Re: RF power chain mods and improvements..

Jerry Gaffke

If the mixers are getting hit hard enough to go into compression, 
then we don't really need 12dB of gain in that transmit side 45mhz amp.
May as well back it off to 8 or 6 dB, 0 dB is fine, whatever a 2n3904 can reliably do at 45mhz.
Buy it back with more gain in the little back-side daughterboard.

If we come to a solution here, I'm hoping it resolves mostly to stacking resistors on top of existing parts.
I assume we are just lowering that feedback resistor from collector to base, and then also the bias resistor
from base to ground by a proportional amount.
All stackable, so just put a new 1206 part on top of the existing one.
This happens at Q40, Q20, Q90, Q911, Q92, Q96 to reduce the gains.  Keep the 2n3904's.
The daughterboard could have more than a few parts, we have lots of room.
Most current owners will be much more inclined to do the mods if they don't involve replacing a dozen 2n3904's.
The daughterboard is easily reversible, just remove the wires from it to T8-5 and the top pin of RV1, then restore C82.
(T8-5 and RV1-1 are through-hole pins, easily accessible from the bottom.)

Maybe kit up the daughterboard along with some other needed stuff, such as parts for a dummy load 
and a diode RF probe.  Would add about $1 to the cost.


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