TopBand: Re: VSWR tests again and again

[W8JITom@aol.com]

In a message dated 97-02-20 00:27:12 EST, you write:

> the following is mere 
>speculation, but how about RF in the shack?  I wonder if Bill is running a 
>feedline choke on this arrangment. If he has only four elevated radials and 
>no feedline choke, then I would expect that there might be some induced 
>currents flowing on the shield of the feedline. If this is the case, and 
>the RF ground (emphasis on RF) in the shack is poor then perhaps the ALC 
>circuit is being affected. An ALC problem would certainly be consistent 
>with the 100W of drive not delivering the goods.
>
>

Hey good suggestion!

If Bill does only have four radials (even elevated) he can have
considerable common mode (the stuff that follows the OUTSIDE of
the cable and flows all the wrong places) current.

A feedline choke is in order, but remember the elevated radials themselves
radiate consider near field energy and can induce currents in things 
even with a feedline choke.

Some SWR meters and much of our other equipment is effected by common
mode RF. The amp will be immune but lower power equipment will not
be.

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