[BC] Harris FM10 250 driver

[Warren Shulz]

One area of concern in FM PA's is instabilities.  I have a Frankenstein
FM Tx with a SV 500-w IPA and I can get the rig to go into odd comb
generator mode under certain conditions of drive level and PA
saturation.  After any conversion a detailed SA needs to be applied to
observe spectrum output under various drive levels, load variations
(narrow band vs. wide-band load), tuning etc.  I had not had a chance to
re-try with original IPA to see if the conditions can be repeated.  How
it was caught when the percent output meter would show a +/- 1.5% slow
(1Hz) dither under screen (power level) settings.  In deeper analysis
the comb sprui were found.  Never omit detail stability testing even
after the traditional sprui checks for 3rd, 4th, 5th ....order products.

Warren Shulz
WLS Radio

MM wrote...

  With a SS IPA, the IPA's metering is moot...at least as far as the TX 
is concerned.  All you care about are the PA's parameters and an 
overload interlock with the new IPA.