Topband: Beverage Question

[Herbert Schoenbohm]

Jim, The DXE boxes are designed for 450 ohm ladder line which has a much 
higher impedance than WD1-A wire.  Using the DXE boxes may work but 
Gary's boxes (KD9SV) will work better as they are designed for the 100 
ohm impedance of WD-1A.  I also understand that DXE may now sell the 
boxes designed for WD-1.

Herb Schoenbohm, KV4FZ
On 9/20/2014 10:06 AM, Jim Garland wrote:
> I want to replace the 450 ohm ladder line for my two DXE 720 ft long
> bi-directional beverages with two lengths of WD-1/TT field telephone wire.
> The wires will be secured only at the ends, but will be suported along their
> length by ceramic insulators mounted on 4x4 posts spaced every 60 ft.  The
> spacing between the parallel wires will be about six inches. Here are my
> quesetions: First, does anybody know what the likely impedance is of this
> configuration, or if not, how to measure it?  Second, if I keep the DxE
> matching trnsformers used with the 450 ohm ladder line, will beverage
> performance be degraded noticeably with the new wures if, say, the impedance
> of the new line turns out to be 600 ohms or so? In other words, as a
> practical matter how important to performance (e.g., F/B ratio and
> low-noise) is it to make sure impedances are matched.
>
>   
>
> Finally, a mechanical question. I want to have a pulley at one end of the
> parallel wires to equalize the tension in the wires. I've not been able to
> find a good pulley with a five or six inch diameter, except for nylon
> pulleys used for clotheslines. Do you think one of these could be used.
> There will be no motion of the pulley, since it is only used to equalize
> tension. The field telephone wire is rated at 200 lbs maximum tension, and
> I'm guessing the actual tension will be about half that.
>
>   
>
> Thanks!
>
> Jim W8ZR
>
> _________________
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