[Amps] What to do about 'Neutral' in HB amp?

Paul Christensen w9ac at arrl.net
Wed Dec 28 10:27:44 EST 2022


>"Neutral to chassis ground and ground, ground, ground everything together, and to the 240 ground coming into the power supply."

That's what ETO did in the Alpha 70/77 series amps.  It's not strictly a NEC violation because NEC is a premise wiring and safety standard, and not a product wiring standard. 

>Use the common connection point between two 120 volt windings, wired in series, on the input of the HV transformer for 240 use.

Yes, another common scheme. 

>"I guess I'm leaning toward a 240/120 step down transformer."

It's a lot of extra work, but I chose to run 4-wire #10 with a dedicated neutral to the shack.  Modification to the Alpha amps is very easy and only requires a slight wiring change on the amp's Cinch-Jones power plug to break the neutral-chassis bond. 

Paul, W9AC 



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