Dave - Let me call your attention to the FMT nuts list if you are not already on it (I didn't find an entry from you in the November ARRL FMT). I'm not sure how many of the gurus there are on this one, although the HP 3586B is a tool used by some. I myself depend on some HP gear, a 105B and 8640B. There you can inquire and learn about AM BC stations locked or not to gps, as well as intentional carrier offset applied to mitigate slow deep fading in zones of overlapping coverage. http://groups.yahoo.com/neo/groups/FMT-nuts/info 73, Ed, k1ggi
-----Original Message----- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of quartz55 Sent: Sunday, December 08, 2013 21:06 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Is this measurement for real? Well, thanks for the comments. I really didn't know what to expect from the SoundBlaster card. I thought AM stations were better than that. I started everything cold today and the 1K from the SM started at around 999.998600 and drifted up to 999.999800 in about an hour and half, stayed there around 4 hours but then started back down to 999.999290 in another 4 hours. It's going back up a bit tonight, it's around 999.999420 now. I do see in SpecLab there is a way to lock the sound card to a 1pps GPSDO. I may try that, but my Nortel only puts out even second pulses and I really haven't seen them yet. Anyhow, after warm up, it looks like I should be able to detect 1 mHz differences given other things are stable, like the DSP in the TS2000, I'm thinking about running the fan full time in it to try to stabalize that. How about the UHF TV stations, are they locked to something, they all seem to be on even .025 KHz on my service monitor which can only resolve to 1 Hz? I'm looking for frequency standards I can receive better than the 2M/440 beacons (N4MW) I can hardly hear from central VA. WWV is about useless, I get 2 Hz spreads from them with SpecLab at 20 MHz, it may be WWVH interefering. I have to say, I've gone from hardly being able to measure 1 Hz differences with the service moniter to nearly mHz differences, that's what 3 decimel places? It's funny how the closer you get the closer you want to get. And now to figure out how accurate it is. I've got a FT897D I'm not using, been thinking about selling it and get Jackson Labs unit, but I'm not sure what that will get me past the Nortel unless the extra satellites/bands will make it more accurate? Dave N3DT _______________________________________________ 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.
