Field tunable antenna?

[Austin4Wyo]

I just recently purchased a PSR 500, and a 36" mag mount whip to go with it. It stated on the website (TheRadioCompany.com - NASCAR Scanners - Police Scanners) that it was "field tunable," and says the same thing on the packaging. I'm not exactly sure what this particular phrase means, or how to tune a 3 foot whip in the field. The antenna itself had a few instructions on the back of the packaging, but I'm not exactly familiar with this sort of thing...

So, if someone would be so kind as to explain what they mean by "field tunable" and explain how this particular tuning takes place, just to placate my curiosity, I'd be grateful. I'm not looking to adjust the antenna, since it's pulling in anything and everything around this little Wyoming burgh, but I'm still in the dark and wanting to learn.

Many thanks in advance.

 

[W6KRU]

I'm not real impressed with the site that you bought that antenna from. I only see one antenna on that site that seemed like it could be what you bought and their description is contradictory. Magnet Roof mount scanner antenna is low profile and requires a 3/4" hole on flat horizontal surface for installation. Huh?

Anyway, the way we usually tune an antenna is with an antenna analyzer or a transmitter and an SWR meter. The antenna is trimmed to the proper length to give the lowest SWR reading for the frequency it is to be used for.

 

[Austin4Wyo]

That would be the one I purchased. Not sure what the 3/4" hole routine is about, but it's a great antenna.

Not sure about their other stuff, but the radio was cheaper there than anywhere else I could find. I got the radio and the antenna with UPS insured shipping for $502. Not bad at all. I suppose I'd have been annoyed if the antenna didn't work, but it pulls in anything and everything, and has let me listen to all the other stuff that wasn't available on my old machine (an ancient Uniden BC80XLT).

Thanks for the reply. Nothing I should worry about much, then, I suppose.

 

[blueangel-eric]

doesn't it come with a cutting chart to tell you where to cut it for the desired frequencies?

 

[rfradioconsult]

To "tune" an antenna you need to specify the range of frequencies you desire i.e., 150-160 MHz. If you are listening to a wide band of frequencies then "tuning" your antenna may actually degrade its over-all performance. Antennas are a little bit of physics and a lot of magic; so if you are happy with the performance then enjoy.

A LOT of antennas have ended up on the scrap pile because sombody decided to cut the antenna to "tune" it.

 

[blueangel-eric]

To "tune" an antenna you need to specify the range of frequencies you desire i.e., 150-160 MHz. If you are listening to a wide band of frequencies then "tuning" your antenna may actually degrade its over-all performance. Antennas are a little bit of physics and a lot of magic; so if you are happy with the performance then enjoy.

A LOT of antennas have ended up on the scrap pile because sombody decided to cut the antenna to "tune" it.

not if it's a plain simple 1/4 wave and you want to cut it for a specific freq. this looks like a 1/4 wave antenna. funny on Hustlers website they have the scanner antenna in the CB category. and don't forget there's formula's for figuring out the lengths to cut to. the RR band is 17.4inches.