The AM Forum

Since WA1GFZ brought Teflon coax up -

Stranded PVC insulated wire is the norm for chassis wiring and since the demise of good old double cotton coated wire, that is what is generally used.

But stranded Teflon is great and it lasts forever.

But for sheer speed and solder-ability, I like tinned solid #22 Teflon when I am wiring a chassis. I am lazy and tend to burn the insulation on PVC and stranded wire is pain to put through terminals.

Mike WU2D

I use Teflon for everything. Just came into a lifetime supply of Teflon twisted shielded pair and some double shielded. I like Teflon solid and sometimes I put Teflon tubing over solid wire. You can find spools of the stuff at flea markets and surplus joints so why not.  The only thing I don't use teflon on is high voltage when I switch over to Packard 440 wire. Teflon is only rated for around 500 volts unless you slide teflon tubing over it. It cold flows so you have to be careful with lacing and sharp bends. fc

Teflon is nice to work with but you have to becareful not to overheat it. It starts to decompose and release phosgene gas and that's not good :-\

Same here. I also have a lifetime supply of silver-plated teflon wire in numerous gauges and colors that I acquired a number of years ago when I worked in the defense electronics industry (surplus inventory), and from a fellow that sold a ton of it dirt-cheap to several of us local hams here on Long Island. I wire everything that I build with that wire; it's all that I ever use at this point. I also have two large reels of the teflon sleeving that's great for insulating the leads of resistors, capacitors, solid bus wire, etc., when doing point-to-point wiring.

Like Frank, when I cross over to the HV region, I use the Packard 440 cable, which you can get at most of the better-stocked auto parts stores.

73,

Bruce

Teflon wire is really cool.

It's one of the reasons the 1966-1968 R390A commands more money than earlier examples, because that's when the production line began using Teflon wire in the harnesses. 

After a few years of scuffing in and out of a rack, the Teflon tends to hold up better than the vinyl insulated stuff.

It seems like overkill, but I've used a lot of Teflon wire for antennas.  The insulation does not break down in sunlight and I can get years of life out of it. Much of the stuff you pick up at the hamfests is silver plated copper egads ! 

Makes my dipole have GAIN, caw maw.

Phosgene gas is generated well above the normal soldering temperature. It is important to fuse things so it won't burn if it has excessive current going through it. Kapton will also kill you if it burns.

i use either teflon sleeving or wire for everything, and every coax inside the house is either RGS 400 or RG142. Love how the silver teflon stuff solders, just so easy. greatest patch and interconnect coax evar, and you can get it so cheap on ebay from surplus pulls. I have 50 ft+ of patch cables with male bncs or female N's or bulkhead N's on them, like 22" length 5 pieces for 5 bucks.

Frank said:
Yeah, well while I was assigned to Unkle Sam's Yacht Club (USN), during my 2M class, the instructor made a point of telling us not to use resistive wire stripers on Teflon wire. Better not to even give it a chance of decomposition.

I agree mike. Smaller stuff I crush the end cut a split and peel it back like a banana so there are no nicked strands. My Dad showed me my first hunk of Teflon wire in the 60s. His only instruction was to never burn it.
I was working on a Navy TACAN test set once and the clown who wired the power outlet crossed a ground and 1 phase of 400 Hz. The internal #20 ground wire went up in smoke and cleared us right out.

Anyone remember Apollo 1?

A very sad, 100% preventable day.

klc

But was that tragedy really attributable to teflon wire or the lack thereof???

I think not.

If I recall correctly, the atmosphere in the Apollo 1 cabin was 100% oxygen, unlike the partial oxygen/nitrogen atmosphere utilized in the earlier Mercury and Gemini manned missions. The insulation used for the miles of wiring within the spacecraft was indeed teflon insulated. But due to poor workmanship and engineering-related issues, the integrity of the insulation was compromised in several places, resulting in an electrical arc. This, of course, spelled disaster in such a flamable environment.

Thousands of ECNs (engineering change notices) were issued by North American Aviation (the prime contractor for the Apollo spacecraft) and NASA to design out the pure oxygen atmosphere and improve the integrity of those wiring runs that were subject to chafing and other possible sources of abrasion, as well as the general fire safety of the spacecraft. Pressure suits and anything even remotely flammable were redesigned to employ flame-retardant materials. And the entrance/egress hatch was completely redesigned to allow rapid escape from the spacecraft in an emergency situation whilst it was still on the ground. The original design hatch required several minutes to open.

Yes, it was completely preventable, but the intense pressure of beating the Russians to the moon before the decade was out necessitated many cost and schedule-cutting measures.

73,

Bruce

  "  The insulation used for the miles of wiring within the spacecraft was indeed teflon insulated. But due to poor workmanship and engineering issues, the integrity of the insulation was compromised in several places, resulting in an electrical arc. "

Yes, there were several factors other than the teflon. I guess the phosgene gas comment triggered the memory.

.... Probably the real killer was the race with the Russians....

There is a small memorial on pad 34A. It's open via a tour.

klc