Re: Topband: Fw: RX antenna transformer winding(pureresistancetransformation issues)

["Bill Aycock" <billaycock@centurytel.net>]

Carl--
Earlier, you claimed that Tom had taken apposing sides on the turns spacing 
question, and, at his request, furnished a quote of his for reference. That 
was the base for my post, not any tests you had done.
Bill--W4BSG

-----Original Message----- 
From: ZR
Sent: Wednesday, August 21, 2013 10:52 AM
To: Bill Aycock ; topband@contesting.com
Subject: Re: Topband: Fw: RX antenna transformer 
winding(pureresistancetransformation issues)
I dont understand your question Bill.

My tests were with maximum common mode reduction on the feedline prior to
starting the process. Common mode isnt a factor in that case and the
improvements gained by reducing interwinding C can be seen especially with
increasing frequency.

Carl
KM1H


----- Original Message ----- 
From: "Bill Aycock" <billaycock@centurytel.net>
To: <topband@contesting.com>
Sent: Wednesday, August 21, 2013 10:38 AM
Subject: Topband: Fw: RX antenna transformer
winding(pureresistancetransformation issues)


> -----Original Message----- 
> From: Bill Aycock
> Sent: Wednesday, August 21, 2013 9:37 AM
> To: ZR
> Subject: Re: Topband: RX antenna transformer winding 
> (pureresistancetransformation issues)
> ZR-- Don't those two statements say the same thing? ie, with high common
> mode impedance, spacing can count.
> Bill--W4BSG
>
> -----Original Message----- 
> From: ZR
> Sent: Tuesday, August 20, 2013 4:49 PM
> To: Tom W8JI ; topband
> Subject: Re: Topband: RX antenna transformer winding
> (pureresistancetransformation issues)
>
>
> ----- Original Message ----- 
> From: "Tom W8JI" <w8ji@w8ji.com>
> To: "topband" <topband@contesting.com>
> Sent: Tuesday, August 20, 2013 4:00 PM
> Subject: Re: Topband: RX antenna transformer winding (pure
> resistancetransformation issues)
>
> <SNIP>
>
>
> Unless you have a system with pretty high common mode impedances, winding
> spacing means nothing.
>
> ** Contrary to what you have stated elsewhere
>
>
> The primary reason I (and DXE) isolate windings with
> Teflon tubes is to reduce lighting damage, and to greatly reduce assembly
> damage. If the system has pretty high common mode impedances there might 
> be
> some small advantage in pushing windings apart, but the primary-secondary
> capacitance is never going to be important in Beverages or other low or
> modest common mode impedance antennas. Balancing a small loop might be an
> issue.
>
> ** Common mode is an overworked response for perceived ailments.
> I took your low capacitance suggestions a step further after carefully
> measuring C and frequency response for maintaining high directivity and 
> F/B.
> Many Topband operators use their Beverages above 2 MHz.
>
>
> I started using Teflon sleeves in windings because I ran out of small 
> Teflon
> wire wrap wire I was using. Without Teflon on the wires, and with normal 
> mag
> wire, the enamel was easily scratched. Not only that, lightning would 
> punch
> through from enamel to core, or from wire to wire.
>
> ** Telon is easily nicked, the type of wire used in modern vehicles is 
> very
> robust but with the sleeves plain ole magnet wire works well and allows 
> even
> smaller winding bundles.
> Since I was more interested in performance rather than production problems 
> I
> took the time to evaluate a large number of variations.
>
> Carl
> KM1H
>
>
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