NMO mounting a 1/2 antenna

[BonziBuddy]

I would like to have a 1/2 wave UHF antenna in place of my 5/8th wave. I'm curious... would this be a HUGE improvement or just so-so? Could it cause the opposite effect somehow?

The antenna I have now is a BB4503. I would like to have a "No ground plane" B4502NS with the spring.

 

[davidgcet]

do you have a ground plane or is it mounted on something like fiberglass? you would be giving up 1 db of gain by going to the NGP, but honestly that is not enough to really notice unless you are already on teh very fringe of coverage.

 

[BonziBuddy]

It would be mounted NMO dead center in the roof of my truck. It's more desirable to me because the 1/2 wave whip is shorter than the 5/8th wave whip. Would that recover the lost gain?

 

[davidgcet]

you won't recover gain by giving up part of a wavelength. you can try it, the results may not be very different than the 3db you currently have. like i said, it is only 1 db and you probably won't see much difference if any.

 

[LtDoc]

Going from a typical 5/8 wave antenna to a 1/2 wave antenna will mean giving up some slight bit of 'performance'. That 'loss' may, or may not be noticeable at all, probably not much if any.
Using a 'NGP' antenna when it's not necessary is a waste of time and money. They work if there's no metal to mount them on. That NGP thingy uses the feed line as the 'groundplane', which is certainly okay if you don't have some metal for the antenna to use. You have the required 'metal', so why mess with a NGP antenna?
I assume the problem is in the height of the 5/8 wave antenna. If that's the case, and if you haven't already got a hole in the roof, why not just mount that 5/8 wave on a fender? There would be some degradation in performance, but probably no more than using a 1/2 wave antenna.
- 'Doc

 

[mrweather]

Going from a 5/8 to a 1/2 wave antenna results int a theoretical drop in gain. Is it noticeable on the radio? Probably not.

I run a 1/2 wave for my VHF antenna instead of a 5/8 due to overhead clearance issues. I honestly have not been able discern any noticeable difference.