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

0.00011 mf caps in bakelite blocks
#1

I'm working on my model 116.  What is the concensus?  Are these 0.00011 mf capacitors replaced during restoration?  On one hand, that value suggests they're mica, which is usually left alone.  But on the other hand, why would these capacitors be potted in tar?  This suggests they are subject to degradation over time.
#2

Inside backelites these are not mica.
Even if they are safe they have likely drifted, they are typically replaced.
#3

I've always used dipped mica 110pF caps here; they are cheap and perfectly suitable for the purpose. I buy at least 20 at a time. These are the caps that look like dark caramel candy.

Pete AI2V
#4

From all of the Philcos that have crossed my bench...and they number in the hundreds, I never bothered to count them...out of those that have 110 pF caps in bakelite block shells, the majority were small paper caps. I have encountered a few that had mica caps encapsulated in the tar, though...but as I said, the majority were paper.

As Pete (AI2V) said, dipped micas are excellent replacements for these. And, yes, I replace them as a matter of course in the Philco sets that use them.

--
Ron Ramirez
Ferdinand IN
#5

[Image: http://www.talonix.com/images/caps4/39pfDSM.jpg]

Looks like this.  Some are larger or smaller, depending 
on the capacitance and working voltage.
#6

I just pulled 4 of those out of bakelite block shells last week and all 4 were paper. I used the dipped micas like in Chuck's photo.
#7

Another question, about the voltage rating on these caps; what were they originally? I would assume 500V micas would be fine?
#8

Yes 500 volt micas will be OK.
#9

Can you double check that? The bakelite block I'm restoring is pn 8035-DG. Philco Service Bulletin No. 289 suggests these capacitors have a working voltage of 1200v.
#10

The maximum voltage these are going to see in the 2nd Detector circuit will be so low as to not be consequential, really.

You can use 1200 VDC caps if you wish. H**l, you can use 12,000 volt caps if you want to. But Codefox is correct, 500 WVDC caps are fine. Even 300 WVDC micas are fine. I use the 500 WVDC micas all of the time to replace these and I haven't had a single failure yet...and I do not expect to since they will only be exposed to somewhere between 0 and 10 volts in this circuit.

--
Ron Ramirez
Ferdinand IN
#11

(12-09-2014, 05:19 PM)Kestas Wrote:  I'm working on my model 116.  What is the concensus?  Are these 0.00011 mf capacitors replaced during restoration?  On one hand, that value suggests they're mica, which is usually left alone.  But on the other hand, why would these capacitors be potted in tar?  This suggests they are subject to degradation over time.

Hi guys, I have run into the same bakelite block in my 38-2 as Kestas.Just a question would 0.0002 @ 630V be to much to use in place of the 0.00011? I have these on hand,but if I have to I will order the correct replacements.
Thanks 
#12

Quote:Just a question would 0.0002 @ 630V be to much to use in place of the 0.00011?
You should stay within a 10 to 20 percent tolerance.
#13

Just ordered up some 110pf caps so i should be good until I tackle THE BEAST my 38-116. After the 38-2, i
would hope things will be easier,still will be a challenge I know. Icon_thumbup but I'm up for it.
#14

Oh...it's just a bunch of wires, glass an metal....nothing a man with a scredriver couldn't take on.
#15

FIRE UP that soldering iron an lemme at it.Wait, I still have to finish the 38-2. Icon_biggrin




Users browsing this thread:
[-]
Recent Posts
Philco 42-345 Restoration/Repair
With regard to the speaker, unless the cone is so brittle that it crumbles as soon as you touch it I would try to repair...Arran — 04:07 AM
Philco 42-345 Restoration/Repair
That silver can capacitor is an aluminum electrolytic. You should replace it with an aluminum electrolytic with the valu...RodB — 11:46 PM
Philco 42-345 Restoration/Repair
Thank you Rodb and Gary for helping with clarification on these capacitors. Other than the Tiny 630volt one I'm not sure...osanders0311 — 10:17 PM
1949 Motorola 5A9M
Hello All; I found the CMB41L down in the basement, it is definitely a 1950-51 model, the capacitors have date codes ...Arran — 07:48 PM
Philco 42-345 Restoration/Repair
Hi, all the caps I order, other than the electrolytics, are of the 630V rating. No worries on it being too high, and no ...gary rabbitt — 05:46 PM
Philco 42-345 Restoration/Repair
Hi, there's a lot to consider when designing these circuits so you shouldn't have a lot of concern when replacing caps. ...RodB — 02:03 PM
Philco 42-345 Restoration/Repair
I have ordered and received new caps for this radio and hope I've ordered the correct ones. I tried matching them to the...osanders0311 — 11:35 AM
Philco newbie with P-1891-WA console questions
Hello Jeff , Far as the Electrolytic capacitors go here is a list of parts. that will work . I like using Nichicon and...radiorich — 09:50 PM
Philco newbie with P-1891-WA console questions
Well, I've been stumped at trying to get the first of 11 electrolytic capacitors. I got a schematic and have a list of t...Jeffcon — 07:54 PM
Model 80 Antenna Issue?
Thanks Gary and Rod.  I also found an article in the Philco Repair Bench under Service Hints and Tips, about installi...Hamilton — 12:32 PM

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

>