[TowerTalk] Coax radius

[K8RI]

On 10/6/2012 8:07 PM, Mike wrote:
> I'm planning on using Buryflex coax to wind common mode chokes using
> type 31 ferrites for my 80/160M slopers. I'll be able to get 5 turns
> thru 2 stacks  of 4 each ferrites. A sort of oval roll of coax with 4
> ferrites on each "straight" side.
>
> The Davis website lists 2"min as the bending radius. What's the smallest
> practical coil to make in hopes of mitigating conductor migration?

I have several configurations.
The one on the 75 meter fan dipole is 5 core, 6T of BuryFlex(TM)
http://www.rogerhalstead.com/ham_files/AntennaFeed1.htm
I have one that is 6 core, 7T for the 160 half sloper that is laying on 
the work bench at present.  It does take a little wire soap to get 7 
turns on a single stack.

Turn radius varies from 3" to almost 5" with the larger radius being on 
the longer stacks.

So far all are single stacks, but I may go with a pair similar to yours 
for 160 which will go into a PVC electrical box. with the aim of making 
a circle out of the 6 coax turns.

I need to set them up and run tests with the VNA to see just how well 
they do.

73

Roger (K8RI)


>
> 73, Mike NF4L
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