HI Probably what is going on is that the OCXO’s have a parasitic oscillaton in the UHF region. It has injection locked to the 10 MHz. You get a signal that is much higher level than any harmonic relation would predict.
I’d try fiddling the bypassing and load …. Bob > On Oct 28, 2016, at 8:43 PM, Joseph Gray <jg...@zianet.com> wrote: > > This really is Time Nuts related. Keep reading. > > I recently bought some surplus Motorola UHF mobiles. They came with > the previous frequencies blanked and only channel one programmed with > 460.000 MHz. > > I put all of them on the bench to do a quick test to see if they > transmitted and received. Upon power on, every one was receiving a > strong carrier on the programmed frequency of 460 MHz. Firing up the > service monitor with a small whip antenna, I found a -70 dBm carrier, > right on 460 MHz. > > Taking a handheld scanner around the house and outside, it seemed that > the problem was in my house, but I couldn't localize it with the > scanner. I started turning off circuit breakers until the carrier went > away. Then I went around, unplugging things individually. You won't > believe what the culprit was. > > I have had some 10 MHz, Micro Crystal OCXO's (DIP 14) aging for quite > a while, intending to use them in a few projects eventually. Yep, it > was the OCXO's. I am surprised that the OXCO's would be putting out a > carrier at 460 MHz, and such a strong one. > > This has been going on for quite a while. If I hadn't had these > Motorola radios that just happened to be programmed for 460 MHz, who > knows if or when I would have noticed this. > > Joe Gray > W5JG > _______________________________________________ > 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.