1. The PHILCO Phorum
  2. Philco Radio Discussions
  3. Philco Electronic Restoration
Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5

Linear Mode
Replace mica caps in Bakelite blocks?
k9uw
Junior Member
**
Posts: 35
Threads: 12
Joined: Nov 2014
City: Amherst, WI
#8

09-19-2018, 04:08 PM
(09-17-2018, 10:28 AM)morzh Wrote:  I guess (purely out of interest) one way to find out whether they are mica or not is to measure them. It might be a bit tricky with a regular meter as it will show about 100pF when not connected so it needs too be zeroed first; if it shows close to the nominal value, it is then a mica; if it shows a different value (paper caps migrate as fas as 2x to more the value) then it is paper.
Has to measured out of circuit, with the wires around clipped.

Good suggestion, Morzh!  It took a while to isolate the leads from one of the caps inside the Bakelite block but, after adjusting the meter to compensate for capacitance in the leads, the cap that had been 110 pf had jumped in value to 245 pf.  They must be paper, and they're coming out!
Mike, K9UW
Amherst, WI
Find
« Next Oldest | Next Newest »


Messages In This Thread
Replace mica caps in Bakelite blocks? - by k9uw - 09-17-2018, 12:36 AM
RE: Replace mica caps in Bakelite blocks? - by k9uw - 09-19-2018, 04:08 PM



Users browsing this thread: 6 Guest(s)
[-]
Recent Posts
trying to identify this wire type
Thanks to all for the feedback. As Arran said, it is probably an older replacement and yes it has a grid cap so I will ...georgetownjohn — 09:32 PM
trying to identify this wire type
It's possible that the red wire, actually a grid cap lead, is a very old replacement, I can't remember seeing a pre 1939...Arran — 09:18 PM
Gilfillan Brothers Car Radio?
Hi everyone,  Special thanks to Joe Rossi for tracking down this obscure radio and thanks to others who took up the hun...Antipodal — 08:15 PM
trying to identify this wire type
Here's one source for your wire of many. Take care and BE HEALTHY! Gary P.S. Can't get the right color you need? I ...GarySP — 06:40 PM
trying to identify this wire type
...and modern wire of the appropriate gauges and insulation V-rating (300V minimum, usually shown right on the wire) is ...morzh — 05:47 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
I have a question about this radio, is there anyone that has access to this radio that has an intact unmolested speaker ...captainclock1988 — 04:28 PM
1930s Stromberg-Carlson Tombstone Radio need help identifying model number
Well what makes me confuse all of those companies is that all three of those companies (Setchell-Carlson, Stromberg-Carl...captainclock1988 — 04:21 PM
trying to identify this wire type
The red wire is rubber covered wire. The others are cotton braid over rubber often in colors or a tracer, also strand...Chas — 02:43 PM
trying to identify this wire type
Greetings Phorum members, Hope you can help me identify this type of wire in the photo I have attached.  I am not sure ...georgetownjohn — 01:53 PM
Philco 60 Squealing
All correct shields must be in place, all tubes correct no subs of any kind. Check any soldered, riveted ground conne...Chas — 01:24 PM

[-]
Who's Online
There are currently 6174 online users. [Complete List]
» 1 Member(s) | 6173 Guest(s)
Avatar

>
  1. The PHILCO Phorum
  2. Philco Radio Discussions
  3. Philco Electronic Restoration