100W HF RF afterburner.
Afterburner for Elecraft KX3 or Flex 1500 transceivers.
When the need for speed, er, power arises, I decided to adapt a commercial HF PA to suit my needs. The PA is pretty much complete and just needs a milliwatt or two to be able to produce about 100W RF output. All I had to do was provide some input Tx / Rx switching (relay), an RF attenuator pad (custom) for correct drive requirements, a band switch for manual selection of output filter (no micro required) and some visual (led) indicators.
Initial results.
It went pretty well and quite stable. No RF crazies with the lid off or on. There are several versions of these PAs found around the traps. Some PTH and some SMD versions as well as there being different band spreads. I was lucky to get a SMD variant, so it is a later unit (less dated) but one of the filter selection switching occuring in one of the ham bands. After studying the schematics, some changes will be happening soon to fix this. This will be used in the ham bands and the band selection switch will reflect this. So, with the filter modification table done, I hope to change the relevant parts soon and then re-test. More on this, when time permits.