I had my doubts it could be sniffed as well, but it was a topic on usenet and I had all the gear.
Just as a FYI, you can get portable L-band spectrum analyzers relatively cheaply since they are commonly used in satellite work. If you go on ebay, the avcom PSA-45 goes for $300. They are pulled from an old government project and lived in racks. They are digital since there is no sweep rate that I can see. There are a few persistance options including infinite. This is not HP quality. Just cheap and dirty to have a look see. I rebuilt the battery pack on mine for about $50. However, the unit seems to draw on the pack when it is not in use so it tends to be dead in 3 days. If you use it right away, you get the rated operating time. They are daylight readable and very light, basically field instrumentation rather than lab gear. ------Original Message------ From: Philip Pemberton To: li...@lazygranch.com To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Distance between GPS Antenni Sent: Dec 18, 2011 10:48 AM On 18/12/11 16:44, li...@lazygranch.com wrote: > I did manage to see the > actual GPS signal on the spectrum analyzer with the amplified > antenna. But like I said, I never sniffed an local oscillator > leakage. I doubt you would -- the level of LO -> RF leakage in the mixer should be pretty minimal, and the MMIC amplifiers used in most active GPS antennas are (as I understand it) essentially a "one way path" for RF. The RF BPF will probably do a very good job of killing LO leakage, too. If tracking down an unlicensed TV using LO leakage is "hard", then tracking down a GPS receiver would probably be like trying to find a bone needle in a field of haystacks. -- Phil. li...@philpem.me.uk http://www.philpem.me.uk/ _______________________________________________ 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.
