[UK-CONTEST] Long Distance Feedlines

[Adrian Rees]

Slightly O/T but this is the Forum that an accurate answer will come from....
 
I am planning on having a go in CQWW SSB, but will have to enter "Field Day" Style, as I have nothing in the air at the moment....so:
 
I will use an A3S for 10-15-20 and a Battle Creek Special for 160-80-40. Feeding the lower band aerial is not a problem, as it will be about 60-70 Feet From the shack, (which in reality will be an old cow shed. Told you it was Field Day Style !).
 
However, the A3S will be on a short mast, about 10 metres in the air, and about 300 metres from the shack.
(I could move the A3S closer to the shack, but would loose the benefit of its location..... Its located effectively on a 300m Cliff, giving significant benefit to the US / Pacific and Europe. Moving it would reduce this benefit.)
 
But ... feeding the A3S with RG213 would cause something like 7 - 8 dB of Loss. Feeding with Heliax would be better, but, the Heliax I have is in 55-60m Runs, and I don't really want to use this for a temporary installation.
 
What I do have is some 300 m of 450 Ohm Open wire feeder. So, I was thinking, how about a pair of 9:1 Baluns at each end, thereby using the 450 Ohm Feeder as "transmission line" across the field to the A3S.
 
The question is, has any one done this, and if so what losses do you incur. (I am trying to figure out is it really worth doing this, or should I just think about moving the shack and or the A3S ?) 
 
Thanks
 
Adrian MW1LCR