I just bought a Philco model 630 am radio and am going to attempt to replace its capacitors. How do I know what replacement capacitors to buy? I want to make sure I buy the right values but the old capacitors dont appear to have any information on them with the exception of numbers like 30-4215M and30-4191S. Also it looks as though one capacitor was replaced but it reads Tubular Condenser .1Mfd. I think I might need some help on the lingo here.
Thanks for the help.
Greetings,
A schematic and parts breakdown would help you tremendously. I recommend the package from Chuck. For $7. you get all the info you will need including good large scans of part locations, part ID's including the original Philco part numbers. His web site is :
http://www.philcorepairbench.com/schematics.htm
Glenn
Dave at justradios.com used to put together cap kits for radios. Don't know if he still does this or not.
I have figured out all the paper capacitor values for the underside of the chassis, my next question is about the electrolytic capacitors on top of the chassis. When I replace those I have noticed that modern electrolytic capacitors have two leads however these old capacitors have what appears to be one "nipple" on the bottom of the shorter capacitor labeled 16mfd and 4 leads on the larger capacitor labeled 8mfd 8mfd 10mfd. how do i go about connecting these new capacitors? Also, I cant seem to find out what the voltage for these capacitors should be.
kmskunk4 Wrote:When I replace those I have noticed that modern electrolytic capacitors have two leads however these old capacitors have what appears to be one "nipple" on the bottom of the shorter capacitor labeled 16mfd and 4 leads on the larger capacitor labeled 8mfd 8mfd 10mfd. how do i go about connecting these new capacitors? Also, I cant seem to find out what the voltage for these capacitors should be.
This is tricky to explain in words but I'll do my best. The old type can cap with the "nipple" on the bottom is a single section cap. The can is negative, the nipple post is positive. That corresponds directly to your new caps.
The 4-wire, three section cap is #67 at
http://www.nostalgiaair.org/PagesByModel...013811.pdf
The negative lead is common to all three of the individual caps (8, 8, 10). The positive leads go to their appropriate destination and the negative lead connects electrically to the center tap of the transformer, not the chassis.
Now here it gets tricky for the first timer. Negative does not mean or imply ground or chassis. Often it does but you'll encounter those can caps mounted on insulated wafers to isolate them from the chassis. There will be a ring lug of some sort on the threaded mount where the negative connection is made. In the case of your 3-section cap you'll see the POSITIVE of one of the sections goes to chassis. That's the 10uf in the diagram.
As for voltage....in most radio work on models such as this just use 450v electrolytic caps and call it a day. That 10uf section could use a much lower voltage but other than a few pennies there's no need for concern.
Makes sense?
-Bill
Hey Bill
Makes good sense to me!!
But I'm a radio guy
Terry
Thanks Bill,
It makes a small amount of sense, as a beginner I am finding this rather confusing but lets see if I understand correctly. The single section cap seems easy enough however im not sure of where i will connect the negative lead, maybe this will be more clear when i disconnect the cap itself. As for the 3 section cap its sounding like I will solder all wires now connected to the three separate leads of the old cap to the one positive lead of the new cap and connect the wires of the 4th negative lead end to the center of the power transformer which i hope i am able to find. I am very new with the whole schematic reading and interpreting im just slightly starting to figure out the paper capacitor replacement so i hope i am able to successfully do this myself.
P.S. Sorry about the multiple threads Ron i'm new to this didn't realize it wasn't allowed. Just trying to get this beauty working again.
That's okay, thanks for your understanding. With the help of some of the best guys in this hobby here, you'll have that 630 up and running again soon, I am sure.
kmskunk4 Wrote:Thanks Bill,
It makes a small amount of sense, as a beginner I am finding this rather confusing but lets see if I understand correctly. The single section cap seems easy enough however im not sure of where i will connect the negative lead, maybe this will be more clear when i disconnect the cap itself.
Yes, it should be more apparent once you dig in.
Quote: As for the 3 section cap its sounding like I will solder all wires now connected to the three separate leads of the old cap to the one positive lead of the new cap and connect the wires of the 4th negative lead end to the center of the power transformer which i hope i am able to find. I am very new with the whole schematic reading and interpreting im just slightly starting to figure out the paper capacitor replacement so i hope i am able to successfully do this myself.
Maybe I'm reading you wrong but you need THREE new caps to replace that 3-section, 4-wire unit. 8uf isn't common these days but you can use 10uf for each of them.
Okay thanks Bill its all starting to come together nicely.
Okay, next issue. I was out buying capacitors today at my local electronics supply store and noticed that they do not sell a 16uf single section electrolytic capacitor. What other value might do the trick? I noticed both 10uf and 22uf capacitors there.
Also I went ahead and replaced the three section electrolytic, no problems, however im still having an issue with the single section. (I thought this would be the easy one) it appears as though all the wires are connected to the positive "nipple" which is insulated from the can by a small rubber washer but i can't see anywhere that the negative lead might attach to. The 3 section had a lead attached directly to the can, i suppose this what is confusing me about the single section there is no such lead.
Replacing your 16uf with 22uf @450v is fine on problem there. As for your other issue You've got four filter caps. Three are one can. Pn #67 see
http://www.nostalgiaair.org/PagesByModel...013811.pdf
The tricky thing is that one of those caps is wired backwards compared to the others. The one that is closest to the bottom (10uf section) the- side connect to the transformer tap and the + side connects to the chassis. You will need separate. cap for this as the one in the can the - is connected to the tap not chassis ground. You can use a lower voltage cap there like 50v of so.
Terry
Terry,
Not completely sure what you are trying to say here, but then again i am extremely new at this. What i did was replace the three section can with three separate capacitors all of which are 10mfd. The old can had what i assumed were three positive leads all located in the center of the can, and one assumed negative lead located on the outer edge of the can. What i did is used the assumed negative lead on the outer edge as my negative lead connection for all 3 new capacitors, I then gave the positive ends their respective wires as they were originally on the center of the old capacitor. Is this right? What I figured was that all three sections of the old capacitor shared a common negative lead but was split up for different components on the positive. I hope you can understand this I have very very limited knowledge in electronic lingo as well as schematics so I am kind of going based on the old wires in the chassis.
Thanks for the understanding.