Rewiring valve radio - colours

[JacKam_]

Originally almost all wires in my CR100 were red rubber coated 6x0.25 and 14x0.2 .

I am going to use silicone insulated flex 16x0.2 . It is available in different colours and I am wondering if there is any standard, anyway I am planning to use:

red - for power and anodes
purple or yellow - valve heaters +
green - to chassis
black - cathodes, bias and to the 24 100nf caps
orange - for >60V signals
blue - low voltage signals
white - other

(with exception that colours will be the same as in manual, if specified.)

Does that make sense or should I change anything?

[G6Tanuki]

There's no 'official' standard.

If it was being rebuilt by a Navy workshop or MoD contractor any time after about 1960 they'd use pink PTFE-insulated wire throughout, with coloured/numbered sleeves on the end of each wire to identify function and location.

[The PTFE insulation was because old-style PVC insulation gives off corrosive/toxic fumes if it overheats/burns].

[Silicon]

Eddystone radios had a preferred colour scheme and possibly HMV.

Have you searched this website for previous posts?

[ukcol]

Originally Posted by Silicon

Eddystone radios had a preferred colour scheme and possibly HMV.

There is a thread about HMV colours that I started back in 2003 here.

they'd use pink PTFE-insulated wire

I think it was (is) ETFE or crosslinked polyester, a half way house twixt PTFE and polythene, a bit like super tough PVC, nice to use.

[JacKam_]

Thank you all, Apologize for not digging hard enough, but hope it was a good knowledge refresh for all restorers.

I think that the thread can be closed.

[frankmcvey]

Here's the ARRL standard:

BLA - grounds, grounded elements, returns
BRO - heaters/filaments, off ground
RED - power supply B+
ORA - screen grids (and base 2 of transistors)
YEL - cathodes (and transistor emitters)
GRN - control grids, diode plates (and base 1 of transistors)
BLU - plates (and transistor collectors)
VIO - power supply, minus leads
GRA - AC power line leads
WHI - bias supply, B or C minus, AGC

Certainly I've seen many amps using a brown twisted pair for heaters.

I expect your soldering and cable routing will be a lot more important than the colours! Good luck with it.

Cheers,

Frank

[G6Tanuki]

Originally Posted by merlinmaxwell

I think it was (is) ETFE or crosslinked polyester, a half way house twixt PTFE and polythene, a bit like super tough PVC, nice to use.

Was that the pink stuff or the earlier clear-jacketed version [as shown below - part of the chassis of my ST&C R4187 receiver, dated October '57].

Either way, if I was rebuilding a CR100 with the emphasis on function and future usable-life over mere appearance, I'd have no ethical issues in using PTFE/ETFE wire, because that's what they'd have used in Navy [and Marconi] workshops from the late-1950s onwards.

I've seen at least one early-1960s rebuilt-by-REME AR88D with pink wire!

[Oldcodger]

Originally Posted by G6Tanuki

If it was being rebuilt by a Navy workshop or MoD contractor any time after about 1960 they'd use pink PTFE-insulated wire throughout, with coloured/numbered sleeves on the end of each wire to identify function and location.

[The PTFE insulation was because old-style PVC insulation gives off corrosive/toxic fumes if it overheats/burns].

Bit O/T, but on subject of fumes. Unless memory is playing tricks, in the late 60's there was a warning about PTFE "Fume "disease. Nothing nasty, but inhaling the fumes excessively when soldering PTFE coated wire could give rise to cold like symtoms etc.

[Skywave]

With the exception of A.C. power wires, the coding that Frank has specified in post #7 is the one I use when wiring - or rewiring - equipment.

Al.

[joebog1]

I also follow Frank's standard. The ARRL handbook is easy to get in Aust.
RSGB handbook is like hens teeth!!

Joe

[Skywave]

Originally Posted by joebog1

RSGB handbook is like hens teeth!!

And, IMHO, you are far better off without them. They tend to have many errors, editorial and technical. The ARRL publications are a lot better!

Al.

[joebog1]

I speak and write poorly!!! as you have pointed out! ( previously)
Somehow I understand the English method better

English presentation and diagrams are far better than those US derived.
Howard W Sams is an example!! MANY thousands of circuit diagrams available,
BUT parts listed as "For 6L6 PP ", doesnt even mean much to me !!

Coils are "mostly" hand wound in RSGB handbooks, making it "easy" to copy. American publications listing a coil/transformer/IF, as BA2846429862598261 isnt useful!! PLUS if I can buy it from Eblech, its $1000 plus the cost of the origional part.

I must be getting old :-(

Best regards to all
Joe