Hamboneyard.comSurplus · Vintage · Shack-tested
Bias zener replacement upgrade for Heathkit SB220 or 221 — photo 1

Description

You did agree not to, after all. The 10-Watt zener diode in the Heathkit SB220 will last for decades if you treat it nicely. And if there are any surges or hard mileage the bias zener frequently fails.

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