Topband: Beverage Question

[Herbert Schoenbohm]

No my mistake as the spacing of the two parallel conductors would 
determine the impedance but  the mismatch from 600 ohms to 450 would 
also not be good.  It wold be easier to get working IMHO with a single 
run of WD-1a and the proper feed and termination transformers.  Perhaps 
Gary KD9SV would give you the winding ratio for a home built ferrite box 
of your own. In this case it is the same principle but only a turns 
ratio that counts.

Herb
On 9/20/2014 11:04 AM, MU 4CX250B wrote:
>> Thanks for the info and suggestions, Herb. One additional question,
>> however. Are you certain the 100 ohm impedance of the WD – 1 pertains
>> to two parallel links of the wire, with 6 inch spacing? I know that
>> open wire feeders with 6 inch spacing typically have about 600 ohms of
>> impedance.
>> 73,
>> Jim W8ZiR
>>
>> Sent from my iPad
>>
>>> On Sep 20, 2014, at 8:34 AM, Herbert Schoenbohm <herbert.schoenbohm at gmail.com> wrote:
>>>
>>> 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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