I also use wire wrap wire. The Kynar insulation is designed to not cut
thru against a sharp corner wire wrap post, no need to insulate
ferrite. I use 26 or 30 gauge. Multi colors are fun and available in
small spools on ebay in both gauges. No messing with Xacto scraping off
the polyimide insulation on magnet wire is another big plus. A small
multi-gauge wire stripper is a good investment to prevent nicks. Hakko,
Klein, and Ideal make them, check Amazon.
Grant KZ1W
On 2/3/2018 15:36 PM, donovanf@starpower.net wrote:
I wind matching transformers for receiving antennas with 30 AWG
wire wrap wire. A BN73-202 binocular core will accept up to 18 full
turns (36 passes). The insulation is very tough and it will not short to
the ferrite core. The insulation is so tough that you'll need a wire
stripper intended for 30 AWG wire wrap wire.
https://www.adafruit.com/product/1446
26 AWG stranded wire from old telephone cables also works very
well, will not short to the ferrite core and is very easy to strip.
A BN73-202 binocular core will accept up to 14 turns.
73
Frank
W3LPL
----- Original Message -----
From: "Mike Waters" <mikewate@gmail.com>
To: "MR TREVOR DUNNE" <ei2glb@eircom.net>
Cc: "topband" <topband@contesting.com>
Sent: Friday, February 2, 2018 6:04:01 PM
Subject: Re: Topband: Beverage transformer and testing
The instructions are at
www.w0btu.com/Beverage_antennas.html
To test it, put a 450 ohm resistor on the high impedance winding and an
antenna analyzer on the low-Z.
And make sure there is infinite resistance between each winding and the
core, as 73 material is conductive.
73, Mike
www.w0btu.com
On Feb 2, 2018 9:59 AM, "MR TREVOR DUNNE" <ei2glb@eircom.net> wrote:
Hi I know it's probably been covered here hundreds of times but I'm looking
to make a matching Transformer for a 550ft beverage to 75 ohm coax,
I have so bn73-202 cores
Also how can I test it once it's built
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