Art, Until I installed one of those GPS-disciplined 10 MHz oscillators on my bench, I used my local cellular telephone site to provide an extremely precise signal for checking my service monitor's time base.
Each analog cell site transmits a control channel at about 880 MHz. The exact frequency depends upon whether the cell site is Block A or Block B. This carrier is continuous, and it is modulated with a raspy tone. Since this control channel carries no voice, you are not violating the FCC eavesdropping rules. The control carrier is used by mobile phones to know what power setting to use and to know what other sites are available. It my area, the Verizon Wireless system is Block B, which is GPS synchronized, while AT&T uses Block A, which is not GPS synchronized. I only need to tune in the control channel, and I have a rock-stable carrier that I can zero the service monitor's carrier meter on, to about 0.1 Hz. That's a resolution of about 0.001 parts per million. 73, Eric Lemmon WB6FLY [EMAIL PROTECTED] wrote: > > Perhaps I wasn't clear. I have been using this simple comparison method for > years to align my IFR timebase to WWV. It gets you within 1 cycle or so at the > 10 MHz. (or closer if you compare the second harmonic of the 10 MHz timebase > with the 20 MHz WWV signal when it's strong enough.) What I was asking was, > Is > there anyone out there using another method (short of having your service > monitor locked to the 10 MHz output of a GPS receiver) that gives you a more > accurate measurement. I am looking for a method that would give you a visual > indication similar to using a lissajous figure as in when comparing two audio > frequencies. > > Art - KC7GF > > > > Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/
