As I've tried to emphasize, the most important reason for using a
choke is to suppress RX noise, but by suppressing common mode current
during TX, we minimize crosstalk to other antennas.
By suppressing common mode current in TX you prevent the "random radial"
phenomenon. In doing so, you mitigate the "pin 1" problem by reducing
the RF voltage on equipment cases/connecting cables and avoid issues
of a "biting mic" (if you're old enough to remember RF burns to the lips
from the case of a D-104).
73,
... Joe, W4TV
On 9/21/2017 8:26 PM, Jim Brown wrote:
On 9/21/2017 3:20 PM, Wes Stewart wrote:
I thought the CM current in question came from the antenna in the
first place.
It depends whether it's receive or transmit. The principle of
reciprocity applies. As I've tried to emphasize, the most important
reason for using a choke is to suppress RX noise, but by suppressing
common mode current during TX, we minimize crosstalk to other antennas.
73, Jim K9YC
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