Topband: E51D Oct 1

[Jim Brown]

On 10/3/2024 7:00 PM, Tim Duffy wrote:
> Here is a great high common mode impedance choke that I use just as George
> explains. At the beginning and end of the feedline to all RX antennas.
> 
> https://www.dxengineering.com/parts/dxe-rxfc-75

I published these designs for chokes and transformers for RX antennas in 
2018. The chokes are wound with one of the twisted pairs from CAT5 
cable. Both transformers and chokes are wound on very low cost cores, 
and intended for mounting in off-the-shelf weatherproof boxes.

http://k9yc.com/RXChokesTransformers.pdf

They've been in use here since around 2019 on Beverages and a spaced 
pair of VE3DO loops steered with an NCC-1. My report on that system, 
which includes extensive measurements of the NCC-1, is at

http://k9yc.com/VE3DO.pdf

73, Jim K9YC