144MHz PA GW4RWR

Introduction
I originally used a nice module, labelled 'Ministry of Defence', dated 1986. 2N6080, MRF238, MRF247; only the first stage had any biasing as this was clearly intended for PMR-type FM use. The entire module, complete with its heatsink, fitted perfectly on the 2U-height rear panel. There was plenty of gain, just as a PA strip should be! 10mW in for 60W out. But during linearisation of the final stage it all went wrong, somehow I connected Vcc to the base. I had a panic moment when the white cover came away from the faulty failed mrf as I desoldered it. Worried that I'd exposed myself to BeO, I abandoned the shack, to return in Noddy Suit to remove everything and clean up. A replacement device (from China, ahem), never produced more than 25W out. Had I damaged any of the caps during desoldering, or was the mrf faulty?

I just gave up with the mrf247 approach, since I found a RA60H1317M1A module for similar cost to another mrf. By this time the rear panel was already drilled for the Ministry heatsink, so I had to install the Mitusbishi device diagonally across it, which looks strange.

I'm convinced that these modules are 'the way to go'; they're plug-and-play. The only downside is their relative inefficiency.

Closer in: