That would be the right ballpark. 3 paralleled strands of 29 AWG copper
running for 400m would be 36 ohms. 3 paralleled strands of 30 AWG copper
running for 400M would be 45 ohms. (Usually when I do these calculations
for traction power networks we are paralleling multiple 600 or 1000kcmil
cables!!!)
I would not worry too much about 40 ohms resistance in a 600 ohm impedance
antenna that already has an intentional terminating resistance at the end.
Although I've never modeled what happens when the resistance is somewhat
distributed instead of lumped at the end, probably some loss in directivity.
Tim N3QE
On Wed, Dec 3, 2014 at 12:08 PM, Martin <dm4im@t-online.de> wrote:
> Each strand is 0.27mm ( abt. AWG 29-30 or 0.0100 - 0.0113 inch).
>
>
>
> Am 03.12.2014 um 17:19 schrieb Tim Shoppa:
>
>> 400M of 19 gauge carbon steel wire (1.4e-7 ohm*m) is almost exactly 25
>> ohms.
>>
>> For some reason I have stuck in my head that some variety of phone wire
>> has a 19 gauge steel support strand. I would be surprised if it had more
>> than one steel support strand. If you can measure the wire diameters of
>> the various strands that could be interesting.
>>
>> Tim N3QE
>>
>> On Wed, Dec 3, 2014 at 8:24 AM, Martin <dm4im@t-online.de
>> <mailto:dm4im@t-online.de>> wrote:
>>
>> Topbanders,
>> i have a spool of twisted wire for military field telephone use,
>> similar to WD1-A . It has some strands of copper and some strands of
>> steel.
>> I built the reflection transformer and installed both the
>> transformer and the wire . The length of the beverage is about 200m.
>> To my surprise i measure about 25Ohms with a Multimeter at the feed
>> end of the beverage.
>> So there is 200m one way, the transformer, and 200m back = 400m of
>> wire.
>> I believe 25 Ohms is way to high for 400m?
>>
>> Any advise welcome.
>>
>>
>>
>> --
>>
>> Ohne CW ist es nur CB..
>>
>> 73, Martin DM4iM
>> _________________
>> Topband Reflector Archives - http://www.contesting.com/___topband
>> <http://www.contesting.com/_topband>
>>
>>
>>
> --
>
> Ohne CW ist es nur CB..
>
> 73, Martin DM4iM
>
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