> If you add a choke tuned to 160M, it will isolate the driven
> element from the feedline on 160M, so you won't see changes
> in the loading on 160 as you change the SteppIR driven element.
Since the drive element connection for an HF yagi or 80/40
meter dipole tends to be at a HIGH Impedance point when the
tower is shunt fed, the typical common mode choke - even one
with 3 - 5K choking impedance will not be very effective on
160 meters. This is much like the situation faced when feeding
VHF across the base insulator of a "greater than quarter wave
AM tower. You just about need a tuned choke to get enough
isolation.
73,
... Joe, W4TV
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160 meters is a serious band, it should be treated with respect. - TF4M
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