Re: Topband: transformers, teflon tubing

[P H via Topband]

Thank you, Gentlemen
Piotr, SP2BPD
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Re: Topband: transformers, teflon tubing

[JC]

Hi Piotr

Yes, the WF load the tower and if you use the same tower to transmits, like
I do,  the voltage can me over 10KV. Also the transformer and resistor
should stand 900 joules or 1 KW for one second, 100 for 10 seconds, you font
want to burn the phasing system, and replaced it any time you have a
thunderstorm nearby.

The logistic to get the antenna at the tower most of the time  cost more
than the antenna itself, repeating the installation several times a year is
not a good idea.

Regards
JC


 

-Original Message-
From: Topband [mailto:topband-boun...@contesting.com] On Behalf Of P H via
Topband
Sent: Friday, April 28, 2017 9:14 AM
To: topband@contesting.com
Subject: Topband: transformers, teflon tubing

I've noticed use of teflon tubing in a Flag family transformers.
Apart from low losses: is there another reason to use teflon coated wires?
Regards
Piotr, SP2BPD
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Re: Topband: transformers, teflon tubing

[Mike Waters]

73 material is conductive. The holes are lined with insulation to prevent
the enamel coating on magnet wire from scraping off and shorting to the
core as it is being pulled through the holes.

Also, it is easier to get more turns in a winding using Teflon wire vs.
some other types. The latest edition of Low Band Dxing by ON4UN goes into
more detail about this.

73, Mike
www.w0btu.com

On Apr 28, 2017 8:14 AM, "P H via Topband"  wrote:

I've noticed use of teflon tubing in a Flag family transformers.
Apart from low losses: is there another reason to use teflon coated wires?
_
Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: transformers, teflon tubing

[Tim Shoppa]

Enamel-insulated magnet wire easily gets knicked going around the sharp
corners of a core. Although the core isn't very ohmically conductive, a
knick at a corner is enough to affect the operation of the transformer.

I think the old Clifton Laboratories page had a little section of
measurements of transformer degradation caused by these knicks on corners?
Not accessible anymore.

One way of avoiding knicks, is to use Teflon tubing over the enamel (or
bare) wire.

But there's a better solution: Kynar wire wrap wire doesn't require the
second overtube.

I use Kynar wire-wrap wire from decades past. I think Kynar is just a type
of Teflon.

It's a PITA to strip Teflon wire ends without proper equipment. With the
wire wrap wire, every cheap wire wrap tool has a decent stripper.

Lots and lots of 30AWG Kynar is available both new and surplus. It's
commonly available in lots of nice colors to help you figure out which end
is which winding. The silver plating makes it a joy to solder to.

The 30AWG stuff is obviously too skinny for a transmitter winding but works
fine for receiver antennas. For transmitter transformers, teflon over
thicker copper wire works very nicely and is easy to wind and doesn't melt.

Tim N3QE

On Fri, Apr 28, 2017 at 9:14 AM, P H via Topband 
wrote:

> I've noticed use of teflon tubing in a Flag family transformers.
> Apart from low losses: is there another reason to use teflon coated wires?
> Regards
> Piotr, SP2BPD
> _
> Topband Reflector Archives - http://www.contesting.com/_topband
>
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Topband Reflector Archives - http://www.contesting.com/_topband

Re: Topband: transformers, teflon tubing

[Augie "Gus" Hansen]

Minimize inter-winding capacitance.

73,
Gus Hansen
KB0YH


On 4/28/2017 7:14 AM, P H via Topband wrote:

I've noticed use of teflon tubing in a Flag family transformers.
Apart from low losses: is there another reason to use teflon coated wires?
Regards
Piotr, SP2BPD
_
Topband Reflector Archives - http://www.contesting.com/_topband



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Topband Reflector Archives - http://www.contesting.com/_topband