A nostalgic sidebar (and a weak attempt to divert the reflector from the
current threads).
In case there are any newcomers out there who do not get the reference, "tune
for maximum fun" is derived from the facetious adage from the days of vacuum
tube transmitters, "tune for maximum smoke". That adage, in turn was derived
from actual instructions like "tune for maximum signal level" (e.g., for
adjusting receiver front ends and IF strips) or "tune for maximum antenna
current" (for adjusting transmitters). "Maximum smoke" probably does not apply
to solid state.
But, as they say, there is truth in humor. My first transmitter was a modified
surplus BC-459 (also known as an ARC-5), that used a pair of 1625's (807's,
with the other filament voltage) in the output. The homebrew power supply was
built on a 17"x13"x3" black wrinkle finish steel chassis. It had six surplus
multi-winding transformers, a pair of 866A mercury vapor rectifiers, a couple
of VR tubes, a couple of rectanular oil-filled capacitors, and one safety
feature: bleeder resistors. The supply weighed about 40 pounds; a good 750VDC
for the plates. All of this was provided by my Elmer, K3ENP, who also allowed
me to use his home workshop to build it. Lots of cutting, drilling and
soldering. I learned a lot.
The power supply had a front panel hole for a plate current meter, but I never
got around to buying the meter. Lacking a plate current meter, I tuned the
transmitter by using a wooden pencil to draw blue RF arcs off the 1625 plate
caps. Tune for maximum arc. Really.
A related story. The power supply sat on the desk next to the transmitter. I
had the leads in place for the plate current meter, and I had them hanging out
the hole, soldered together. While I was operating one night, preparing to
transmit, I went to flip on the plate voltage toggle switch with my left hand
while my right hand reached for the bug. With my left thumb pushing up on the
toggle switch, my left outside knuckle was brushing those meter leads. OUCH!!
Little burn on the knuckle, little burn on the tip of the thumb. I had not had
the presence of mind to suppress my cry of pain. Parents came running
downstairs, saw the evidence, and made me QRT for the night.
What, you never did anything stupid?? I was 17 years old.
73, Art K3KU
Tune for maximum fun (but safely)
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