CB Mag-Mount/ for GMRS use?

[Radioneer]

Hello; New to GMRS. I'm wondering if CB Mag-Mount Antenna can be made to work on GMRS frequencies, by cutting the whip length? thank you for your input.  WRFP757

[gortex2]

Never say never but no. Just pick up a standard 1/4 wave uhf mag mount on amazon.

 

[dhardin53]

Not a expert here. I would say general speaking Yes it could work. But i see some down sides. The lower 15 to 24 inches of a CB antenna is very stiff wire on a mag mount would not work without a spring at the base. You would hit anything and knock it off rather easly. Setting a SWR would be difficult (not imposable). 

Buy the time you buy a UHF 460Mhz swr meter you just as well get a GMRS pre-tuned antenna. 

I looked at what came with my  MXT 275 and said this won't work. I bit the bullet and got the Midland 6db gain with a mag mount. Kind of pricey but why spend the money on a good radio and throttle it back with a negative db output antenna and cable. Or in your case end up with a less than desirable SWR. The Midland 6 db gain on the mag mount has a 1.1-1 swr. 

[OldRadioGuy]

It would not make any sense at all to try and convert it.  465MHz/28MHz is16.6x higher frequency. 

Even if you cut it down short there may be matching components that will filter out the 465MHz.

1/4 wave at 465MHz is only about 6-1/4 inches. 

Vince

[wayoverthere]

If the whip separates from the mag mount, you may be able to reuse the mount if it's a standard connector (such as a uhf/pl259 or nmo).

[PACNWComms]

On 12/9/2021 at 1:03 PM, wayoverthere said:

If the whip separates from the mag mount, you may be able to reuse the mount if it's a standard connector (such as a uhf/pl259 or nmo).

Great info......I was once told by a member of my crew, while stationed in Iraq and in charge of a military radio shop, that we were out of UHF antennas, but had many VHF antennas as spares. Then I introduced these younger and less experienced personnel to the art of antenna cutting. These were magnet NMO (New Motorola) style mounts and Laird VHF whip antennas. An Internet search led to the UHF antenna cutting chart and we were back in business. Magnet mounts were used, as many vehicles were locally procured Toyota pickup trucks and Mercedes sedans.