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

Silver mica voltage for 39-30 needed.
#11

Ceramic caps did not see widespread use until WW2 where they were first used in military equipment. After the war they began to show up in consumer electronics and became very common in the 1950s.

Regular stacked foil mica caps were common up into the 1950's when they were replaced by the modern dipped silver micas and ceramics. Except for special power RF versions (Unelco's) regular stacked mica caps are no longer made.

In their early "postage stamp" varieties, regular micas have brown or tan plastic cases while silver micas have red cases, so it is easy to tell the difference. All presently available epoxy dipped types are now silver mica construction, which involves depositing a thin coating of silver conductor directly on the mica dielectric.


Messages In This Thread
RE: Silver mica voltage for 39-30 needed. - by Mondial - 06-14-2013, 09:10 PM



Users browsing this thread: 1 Guest(s)
[-]
Recent Posts
Part numbers to model cross
I looked thru the documents and did not see one. Might have missed it though.Jim Dutridge — 07:16 PM
Philco 42-345 Restoration/Repair
Please tell me this was it, I replaced resistor 27 and it's playing on the broadcast band. I am afraid to change the ban...osanders0311 — 06:12 PM
Philco 42-345 Restoration/Repair
So far still no broadcast, I am posting pictures of #14 Oscillator and also a resistor #27 which connects to an XXL tube...osanders0311 — 04:02 PM
Part numbers to model cross
I believe there is that document, and I think we might have it in the Library.morzh — 03:29 PM
Philco 42-345 Restoration/Repair
Ok MrFixr55,  I have tried the DeoxIT D5 on the band switch and even though it has relieved the tension I felt when turn...osanders0311 — 11:11 AM
Part numbers to model cross
Is there a reference somewhere where you can punch in Philco part numbers and see what models those parts were used in?Jim Dutridge — 10:17 AM
Philco 42-345 Restoration/Repair
Hi OSanders, Look carefully at the band switch. Turn it slowly and "wiggle" it around the desired band. ...MrFixr55 — 12:33 AM
5U4 vs 5Z4 tubes
I think that RCA and GE introduced metal tubes in the USA in 1936.  I don't know if they were being made by RCA, GE or b...MrFixr55 — 11:20 PM
Philco 42-345 Restoration/Repair
Vlad95, Thank you for the stringing guides and wow there are so manyosanders0311 — 06:01 PM
5U4 vs 5Z4 tubes
A pre war Hallicrafters, and an early one too, very nice! 1936 is pretty early for metal tubes too, which would explain ...Arran — 05:58 PM

[-]
Who's Online
There are currently 1033 online users. [Complete List]
» 1 Member(s) | 1032 Guest(s)
Avatar

>