When I was testing the transmit power of a radio, a spur with Fc-150kHz was observed in spectrum analyzer. It appears across the frequency band 403MHz to 470MHz while transmitting. Spurs amplitude was about -70dBm, might be significant enough to cause interference to adjacent channel frequencies. Could the 150kHz be the harmonics of clock freq or something else...
Switching power supply?
--Mac
Check the FCC spec, but I think -70 db is OK. The fact thay you are getting f -150, and not f +/- 150 would indicate that it is a mixer product somewhere. I would start looking back from the output stage until you find it.
Tam
might be a harmonic of the Lo in the radio... Could be a wireless microphone too.
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