Software Defined Radio

The PA unit. With 13.8 Volts and around 1W input, this unit gives 16W output from 180 meters to 10 meters. The original design is released by Mike Kossor - WA2EBY and can also be found from later ARRL handbooks with name "A broadband amplifier using low-cost power mosfets". Indeed, the fets are IRF510 hex power mosfets, really cheap. These are pretty much the only power fets that are suitable for wideband matching, since the input capacitance is only around 135pF. Most of the power mosfets have input capacitance in a range of several hundred pico Farads. Anyways, using 28 Volts, I can have output of 40W, but since the difference is below 1 S-unit, I decided to stay with the 16W output. With 13.8V/16W the amplifier runs pretty cool. My design differs a little bit from the original.

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