Topband: Vertical choke needed?

[Wes]

Hi Mike,

I've read all of that stuff and more many times.  Frankly, I'm not motivated to 
put a 10 pound lump of ferrite on every wire into or out of my shack.  It 
appears that common-mode chokes and articles about them, have become a cottage 
industry.  I will leave my opinion of the topic at that.

Back to the actual case at hand, a ground-mounted, inherently unbalanced 
antenna, with a bunch of radials.  I contend that the coax outer conductor is 
just another radial.  As an approximation the currents in the radials will 
divide by the number of radials.  Because of its different length, there will be 
asymmetry in the coax "radial" current but it could go either way.  So tell me 
where exactly do I choke this "radial" and why?

Wes  N7WS

On 12/31/2020 8:22 PM, Michael Walker wrote:
> Hi Wes
>
> The chokes do a few things.   For transmitting, they keep the RF off the 
> feedline.   It is critical for RX and TX.
>
> Just as importantly, they keep RF and Noise off the feedline while receiving, 
> and this is what you want.  The quieter you are, the more you can hear.
>
> Common Mode Currents can raise make it harder to hear weak signals and I 
> have seen and heard this with my own ears, as many others have.  How about I 
> reduced my 80M noise floor from S9 to lower than S6.  I'm not sure on 160M as 
> I didn't really get going on 160 until after I was loving chokes.  I now buy 
> them in lots of 50 in bulk from Digikey.
>
> Read these pages.  This is where I started a long time ago 
> http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf 
> <http://www.yccc.org/Articles/W1HIS/CommonModeChokesW1HIS2006Apr06.pdf>. Well 
> worth the read.
>
> Next, read Jim's stuff http://k9yc.com/2018Cookbook.pdf 
> <http://k9yc.com/2018Cookbook.pdf>
>
> He is part of this group, and I know he will comment at some point.
>
> Mike va3mw
>
>
> On Thu, Dec 31, 2020 at 9:50 PM Wes <wes_n7ws at triconet.org 
> <mailto:wes_n7ws at triconet.org>> wrote:
>
>     I have the same situation and no choke.  IMHO the transmission line is just
>     another random length radial.  I don't have chokes on any of the others
>     either.
>
>     Wes  N7WS
>
>
>     On 12/31/2020 5:15 PM, Kenneth Silverman wrote:
>     > Hello, I have an inverted-L and the radials are laying on the ground AND
>     > the coax is on the ground too with radials right near the coax run.  Do I
>     > need a choke to stop any feedline coupling/radiation, and if so, where in
>     > the feedline?
>     >
>     > The antenna is in the woods so burying either the radials or coax won't be
>     > easy.
>     >
>     > Many thanks, Kenny K2KW
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