Welcome Guest! Be sure you know and follow the Phorum Rules before posting. Thank you and Enjoy! (January 12) x

Thread Closed
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Philco 91-221 (25 HZ) metal capacitor block 4989-K
#1

This is my first post.
http://www.nostalgiaair.org/pagesbymodel...013884.pdf

#56 in schematic

This is my first foray into the Philco bakelite blocks.  The regular ones go just fine.  I have the master key with the connections and the discontinued's, etc.  My problem is with the metal encased blocks, specifically 4989-k, noted as a 0.18mfd or, actually, two 0.09's.  There is no actual bakelite in this condenser bank.

Upon dissection of the old capacitor, there were 2 halves in the tar, separated by a paper insulator.  I could find no connection between the 2 halves.  There is no number on the metal case.

3 wires come out one end of the block. A bare ground wire to the metal case (subsequently grounded to chassis) was present on other end.

One half of the bank is wired to the filter choke and the rectifier tube.
The other half is wired to the electrolytics, the other wire to the ground as noted above.
Again, no apparent connection between the halves of the condenser block.

I have to admit my sophomoric level of understanding with regards to reading schematics.

My question regards rebuilding the block:
Should I re-wire it as I dissected it, using a 0.1 mfd in place of each side of the bank, or try to directly place them in parallel and somehow then make the connections?

Thank you, in advance.
Brian
#2

It does not matter.

First of I am not sure why you think #56 is a backelite inside the block. It is probably just a standalone backelite cap.
Better yet it was determinded the #56 cap is pretty useless and could be dropped altogether.

When I rebuild my blocks i twist all teh caps that go to GND together, solder it to teh case with a flexible wire, wrap in fish paper and push inside.
Those not grounded, just put out the wires the way they are shown on the sch.

People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.




Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Electrolytic restuffing/internals
I don’t have a vise so I had to hold it in my hand. Not optimal but covered up by the hvac tape in the end. I have a few...bridkarl — 11:52 PM
Electrolytic restuffing/internals
Bridkarl A question. For a hacksaw the cut looks a little...jagged. Why?morzh — 11:45 PM
The list of my radio & TV collection!
As usual, an interesting post from you, Peter. This seems to be similar to the RCA 3-BX-671 and the Zenith Transoceanic...MrFixr55 — 11:41 PM
The list of my radio & TV collection!
Hello Peter, Thank you for sharing your new video and looks like your weather is nice their too. it was like 25 Cel...radiorich — 11:05 PM
Electrolytic restuffing/internals
hello bridkarl, I will post some better photos ! Sincerely Richardradiorich — 10:14 PM
Electrolytic restuffing/internals
I just taped the two pieces of the cap together, but I can see your method is better. I just held the lead in with solde...bridkarl — 08:18 PM
Electrolytic restuffing/internals
hello bridkarl, Well done ! Here is a Photo of the base of Philco capacitor that I cut open you can see how I glued th...radiorich — 08:14 PM
philco predicta
Hi CGL18, Here is a link for the schematic from the Early television Foundation: WARNING!! One side of the Chassis i...MrFixr55 — 08:09 PM
The list of my radio & TV collection!
Peter; I like Canadian General Electric sets, whilst the model numbers are often the same as their U.S General Electr...Arran — 05:44 PM
Electrolytic restuffing/internals
Did as suggested. Cut can with hacksaw, removed internals, attached new 8mf cap - with ample use of cardboard and elec...bridkarl — 03:36 PM

[-]
Who's Online
There are currently no members online.

>