VDR colour codes

[Refugee]

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?

[Murphyv310]

Hi Ref.
I've lots of old VDRs and no data. Could be handy if there was some cut and dried way of deciphering what they are.

[pwdrive]

Mullard ones are in their data book:

https://archive.org/stream/MullardBook3P...1/mode/2up

Lawrence.

[Refugee]

The Mullard ones are three bands and are less confusing.
Mine look like top dot band. In the first photo in post #1 the dot can be seen on one of them where the lead goes in but the other is leaning over hiding the dot.

[Murphyv310]

I've some of the same as yours Ref. Also got mullard ones and other obscure ones in seme packets that have lost some of the print.

[Refugee]

I have got some black ones that were used to go across a 24 volt coil to stop it radiating into some digital stuff close by..
I could connect one in series with a 10K resistor across the scope and see what it clips at with the resistor fed by an isolated Variac.