Block Capacitor Questions -
Philco444 - 12-14-2018
Oh yes again another Philco NOOB venturing out into the land of the dreaded Bakelite Philco Capacitor Block
![Icon_eek Icon_eek](https://philcoradio.com/phorum/images/smilies/icon_eek.gif)
reminding me of the Spaghetti Western "The Good, The Bad, and The Ugly"
As per this link
https://web.archive.org/web/20160324232735/http://philcorepairbench.com/bblokcap.htm
There is mention of these part numbers and before "to boldly going where no man has gone before" do these blocks have numbers on them?
I haven't started dissecting my Philco 444 yet so I have yet to scrutinize these little black devils and as for the numbers perhaps being a British set is opening up a can of worms of different part numbers etc.?
As I have read searching this forum has informed me that some even contain resistors and hopefully the schematic I have (thank goodness) indicates this? The schematic might not reveal this if there is a part number where the value of capacitors and resistors is indicated including voltage.
Anyway as I wait for the words of wisdom from senior Philco owners and restorers another question is the desired type of capacitor to use for "stuffage"
In my inventory I have:
a very fine selection compliments of Sal Brisindi of the typical yellow Polypropylene Axial capacitors of about 630 volts and a great assortment of Axial, and Radial Electrolytic Capacitors
Numerous 630 volt green dipped Mylar type Polypropylene I found at very reasonable prices on eeevilPay
And of course piles of NOS disk Ceramic capacitors I have accumulated over the 40+ years I have been messing with this shtuff. I also have many very good new American and Canadian made Mica (probably older than myself) as well, which seldom need replacing, and in case I have to these are on hand. I was warned by British radio collectors that there was a British brand of the Mica that logic dictates you rip em out and tip them because they are seldom any good but mine appear to be British Philco Mica Capacitors that will be tested as well.
Other than size being a factor for the blocks with multiple capacitors, what type, if it fits, are the best?
Don
RE: Block Capacitor Questions -
morzh - 12-14-2018
Any type of proper capacitance and voltage, plus tolerance.
I use film axials. Any. I buy 630V mostly so not to think about it.
RE: Block Capacitor Questions -
Philco444 - 12-14-2018
Thanks morzh
As for film axials I would assume you are talking about those yellow fellows?
I guess other than that it would be whatever fits as these blocks are quite small. This is the good point about those little green, red, orange, or whatever flavor you desire capacitors or if space is quite a premium disk ceramic and I have seen them subbed for Mica as well but given the choice I would choose mica for mica.
Are the part numbers casted in the Bakelite mold or marked on the sides of these blocks so I can look them up on the Philco web site posted above?
RE: Block Capacitor Questions -
klondike98 - 12-15-2018
The bakelite block capacitors have numbers on the side of them cast in the bakelite. the numbers give you the capacitor configuration and values when you look them up on the
service bulletin posted in the
Tech Section.
morzh has posted a nice
thread on how to get the guts out of them without taking them completely out of the chassis, although I often find it just easier to take them out and work on them.
For bakelite block numbers that are not listed in the service bulletin, Ray Blintiff wrote a book listing a lot more of them
Philco Condensors and More. Although it is no longer in print, many of us have a copy and can give you the info when needed.
RE: Block Capacitor Questions -
Phlogiston - 12-15-2018
Be careful, some of the blocks have more than capacitors in them (resistors) that don't need to be replaced unless they are damaged in the removal process.
RE: Block Capacitor Questions -
klondike98 - 12-15-2018
Good point Russ! Here's a
picture of one of those resistors that I had in my Philco 91 restoration thread. I had broken the lead on it but was able to make a repair.
RE: Block Capacitor Questions -
Philco444 - 12-15-2018
Thanks again everybody!
The tools Steve made and demonstrated on his thread actually has a picture with a number ink or paint stamped on the end and I looked up the number on the link I posted and yes that is a good number! I purchased a heat gun today and a number of months ago I purchased a very fine Weller brand solder sucker as I knew removing the soldered leads from tube socket and terminal strip lugs can be difficult leading to damage wrestling partially soldered wires from them. Remove all of the solder, jiggle the wires and leads until what little is left solidifies as it becomes cold and use a sharp pointy pen knife to bend open and remove, especially for disconnecting to test if the component is to be reused. Drilling the holes to cut the wires is a great idea but the connection terminals need to be cleaned anyway so I will give this a try.
RE: Block Capacitor Questions -
Philco444 - 12-15-2018
Quote from morzh
"Ron,
If you think it is worth it, maybe you could either make it sticky for a while or stash it with a link so it does not get lost.
This is step by step instructions of how to rebuild bakelite Philco capacitors without desoldering."
And I most certainly agree as older posts and threads get lost!
This is a great thread for this situation but at the end of the day this is merely a walk in the park compared to a Westinghouse 1931 Columaire WR-8, two of which are for sale in my area, that use the same chassis as an RCA model 82. OMG the cans and boxes containing the tarred in transformers and capacitors, to the point of one fellow restoring one on another forum using a propane radiant heater to cook the large amount of almost 90 year tar out to remove the guts. They are sitting for sale and perhaps I might be Phoolish enough to venture into this area and I might add they are closer than London or Germany.
RE: Block Capacitor Questions -
Philco444 - 12-15-2018
As for exact values in these blocks? What can one usually get away with for tolerance IE .05uf, will usual Philcos and other radios of this vintage tolerate .047 or .056 in their place?
RE: Block Capacitor Questions -
klondike98 - 12-16-2018
0.047uF is just fine to replace the 0.05uF in the block. .056 would be OK also.
RE: Block Capacitor Questions -
Philco444 - 12-16-2018
Well morhz looking at your tutorial there is very little tar at the bottom as you pushed the crapacitors out. These blocks are filled to the top that much heating was required multiple times. I even used a razor blade to slice among the sides. If the rest are like this I may as well disconnect and place them in an old toaster oven on very low heat and perhaps use varsol a mild petroleum solvent used in repair shops to clean engine parts. The heat gun is almost way to hot even on low and isn't kind to the dog bones. It is equiv. to a propane torch as it will burn paint black in a split second. This is all going on with resistors attached going to other circuits etc. Being a British set as they would say somebody went "Willy Nilly" with the tar, enough to tar and feather an individual.
RE: Block Capacitor Questions -
Philco444 - 12-16-2018
This is just one block
RE: Block Capacitor Questions -
Phlogiston - 12-16-2018
I just chip the tar out with a little screwdriver - no heating at all. It takes some practice. DO NOT pry on the edge of the Bakelite, it will break.
RE: Block Capacitor Questions -
klondike98 - 12-16-2018
Yes I've encountered block capacitors that did not slide out as easily as others I've stuffed. In those cases, I do take them out of the chassis, heat them with a hair dryer or heat gun and then do a little digging with a flat screw driver, spatula or utility knife to get the guts out. Once you get the bottom tar out the cap(s) will usually pry out easily. Do be careful though about prying against the side of the bakelite block as I have broken one when I pried a bit too hard. I then use WD40 to clean out the residual tar in the block (mineral spirits works also).
RE: Block Capacitor Questions -
Phlogiston - 12-16-2018
Oh yeah, I forgot to mention that I take them out. The whole process takes about 5 minutes. I don't put the tar back. When remounting the cap I address all wiring and other component issues surrounding that cap. Again, it is best to work fast and avoid over-heating wire and components. A hot iron (HOT) will melt the solder fast and avoid the overheating experienced with a long (cool) contact.
For me, they are clean enough without the wash-down. You can wipe down the external contact area or hit it with a quick polish on the wire wheel.