I build a rf amplifier 1.8 to 30 Mhz using 2 MRF101 mosfets. But by reading the specsheet again, I saw I missed something. The output impedance of these fets are about 12 ohm. That is if you have 2 fets I need to match 24 ohm too 50 ohm which need an 2:1 impedance transformer. Not a simple 4:1.
Does anybody know some examples of such matching?
There are some possibilities like:
1) Match 1:4 and match 9:1 (50 ohm to 200, 200 to 22) but step up 9x creates quite high voltage on the transformer connections and a lot of cores are necessary
2) 2 times a 1:4 transformer one for each fet and have outputs in parallel. I don't know if possible.
3) a 2:3 transformer, I don't know if I can build it with tubes or just use wires something to be tested.
But maybe there are more options.