[TowerTalk] Common-mode choke for remote tuner

[Jim Lux]

On 10/26/12 2:49 AM, Phil Zminda wrote:
> I will be installing a SGC-237 remote tuner at the base of my 43 ft.
> vertical. I would like to add a common-mode choke at the base as part of
> the install. I built but haven't used, a bifilar choke with a 2.4 in.
> type 31 core, but since the tuner has an 8 ft coax pigtail for the input
> could do as well with a large type 31 clamp on with multiple turns of
> the RG-58 coax through it? This would reduce the number of PL-259
> connections and would just be a simpler installation. Any comments
> appreciated. Thanks.
>

with a 2.4" diameter core, you can pass the PL259 through it at least 5 
times with RG58. If you want more choking impedance, use more cores.

don't forget to choke the DC power/control wires too.