Question? I need to replace the wiring from the eye down, the speaker wire and the wire to the WaveMagnet. Would you use the cloth or plastic and does the color matter? It's a 1940 Zenith with cloth right now.

Thanks, Andy

Hi Andy

Neither color or wire insulation type matters. Plastic covered wire is less expensive. Nice to keep wiring original but color may be hard to determine.

You can find schematics here:

http://www.nostalgiaair.org/Resources/458/T0000458.htm

If you're going thru the effort you might as well attempt to use wire that matches the original. May cost a few dollars more.

As you may have already noted, the original eye tube and wave magnet wiring was rubber insulated. This wire would be hard to find an exact replacement for. The original stuff is usually falling apart after years of deterioration. Modern stranded wire of equal gauge and thermoplastic insulation is a good substitute.

Original speaker wiring is usually cloth insulated. and is tougher to find a replacement for. If you are not a stickler for originality, any stranded wire of equal gauge will do the job just fine. If you want to stay original, there are suppliers of the cloth insulated wire that can be had - at a price.

depends on what you are after. what matters to you. if you have available multi color wire spools then by all means use distinctive colors. if you are looking for museum quality craft then go for replacement replication. if you want to fix it use black stranded or solid core wire. both work equally well. solid core is easier to solder to conectors

Just avoid the 600 volt rated wire sold by Radio Daze and Antique Electronic Supply - it is TOO LARGE and not suitable for radio work. I recommend the NON RATED wire, stranded or solid, available in 8 colors. Speaker wiring would have been stranded, originally. Eye tube could have been either solid or stranded. For the speaker, if the original colors were not obvious, I would use RED (B+), BLUE (output plate), Yellow and black for the field coil.

The problem with a lot of foreign made wire is that when soldered, the insulation shrinks back exposing the bare wire. Due to poor materials used, it kind of acts like heat shrink tubing. To avoid this problem, you can shop at military surplus stores (in person or mail order) and buy a piece of junk or an actual wiring harness. Good quality mil-spec wire is pretty easy to find since miles of it are run through aircraft bodies. Since the typical radio only requires less then 3' of hookup wire, it's not all that expensive. I recommend 22 or 24 gauge.

http://www.skycraftsurplus.com/milspechookupwire.aspx

Thanks for the great replies! Since this radio will grace my home office I think the multi-colored plastic will work. I have no intention on selling the radio and my kids can handle it after I'm gone.
Reading the Forums I've noticed that wire size seems to be an issue with some? Some say 22/24 gauge is fine....some say they wouldn't use anything smaller than 20. I think the 20/22/24 will will work for what I'm going to do.

Thanks again,

Andy

Remember that most (possibly all) of the wires in the speaker harness will be carrying full B+ voltage.

Thanks JS,

So, 20 can carry about 11 amps...is that going to be a problem?

Thanks

B+ current won't be more than about 100 milliamps. Its not so much the current capability. One, you want a wire which is flexible (stranded) and won't break so easily since harnesses do get moved around. Second, you want decent insulation. Plastic or cloth is immaterial for other than aesthetics but you want the insulation to be robust enough with withstand nicks and pinches. That's why I mentioned its carrying full B+. You might not see a little nick but you'll sure feel it!

My preference would be the #20 stranded, unrated, cloth type from RDaze. Fits all the criteria and looks good too!

Its more an issue of insulation quality and safety at the higher voltages, rather than current carrying ability of the wire.

Typical speaker wiring will rarely exceed 100 mA in normal operation.

Ok....understood...and thanks to all again.

Andy

I've been saving all the old wax capacitors and wiring from a variety of RCA chassis. I save the wire to make splice coils and the old caps for the bees wax. Most of the wire is covered with a yellow rubber insulation that dries out, crumbles, and falls away from the wire when moved or touched. This wire was used for just about everything from filaments to RF and is measuring number 23 on my wire gauge. Sometimes, they measure #22 but most of the time #23. If we use #22 as an example, it has a resistance of 22 ohms per 1,000 feet with a current capacity of 7A. Since the longest wire on a point-to-point chassis is six inches or less, the voltage drop across that wire is going to be miniscule. I think you'll find that ROHS compliant wire has a voltage rating of 600V.

IMO #24 is a little small #20 is on the large side #22 is just right

Many of the original wire size choices in radio sets were not based on current carrying requirements, but rather on other criteria like mechanical wear resistance and general durability. You see this in areas external to the chassis like speaker wiring, eye tubes, external power supply wire harness, and antenna loops and anywhere the wiring might catch a little more abuse.

Well that's the key word, abuse. Father time being the main abuser.
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