This amplifier was designed to run 1500 Watts average power on 40 meters in RTTY mode. It used Sinewave Drive to 10 IRFP32N50K FETs, two groups of 5 in Push/pull. Driving power was 30 watts.
It was tested on a dummy load at 1800 watts for 1 hour with very little heating in any component or heatsink. Efficiency was in the 85-90% range. It has a 50/50 ohm bandpass filter included in addition to the output tuning network. The filter gives another 24db of attenuation to the 2nd harmonic.
Both coils in the output were wound on 1 inch PVC with 1/4 inch copper tubing. The capacitors used in the output are ATC-100 types derated to less than 5amps each.
A few 47pf, npo ceramics are used to position the tuning to midrange and loading capacitance is fixed.
The amplifier has a built in 2KVA Variac for setting the power output.
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http://home.tampabay.rr.com/hamradio/ 1500watt0001.jpg
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