Hi Carl,
I temprorary used 200m of CAT6 cable to connect two reversable
Beverages - one direction per one pair few summers ago.
Worked well.
I used regular binocles from 73 material for transformers both at Beverages
(450 >> 100 Ohm) and for baluns at radio. So had 4 directions with one
CAT cable.
ZL3IX provided measurements for "crosstalk" between pairs - ir was in 50dB
range for CAT5E he had for same lenght.
73
Arunas LY2ij
> Would shielded CAT5 be useable as a Beverage feed? It would be easy enough
> to match with a binocular core at both ends and I just happen to have
> about
> 300' doing nothing.
>
> Carl
> KM1H
>
>
>
> ----- Original Message -----
> From: "Jim Brown" <jim@audiosystemsgroup.com>
> To: <topband@contesting.com>
> Sent: Monday, September 09, 2013 2:12 AM
> Subject: Re: Topband: CAT5 for Flag Antenna Feedline ?
>
>
>> On 9/8/2013 10:30 PM, Bob K6UJ wrote:
>>> I got the impression from the post
>>> that CAT5 is immune to common mode noise.
>>
>> I've not heard that, nor can I think of a theoretical basis for saying
>> so.
>> CAT5 is very good twisted pair, with a high twist ratio, Zo = 100 ohms,
>> and its loss is low enough to make it work fine on 160M. The primary
>> advantage of twisted pair is that it rejects DIFFERENTIAL mode noise.
>> Rejection is greatest when both ends of the line are balanced.
>>
>> One possible source of your confusion may be reading, but not fully
>> understanding, my work, and Neil Muncy's work, on SCIN, whereby certain
>> deficiencies in the construction of a cable shield convert common mode
>> current to a differential voltage on the signal pair. I have on several
>> occasions observed that high quality unshielded twisted pair, like
>> CAT5/6/7, would have much better noise rejection than that sort of
>> cable.
>> Read about it in several tech papers and tutorials on my website. No
>> need
>> to burden the list with it.
>>
>> 73, Jim K9YC
>>
>> _________________
>> Topband Reflector
>>
>>
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>
> _________________
> Topband Reflector
>
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