>"In the days before these manufactured assemblies and dipoles were made
and sold, EVERYONE "homebrewed" their feedlines and antennas. those
SKs must be turning over in their graves."
Go back even further in time and we find that entire stations were
homebrewed. Over the years, I've acquired a large collection of pre-WWII
QSL cards, many dating to the early 1920s. It's interesting to take note of
the gear used at that time. If you wanted to be on the air in the 1920s,
homebrewing was a must. Transmitters mostly consisted of single-tube
Hartley, TNT, TPTG, and Colpitts designs. These designs are really
self-excited power oscillators, most of which were constructed on wood
breadboards. Hams of the day could almost build their transmitters in an
evening. Lucky for them, most operating was done between 200-80 meters. As
operating frequency increased, homebrewing revealed problems with coil loss,
stability, frequency shift with an antenna swinging in the wind, etc.
Receivers? Apart from the very wealthy who could afford Grebe, CRL, and
Paragon models, probably 95% of all receivers used during the 1920s were
homebrewed regens as evidenced by the QSL card descriptions. The cards all
make note of the op's preferred circuit, so it's common to see terms like
Reinartz, Schnell, 1BGF, and Hassell. Open any 1920s QST, and you'll see an
obsession with "low loss" homebrewed receiver designs. Component ads for
coil assemblies and capacitors all touted their low-loss construction.
Hopefully, some of you had a chance to hear some of these transmitters in
operation during the last couple weekends. The AWA sponsors the Bruce Kelly
event to commemorate Kelly as one of AWA's co-founders. The event is
limited to self-excited transmitters and each transmitter's note is
different than the next; each transmitter has its own character. This was
the first year I heard stations running raw AC on the plate. I had
envisioned these stations occupying bandwidth much like spark, but not so.
Looking at RAC transmissions on a panadapter, there's certainly more
bandwidth than we see with pure CW, but the note is composed of several
peaks that almost make it "melodic."
QST articles of the day supported use of RAC. Two reasons: first, since
stability was an issue, copying a slightly wider signal helped the operator
on the receiving end and secondly, the RAC oscillator exhibited less keying
thump and clicks. I've seen this mentioned time and again in QST. I have
no idea why. Perhaps someone here can explain.
It was because of these simple feedback circuits that homebrewing an entire
station was even possible. Imagine the effect on homebrewing and the
evolution of electronics if the triode had not been discovered until after
the invention of the transistor.
Paul, W9AC
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