[RFI] Tower/Antenna Reradiation

[Jim Brown]

I spent years. #43 is NOT a good material for HF because of 
manufacturing tolerances. The problem is that we must measure each choke 
to take tolerances into account, but correct measurement is a 
destructive process. I measured at least a thousand chokes, wound on 
cores at the limits of component tolerances.

See the discussion in
http://k9yc.com/2018Cookbook.pdf

73, Jim K9YC


On 12/22/2021 1:21 PM, David Eckhardt wrote:
> Yes, 31 material is the preferred material, especially for 160 and 75/80 
> meters.  40-meters is roughly the break-even frequency.  15-meters on 
> upward, yes, 43 material is best.  I spent almost the whole month of 
> January and into February measuring various CMCs using both 43 and 31 
> material.