Colour Coding of Vintage Ceramics - UK Vintage Radio Repair and Restoration Discussion Forum

Bazz4CQJ · 10th Mar 2023, 6:43 pm

Back in the ‘60’s, there were small tubular ceramic capacitors around with various temperature coefficients. I think we are talking about values of 1-100pf and they were great for getting thermal stability in RF oscillators. They were coded with 4 or 5 colour spots, giving the capacitance and the tempco.

Does anyone have a record of how the colour coding worked?

I recall buying them from some part of ITT, and still have quantity of them but no tech info at all.

Thanks
B

Cobaltblue · 10th Mar 2023, 6:50 pm

Colour code here:

https://www.eevblog.com/forum/projec...%28dogbone%29/

Cheers

Mike T

Bazz4CQJ · 10th Mar 2023, 7:29 pm

Thanks for that Mike, but the link just comes back with Error 404, Page not Found, at least on my PC.

I've found various colour coding systems on the web, but all of them for modern film caps.

B

dazzlevision · 10th Mar 2023, 7:36 pm

Here are pages from an old Erie Electronics Ltd catalogues (1972 on). Erie UK was later absorbed into ITT Components Group Europe.

Bazz4CQJ · 10th Mar 2023, 8:22 pm

Many thanks for that info guys. A while ago there was discussion on the forum about drift on the Codar AT5 and its look-alikes. If I ever get around to building my AT5 clone, these are the sorts of components that could be very useful in dealing with that problem.

Just a guess, but I suspect nobody makes anything like this now?

B

CambridgeWorks · 10th Mar 2023, 8:50 pm

Mike's link, post #2 works fine for me using my google account android tablet.
Rob

Bazz4CQJ · 10th Mar 2023, 9:37 pm

Mike's link to EEV worked, but it was the link on EEV to the data that I could not open. I'm using Chrome

and I must make more effort to get back to Firefox!

B

Ed_Dinning · 10th Mar 2023, 10:29 pm

Hi Folks, If anyone has a copy of the ITT/STC big yellow book from that era, it is packed in its 1000+ pages with all sorts of colourcodes andcomponent and connector data from that era.

I wonder if there is an upload of it anywhere?

Ed

Bazz4CQJ · 10th Mar 2023, 10:44 pm

Sorry Ed, that's a new one on me.

B

Ed_Dinning · 10th Mar 2023, 10:52 pm

Sometimes seen at rallies etc in boxes of books approx A4 size and the size of a family bible. I'll see if I can post a pic when I get home

Ed

factory · 11th Mar 2023, 2:47 pm

From the Tektronix 214 manual, it doesn't have Temp Co. in the table, but mentions both Tolerance & Temp Co. colour markings vary by manufacturer, capacitor type and might not be present.

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David

Bazz4CQJ · 11th Mar 2023, 3:38 pm

Thanks David.
B

10th Mar 2023, 6:43 pm	#1
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Colour Coding of Vintage Ceramics Back in the ‘60’s, there were small tubular ceramic capacitors around with various temperature coefficients. I think we are talking about values of 1-100pf and they were great for getting thermal stability in RF oscillators. They were coded with 4 or 5 colour spots, giving the capacitance and the tempco. Does anyone have a record of how the colour coding worked? I recall buying them from some part of ITT, and still have quantity of them but no tech info at all. Thanks B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.

10th Mar 2023, 7:29 pm	#3
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Colour Coding of Vintage Ceramics Thanks for that Mike, but the link just comes back with Error 404, Page not Found, at least on my PC. I've found various colour coding systems on the web, but all of them for modern film caps. B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.

10th Mar 2023, 8:22 pm	#5
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Colour Coding of Vintage Ceramics Many thanks for that info guys. A while ago there was discussion on the forum about drift on the Codar AT5 and its look-alikes. If I ever get around to building my AT5 clone, these are the sorts of components that could be very useful in dealing with that problem. Just a guess, but I suspect nobody makes anything like this now? B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.

10th Mar 2023, 8:50 pm	#6
CambridgeWorks Nonode Join Date: Jun 2010 Location: Spalding, Peterborough, Cambridgeshire, UK. Posts: 2,858	Re: Colour Coding of Vintage Ceramics Mike's link, post #2 works fine for me using my google account android tablet. Rob __________________ Apprehension creeping like a tube train up your spine - Cymbaline. Film More soundtrack - Pink Floyd

10th Mar 2023, 9:37 pm	#7
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Colour Coding of Vintage Ceramics Mike's link to EEV worked, but it was the link on EEV to the data that I could not open. I'm using Chrome and I must make more effort to get back to Firefox! B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.

10th Mar 2023, 6:50 pm	#2
Cobaltblue Moderator Join Date: Dec 2010 Location: Exeter, Devon and Poole, Dorset UK. Posts: 6,857	Re: Colour Coding of Vintage Ceramics Colour code here: https://www.eevblog.com/forum/projec...%28dogbone%29/ Cheers Mike T Attached Thumbnails __________________ Invisible airwaves crackle with life or at least they used to Mike T BVWS member. www.cossor.co.uk

10th Mar 2023, 10:29 pm	#8
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: Colour Coding of Vintage Ceramics Hi Folks, If anyone has a copy of the ITT/STC big yellow book from that era, it is packed in its 1000+ pages with all sorts of colourcodes andcomponent and connector data from that era. I wonder if there is an upload of it anywhere? Ed

10th Mar 2023, 10:44 pm	#9
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Colour Coding of Vintage Ceramics Sorry Ed, that's a new one on me. B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.

10th Mar 2023, 10:52 pm	#10
Ed_Dinning Dekatron Join Date: Jan 2004 Location: Newcastle upon Tyne, Tyne & Wear, UK. Posts: 8,194	Re: Colour Coding of Vintage Ceramics Sometimes seen at rallies etc in boxes of books approx A4 size and the size of a family bible. I'll see if I can post a pic when I get home Ed

11th Mar 2023, 2:47 pm	#11
factory Octode Join Date: Jul 2009 Location: Cheshire, UK. Posts: 1,732	Re: Colour Coding of Vintage Ceramics From the Tektronix 214 manual, it doesn't have Temp Co. in the table, but mentions both Tolerance & Temp Co. colour markings vary by manufacturer, capacitor type and might not be present. David Last edited by factory; 11th Mar 2023 at 2:53 pm.

11th Mar 2023, 3:38 pm	#12
Bazz4CQJ Dekatron Join Date: Apr 2009 Location: Oxfordshire, UK. Posts: 4,934	Re: Colour Coding of Vintage Ceramics Thanks David. B __________________ Saturn V had 6 million pounds of fuel. It would take thirty thousand strong men to lift it an inch.