Robert, I'm 99% certain that Trimble didn't use down conversion on their GPS engines even on this older unit. Unfortunately even if you get the manual, it will probably only be operational as Datum were always very guarded about providing schematics etc to customers! Will see what I can glean from 9390-55100 and -55183 manuals I have, which may help. Rob -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Robert E. Martinson Sent: 04 January 2006 21:59 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Austron 2200A Manual My Datum 0390-5533 has a "Trimble Navigation Board, Assy 11179 Rev F", and another Trimble board that is marked "Datum SNP board 11874 Rev A & Trimble Navigation". This first board also contains a 16.368 MHz "frequency source" by Greenway. I do not have the original antenna. I bought 2 antennas from NavSphere , they are advertised as 2.5 to 12 VDC on the NavSphere website and clearly labeled as 2.5 - 12 VDC. The first one failed after some hours, thinking maybe it was a fluke I tried a second one. Same thing it failed after some hours. The company refuses to answer my requests for replacements that will work at 12 VDC as advertised. Option is to use a Bias-T, isolate the 12 VDC & insert 5 VDC. Or obtain a 12 VDC antenna, or even the Datum or Trimble antenna. Looking at the board near the TNC antenna connector I see a choke L3 and a cap C5 with a ferrite bead on one leg. Maybe this is the 12 VDC feed to the antenna. Will put back together later and measure voltages later. If this Trimble receiver down converts in the antenna, it makes the problem considerably more difficult to solve. What is the IF frequency? Any hints appreciated. REM -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Rob Kimberley Sent: Wednesday, January 04, 2006 15:03 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Austron 2200A Manual Robert, My pleasure Sir! The problem here is that the antenna may not work with +5v, and may actually need +12V. However, I have successfully done this with an Odetics receiver in the past, but the GPS engine was not a Trimble, and I don't actually know who made the antennae, but I do remember that they had both 12V and 5V versions. Worth a try though. For the record guys, I have worked directly for Systron-Donner, Austron, Odetics/Zyfer and have represented TrueTime, Datum, Meinberg, and KSI, so have some useful experience (plus a load of old manuals!!) Rob -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Robert E. Martinson Sent: 04 January 2006 18:38 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Austron 2200A Manual Wow, thanks for the quick response!!! Any help will be appreciated. Maybe I can disconnect the 12 V & put 5 V on the antenna (internally), will try and trace the traces. REM -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Rob Kimberley Sent: Wednesday, January 04, 2006 13:20 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Austron 2200A Manual Hi Robert, I do have some 9390 manuals as well but doubt if I have that one (looks like I better check out what I have and post the list). However I do know that Datum used Trimble engines in their GPS products which did not down convert and some of the earlier models did have +12V feeds for the LNA inside the antenna rather than the later and more common +5V types. Will check and let you know. Rob Kimberley -----Original Message----- From: Robert E. Martinson [mailto:REMartinson@RCN.com] Sent: 04 January 2006 18:06 To: 'Discussion of precise time and frequency measurement' Cc: time.bandit@btinternet.com Subject: RE: [time-nuts] Austron 2200A Manual Hi Bob, While you look through your box of manuals, could you please look for a manual for the Datum 9390-5533 which I acquired via EBay. Any info would be helpful, I note that it has 12 VDC on the antenna connector so I am curious if its for a preamplified antenna or an antenna/dowmconverter. I am more then happy to pay for it. REM REMartinson@RCN.com -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Rob Kimberley Sent: Wednesday, January 04, 2006 10:39 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Austron 2200A Manual Luciano, I used to work for Austron before they were acquired by Datum, and have a box of old manuals in my garage. Not sure if I have this particular one, but will check and let you know. Kind Regards Rob Kimberley -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Paramithiotti, Luciano Paolo S Sent: 04 January 2006 15:07 To: time-nuts@febo.com Subject: [time-nuts] Austron 2200A Manual I have bought an Austron 2200A GPS receiver with internal rubidium. Unfortunately I haven't the antenna that really is a special converter. I am looking for the service manual copy . Symmetricom say it haven't. I remember my Austron is only 10 years old. Someone in the word can help me? Thanks to all in advance Luciano P. S. 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    http://www.navtechgps.com/supply/rerad.asp

    http://www.prairie.mb.ca/tri_m.htm

Björn

"Charles S. Osborne" <cosborne@pari.edu> writes: > If this has come up before, I must have missed it. Frequent lightning storms > in summer keeps me in the hunt for these boards. Even with lightning > protection on the coaxes the EMP still gets a few every year. Ever tried a reradiating antenna to further separate the GPS from the dangerous outside? Does such a solution have any technical drawbacks wrt timing accuracy? It might not be cheaper than to buy a new lowcost oem receiver board, but if you want to protect hard to replace units it could be a solution. I have only used the "professional" type of kits like found here, http://www.navtechgps.com/supply/rerad.asp I know there is also a lower end market for use inside cars and the like, http://www.prairie.mb.ca/tri_m.htm -- Björn

     http://www.navtechgps.com/supply/rerad.asp

     http://www.prairie.mb.ca/tri_m.htm

 Björn

Reradiating the GPS antenna signal for isolation is an interesting idea. I had not considered it. I had a Trimble Scout handheld GPS that used that method to couple in a magnet mounted car rooftop GPS antenna signal into the built in antenna inside the handheld. It used a little clip on reradiating adapter. Wish the Trimble Scout was still alive. It had an excellent well thought out feature set in software. It's display gradually quit working and Trimble considered it obsolete and unreparable when I asked six or seven years ago. I saw one of those units in a GPS historical display in the Smithsonian museum in Washington. That's when you know your technology is becoming dated. Hi! Thanks, Charles S. Osborne Technical Director Pisgah Astronomical Research Institute 1 PARI Drive, HC 73, Box 638 Rosman, NC 28772-9614 http://www.pari.edu 828-862-5813 direct 828-862-5554 main 828-862-5877 FAX cosborne@pari.edu ----- Original Message ----- From: "Bjorn Gabrielsson" <bg@lysator.liu.se> To: "Charles S. Osborne" <cosborne@pari.edu> Cc: "Discussion of precise time and frequency measurement" <time-nuts@febo.com> Sent: Thursday, January 05, 2006 8:53 AM Subject: Re: [time-nuts] GPS receiver replacements for UT+ > "Charles S. Osborne" <cosborne@pari.edu> writes: > > > If this has come up before, I must have missed it. Frequent lightning storms > > in summer keeps me in the hunt for these boards. Even with lightning > > protection on the coaxes the EMP still gets a few every year. > > Ever tried a reradiating antenna to further separate the GPS from the > dangerous outside? Does such a solution have any technical drawbacks > wrt timing accuracy? > > It might not be cheaper than to buy a new lowcost oem receiver board, > but if you want to protect hard to replace units it could be a > solution. > > I have only used the "professional" type of kits like found here, > > http://www.navtechgps.com/supply/rerad.asp > > I know there is also a lower end market for use inside cars and the > like, > > http://www.prairie.mb.ca/tri_m.htm > > > -- > > Björn >