Topband: Beverage question answered...
ian.keyser at btopenworld.com
Wed Feb 21 13:47:29 EST 2007
Hello Bill, well I have experienced both your questions.
My power line is only an 1100volt line feeding three hamlets but is noisey.
it is only 15 feet up and my beverage was to pass at right angles beneath
it. Forget it! S9 noise.
I then moved the beverage 100yards away from the line and slowly shunted it
backwards until the noise minimised,...in fact it went! I was slotting the
power line into one of the deepvertical nuls.
The other problem with the fence.... well my east west beverage is 0.5 m
above a fence and burried in a hedgerow..... it still exhibits a good S/N
when refered to the Marconi T but if terminated or not makes not a shaddow
I then fed the whole lot into EZNEC and it agreed with what happened in
practice.... two way fire but good off the sides. The way I look at it is
that m'ybeverage is coupling to the fence 'beverage'.... so terminating mine
makes no difference.
I did think I might add ferrite decoupling on the fence line every 20 yards
or so.... but really I find a K9AY loop just as effective, if not more so
and a lot smaller.
The K9AY is not perfect by any means and am at present changing it to
Pennants.... as the F/B is better. In the UK we are severely limitied by
space and the pennant is so compact.... Perhaps If I had room for ten or so
bevs in different direction it might be better but.....!
Good fun thought, isn't it!!
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