Yes I believe the general recommendation should be 10K instead of 47K.
So that it gives sufficient drive in all cases.
I will update the instructions accordingly.
73 Allard PE1NWL
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On Wed, May 31, 2017 14:40, Jerry Gaffke via Groups.Io wrote:
Some have found that they need a smaller resistor value than Allard's 47k
to get 5 watts out, some have gone as low as 10k. ??That's a better
solution than turning up R136. ??That variation is due to how the BFO
lands on the edge of the crystal filter, so different rigs wind up with
different drive levels into the IRF510. ??My guess is that everybody could
do just fine using 10k and thus drive the IRF510 relatively hard, since
the IRF510 does not have to be a linear amp when transmitting CW. ??Though
Q13 is already out beyond its dissipation limits, as is R141. ??So those
parts might possibly blow with too high of a drive level, though nobody
has reported a problem like that recently.
I'll let somebody who has gotten around to doing it give advice on how to
get digital modes going.
On Tue, May 30, 2017 at 11:42 pm, John Smith wrote:
When you say BFO is on the skirt of the filter, do you mean CW will need
to be turned up?
And with clean CW we drive it really hard.--- How hard?
Do you offer any words of advice about safely interfacing with isolated
audio and switches? I am planning on something like Easy Digi from
scratch
with a DB9 breakout board with screw terminals, plus the two audio cable
connections. Do I need pots for audio levels? Or do you think in windows
audio settings will be enough.
Allard PE1NWL