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Model 620 Electrolytic bypass
#5

The filter caps do NOT go to ground. They go from B+ to the top of the large (usually overheated looking) rectifier B- resistors (#70 on schematic). Download your schematic and parts locator from NostalgiaAir.com

Sometimes it helps the radio by connecting an extra 10uuf from B+ to ground, but first the raw filter caps, the ones connected directly to the cathode of the 80, must be replaced.

As mentioned in the other post, you MUST disconnect at least one side of each of the old filter caps. Most restorers do the one-lead disconnect so that the original cap can be left in place for appearances. Leaving both sides connected leads to disaster- and lots of hum.

Pete AI2V


Messages In This Thread
Model 620 Electrolytic bypass - by David B - 01-27-2008, 04:07 PM
[No subject] - by rghines1 - 01-27-2008, 06:41 PM
Philco 620 - by David B - 01-27-2008, 09:12 PM
[No subject] - by planigan - 02-11-2008, 01:23 AM
Filter caps do NOT go to ground - by AI2V - 02-11-2008, 11:18 AM
[No subject] - by planigan - 02-11-2008, 03:31 PM



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