[Lowfer] Amplifiers for 136 kHz

[Lyle Koehler]

I agree with John that a linear amplifier and SSB type of exciter is the way
to go. The power level, whatever it may be, is almost sure to be specified
in terms of transmitter output as it is now (I can remember the ham limit
being 1 kW DC input) on all the other ham bands, rather than DC power input
as on the LowFER band. Aside from a little electricity, it makes little
difference whether the final efficiency on the proposed ham band is 60 per
cent or 90 per cent. An SSB exciter will make all of the sound-card modes
available, and at the same time offer the frequency agility that these modes
offer. We'll be able to QSY anyplace in the band (assuming it's only 2.1 kHz
wide) with one carrier frequency and a variable sound-card audio output.

Actually the very narrow FSK/MFSK and very slow CW modes are the only ones
where you don't have to worry about "key clicks" generated by fast rise and
fall times. Slow CW generates key clicks, too, but who's going to notice one
click a minute on LF? In reality, even at 100 watts the clicks are not
likely to be much of a problem on LF, at least for those of us who live in
the boondocks. Except at short distances, we will still find it a big
challenge just to "hear" each other's signals. But at that power level I'd
want to make sure the signal is as clean as possible, just on general
principles.

Lyle, K0LR