Topband: Hi Z amplifiers for 160m

Chris Moulding chrism at crosscountrywireless.net
Wed Mar 11 14:31:25 EDT 2020


Thanks for all the very helpful replies and suggestions.

I'll change the BNC connector to a 4 hole F connector with 75 ohm output.

The design already has a 20 kA gas discharge tube and DC biased diode 
limiter for lightning and surge protection. It also has an optional (by 
internal link) diode limiter on the output so that it can be used by 
"weak" SDR receivers such as the SDRPlay RSP series that cannot take 
high RF levels.

I agree with the comment on adding a common mode choke on the coax 
output. The amplifier device I'm using has very low noise so it needs 
extra common mode isolation to allow use at very RF quiet locations.

I'm planning to take a trip to the nearest beach this weekend to try the 
prototype in a very low noise location.

73, Chris G4HYG



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