Philco E976 - Printable Version

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Philco E976 - vecher - 01-14-2021

ALL, this has a old type rectifier.. I want to replace it.. I will use a 1N5408 ..what value of resistor do i need with it..

[Image: https://live.staticflickr.com/65535/50834527213_1f92aafd89_c.jpg]

Schemati

[Image: https://live.staticflickr.com/65535/50834527073_0988861798_c.jpg]

2nd Question is What can In use for the 2 caps on the AC line? they are .004 uf

i have a y2 cap -0047 and a x2 cap .0047 can i use either of these?

thanks
Skip

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RE: Philco E976 - Radioroslyn - 01-14-2021

To answer your questions sir, I would take a guess at abt 100 ohms or less. You may be able to install the diode and not have to add a series resistor. Just check your B+ to see if it's @ 120vdc under load. Note the diagram has the diode drawn backwards.[Image: https://philcoradio.com/phorum/images/smilies/icon_eek.gif] The band goes to that white loop thingy (22 ohm resistor).[Image: https://philcoradio.com/phorum/images/smilies/icon_twisted.gif]  The trick is that the filter caps are going to charge up before the the tubes get hot to provide a load for the B+. This means that for a few seconds after the set is turned on the filters may be seeing 160-170vdc till the tube warm.

The .0047 are fine to replace the line bypass caps.

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RE: Philco E976 - RodB - 01-14-2021

Hi Skip, If the set has FM, which it appears this does, then the B+ should be as close to what is on the schematic as possible. So, you can try different values starting with 47 ohms, 1 watt. I usually use a variac to bring it up slowly. If I hit B+ before getting to line voltage then I need a higher value. You can use the X2 caps on the line. Y2s are for transformer primaries.

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