[UK-CONTEST] Long Distance Feedlines

[G3SVL]

At 10:44 25/09/2006, Adrian Rees wrote:
>However, the A3S will be on a short mast, about 10 metres in the 
>air, and about 300 metres from the shack.  .... Its located 
>effectively on a 300m Cliff, giving significant benefit to the US / 
>Pacific and Europe.
>But ... feeding the A3S with RG213 would cause something like 7 - 8 
>dB of Loss.

Adrain,

I think you need to decide just how much 'gain' you get from placing 
the antenna that far away. As others have said, open wire is 
mechanically difficult and there is the rotator cable to consider.

For Tx the feeder loss doesn't matter if you have a linear - its 
power at the antenna so just crank the linear up by the amount of the 
feeder loss.  But on rx (especially on 10m) the gain of the beam will 
be lost in the feeder - and some.  So it's possible that you will 
lose out to rx front end noise on really weak signals unless the 
cliff top location gives that much signal advantage.

I'd move the shack much nearer to the antenna if that's possible.

73 Chris G3SVL