[TowerTalk] VHF/UHF Common Mode Choke

Jim Brown jim at audiosystemsgroup.com
Sat Jun 29 00:29:26 EDT 2019

On 6/28/2019 5:49 PM, jimlux wrote:
> Is 31 a good material for UHF? I always think of it as a HF material, 
> but it could well be useful up to 500 MHz. 

Yes, it's a very good material for 6M and 2M. From that table of chokes, 
click on any part number to see the data sheet. Scroll down to see plots 
of Zmag for 1, 2, and 3 turns. For practical chokes, these 
characteristics will vary with cable diameter, turn diameter, and turn 
spacing. My recommendations are based on measurements of tightly spaced 
turns with diameters on the order of min bend radius.

The reason #31 is a bit better than #43 is that it's lower Q, so the 
resonance is a bit broader.

73, Jim K9YC

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