You need to be careful as Nigel says as Datum had special SVeeSix units from Trimble in the early days which were specifically modified for timing.
Rob Kimberley -----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of gandal...@aol.com Sent: 07 April 2013 18:37 To: time-nuts@febo.com Subject: Re: [time-nuts] Trimble SVeeSix -- was DATUM 9390-52054 Grief again... Hi Robert, You need to be careful on this one. I've never owned a Placer 400, so can't be 100% sure, but whilst I have seen it suggested that it contained an SVeeSix I've have also seen at least one quite emphatic comment, from a not very happy user, stating that it's definitely not an SVeeSix, but that there was a firmware upgrade available for the Placer 400 at one time to make it SVeeSix compatible, whatever that might imply. What I can confirm is that the version that's more generally available on Ebay, the Placer 450, consists of a single board inside the housing that integrates a GPS receiver with the control section. I discovered this the hard way after I bought a couple, and expecting them to contain one of the usual Trimble GPS modules with a separate PCB for the control section, silly me:-) Quite what the GPS section of that board might be derived from I don't know, but it would seem very unlikely that it's going to be a drop in replacement for a standard module. Nigel GM8PZR In a message dated 07/04/2013 17:47:40 GMT Daylight Time, robert8...@yahoo.co.uk writes: Hi, IIRC the early Trimble Placer vehicle tracking GPS receivers used the SVee6 and SVee8. I think the Placer 400 used the SVee6. These units turn up on ebay etc at very low cost. Robert G8RPI. ________________________________ From: "gandal...@aol.com" <gandal...@aol.com> To: time-nuts@febo.com Sent: Sunday, 7 April 2013, 8:53 Subject: [time-nuts] Trimble SVeeSix -- was DATUM 9390-52054 Grief again... The Trimble TNL 22880-B was indeed the original SV6, or SVeeSix as Trimble chose to call it, I have just confirmed this from a photo I took some time ago, and of which I can supply a copy if required. The SVeeSix manual from 1992 is here..... http://rapidshare.com/files/446743737/Trimble_SveeSix.pdf and a much smaller, optimised version, here...... http://rapidshare.com/files/446744995/Trimble_SveeSix_Optimised.pdf Thanks for these should be directed to Rob Kimberley on the list who provided the original printed copy. This original SVeeSix was approx 4 x 3.5 inches and was eventually replaced by the SVeeEight of similar appearance and again the same size. The SVeeSix Plus and SVeeEight Plus were the same modules mounted in metal boxes. The SVeeEight Plus manual from 2000 is available on the Trimble ftp site. I know of at least one application where an SVeeEight PCB module has been used as a drop in replacement for an SVeeSix, the Rapco 1804M GPS frequency standard, albeit using the opposite serial port, but don't know if this was an "out of the box" drop in or whether the port needed to be configured first. The smaller, 1.8 x 3.3 inches, version of the SVeeSix is the SVeeSix-CM3 embedded module, and the 1997 manual for that is also on the Trimble ftp site in the manuals/CM3 folder. It's possible that an SVeeSix-CM3 could be configured as an SVeeSix replacement but I've not investigated this, both the SVeeSix and SVeeEight came fitted with 1 or 2 standard serial ports on DB9 connectors, the SVeeSix-CM3 used an 8 pin header with I/O at TTL levels. Regards Nigel GM8PZR In a message dated 06/04/2013 23:10:28 GMT Daylight Time, b...@att.net writes: (Note: additional information about the receiver module has been added.) Burt Gang, You will remember several months ago I had some stranges that I thought were related to a defective Vectron oscillator in one of my DATUM 9390-52054. That turned out to be a the internal switching power supply so I replaced it with an external Cisco unit. I've done this in three units, two are mine and one belongs to Stu, K6YAZ. Well, I now have a different grief in one of my units. It had been cooking along swell with no problem ever since I replaced the power supply. This morning I notice that one of my units had the lock and tracking lights out. The display said that the signal level was low and there were no usable satellites. The 10 MHz output is also about 20 or more dB low. I assumed the power supply is all right because the display was working and it said it was 9-E9, not so good, but working - sorta. I swapped antennas and the good Datum was happy so I know the antenna is ok. when I got inside I checked the power supply rails and they're within .05 Volts of where they should be. There is 5 Volts on the GPS module and there is 4.96 Volts on the antenna Type-N connector (measured with the antenna line disconnected.) Power cycling the DATUM did not resolve the problem. Does anyone know if the symptoms above will occur if the 10 MHz oscillator is defective? I can understand it not tracking or not locked, but could this cause the receiver to not see or indicate any satellites? Since I only have two of these units on line, I'm very reluctant to start swapping modules because I would be without any working reference, so I need to keep one up and running. Both of my units are on a UPS, and according to the clocks in the kitchen, the bedroom, and the old VCR, we've not had a power interruption. I do not recognize the GPS receiver module, but it has the following number on it: TNL 22880-B. I have the schematics for the overall DATUM 9390-25054, but the GPS module in just a block. By the way, the GPS block on the DATUM overall schematic is marked, "SV6 / (TANS)". I suspect this means something noteworthy. Any guidance would be appreciated. Thanks, Burt Burt I. Weiner Associates Broadcast Technical Services Glendale, California U.S.A. b...@att.net www.biwa.cc K6OQK _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.