Topband: Beverage transformer and testing

[Grant Saviers]

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 at 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 at gmail.com>
> To: "MR TREVOR DUNNE" <ei2glb at eircom.net>
> Cc: "topband" <topband at 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 at 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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