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Lower SWR with 102 than 108

Captain Chaos

New Member
Jul 28, 2019
6
6
3
47
I am getting a lower SWR with SS 102" whip (aprox. 1.3:1) than 108" (1.6:1) on 27.205
I'm using HD stud mirrot mount on my semi. If I go down to 25.405 I get 1.2:1 with the SS 108" whip. Should I roll with the 108 or put the 102 back on?
Sorry in advance for the newb question.
 

No spring. However, I did have a fairly tall mount.

I would go with whatever tunes better for your application. If the 102” is it, then you’re good.

Aside from off-road vehicles or applications where the antenna needs to be tied down, I don’t like springs...especially on a 9’ long wet noodle.
 
I’m not sure how folks come up with 108”, to be honest. I never remember hearing this in years past, but it seems like everyone talks about 108” now.

Here’s a 1/4 wave calculator for you to play with. Assuming .956 as a generic velocity factor for stainless, I come up with 103.76”. Your 102” whip, plus your mounting stud, is probably very close to that. Sounds like you could be a hair longer, but definitely not six inches.

https://m0ukd.com/calculators/quarter-wave-ground-plane-antenna-calculator/
 
I’m not sure how folks come up with 108”, to be honest. I never remember hearing this in years past, but it seems like everyone talks about 108” now.

Here’s a 1/4 wave calculator for you to play with. Assuming .956 as a generic velocity factor for stainless, I come up with 103.76”. Your 102” whip, plus your mounting stud, is probably very close to that. Sounds like you could be a hair longer, but definitely not six inches.

https://m0ukd.com/calculators/quarter-wave-ground-plane-antenna-calculator/
Thanks for that info
 

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