Only to the extent that less RF current flows into equipment with Pin
One Problems. But that feedline still radiates -- the only thing that
changes is the tuner chassis is now hot with RF, and the tuner modifies
the current distribution on the line depending on how it's tuned. And
none of this changes the fact that off-center-fed antennas are
inherently noisy BECAUSE they are imbalanced, nor does it change the
fact that it is simply not practical to choke open wire line at the
feedpoint.
What COULD block feedline current is a real transformer on a low loss
ferrite core, IF the transformer had very low capacitance between
windings (because common mode current would couple through interwinding
capacitance). This means that windings could NOT lay next to each other
as is often done (bifilar, but connected as a transformer), but would
have to be on opposite sides of the core. And, of course, to handle
power, a beefy, low loss core would be needed. Something like Fair-Rite
#67, which N6RK has used for high power transformers.
73, Jim K9YC
On Fri,12/9/2016 3:46 PM, Hans Hammarquist via TowerTalk wrote:
One way to get control over the common mode current is to place a good common mode choke
between the tuner and the transceiver and let the tuner "float" electrically.
Don't ground the tuner and leave it far from any grounded equipment. You don't stop the
contribution from the feeder to the radiated feild but you reduce the RF in the shack
generated by the common mode current.
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