For general info:
This Jan/Feb QEX magazine from the ARRL has a number of articles of potential
interest to the LF constructor / operator.
1) Class E RF power amplifiers by WA1HQC
10 pages on class E design. Includes waveforms that shows the effect of
tuning on the voltage / current flowing in the semiconductors. i.e. If your
waveform looks like this, then increase C4 etc etc. Ends with 43 references
to class E papers including a 92% eff 50kHz to 1.7MHz design with 44kW
output. (probably not suited for use on the Ropex frequency Hi)
2) A keyed Power Supply for Class E Amplifiers.
" Supply 500W for your class E Power Amp.......for less than $100"
Similar to Andy's concept but switching at up to 100k (73k possibilities?).
Using 2 IRFP240s and a MC34025 controller
3) More on Atmospheric Ozone and Low frequency propagation. (NM7M)
9 pages of experimental results from monitoring a 55.5kHz transmission
between California and Washington state. Looks at single hop and ground wave
and some enhanced 'dawn' propagation claimed to be due to "....The
Ozonosphere"
73
David G0MRF
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