MOSFET Linear Amplifier: Output Filtering

Here I present the filters you should have after the amplifier, and before the station ATU or aerial. These filters should be considered to be the minimum to suppress unwanted harmonics. SWR protection should be sensed *before* these filters, so the amp will be protected in the event you select the wrong output filter with the band switch!

LPFAll capacitors must be selected to be ones that don’t warm up AT ALL during prolonged full power output. Silver mica preferred. Inductors can be wound on a waste pipe PVC pipe as a former and an air core.

Here is the main cheap MOSFET RF linear amplifer page