Steve Hunt wrote:
>If the coax in the shack sees a low impedance path to ground, and it is
>an odd multiple of a quarter-wave up to the feedpoint, very little CM
>current flows; and for any that does flow the shack end is at a voltage
>*minimum* of the CM standing wave. It's very clear if you look at the
>current distributions in a model.
>Of course, if the shack is on a second floor all bets are off - the coax
>may well not see a low impedance path to ground.
From that information can I conclude that if I have a decent, short
length ground connection and a feedline that is an odd multiple of
quarter wavelengths long, I don't need a CM choke?
Consider as application a 2 meter quagi at 40 feet.
Also how about a longer ground that is a multiple quarter wavelengths
long. If that works for the feedline why wouldn't it work for the
I would much rather not have to invest in a CM choke and then find out
later that there was no real difference with or without the choke. If I
need special equipment to discern a difference, I will probably not want
to fool with it.
Unless I can hear a difference in the headphones, I have to conclude
that there is no difference. At least no difference that I would be
willing to pay for or spend time on.
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