At 12/13/2007 09:48, you wrote: >Randy, > >I've experienced problems similar to what you describe on several MII and >found it to be harmonic noise on the ptt (osc 10v) line. Installing >a >10 uh inductor where the line enters the exciter pcb did wonders for >mine. You may also want to install a pair of inductors on the 12v lines in >the PA (at the feed through caps). The original GE design has this on a >number of their PAs. > >While, once I did have a spur that required me to move the entire mobile >radio away from another mobile cased unit, I've never had a desense >problem internally between the tx and rx in a mobile. NO6B may want to >revisit his problem MII and look at the ptt line. He may be pleasantly >surprised.
I'll have to try that next time I have the radio in front of me; thanks Steve. The spurs I'm seeing are not being manufactured in the PA, as they're present on the exciter output. I tried capacitive bypassing on the OSC 10V line, but perhaps that wasn't enough. Bob NO6B
