I would say that the amp works, but construction has been completely changed in terms of amplifier developed by Baruch, are listed transformers input and proposition because it is warming and has not worked properly on the 50MHz band, bad choice of materials and cause terrible harmonic distortion of the amplifier.
I'm not saying that the construction carried out by Baruch is bad, but required a thorough revision of construction and use of appropriate materials, besides the amplifier generates large amounts of unwanted signals, resulting in older should load components on the power and excessive heat.
used a 14dB attenuator that allows you to develop the full power of the control of up to 50W.
With the right load transistor output power> 2KW in the 1.8 to 50MHz for BLF578XR also tested (mrf6vp11kh, mrfe6vp61k25h, blf578), used a very stiff 50V PSU that even at the peak will give 120A. linearity of the amplifier at an acceptable level.
Measurements performed on artificial 50ohm load,
laboratory using a moderately power 10kw, by direct measurement of voltage at the fundamental frequency of all harmonic filtering for LPF. (3rd harmonic suppression of-60dB relative to the fundamental frequency).
which was also properly connected Tektronix Spectrum Analyzer for 1.8GHz.
ofc amp working in class AB and C. I used a AVR Mega2560 to control all events and save all measurments on SD card in development version.
At present working with the power of 1.8 kW during the pileup about 4 hours at an ambient temperature gave 26 melted inside the amplifier heat sink 29 degree and 30 degrees. supply temperature of 28 degrees Celsius.
Weight with power amplifier and filters to 20kg.
today tested the amplifier based on four transistors BLF578.
More info on sp5g.net, soon puts the results of measurements of the instrument and the linearity plots and shots of a spectrum analyzer.
sorry for the translation
, good luck.
atb, Robert SP5G