For some reason, the "No GPS" LED is back - although the GPS is tracking 8 satellites in 3D mode and according to the TRAIM status the timing error is below the alarm threshhold (alarm = 1300ns, current = 43ns) - I guess the uinit has it's own standards for the GPS quality, and they are being violated in some way.
Still. at ;least I have seen it running with that LED off, which is a positve sign :) On Wed, Oct 12, 2011 at 5:42 AM, k4...@aol.com <k4...@aol.com> wrote: > If I recall, the firmware in the RFTGm collects about an hours worth of > position info and does an average to establish a self-survey. The next time > you cycle power, it will check the new position against the stored one and if > within 50 feet or so, it will use the stored position. That's probably why > it took a while for the LED to extinguish. > > Connected by DROID on Verizon Wireless > > -----Original message----- > From: Peter Bell <bell.pe...@gmail.com> > To: Discussion of precise time and frequency measurement <time-nuts@febo.com> > Sent: Tue, Oct 11, 2011 12:49:45 GMT+00:00 > Subject: Re: [time-nuts] Lucent RFTG-m-XO GPSDO > > The Rx was defective - I just got the new one, hooked it up to my > little test rig anf the antenna, and it happily picked up satellites > and got a position fix. > > Swapped it into the box, and found a TTL level copy of the RX data > stream from the encore on pin 2 of the interface connector, so hooked > that up to a TTL->RS232 converter so I could monitor what was > happening. It all seemed to be tracking OK, although the "No GPS" LED > was still on, so I just left it and after a couple of hours the LED > went out. > > Next step is getting the Rb working :) > > > On Mon, Oct 10, 2011 at 2:41 AM, k4...@aol.com <k4...@aol.com> wrote: >> Hi Peter, yes it sounds like the UT+ is defective if it never gets any sats. >> You can probably find one on eBay. Someone probably fired RF into the >> receiver front-end and zapped it. I think the antenna you are using should >> be OK. >> >> I will look for my drawings on this unit and send copies to you. And I know >> I have the software too, just need to find it! >> >> I have read in some of the notes here on time-nuts that people may be able >> to use RS232 for communicating with the RFTG units. But it was designed for >> RS422 and I would suggest you use RS422 for best results. I use a little >> RS422-4S232 converter which has worked fine for me. >> >> The early units had FRS rubidiums in them. The LPRO was used in the newer >> units. So, you have the more recent design. >> Connected by DROID on Verizon Wireless >> >> -----Original message----- >> From: Peter Bell <bell.pe...@gmail.com> >> To: Discussion of precise time and frequency measurement <time-nuts@febo.com> >> Sent: Sun, Oct 9, 2011 05:52:25 GMT+00:00 >> Subject: Re: [time-nuts] Lucent RFTG-m-XO GPSDO >> >> On Sun, Oct 9, 2011 at 3:31 AM, k4...@aol.com <k4...@aol.com> wrote: >>> Peter, do you have the software for this unit? The GPS antenna is supposed >>> to draw apx. 20 mA at 5 volts in order for the NO GPS LED to turn off. AT&T >>> (Lucent) used the MicroPulse timing antenna (later sold and now provided by >>> PCTE). You are correct in that Efratom used the Motorola UT+ 8 channel GPS >>> receiver on these units. The rubidium companion box used the data from the >>> same receiver (via an interconnect cable between the two units). Let me >>> know if you have questions on this unit, Regards, Doug.... >>> Connected by DROID on Verizon Wireless >>> >>> -----Original message----- >>> From: Peter Bell <bell.pe...@gmail.com> >>> To: time-nuts@febo.com >>> Sent: Fri, Oct 7, 2011 14:13:31 GMT+00:00 >>> Subject: [time-nuts] Lucent RFTG-m-XO GPSDO >>> >>> I have been playing with one of these units, and noticed that there >>> has been some discussion on them before on this list, so I wondered if >>> anyone might have any suggestions. >>> >>> Basically, the unit powers up correctly, but the "No GPS" LED never >>> goes off - this obviously could be because it's broken or doesn't like >>> my antenna, but with some of these telecom GPSDOs you have to manually >>> trigger a site survey if you move them to another location. Does >>> anyone know if this Lucent box is like that? >>> >>> Everything else seems to be working - once the "OK" light comes on the >>> 15MHz output is enbled, the "No GPS" LED goes from solid to blinking >>> if you disconnect the antenna - it just doesn't want to get GPS lock. >>> >>> I suppose I could pull the Oncore board (a UT+ according to the label) >>> out of it and test that on it's own - but I thiought I would see if >>> maybe it's a known issue first. >>> >> Hi, Doug >> >> I don't have any documentation at all - just the actual box. The >> antenna is one that originally came with a Furuno marine GPS, but the >> spec looks plausible (+5V @ 40mA, Internal L1 preamp with 26dB gain - >> and it has worked with several other GPS units without problems. >> >> I just pulled the oncore out, and connected it up outside the box - >> and it doesn't work. It passes the self test with a response code of >> 0000 (or 8000 with the antenna disconnected / 4000 with a short on the >> antenna socket - so it seems the current consumption is OK) - but no >> matter how long you leave it it still says it's tracking 0 satellites, >> although it happiy generates status reports. >> >> I wonder if this UT+ version is expecially sensitive to the antenna? >> I remember that the oncore VP would work with pretty much anything you >> hooked up to it. Of course, it's equally possible that the GPS module >> is defective. >> >> I'm tending towards broken - I also got an RTFG-m-RB with this unit, >> and that has a faulty LPRO-101 in it (it's probably fixable - it looks >> like the FET that heats up the Rb cell had gone open circuit) - and >> the two units together only cost me $40 supplied on a "status unkown, >> but likely defective" basis. I should get at least $40 of >> entertainment out of trying to fix them :) >> >> _______________________________________________ >> 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.