Per Jim Brown, K9YC, one of the experts in the field -
"I recently did some work on chokes for 6M and posted the result to an
email reflector devoted to grid chasers for that band. Two turns of
RG8-size coax through a 1-in id. #31 clamp-on is optimum for 6M, and
yields about 1K ohms resistive choking Z. I recommend at least two such
chokes in series at the feedpoint. For RG8X or RG400, two turns through
TWO 3/4-in i.d. cores is optimum for 6M, and yields about 1.2K choking
Z. Again, use at least two such chokes in series.
For 2M, use multiple #31 clamp-ons, sized to fit the coax. Use the link
below to select the size that fits your coax. Each will provide about
250 ohms choking Z on 2M. Do not wind turns, just clamp them onto the
coax. I would use at least five, and ten is better. :) Arrow is a good
vendor for parts they have in stock.
https://www.fair-rite.com/product-category/suppression-components/round-cable-snap-its/lower-broadband-frequencies-1-300-mhz-31-material-round-cable-snap-its/
73, Jim K9YC
"
Hope that helps
On Sun, Jul 21, 2019, 10:37 Mark Spencer <mark@alignedsolutions.com> wrote:
> Hi:
>
> I'm curious if anyone has any thoughts about the relative merits of using
> mix 31 or mix 43 ferrite snap on cores for pro active use on
> interconnection cables at 50 MHz. Over the years I have used both and
> have managed to avoid any notable RFI issues in my portable setups.
>
> I figure for HF Mix 31 is almost a no brainer, but I am less certain about
> the best choice at 50 MHz.
>
> Thanks in advance for any comments.
>
> 73
>
> Mark S
> VE7AFZ
>
> mark@alignedsolutions.com
> 604 762 4099
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