[TowerTalk] HELP - Hy-Gain TH-3JRS

[Jim Brown]

On 5/17/2025 6:04 PM, Gary Mayfield wrote:
> We have also added a balun made from type 31 ferrite material.

Hi Gary,

Don't know anything about that antenna or have a solution for your 
problem, BUT -- if that #31 is a lot of turns of transmission line wound 
around a 2.4-in o.d. core, it is a Common Mode Choke, NOT a "balun." 
Antennas like yours are designed for specific matching networks or 
feeding methods. A choke is used between the transmission line and that 
matching system, whatever it is. These matching systems are often called 
baluns.

And with respect to your problem and on-the-ground testing -- did you 
have a long length of coax on it when testing on the ground, or just the 
analyzer connected with a few feet of coax?  Their matching networks 
often want to be driven by that coax.

Also, study carefully as you can what the original matching system was. 
With gamma and hairpin matching, both the length and the diameter of the 
rod(s) matter.

73, Jim K9YC