Re: UBITX V3 TX GAIN VARIATIONS
Gordon Gibby <ggibby@...>
toggle quoted messageShow quoted text
On Aug 30, 2018, at 14:44, ajparent1/KB1GMX <kb1gmx@...
For better than 10W on 80 and at least 7 on 20....
Replace q90 with something better, BFR106 was good.
MMBT2369 is ok.
Replace the standing 3904s with 2n2222A(to18) part.
Hint installing them from the bottom makes for better and easy.
take care to get them oriented the right way. Also the cans for
adjacent devices can touch as they get connected together
at the board.
Test results. On 5 of 5 that got the power up with minimum fuss.
10M will be better but not great maybe 2-3 more watts.
IF you don't want the power to soar on 80 try 470 to 1000PF at C81
(470, 510, 680, 820, 910, 1000pf are standard parts).
Pick the one that gets 80 tamed and 40 and 20 decent. Getting
12W at 80 and 8 at 20 should be easy. IF 30M is down its the
output low pass filter as 30M is near the cutoff frequency but
not less than 5W and I usually saw 7w or more.
Join BITX20@groups.io to automatically receive all group messages.