We had this problem in Johnson radios. What it turned out to be was a plate of a silver mica capacitor coming disconnected internally in the capacitor. This caused the capacitor to shift to a lower capacitance by the amount that the plate contributed to the capacitor. The lower capacitance caused the radio frequency to shift high and outside the tuning range of the netting device. I cannot tell you what capacitor has failed. Check the silver mica capacitors in the tuning circuit and replace the one that is low in value.
I also have not been in a Micor element in many years. Hope this helps. This appears to be a somewhat common failure for silver mica capacitor due to the way the capacitor is physically constructed. 73 Glenn WB4UIV At 09:09 PM 8/8/2010, you wrote: >Glenn, OZ and group > >Its a step jump 5 khz up and get - 200 hz of crystal movment. What >silver mica Cap is it? I have not looked inside a channel element in >years usally send them out and trust the mfg. > >I also gave the crystal movement a thought but was is a temp >controlled enviroment. > >Ryan > >--- In [email protected], Glenn Little WB4UIV ><glennmaill...@...> wrote: > > > > Was the shift a drift or a step jump? > > > > If a step jump, you probably have a bad silver mica capacitor. > > > > 73 > > Glenn > > WB4UIV > > > > At 04:23 PM 8/8/2010, you wrote: > > >Hi Group, > > > > > >I have a Micor mobile set up as repeater. Worked great and was on > > >frequency for over 8 years no problems.(lost rpt site May 2010) and > > >have a new site to get on.The problem i am having is the TX drifted > > >5 khz up on TX from 145.310 to 145.315. I get plenty of deviation > > >and audio drive and 9.6 v to crystal element. I am not having any > > >luck messing with Netting adjustment i get -200 hz max. I also have > > >a UHF Rx unit for control installed and it is 10khz low on frequency. > > > > > > > > >The 144.710 RX crystal is right on the money for specs. Very odd > > >situation. anyone have ideas where to check or a fluke the crystals > > >are both bad. > > > > > >Ryan n3ssl > > > > > > > > > > > >------------------------------------ > > > > > > > > > > > >Yahoo! Groups Links > > > > > > > > > > > > > > > >------------------------------------ > > > >Yahoo! Groups Links > > >
