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Components and Circuits For discussions about component types, alternatives and availability, circuit configurations and modifications etc. Discussions here should be of a general nature and not about specific sets. |
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22nd Sep 2017, 1:18 pm | #1 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,554
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VDR colour codes
I have found that many VDRs use colour codes that vary quite a bit.
These ones look like it reads Top Dot Band using my own judgement based on the fact that that the early 1970s transistors close by will most likely be rated at 30 to 50 volts. Red white black being 28 would make it 28 volts. Is there a magic answer or are they like capacitors? |
22nd Sep 2017, 4:19 pm | #2 |
Dekatron
Join Date: Nov 2003
Location: Heckmondwike, West Yorkshire, UK.
Posts: 9,643
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Re: VDR colour codes
There's a chart here: https://frank.pocnet.net/other/Phili...CodeRC1966.pdf
It appears to be a Mullard document, other manufacturers may have had their own. |
22nd Sep 2017, 10:13 pm | #3 |
Nonode
Join Date: Dec 2012
Location: Kirk Michael, Isle of Man
Posts: 2,350
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Re: VDR colour codes
I think the colour code means a VDR with a specified turnover point. I have quite a few new ones and they cover a wide range of turnover voltages. There are tables of these in some of the little Mullard handbook of the 1970's. (There may be other mfgs than Mullard / Philips of course).
Les. |
23rd Sep 2017, 12:43 am | #4 |
Dekatron
Join Date: Apr 2012
Location: Worksop, Nottinghamshire, UK.
Posts: 5,554
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Re: VDR colour codes
It is certainly not a Mullard one as it has two bands and a dot. Also the "dip" is much more substantial.
The dot can be seen by one of the leads on the one that is not leaning over to hide it from the camera. |