[Amps] Earliest Commercial Amateur Linear Amplifier

[Paul Christensen]

> Early days there was very little use for linear amplifiers.
> Most were using AM (plate modulation) or CW.
> So the question may be what was the first Radio Amateur RF Power Amplifier
> ( with or without modulator) sold commercially?

If we look back to the period between 1900 and 1930, commercially manufactured "amateur" transmitters did not exist.  In the era
between 1919 and 1921, we find that CW begins replacing homebrew spark transmitters for several reasons.

By the time of the 1921 transatlantic tests, the epilogue is that Paul Godley, while listening in his pitched tent on the shores of
Scotland heard many more CW signals than spark.  CW stations like 1BCG headed by Minton Cronkite and Edwin Armstrong quickly took
the limelight away from the rock-crushing spark stations like 9ZN in Chicago.   Spark died a relatively quick death such that by
1926, nearly every station heard on the air was CW and/or AM phone and as far as I know every transmitter was homebrew (until
perhaps ca. 1928 with the first kits) using Hartley, TPTG, and MOPA designs together with homebrew modulators.

Beginning in 1930, the first commercial transmitter/amplifiers became available.  More kit-type transmitters (Gross Radio and Aero)
were available in the early '30s, but I'll say that none other than Arthur Collins, W9CXX, manufactured the first or certainly one
of the first commercial amateur transmitter/amplifiers with his model 30W, followed shortly by the 30B, 30FX, etc.  I once owned the
rare 30FX and I believe it had a separate power amplifier cabinet (its own rack-mounted chassis above the oscillator/buffer chassis)
with Bakelite panels and "real-man" Westinghouse panel meters.  Art certainly assembled some great-looking and performing
transmitters from his Cedar Rapids basement in the early '30s.

-Paul, W9AC