[CQ-Contest] station re-building, distortion when multiple 600 Ohm lines in parallel?

[K9MA]

I think Holger means crosstalk, rather than distortion. The critical issue will be whether the feedline crosstalk is greater than that from the antennas. There may be ways to estimate the feedline crosstalk, but I don’t know without doing some research. However, it might be worthwhile spacing the wires for less than 600 Ohms as that will reduce crosstalk for a given distance between feedlines. The tradeoff will be slightly more loss due to more spacers.

73,
Scott K9MA 

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Scott Ellington

 --- via iPad

> On Mar 16, 2019, at 11:48 AM, Jim Brown <k9yc at audiosystemsgroup.com> wrote:
> 
>> On 3/15/2019 7:08 PM, Holger Hannemann wrote:
>> Does anyone has experience with potential distortion when operating parallel
>> running open feeder lines?
> 
> Distortion requires a non-linear element in the signal path. Transmission lines are inherently linear. There IS the possibility of distortion in a ferrite core device used to transform impedance at either end of the line. Air core transformers would not have this problem.
> 
> I think you're right to be concerned about crosstalk between multiple lines running parallel to each other for these long distances, which will be in addition to the crosstalk between antennas. In any event, you will need serious filtering for amplifier harmonics just as with any other multi-transmitter station.
> 
> 73, Jim K9YC
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