The power amplifier is R2. For amateur radio repeater operation, include your call sign in checkout or send me a message if you wish and along with requesting I do so and I'll convert it to R1. I will warrant rated power for full amateur band rather than just down to 146MHz.
The external preselector plot from my 8510C vector network analyzer is shown as an exmple with a general tune for amateur band operation around 146MHz. I can tune for a steeper cutoff to one side or other if the exact frequency desired is known. This would have the effect of increasing rejection without having to use more duplexer cans to accomplish the same. Note as tuned the 3db bandwidth is about 3.6-4MHz (specification is 5MHz) and this is achieved without added insertion loss as a result of precision instrumentation in use.
If you're purchasing internationally, this may make sense to break into several packages and reassemble if weight limits apply
My conversion will not simply be to change a couple chip resistors, but also to replace several other chip components per the depot service manual so it will be "correct" rather than a hack.
If you're purchasing internationally, this may make sense to break into several packages and reassemble if weight limits apply