Thanks Tom for the explanation. As always, this is a learning Reflector. Part
of my location involves potential BCB, power line, adjacent home electronics,
and of course the legal limit transmissions close to the loop/feed/rotator
controller. Common mode supression is an absolute requirement on all lines.
As to it's +- effect on the loop, well, as I mentioned, it was a shotgun
process during the installation. Without common mode filtering on all cabling I
couldn't operate. Such is the dilemma of the city dweller who has an S4-7 noise
floor depending upon season. It's substantially worse in winter as explained
below.
I'm told that the effective RF ground in these parts of Alaska is 15+ meters
down, and it'll find a way into the shack unless crowbarred at the door. Ground
rods surrounded by 4-5' of winter frost and non-conductive soils are useless.
73, Gary NL7Y
> This doesn't mean loops will never work, or loops with poor feed systems will
> never make people happy. It just means it is almost impossible to correct a
> bad feed design by stringing beads or winding conventional chokes, even if
> you get up to 5,000 ohms. It is always far better to make the antenna with a
> correct feed system, because a proper feed has far less common mode response
> without any common mode foolery.
>
> 73 Tom
All good topband ops know how to put up a beverage at night.
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Topband Reflector
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