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3.0uf cap? on 116PX - Printable Version

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3.0uf cap? on 116PX - Skip - 06-09-2013

I am starting on my 116PX. I noticed a large cap 3.0uf; can I use a 2.2uf for that of should I get a 3.0? Could I use a 3.0 e-cap? I have attached the link to the schematic but the cap in question does not have a part number, it is next to the 30K resistor part#97 on the drawing.

http://www.philcoradio.com/tech/images/116px.jpg


Thanks
Skip

RE: 3.0uf cap? on 116PX - jerryhawthorne - 06-09-2013

Skip, I would think a 5mfd would work just dandy there and they are a common value.
Jerry

RE: 3.0uf cap? on 116PX - Arran - 06-09-2013

I would use a non polarized capacitor, or a pair of, since the value is small. I think you could pair a 1 uf with that 2.2 uf in parallel to make it a 3.2 uf.
Regards
Arran

RE: 3.0uf cap? on 116PX - Skip - 06-09-2013

Thanks guys. I figured the value was not too critical, just wanted to confirm.

RE: 3.0uf cap? on 116PX - morzh - 06-09-2013

WHen I needed 3uF I pared 3.2uF and 1uF in parallel.

However I have just bought some I think 3.3uF which I intend to use in place of 3uF in the 37-116, which has both 2uF and 3uF values in it.

RE: 3.0uf cap? on 116PX - TA Forbes - 06-09-2013

3.2 and 1 in parallel will yield 4.2 mFd.

Caps in parallel are additive in nature.

RE: 3.0uf cap? on 116PX - morzh - 06-09-2013

Sorry, meant 2.2uF. (I kinda guessed they add when in parallel) Icon_lol
3.2uF value is not even standard; 3.3uF is.

RE: 3.0uf cap? on 116PX - jerryhawthorne - 06-09-2013

I love this stuff. Why worry so much about getting an e-cap to the precise old value?
Going all the way to parallel caps? That is ugly! Just toss in a 5mfd and relax. It will work nice. Higher seldom will hurt where this is located.
Jerry

RE: 3.0uf cap? on 116PX - morzh - 06-09-2013

Actually most of the places where those smaler values electrolyte caps are are not sensitive to higher value at all, the lower value being probably a budgetary consideration rather than electrical.

And the filtrer caps.....the one that probably should be observed is the very first one across the rectifier. The voltage will go up as you increase the value, and copupled with today's higher line voltage in the first place it will add that unnecessary extra we can do without. The one after the choke is less critical as it mostly affects the voltage when there is no load.

RE: 3.0uf cap? on 116PX - BrendaAnnD - 06-09-2013

That, and 'lytics are far from precise as far as tolerance is concerned. IIRC, the basic tolerances for 'lytics are something like -20/+100..

RE: 3.0uf cap? on 116PX - TA Forbes - 06-10-2013

Yes, that's true!

Just for grins, try testing your new caps on your cap checkers.

RE: 3.0uf cap? on 116PX - morzh - 06-10-2013

Well, the tolerance of the Panasonic caps I use is +/- 20% at 120Hz at room temp and I did test them and it is right on the money. Cheaper kind general purpose can be that +20/-80%. Though when you test them new at room temp they are rarely grossly outside 10%.