[TowerTalk] Coax radius

[Mike]

On 10/6/12 10:01 PM, K8RI wrote:
> 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)
>
>
Thanks, Roger. The choke in the pic looksw like it's been up a while, I 
guess you haven't noticed any change due to conductor migration.

73, Mike NF4L