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71b, please help with checking coils
#6

The link I posted above from Nostalgia air has both a voltage reading chart, tube pinout diagram and schematic. The chart shows voltages measured with the negative of the voltmeter to the cathode of the tube, but you will get close enough readings with the negative to chassis. The cathode to filament voltage column measures the voltage across the bias resistor for the output tube (15 to 20 V), so not really significant for the RF section.

It is most important to measure the plate and screen grid voltages of the RF, det/osc and IF tubes. Should be around 200V-250V on the plates and around 90V on the screens. If you don't have close to these voltages, you will get poor or no reception.

Here is the link to the info again:

http://www.nostalgiaair.org/PagesByModel...013837.pdf


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RE: 71b, please help with checking coils - by Mondial - 05-04-2013, 03:38 PM



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