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
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|