Capacitor puffage please - UK Vintage Radio Repair and Restoration Discussion Forum

llama · 3rd Feb 2018, 10:58 am

Deliberately avoiding “values” – these are negligible, monetarily.

I have a few of each of these new caps but the values and other ratings are a bit of a mystery to me. They are all in brown ceramic cases.

1) A square one marked:

750J
SOSHIN

2) A circular one:

390pM
An orange blob on top with a green dot on top of that

3) A small circular one:

1 [but like a horizontal bar]
A purple dot, red dot on top of that

4) A small circular one:

18Jb
Black dot on top

5) A small circular one:

22p
Orange dot on top

6) A small square one:

68M
Violet dot on top

7 & 8) Two varieties of small square ones:

33J
Orange or black dot on top

I don’t feel I can assume they are all pF as I guess the coloured dot(s) are some sort of multipier. Explanations most welcome, please.
Graham

Boater Sam · 3rd Feb 2018, 11:10 am

Guesses.
They are all pf IF THEY ARE CAPACITORS and not other devices like thermistors, surge arrestors.

1) 750pf
2) 390pf
3) 27pf
4) 18pf
5) 22pf
6) 68pf
7&8) 33pf

A picture would help. I'm particularly unsure on the square ones.
Stick them on a capacitor tester?

Herald1360 · 3rd Feb 2018, 11:56 am

Letters like J and M may refer to tolerances. Coloured blobs ditto, or ceramic type / tempco. Depends who made them. Little square ones sound like obsolete Mullard/Philips jobs.

G8HQP Dave · 3rd Feb 2018, 11:59 am

If the "dot" on top is more like a hat then it probably indicates the ceramic type. Black would be NP0/C0G.

short wave · 3rd Feb 2018, 12:34 pm

Capacitor tolerances found on the web

3rd Feb 2018, 10:58 am	#1
llama Octode Join Date: Jun 2006 Location: St Osyth, Nr Clacton, Essex, UK. Posts: 1,482	Capacitor puffage please Deliberately avoiding “values” – these are negligible, monetarily. I have a few of each of these new caps but the values and other ratings are a bit of a mystery to me. They are all in brown ceramic cases. 1) A square one marked: 750J SOSHIN 2) A circular one: 390pM An orange blob on top with a green dot on top of that 3) A small circular one: 1 [but like a horizontal bar] A purple dot, red dot on top of that 4) A small circular one: 18Jb Black dot on top 5) A small circular one: 22p Orange dot on top 6) A small square one: 68M Violet dot on top 7 & 8) Two varieties of small square ones: 33J Orange or black dot on top I don’t feel I can assume they are all pF as I guess the coloured dot(s) are some sort of multipier. Explanations most welcome, please. Graham __________________ Half my stuff is junk - trouble is, I don't know which half!

3rd Feb 2018, 11:10 am	#2
Boater Sam Banned Join Date: Dec 2013 Location: Middlewich, Cheshire, UK. & Winter in the Philippines. Posts: 3,897	Re: Capacitor puffage please Guesses. They are all pf IF THEY ARE CAPACITORS and not other devices like thermistors, surge arrestors. 1) 750pf 2) 390pf 3) 27pf 4) 18pf 5) 22pf 6) 68pf 7&8) 33pf A picture would help. I'm particularly unsure on the square ones. Stick them on a capacitor tester? Last edited by Boater Sam; 3rd Feb 2018 at 11:11 am. Reason: Added

3rd Feb 2018, 11:56 am	#3
Herald1360 Dekatron Join Date: Feb 2007 Location: Leominster, Herefordshire, UK. Posts: 16,536	Re: Capacitor puffage please Letters like J and M may refer to tolerances. Coloured blobs ditto, or ceramic type / tempco. Depends who made them. Little square ones sound like obsolete Mullard/Philips jobs. __________________ ....__________ ....\|____\|\|__\|__\_____ .=.\| _---\__\|__\|_---_\|. .........O..Chris....O

3rd Feb 2018, 11:59 am	#4
G8HQP Dave Rest in Peace Join Date: Sep 2008 Location: Solihull, West Midlands, UK. Posts: 4,872	Re: Capacitor puffage please If the "dot" on top is more like a hat then it probably indicates the ceramic type. Black would be NP0/C0G.

3rd Feb 2018, 12:34 pm	#5
short wave Pentode Join Date: Mar 2013 Location: Leeds, West Yorkshire, UK. Posts: 246	Re: Capacitor puffage please Capacitor tolerances found on the web Attached Thumbnails