AWG?

[Hsnopi]

So I need to get some wire but now I'm confused. I know I need stranded wire. If I need 18 AWG wire, do they mean each strand is 18 AWG or the whole set of strands together is 18 AWG?
I'm trying to determine the AWG of this wire. It's a tad over 1mm with the jacket. I don't have a good micrometer. I think this is 20 AWG. When I put it in the stripper though, it looked more like 22 or 24.

 

[Tha fios agaibh]

Strands combined its equivalent to 18awg.

If you look on the outer jacket of the cable, it may be labeled 20-3 or something like that.

 

[Tha fios agaibh]

Post a pic of the end of the cable.
You may be able to just cut off the bad section of wire and resplice it.

 

[Hsnopi]

So it's a tad more complex than that. I'm rewiring H-161U headsets for a tank. I cut that wire myself to figure out the size. The strands without the shielding is a tad under .5mm.

I'll try to get a pic.

 

[Hsnopi]

 

[Tha fios agaibh]

 

[Tha fios agaibh]

diameter depends on the number of strands

 

[Tha fios agaibh]

Why do you care as long as the outer jacket has the same diameter?

If the internal conductor has a larger area and the insulation size is the same, that's a "win, win" to me.

Oh btw, look into whether that's tin coated copper or aluminum wire. Huge difference in the ampacity.

 

[Bluejets]

Also if you are considering soldering it at any stage .......

 

[Hsnopi]

So I guess more background info is needed. I'm fixing the commo system for a t-34 tank. However, this system is part of an AN-VIC-1. It has an AM-1780 internal com base. The headsets are from the early 80's or late 70's. They wires are all starting to fray and stuff. The system runs off 24V dc. I have a converter in the tank. The headsets are H-161U variants. I have schematics and such but th wiring is getting very old and frayed. In fact, one set was so bad I ended up replacing it with Cat5. That worked for a bit but it was far too stiff to endure in the tank attached to a headset. That is the reason I'm looking for the stranded wire. I know at low voltages the power specifics are important. I'm still learning. This was dropped in my lap.

Part of the issues is the breakaway connectors do not create solid connections. in addition, since the wiring covering is really crumbling I'm expecting shorts very soon here. We are a non profit all volunteer group so we have to pinch pennies.

I can post schematics, and have in other threads. Alas, there was no way to determine awg. The outer diameter of the jacket makes no difference to me. I have no idea if it has meaning. I do know I want it fire resistant as fire in a tank is what we call "bad". And I want the right awg because I don't want it to overheat. Replacement for this unit are all from that era. They are usually New In Box and such but the stuff is always just degraded simply due to time.

http://radionerds.com/images/a/ac/H-161_U.png

Radio nerds has been immensely helpful. I'm still deciphering the manual.

Thanks for all your help so far!

There re about 34 strands, if I counted right.

 

[KJ6EAD]

I see some copper color in that cut end. Measurement of the insulation diameter is not particularly useful in determining wire gauge but in this case I agree with Tha fios agaibh that it probably isn't critical in this application. You can get a good approximation of the gauge by stripping, twisting to match original twist and measuring the diameter at two or three places, then averaging the readings.

The modern equivalent, unless there's a shielded strand or two somewhere in there for a microphone, would be rubber insulated service cord such as SJEOW.

 

[Hsnopi]

thanks In the twists I've measured, the strands are just under .5 mm. I'd say .4mm. As to the wire. It's all silver colored. I tries scratching it and it's still silver.

 

[Bluejets]

Have no idea what a "commo system" is or for that matter the other reference numbers but in any mobile system such as cars, trucks (and tanks) the objective would be to use flexible cabling. Fire resistant cabling, just in the context alone, will be hard to find, expensive(very) and difficult to work with. Stay away from plastic insulation. Go for beutal rubber or silicon, still expensive but no where near that of fire retarded. I don't understand when you say you cannot measure the existing cabling however the norm would be to get a guage as close to or slightly larger than existing. Voltage drop in low voltage cabling is one source of fire along with chaffing and poor connections. Solder what you can but avoid any stiff joints that need to flex. Eg....leave flexing tails where possible and secure the outer sheath. If you can get cable with a thicker insulation then use it. It is there not only for electrical properties but also mechanical protection.

 

[Gryd3]

@Hsnopi
Things to consider... The AWG of a solid core wire will have a smaller diameter than stranded wires.
Stranded wire varies slightly in diameter... but when I say slightly, I mean you will most likely not run into a condition where this is important.
Please also note that the Cat.5 cable you used is also available in stranded.

Solid core is used in places where the wires are fixed and will not move, stranded are used for mobile connections. IE, handsets and headsets. Stranded Cat.5 for example is sold to consumers more often than not for their desktops and laptops where solid core is bought by contractors and electricians for wiring homes with.

Additionally, if you have schematics, you may be able to swap out the wire for an electrically equal or better version if you know what to expect when it comes to the amperage. There is no harm putting in more capable wiring. If you are wanting to make some 'upgrades', you could swap out many of the parts with easily accessible and replaceable parts so if something breaks later on, you can go buy a new cord from a local best-buy or something and simply plug it in.
If you are wanting to stay closer to 'stock' this will require attention to detail, and I wish you luck. If you have more questions just ask.