This is a homebrew amp for 432 MHz. This is the K2RIW circuit featured in the 1972 April and May issues of QST and the VHF/UHF DX book. This amp was easy to build but a monster to make operational. Prepare to spend many hours cutting and trying and then re-cutting and re-trying. A word of warning. Unless you know how to use a network analyzer to stabilize a power amplifier (and are prepared to be proved wrong) do not build a K2RIW with any tube sockets other than the Eimac SK620/SK630 series. This is the inside of the amp.