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Philco Wirewound Resistor Question - Printable Version

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Philco Wirewound Resistor Question - Geoff - 05-18-2016

Hi Guys,

I have a wirewound resistor in my Philco 640 (P/N 33-3208, #78 in the schematic) .  It is listed as 60 ohms and 100 ohms.  It's pretty cruddy looking and even if it tests good I would like to replace it.  I checked Chuck's site and some Philco part catalogs I've found on the internet but can't find any information on wattage.  What would you guys recommend?  Schematic is attached.

[Image: http://i12.photobucket.com/albums/a241/JoeRadio1938/Miscellaneous/DSC04034_zpsovcexuli.jpg]

Thanks,
Geoff

RE: Philco Wirewound Resistor Question - morzh - 05-18-2016

2W 100 ohm, 1W 60 ohm.

RE: Philco Wirewound Resistor Question - Radioroslyn - 05-18-2016

That's a good looking one. You should see a bad one.

Terry

RE: Philco Wirewound Resistor Question - Geoff - 05-18-2016

Thanks Morzh. Where did you get your information? Do you have a scanned Philco parts book that you could share?

RE: Philco Wirewound Resistor Question - gregb - 05-18-2016

I agree with Terry, that is a really nice one. You should consider leaving it alone if it is good.

Gregb

RE: Philco Wirewound Resistor Question - morzh - 05-18-2016

(05-18-2016, 08:02 PM)Geoff Wrote:  Thanks Morzh.  Where did you get your information?  Do you have a scanned Philco parts book that you could share?

No. I just figured that would do.
IIfthe current draw of the whole thing is 100mA (and it is a lot) then the dissipated power of the 100 ohms is 1W and 60 ohm - 0.6W respectively. Double that for margin.
If you want to have more margin, then 3 and 2 Watts respectively.


Ps. Agree with others - very nice looking resistir, why do you not like it?

RE: Philco Wirewound Resistor Question - Geoff - 05-20-2016

I tested it and the 60 ohm section was fine but the 100 ohm tested at 117 ohms.  Still within a 20% tolerance but I don't want to have to deal with it later on down the line if it becomes an issue.

I know some of you guys don't like to hear this but when I repair a radio I tend to use the "shotgun" approach for resistors and paper capacitors, replacing all of them.  Mainly because I do not want to have to dig back into a set once it is fixed but also, to properly test most resistors you need to unsolder one end.  Since I'm half way there already I just follow through and unsolder the other end.

Please don't beat me up too much on this approach guys  Icon_biggrin .

RE: Philco Wirewound Resistor Question - gregb - 05-20-2016

As it is your radio it is your right to do to as you see fit. Send me all of the old caps and wire wound resistors, I can use them for my detailed restorations.

Gregb

RE: Philco Wirewound Resistor Question - Geoff - 05-21-2016

OK hoser. Send me your mailing address and I'll send you all of my out of tolerance resistors and capacitors and you can knock yourself out, aye.

[Image: https://s-media-cache-ak0.pinimg.com/736x/e3/6f/f6/e36ff6fe4b807aac9be5c7260a9dd23f.jpg]