Wiring Color Code

[PRR]

Wiring Color Code, Popular Electronics, July 1958

[G._Hoffman]

Well, I've never seen that before, but I have always tried to color code my wiring.


Gabriel

[DummyLoad]

i use blue for cathodes, white for signal, green for heaters, violet for neg. bias.


--pete

[jjasilli]

Great! Just tacked that over my workbench.

[PRR]

> i use blue for...

There WAS a semi-standard, not everybody followed it, and the whole wiring racket collapsed in the 1960s when PCBs and ribbon-cable took over.

But we do see wiring errors in our builds (who put that wire there!?). The mental discipline of using a color-code, and the colors themselves, might reduce some errors. Since nobody remembers the RETMA code, you can make-up your own. But if you haven't, then stealing RETMA/EIA's code is kosher.

Green for grids seems right to me. Black for grounds... well, green makes sense but there's a lot more ground wires than grids, black may be cheaper in bulk, black fades into the back-ground, green looks more important.

I would adapt "White = AVC" to be negative bias supply for power tube grids.

But Violet is free and could be bias-supply. Specially if you have other odd negative lines.

Wall-power wires today are "usually" black, not gray. But these should be well segregated from other wires, so that should not be confusing.

[sluckey]

Using a color code scheme makes it easier to trace stuff in true PTP wiring. The colors just kinda lead your eyes in the right direction if you are familiar with the code. Here's an example of that color code in action. See if it doesn't make it easier for you to follow the circuit...

http://home.comcast.net/~seluckey/amps/PeeWee/B_big_bottom.jpg

I try to follow the code but I also like PTFE wire and I don't have all the colors in the gauges that I would need to stay 100% true. I do try to use red, black, blue, green, and yellow consistently and it does make it easier to identify circuits, especially tube pins. I don't have brown but my tube filaments are easy to identify regardless of which color I use.

[terminalgs]

I'll also add a black stripe to color wire to distinguish it from other similarly colored wires.  I do it by dragging a sharpie along an out stretched wire.  Its not often I do it, but sometimes it helps when I've run out of different color wires..

[jojokeo]

This is interesting and always good to know info - even if I don't use it on my own stuff. Could definitely help on troubleshooting something.

For me, I use what I have in stock and don't get overly concerned on the colors as much as being consistent for that particular amp. ie - all B+ will be a certain color, all cathodes their color, etc...

[HotBluePlates]

But Violet is free and could be bias-supply. Specially if you have other odd negative lines.

Marshall often use violet for the negative feedback wire from the speaker jack back to the circuit board. Seems like a good option for that wire (which you might want to call out to dress away from certain other wires).

[jojokeo]

But Violet is free

but Violet gives willingly... (the way I was taught to remember the last part of the color code acronym)

[jojokeo]

Is there a "standard" color code for transformer wiring that is used? Or is like pickup manufacturers and it's all over the place? It seems that power trans are consistent but output trans are not?

[PRR]

There is an old-old standard for simple OTs such as used in radios.

When you get to more than 4 or 5 wires, anything goes.... the winder follows the designer's blueprint.