proper UHF mobile antenna

[gamewarden3006]

Forgive my ignorance guys but I am fairly new to this and I have been doing a lot of research on this but I am not sure I understand all that I know about proper antenna types and lengths.

so here is my situation. I have an older Motorola radius UHF radio in my vehicle. (use for work) I monitor traffic primarily over 2 county channels. both are 465.xxx/460.xxx. I have a mobile antenna mounted through the roof on my vehicle. however I get poor staticy transmisioms often and sometimes broken up traffic. My scanner in the house is nice and clean though.. I checked all the connections and everything is clean and tight. I tested the cable from radio to antenna and there is no resistance on it so the cable is good.
this leads me to believe it is the antenna. I am unsure what type of antenna is on there now cause there are no markings on it. It is 17-inches tall with no coils.

while doing some browsing I came across this antenna. would it (or any similar) help any?? NMO Mount UHF Mobile antenna

I will be using this in a flat coastal/farming environment. No cities...

Thanks for any help or info.
Brian

 

[fineshot1]

If the antenna you have now is a 1/4 wave NMO with no coil then it is cut for about 173Mhz and is
the wrong antenna. If it is indeed an NMO then the one you pointed out with the web link would
be a very suitable replacement. If you want you can cut the length of the one you have(if it is a 1/4 wave)
down to about 6.3 inches that should suffice and your recieve should improve due to being on or about the correct antenna wave length.

 

[gewecke]

Also check continuity between shield and ground to be sure the antenna is not shorted. This can be done at the connector and again at the antenna after you unscrew it from the roof mount.
N9ZAS

 

[gamewarden3006]

Just an update. By shear luck a buddy of mine who works with radio equipment stopped by my house this morning. I told him about the issue and he looked at it and decided that it was a 1/4 wave VHF antenna. He had a UHF antenna with him and we screwed that on an all was well. Did a radio check and everything was crystal clear.

I might still get that antenna in the link though.

Thanks for the advise guys. looks like you were right about it being the wrong wavelength..

 

[fineshot1]

Also check continuity between shield and ground to be sure the antenna is not shorted. This can be done at the connector and again at the antenna after you unscrew it from the roof mount.
N9ZAS

Thank you - that is a very good suggestion I should have mentioned.

 

[motoman118]

I have a similar setup, what type of UHF mobile antenna would give the best performance in the fringe areas? Right now I am using a 1/4 wave antenna with an NMO mount.

 

[fineshot1]

I have a similar setup, what type of UHF mobile antenna would give the best performance in the fringe areas? Right now I am using a 1/4 wave antenna with an NMO mount.

That would depend on the local terrain in your travel areas.

If it is a hilly or mountainous terrain stay with the 1/4 wave whip.

If it is an overall flat terrain then the gain antenna will assist you in the fringe areas.