Antenna guidance needed.

Caryt · Wednesday at 06:05 PM

I have a Jeep Gladaitor with a AluCab canopy Camper with 2ea 200w solar panels.

They are mounted on 3 rails, rails are Alumnum as is the camper and frame work of the ridged panels.

I have a Midland MXT 575 and will be using this to talk to others on overlanding trips from desert to mountains.

I would like a antenna no taller than 18" and would like it mounted if possible on the middle rail or the rail closest to the cab. Note the Jeep tops are fiberglass so not mounting their..

I also will be runing a Kenwood TM-V71A so if anyone has knowledge on it ..same location for its antenna.

I won't be using both at the same time and don't want just 1 antenia for both.

I would rather not mount anywhere else.

Antennias will be permanently mounted.

Thanks!

BoxCar · Wednesday at 06:11 PM

You only need to post the query once. Having the same question in multiple places makes it difficult for you to learn of good suggestions/answers to you issue.

tcp2525 · Saturday at 11:18 AM

On 7/16/2025 at 2:05 PM, Caryt said:

I have a Jeep Gladaitor with a AluCab canopy Camper with 2ea 200w solar panels.

They are mounted on 3 rails, rails are Alumnum as is the camper and frame work of the ridged panels.

I have a Midland MXT 575 and will be using this to talk to others on overlanding trips from desert to mountains.

I would like a antenna no taller than 18" and would like it mounted if possible on the middle rail or the rail closest to the cab. Note the Jeep tops are fiberglass so not mounting their..

I also will be runing a Kenwood TM-V71A so if anyone has knowledge on it ..same location for its antenna.

I won't be using both at the same time and don't want just 1 antenia for both.

I would rather not mount anywhere else.

Antennias will be permanently mounted.

Thanks!

Smart man! That's a really nice setup you have. You bought a V71a, the best dual band radio in the history of amateur radio. As for antennas, get the PulseLarsen NMO2/70BLarsen for the V71a and a simple 1/4 wave NMO mount for GMRS and you will be extremely happy.

https://www.hamradio.com/detail.cfm?pid=H0-000565

SpeedSpeak2Me · Sunday at 11:13 PM

You'll have issues trying to accomplish this with a single antenna that is limited to 18" (or so). You can use the location for a GMRS antenna, but the 2m/70cm antenna for the Kenwood will be much taller. Reason being is that you don't really have a good ground plane. With GMRS you can get away with using a 1/2λ (wave) antenna. It won't require a ground plane to be efficient, and they easily meet your height requirement (about 10-11" tall). For the 2m/70cm antenna to get one that's 18" it's going to need a ground plane. A model like the Comet SBB2NMO will actually cover* the 2m/70cm and GMRS (both simplex and repeater inputs), but it is a 1/4λ for 2m, and 5/8λ for 70cm. Both of which need a good ground plane.

For the 2m/70cm if you went taller (40") you could get something like the Comet SBB5 or Diamond NR770HBNMO (basically the same antenna), which for 2m is 1/2λ and for 70cm it is 5/8λ over 5/8λ, so no ground plane required. However it is 40" tall (with a fold-over mount).

*This is speaking from personal experience, as I have both the Diamond and the Comet SBB2NMO. The Comet is on the trunk of a car, close to the edge where it meets the rear window, but I am directional to the sides and rear of the car. It is fine for population dense areas with lots of repeaters, though its performance is compromised going towards the front of the car (no ground plane). When traveling (road trips) I swap in the Diamond and being directional is no longer a factor.

nokones · Sunday at 11:43 PM

You will need to use two antennae, one for the 70cm freqs and one for GMRS. You should mount each antenna on the side of each cowl near the "A" Pillar using the Rugged Radios mounting brackets and NMO mounts. Don't use the cheap stuff get the Laird Mount and Cable from a reputable Radio Electronics Dealer. As for the GMRS antenna since it appears you are only concerned with GMRS for the trail, you should get thd Midland MXTA25 or the MXTA26.

Attached is a picture of my Highband VHF antenna on the side near the cowl and "A" Pillar. Also attached is a Laird Lip Mount NMO mount I use for my UHF DMR freqs. The Phantom antenna is a Laird.

Just make sure that the mounts have chassis ground continuity without the coax cable connected to the radio.