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, [email protected] <[email protected]> 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 <[email protected]> > To: Discussion of precise time and frequency measurement <[email protected]> > 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, [email protected] <[email protected]> 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 <[email protected]> >> To: [email protected] >> 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 -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
