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power-supply circuit proves to be an expensive, time-consuming operation.

Here's a modified Super-Pro power supply, presently doing yeoman duty on my BC-779, L'sing a combination of old and new ideas, this supply furnishes all operating voltages for the Pro, ¿it a total cost of less than £40 is all parts are purchased new. Any good surplus hound with a fair junk-box to dig through can trim the cost to $10 or less.

This supply uses two 10-amp, 6.3-volt filament transformers, connected back-to-back, for isolation purposes as well as to supply heater power for the receiver. The isolated 117-volt ac then goes to a voltage tripler using silicon diodes. This tripler provides the positive voltages. Highest potential under load is approximately 350 volts. Although this is slightly lower than the design value for the receiver»: no ill effects have been noticed.

In addition to feeding the tripler, the transformers also feed a half-wave rectifier which also uses a silicon diode. This diode is connected with reversed polarity to provide bias voltage.

WELL JIM YOU SHOULD HAVEL YOUR KW F-NAL HOOKED \H NOW, SO LETS SEE HOW IT SOUNDS ACROSS TOWN

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