Can anyone give me (newbie) advice regarding the best
way (with lots of detail :O) on how to go about replacing the filter capacitors and related capacitors
located in the big capacitor can with the two rows of
lugs on the bottom of the can which is on the chassis underside? Are the one and two MFD caps the electrolytics? What do the numbers on the schematic relate to at C-43 which I perceive to be the electrolytic caps? Are there places to get electrolytic cap values lower than 4.7 mfd? The caps on this set appear to use one and two mfd...
Can someone guide me here please?:
Thanks, Bob

Hi Bob

You might like this schematic better?

http://www.philcoradio.com/tech/images/96.jpg

You can use 4.7 mf @ 450 volt electrolytics for the 2 mf caps. However 2 mf poly are still available from AES, www.tubesandmore.com and others. Dave at www.justradios.com can help you with caps. If you use electrolytic caps watch polarity. They have a positive and negative lead.

Cap numbers on the schematic are just locations. They have nothing to do with value.

Norm

:Can anyone give me (newbie) advice regarding the best
:way (with lots of detail :O) on how to go about replacing the filter capacitors and related capacitors
:located in the big capacitor can with the two rows of
:lugs on the bottom of the can which is on the chassis underside? Are the one and two MFD caps the electrolytics? What do the numbers on the schematic relate to at C-43 which I perceive to be the electrolytic caps? Are there places to get electrolytic cap values lower than 4.7 mfd? The caps on this set appear to use one and two mfd...
:Can someone guide me here please?:
:Thanks, Bob

Norm,
Thanks for the more detailed schematic. It makes a lot more sense to me now.
It shows the 2 uf caps being tied together from lug 3 to lug 9 and 10. Are lug 3 and 11 the ground connections? It looks like it to me.
Are 1 uf and 2uf considered electrolytics with polarity connection considerations?
Another question about this set. There are like 4 or so capacitor/resistor in the bakelite blocks. See R8, r9 R16,R17. These are 250 ohms. What wattage should I use if I decide to replace them? I am not sure I want to rebuild the bakelite blocks or not yet. Someone in the past has already replaced 5 of these caps on the outside of the block but they are the wax type. It is a lot of work but it looks much nicer when you are done to tuck them inside the blocks.
(As a side note I found I suppose about a third of an old movie poster used as insulation between the bottom cover of the chassis and the main chassis. It
looks like a War Movie with Japanese Sailors and the letters Ravag.. (part of the movie title) revealed before they cut it off. It would be cool to have the whole poster. I am not sure what year
that would have come out...maybe late 40's??)

Bob

Original caps were not electrolytics in this Philco. That's why values are so small. Although paper/poly caps are available, for more money, you can use low value electroltics. 4.7 mf @ 450 volt are available but I commonly use 10 mf @ 450 volts.

Resistors for 8, 9, 16 and 17 can be 1/2 watt. Some current flows through these but resistance is so low little power is dissipated. Think you will find these resistors in bakelite blocks and are made by using a small bunch of wire. No reason to change resistors unless open or way off value.

Bakelite block caps should be replaced. It's easy to do with a heat gun or hair dryer. First cut wires going to the eyelets. Heat up bakelite block and slide out the tar insides. By heating outside of the block only tar next to it melts. It acts almost like oil and allows the inside to slide out.

It interesting finding items inside these old radios. Some people find coins, stamps or even names written on a radio. You should be able to find when the poster was made?

Norm

:Norm,
:Thanks for the more detailed schematic. It makes a lot more sense to me now.
: It shows the 2 uf caps being tied together from lug 3 to lug 9 and 10. Are lug 3 and 11 the ground connections? It looks like it to me.
:Are 1 uf and 2uf considered electrolytics with polarity connection considerations?
:Another question about this set. There are like 4 or so capacitor/resistor in the bakelite blocks. See R8, r9 R16,R17. These are 250 ohms. What wattage should I use if I decide to replace them? I am not sure I want to rebuild the bakelite blocks or not yet. Someone in the past has already replaced 5 of these caps on the outside of the block but they are the wax type. It is a lot of work but it looks much nicer when you are done to tuck them inside the blocks.
:(As a side note I found I suppose about a third of an old movie poster used as insulation between the bottom cover of the chassis and the main chassis. It
:looks like a War Movie with Japanese Sailors and the letters Ravag.. (part of the movie title) revealed before they cut it off. It would be cool to have the whole poster. I am not sure what year
:that would have come out...maybe late 40's??)
:

I see Radio Daze has AXIAL LEAD METALLIZED POLYESTER FILM CAPACITORS in the 1 uf and 2.2 uf 630 volt size.
I suppose there would be no diffence in operation between these and the 4.7 or 10 uf that you say you commonly use??? they would be a little cheaper maybe.
So lug 3 and 11 are ground on this set in case i decide to go the electrolytic route?
I have removed the gunk from Bakelite blocks before in another old Philco and it went pretty smooth. I guess I will do the same for this set. It is just that there are 10 of them bugers in this one. It gets a little time consuming but looks a lot nicer.
On the back of this set on a metal area someone laments in pencil: Cuts out. whistles, Sounds like fog horn...A previous owner I would suspect :O)

Be careful about 3 and 11. Three is the most negative point in your radio. Eleven is ground to chassis but they aren't connected together. Both are negative terminals for caps.

It will take time rebuilding your Philco 96 but nice when completed.

Norm

: I see Radio Daze has AXIAL LEAD METALLIZED POLYESTER FILM CAPACITORS in the 1 uf and 2.2 uf 630 volt size.
:I suppose there would be no diffence in operation between these and the 4.7 or 10 uf that you say you commonly use??? they would be a little cheaper maybe.
: So lug 3 and 11 are ground on this set in case i decide to go the electrolytic route?
: I have removed the gunk from Bakelite blocks before in another old Philco and it went pretty smooth. I guess I will do the same for this set. It is just that there are 10 of them bugers in this one. It gets a little time consuming but looks a lot nicer.
: On the back of this set on a metal area someone laments in pencil: Cuts out. whistles, Sounds like fog horn...A previous owner I would suspect :O)
:

Norm
My intent is to wire the caps back the way they are now to be safe. :O)
If it were your set would you empty out the big can cap that holds all those caps and the "filter" caps. I think I saw somewhere that it has the same gunk in it as the bakelite blocks. It must weigh five pounds. It measures 3 inchs by 4 inchs by 5 inches tall. It will take some careful documenting of all the wiring that the unit holds for me to get it back together.
Bob

Bob,
Most of what is inside is tar(pitch). The caps themselves are rather large as well. Just plain paper/wax/foil caps of that value/voltage/era are quite large. I removed 3 from a large can on a Grigsby-Grunow 90B chassis, and replaced them with modern day equivalents (much-much smaller) Instead of refilling with the original contents, I used wood shims and hot-melt glue to stabilize them. I used an oven and a disposable container to melt them out of the can. I still have the original contents, including the tar, and 2 of the caps still measure close to original value.

marv

:Norm
:My intent is to wire the caps back the way they are now to be safe. :O)
: If it were your set would you empty out the big can cap that holds all those caps and the "filter" caps. I think I saw somewhere that it has the same gunk in it as the bakelite blocks. It must weigh five pounds. It measures 3 inchs by 4 inchs by 5 inches tall. It will take some careful documenting of all the wiring that the unit holds for me to get it back together.
:Bob
:

Marv,
I am trying to approach this project cautiously. It is a nice looking set and I want to do it right.
So far I have pryed off (pulled away) the sides of the metal cap box from the base and I can open it to about a half inch gap. I can see the wires. They look crumbly and falling apart. Now should I go ahead and cut all those wires so I can release it from the under side lug base and begin cleaning out the can and replacing the caps?
Bob

Bob,
Don't try removing the contents without heat or you'll destroy the can/appearance of originality. Unsolder as many wires as possible, and remove the base plate (phenolic/fish paper) from the can. A heat gun is not a good method, whereas an oven preferrably electric @approx.200-250 degrees)will heat the entire can, softening the tar/pitch, which can be removed, along with the caps. With luck and the can setting on a spacer, the contents will slide out unattended. I say "preferrably electric" because the vapors from the filler (tar/pitch) may be flammable, and an open flame may be dangerous. Microwave is a definite NO-NO.

marv

:Marv,
:I am trying to approach this project cautiously. It is a nice looking set and I want to do it right.
: So far I have pryed off (pulled away) the sides of the metal cap box from the base and I can open it to about a half inch gap. I can see the wires. They look crumbly and falling apart. Now should I go ahead and cut all those wires so I can release it from the under side lug base and begin cleaning out the can and replacing the caps?
:Bob

Marv,
The can separates from the base by means of releasing four snap-in "catchs" so the bottom lid (or plate) that holds the lug base (phenolic/fishpaper?) of the can separates from the rest of the can. Would it be a bad idea to pry the can apart far enough to get cutters in there to cut the wires INSIDE the can that connect to the original caps embedded in the pitch? I am sure there is enough room to do this safely.
There is about 2 inches of wiring from the components that are not stuck into the pitch to each part in there. This way I can leave the wiring that goes to the various places in the chassis in place on the underside and then I can solder in the new caps without worrying about remembering or marking where the wires from the lugs go. I would just be sure I get the caps connected in the correct places which the schematic clearly shows me. Then I am wondering if I could slowly heat the can (now removed from the chassis) with the pitch with a heat gun being careful not to melt or damage the paint...Not sure my wife would think much of the idea of using her oven to smell the house up like that. Wonder if an old BBQ grill would work? :O) Then only my neighbors would think I am out of mind wondering what the hell I was cooking...
Bob

Bob,
Being single, I didn't have the wifey problem. If you can retain ID of the wires and their terminus, cut them, or draw a sketch, then unsolder from the lugs. This is where a digital camera in the macro mode will help. Of course extreme close-ups will require a tripod. The BBQ may scorch the can somewhat, but at least odors would be outside. Heavy foil on the grilling surface and non flammable spacers would allow the contents to slide out the bottom, and of course the grill lid would distribute the heat to the entire can. JUST BE AWARE that the hot tar/pitch will STICK TO YOUR SKIN (and stay) causing severe burn(s) Use hot mitts and other precautions to avoid injury. A first class job would require the complete removal of the contents, but with a heat gun, the first couple inches of tar/wire could be dug out, and allow installation of new modern (smaller) caps. Heating the entire can with a gun for complete removal, may be time consuming and tend to warp the can as each side/top is heated separately.

marv

:Marv,
:The can separates from the base by means of releasing four snap-in "catchs" so the bottom lid (or plate) that holds the lug base (phenolic/fishpaper?) of the can separates from the rest of the can. Would it be a bad idea to pry the can apart far enough to get cutters in there to cut the wires INSIDE the can that connect to the original caps embedded in the pitch? I am sure there is enough room to do this safely.
:There is about 2 inches of wiring from the components that are not stuck into the pitch to each part in there. This way I can leave the wiring that goes to the various places in the chassis in place on the underside and then I can solder in the new caps without worrying about remembering or marking where the wires from the lugs go. I would just be sure I get the caps connected in the correct places which the schematic clearly shows me. Then I am wondering if I could slowly heat the can (now removed from the chassis) with the pitch with a heat gun being careful not to melt or damage the paint...Not sure my wife would think much of the idea of using her oven to smell the house up like that. Wonder if an old BBQ grill would work? :O) Then only my neighbors would think I am out of mind wondering what the hell I was cooking...
:Bob

Marv,
I have no problem with the photography part. I make my living as a professional photographer. On every radio I work on I photograph the whole radio as I take it apart as well as the overall chassis from all sides and then I do detail shots of smaller areas. This has saved me several times. :O)
Since I just wemt through blanching tomatoes last weeekend with an outdoor cooker I got to wondering if boiling it in a pan of water would be an option? But I do not know what the melting point of that stuff is or if that might warp the metal can too.
I know those Philco bakelite blocks are pretty easy to get warm enough to slide the stuff out so I may try to slowly heat the can around all sides to see if it will let loose and allow it to come out.
Bob

Bob,
I did a small Bakelite block a couple months ago, and it was only about 2 cubic inches, but still used the oven and disposable container. With the oven or BBQ, you can walk away and come back when the stew is done. The heat gun requires constant attention, manually rotating and checking the contents. The first one I did, the can was lined with thin cardboard which had come unglued over the years. If your can is likewise, perhaps a long thin spatula can be used to loosen the cardboard from the can, allowing it to slide out with no heat.

marv

: Marv,
:I have no problem with the photography part. I make my living as a professional photographer. On every radio I work on I photograph the whole radio as I take it apart as well as the overall chassis from all sides and then I do detail shots of smaller areas. This has saved me several times. :O)
: Since I just wemt through blanching tomatoes last weeekend with an outdoor cooker I got to wondering if boiling it in a pan of water would be an option? But I do not know what the melting point of that stuff is or if that might warp the metal can too.
: I know those Philco bakelite blocks are pretty easy to get warm enough to slide the stuff out so I may try to slowly heat the can around all sides to see if it will let loose and allow it to come out.
:Bob

Marv,
Well I threw the big cap on the Barb-B...then started mowing my lawn. I used a disposable pan which caught the melt down of the pitch. I laid the pan right on the coals and checked it after about 20 minutes and it was not quite ready. After another 15 minutes or so it was soft and fairly easy to pry out one of the layers and then the rest came out very easily. I used an old corkscrew to get the first layer out of the can. I thought it was 70-80% pitch inside it but was surprised after easily chipping away the first 1/4 inch of hard pitch which then revealed the actual capacitors in rolled foil and paper which were tightly packed in the can. The caps sort of looked like those pocket sized kleenex packages rolled and packed into the cavity of the metal box. There seemed to be a little pitch all around the sides and when that all melted and dripped into the pan it was a simple task to remove the rest of actual individual capacitor masses. Mine too had cardboard around the edges but I could not get it to budge even though it was somewhat loose from the metal sides before I tried heating it. I cleaned the can up with paint thinnner and am ready to start putting in the new capacitors. I got the big honkin 1 UF and 2.2 UF caps from Radio Daze so I am all set.
Thanks and stay tuned for further questions :O)
Bob

Bob,
You were fortunate not to have dealt with a full can of tar, but the next one may be different. Now you have a method for easily disemboweling these monsters. Modern equivalent caps will require much less space, but should be supported to avoid movement inside the can, and mass fireworks. Pay close attention to the heat damage to the can, otherwise a new finish will be short lived.

marv

:Marv,
:Well I threw the big cap on the Barb-B...then started mowing my lawn. I used a disposable pan which caught the melt down of the pitch. I laid the pan right on the coals and checked it after about 20 minutes and it was not quite ready. After another 15 minutes or so it was soft and fairly easy to pry out one of the layers and then the rest came out very easily. I used an old corkscrew to get the first layer out of the can. I thought it was 70-80% pitch inside it but was surprised after easily chipping away the first 1/4 inch of hard pitch which then revealed the actual capacitors in rolled foil and paper which were tightly packed in the can. The caps sort of looked like those pocket sized kleenex packages rolled and packed into the cavity of the metal box. There seemed to be a little pitch all around the sides and when that all melted and dripped into the pan it was a simple task to remove the rest of actual individual capacitor masses. Mine too had cardboard around the edges but I could not get it to budge even though it was somewhat loose from the metal sides before I tried heating it. I cleaned the can up with paint thinnner and am ready to start putting in the new capacitors. I got the big honkin 1 UF and 2.2 UF caps from Radio Daze so I am all set.
:Thanks and stay tuned for further questions :O)
:Bob