[Boatanchors] 1935 Transmitter: Pi Output

[David Stinson]

I go the Pi-output to work.
Diagram at:

http://home.netcom.com/~arc5/HRO/1935txPi.jpg

Interesting:  The tap on the tank coil is critical.
Both power out and keying are affected by moving
the tank tap even a turn or two.
The ratio between the plate tuning cap and 
the tank coil value has to be juuuust so.
"Tweaking" this output is more difficult than
using the link coupling, but I get more power
out and I can band-switch easily.

Crystal activity is also critical for best power out 
and for clean keying.   Getting 25 watts out on 
40 meters and about 20 watts on 80 meters.
Haven't fiddled 160 yet, though I know it will go.

*Real* FT-243 crystals seem to work fine
if they have good activity.  HC-6 crystals
overheat and drift all over,
but I haven't cracked one yet.  
The little HC-25s usually stuffed into
FT-243 holders these days will die instantly.
Those work fine with more modern oscillators
running milliwatts out, 
but not in this gorilla mongo-oscillator.
I understand a pilot lamp in series with the crystal 
can work as a current limiter, 
but haven't tried it yet. 

73 Dave AB5S