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1.5KW Diplexer |
60-120MHz VCO |
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QSE Daughter Board |
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Warning: These boards are prototype pre-production boards and have not been widely tested. There may be errors.
1.5KW Diplexer Filter (11-03-08). The prototype boards are here. I have assembled an 80 M filter.As soon as I inventory my parts, I will offer a parts kit. More Details RF amplifiers require low pass filters to get rid of harminics. This series of boards will provide a low pass filter to block the harmonics from getting to the antenna, and a high pass filter to route the harmonics to a 50 ohm "dump" resister. Each section is a 7 pole Chebychev low pass and 7 section high pass filter. Unlike a low pass only filter, this filter presents a good match to the amplifier at all frequencies. The boards are approximately 8" by 2" on .126" FR4 with 2oz copper for each band.
60MHz to 120MHz VCO The 60-120mhZ vco is designed to be part of a synthesizer. The VCO tunes with 0-12V. The span is coarse tuned with 3 transistors which switch in a combination of 3 tank circuit capacitors. The output is squared and goes through a programmable dividor. A couple of prototypes have been built and are being tested. A new PC layout is complete.
RF Driver Chain This board is designed to take the low power output of a mixer and boost it up to 100 to 250mW to drive a 5W amplifier. Three stages based on the EMRFDfeedback amplifier are cascaded. A prototype with 2 stages has been built and tested. The 3 stage layout is complete and will be part of the next prototype run.QSE Daughter Board for 995x (11-4-08) Prototype boards are on hand. A daughter board for the 995x board is being designed to provide a quad sampling excitor. This board plus the 995x board, the bpf board, RF Driver Chain, a 5W amp, and a QRP low pass filter board will provide a complete transceiver.
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