#16
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The last time, I priced an Eveready 467, it was priced at $39.00. |
#17
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I saw the 67 volt batteries online not too long ago, but not the 90 volt.
Reading this thread has got me in a mood to check out my cousins old Silvertone farm radio. She gave it to me a few years before she died, and I've never tried to power it up. I used to have an old Eico adjustable power supply that could produce up to 450 volts, but since that went by the way-side I could just put together a slew of 9 volt batteries to make up the 90 volt B+. I know the B battery should last a lot longer than the A supply for the filaments. |
#18
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I've built a few battery eliminators, using an LM317 adjustable voltage regulator for the filament supply. You can use Zener diodes for B+ regulation; but, the B+ voltage is not nearly as critical as the filament. For a transformer, you can either wire two low voltage transformers back-to-back and take the filament supply off of where the two transformers connect or you can purchase a single transformer with the necessary HV winding.
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http://www.youtube.com/user/radiotvphononut |
#19
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The biggest reasons why any parts house carries any of these batteries is due to the Nems-Clarke/Potomac Instruments AM Field Intensity Meters used by broadcast engineers. Which used this battery arrangement for many years.
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#20
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Audiokarma |
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