The problem is I don't have the software for the unit, but based on the behaviour of the alarm and status led's I'm confident it is locked. The symmetricom site may have the software but I would need to agree to an eula prior to downloading which I don't want to do with my work account. So far symmetricom hasn't approved my request for a personal log in to their site.
I may try again with another email address (: ------------------------------ On Tue, 1 May, 2012 2:31 PM EDT Bob Camp wrote: >Hi > >The "upstream" time source may or may not be very good. Since it's PCS at >1.9 GHz and not 900 MHz CDMA, the carriers have a lot of wiggle room. You >can go in and fiddle which signal it tracks. > >Bob > >-----Original Message----- >From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On >Behalf Of Mark Spencer >Sent: Tuesday, May 01, 2012 12:41 PM >To: Discussion of precise time and frequency measurement >Subject: Re: [time-nuts] Symmetricom TimeSource 2700 > >Sorry to resurrect an old thread, but I thought someone might find this of >interest. > >I purchased a 2700 intending to harvest the PRS10. Prior to cracking open >the case I powered up the unit to ensure it was basically working so I could >return it if needed. I noticed that despite not having an antenna >connected it seemed to find and track CDMA signals and after a few hours the >10 Mhz output was in a few parts of 10E-12 of my GPSD0. > >After a bit of investigation I found the following > >Adding an external antenna didn't seem to make much difference to the >performance. > >The 1pps output is approx. 75ms out of sync with the 1pps output from my >Fury GPSD0. > >From time to time the 10 Mhz output experiences phase jumps of several tens >of ns. Manipulating the unit (ie. connecting to the RS 422 port) may >induce this. Power cycling the unit seems to cure the problem and the unit >usually takes an hour or two to re lock. It's possible that the lack of a >proper ground in my instalation may be causing some of the issues as well. >This problem would be a show stopper for me in terms of using this unit to >replace my GPSDO's. I'm not sure if this issue is specfic to my unit or >not. > >I've attached some initial ADEV plots showing the typical performance of the >10 Mhz output vs three of my other references. (I wouldn't put a lot of >emphasis on the results of taus of less than 100 seconds or more than 6,000 >or so..) I doubt I'm going to put much more time into this unit but it's an >interesting novelty in it's original state. The results of other units may >well differ (: > >Regards >Mark Spencer > > >--- On Thu, 11/24/11, Charles P. Steinmetz <charles_steinm...@lavabit.com> >wrote: > >> From: Charles P. Steinmetz <charles_steinm...@lavabit.com> >> Subject: Re: [time-nuts] Symmetricom TimeSource 2700 >> To: "Discussion of precise time and frequency measurement" ><time-nuts@febo.com> >> Received: Thursday, November 24, 2011, 11:17 PM >> Kevin wrote: >> >> > I use the Craft connector for monitoring with BTMon >> rather than the RS-232 port. >> > It appears the Craft output, while spontaneously >> emitting alarm/events, does respond >> > to queries from BTMon on the Craft input. >> >> Everything I reported previously involved the Craft port >> feeding a PC COM port using the RJ45-to-DB9 cable supplied >> by Symmetricom. >> >> > Do you happen to have a RS-422/485 interface? I don't, >> but I'm interested to see >> > if any spontaneous output occurs on the TOD port. >> >> I have a 422/485 card here somewhere, but I haven't used it >> (maybe even seen it) in more than 10 years. >> >> I poked a scope at the TOD jack. The TS2500 manual >> says that (in a TS2500) Pin 1 should be PPS (positive), Pin >> 6 should be PPS (negative), Pin 5 should be TXA output >> (positive), Pin 9 should be TXA output (negative), and Pins >> 7 and 3 should be a 20 V external supply positive and >> return, respectively. >> >> I found PPS positive and negative on Pins 1 and 6. >> Logic low is about 1.2 V positive with respect to case >> ground, and logic high is about 3.8 V above case ground, for >> a logic range of approximately 2.6 V. The PPS pulses >> are 500 uS wide with rise and fall times of ~20-25 nS. >> >> I did not see any data on the TXA outputs -- the positive >> TXA output just sits at logic low and the negative TXA >> output sits at logic high. >> >> There is 20 V between Pins 7 and 3. As for the >> unspecified pins -- Pin 2 sits at nominally 0 Vdc, and Pins >> 4 and 8 sit at nominally 0.168 Vdc. All three have >> around 20 mVp-p of hum and noise. >> >> While I was at it, I poked at the RS232 connector, as >> well. Pin 3 (TX Data) has a 16 or 17 mS burst of data >> every 5 seconds (approximately), from -10 V to +10 V with >> respect to case (henceforth, 232 low and high, >> respectively). Between bursts, it sits at 232 >> low. Pins 4 and 7 (DTR and RTS, respectively) sit at >> 232 high. All other pins sit at ground. >> >> Best regards, >> >> Charles >> >> >> >> >> >> _______________________________________________ >> 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.