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mathisschmieder / HL2-MRF101

Hermes-Lite2 Power Amplifier/Filter board using MRF-101
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Directional coupler #3

Closed m5evt closed 2 years ago

m5evt commented 3 years ago

R4 and R11 at 56k clips the op amp input at just over 100 W (provided my external power meter is accurate!). 47k for both of these gives a little bit of room to before reaching the 3v3 limit.

m5evt commented 3 years ago

I have changed to 20 turns on an FT50A-37. FT50A-61 with 10 turns does not present a good impedance on 160m. See here for further discussion.

m1geo commented 10 months ago

Sorry to wake a closed ticket, but I cannot find any reference of FT50A-37. Could you please point me to a supplier. Not even eBay has them, which is what the BoM V0.4 lists as the source.

I'm currently using 10t:1t on FT50A-61 mix and one of the ferrites gets quite hot.

m5evt commented 9 months ago

Try searching FT-50A-37 (or similar variants with the dash in different places). I think I got mine from Spectrum Communications on ebay.