6754G@lists.tapr.org