View Full Version : GMRS radio antennas-KAZ?
cabbie
10-28-2002, 07:18 PM
I heard that changing to a larger antenna for the handheld GMRS radios can really help on transmitting range. Is there any advice/tables or recommendations on this?
Cab
Cab: GRMS, which share some frequency's with FRS, are in the 462.5625 to 462.750 Mhz bands. They are more "Line of Sight" than Marine radios. And, yes an outboard antenna will help increase the range. You must, however, be sure to buy a radio that has a antenna that will disconnect by "unscrewing" or "push and twist". I use the Kenwood TK 3101, which works great for me. Then you need to get a 450/470 Mhz UHF antenna and the connectors to attach it to the radio. It can be mounted just like the public service cars and trucks do, or on a boat with a drill thru hole. The antenna needs to be tuned the same as with Marine radios. Hams use the 442/450 Mhz bands for FM communications and we tune our antennas in the same way. You may check a local Two-Way radio shop or Ham Store to see if they can help you get the parts. Remember though, GRMS is a controled radio service and a licence should be secured.....Kaz
Cabbie
10-30-2002, 05:19 PM
Kaz , Thank you for that information! However I'm a radio idiot and I may not be understanding you. "an outboard antenna" are we still talking about one that can be subsituted for the small rubber ducky one that come with these? I'm thinking we are not talking about the same thing. I have in mind a (longer?) antenna that replaces the little one that helps with the range. I think I remember something about 1/4 wave ,1/2 wave ,full wave antennas ,..(although it was a long time ago and pretty cloudy and may be way off base.)
Cab: Well I was thinking of something you could mount on a car or truck, thru the roof or gutter clip type. If it's not connected to the radio, them I refer to them as "Outboard". I'm not sure if there is a longer one you can just replace one that's on the radio. If it is mounted on a vehicle, then the vehicle acts as as a ground plane giving a better radiation pattern for more coverage. Hope this answers your question....Kaz
Cabbie
10-31-2002, 05:58 PM
OK ,thats good to know, speaking of the car acting as a ground plane giving more coverage,...does magnetic mounts with other antennas also do this? (since you really are riding on the paint)
Cab: They do act as a "coupled" ground plane, but a electrical (direct) contact is better. I don't think Radio Shack will have the necessary parts though. Try the Ham Store or a Two way dealer. It's "Trial and Error" since no one has put out a "Plug and Play" antenna kit yet. Hey maybe a NEW MARKETING NITCH!!....Kaz