[Amps] L4-B

[Mark Bitterlich]

I believe you Bryan.

That said:

The biggest problem it had was wicking up hydrocarbons, which are not 
usually found in the ham shack, or a OEM RF-driven Sealed Laser facility. 
:-)    In any case, the various oils, or fuel, would wick up the wire and 
then through some magic of chemistry turn into carbon.  The carbon would 
eventually start to conduct, get very hot very quickly and then would 
vaporize the whole wire.

Tests were done (and filmed) showing the results of one Kapton wire 
shorting, and how it caused others in the wire bundle to also go up in smoke 
and catch fire.  It worked just fine until the outer insulation became 
cracked and contamination creeped in, or it was damaged from a physical hit, 
say from a bullet ... which is what the film tests documented.

The stuff may be very tough, but it was so freaking dangerous that NAVAIR 
spent tons of money to have whole circuit breaker panels and wiring bundles 
replaced, after Kapton wiring was attributed to several in-flight fires. 
I personally had some of it carrying 3 phase 115 VAC  blow up in my face.

Feel free to use it anyway you like.  I would not put it into anything I own 
even if I was given it for free... which by the way,  I was.

And yep... really.  Sorry if this conflicts with your experience, but what I 
am telling you is factual.

Take care,

Mark Bitterlich
WA3JPY


----- Original Message ----- 
From: "Bryan Swadener" <bswadener at yahoo.com>
To: <amps at contesting.com>; "Mark Bitterlich" <markbitterlich at embarqmail.com>
Sent: Monday, March 31, 2014 7:33 PM
Subject: Re: [Amps] L4-B


Yes, really.

We used it for decades, in both tape form and Kapton-insulated
wire form, in critical applications at the world's largest OEM
of RF-driven sealed CO2 Lasers.

The stuff is VERY tough.  The only way we found to remove
the insulation from wire ends was by blasting it with one of our
more powerful (> 100W) Lasers or, by mechanically scraping it off.

vy 73,
Bryan WA7PRC
--------------------------------------------
On Mon, 3/31/14, Mark Bitterlich wrote:

 Subject: Re: [Amps] L4-B
 To: Bryan WA7PRC, amps at contesting.com
 Date: Monday, March 31, 2014, 4:26 PM

 Really? Interesting.
 Just FYI, Kapton insulated wire was removed from ALL
 military aircraft after some very impressive tests were done
 showing how it
 tended to blow and burn under certain conditions. Of
 course, that was the
 Kapton insulated wire. I know zip, nada, ZERO about
 the tape. Possibly it
 is A-OK.

 v/r,

 Mark Bitterlich
 WA3JPY


 ----- Original Message ----- 
 From: Bryan WA7PRC
 To: <amps at contesting.com>
 Sent: Monday, March 31, 2014 7:18 PM
 Subject: Re: [Amps] L4-B


 > Also, Kapton(tm) aka polyimide tape will work FB.
 > It works well at high temperature and high voltage.
 >
 > vy 73,
 > Bryan WA7PRC
 > --------------------------------------------
 >
 >
 > Date: Sun, 30 Mar 2014 23:07:13 -0500
 > From: Edwin Karl
 > To: amps at contesting.com
 > Subject: [Amps] L4-B
 >
 > Just be very careful with the power resistors used in
 the
 > bias cutoff/
 > bleeder
 > They are mounted on long screws that run through the
 center
 > of the
 > resistor. In
 > repairing an amplifier for a buddy, I had the
 resistors
 > short through the
 > porcelain of the resistor.
 >
 > The fix is use good 3m glass tape to insulate the
 screw, and
 > enough on
 > the ends to insure centering the resistors. Unlike
 > electrical tape,
 > glass tape
 > is rated at 240 degrees and will withstand the high
 heat.
 > Make sure to
 > reinstall
 > the mica insulators.
 >
 > Good Luck!
 > We're all counting on you ...
 >
 > 73
 >
 > Ed K0Kl