Antenna Advice for Dual Band Radio and Ford Truck

[fschoenheit]

Hello,

I’m looking for some antenna advice. I have an ICOM 2730B with the MARS modification to transmit on race frequencies in the 151 MHz range and VHF Marine frequencies. I have a 2023 Ford F-250 with an aluminum body. I plan on mounting an antenna forward of the third brake light.

I have a house down in Baja and we use Marine band to communicate between homes and to emergency services. We use race frequencies on most desert rides and to listen to off-road races with the occasional GMRS use for Baja desert rides.

In San Diego, I monitor our local amateur radio club, GMRS and the various CalFIRE frequencies for situational awareness during major events which appear to be more and more frequent. I also travel to the Eastern Sierra and monitor Fire Frequencies also.

Most of my radio transmissions are on 151.265 and 156.475.

Can someone please give advice on a good antenna? Should I get a dual band antenna or buy separate VHF and UHF antennas for the rare chance I’ll actually transmit on GMRS.

Thanks for reading and I appreciate the advice!

 

[petnrdx]

What I use is the NMO-Q by Larson. Its a SIMPLE quarter wave at VHF and is "tunable". Meaning you cut the rod
to the length you need. Sold with the range of like 136 to 512 mhz (cut for specific range).
They come about 21" inches long and cost less than 20 dollars. Fit on a normal NMO base which is also less than 20 dollars.
Since you say you mostly use 151 and 156 to Tx. cut the rod in between that around 154 mhz to get usable SWR at both
freq ranges. 154 Mhz times three equals 462 mhz.
At 462 mhz the antenna will be 3/4 wave length and give usable SWR.
The transmit radiation angle will be "uptilted" at UHF but works fine when the least bit close.
I have been doing this on two meters / 70 CM, and 155 / 460 for decades.
Inexpensive and more durable than most true dual band antennas.
You might have difficulty getting "great" SWR if mounting on the high brake light as they are usually plastic, but usually
works well enough.
Cut using measurements taken with a good VHF wattmeter, Start long and cut a little at a time til you get the length you
need for usable SWR.

 

[fschoenheit]

Thanks very much for your thoughts. Would a base loaded antenna with db gain be ok. Our travels sometimes take us remote and when we need distance, we need distance. No repeaters available! Thank you again!!!

 

[petnrdx]

Nope. Base loaded, gain single band antennas won't work that way.
Not that I have tried anyway.
If you need gain, then you would have to get a gain type dual band that can work on the two splits you want.
That is hard to find and get real gain, as opposed to hype, AND the exact two splits you want.
Also, in my experience you don't really get that much improvement in coverage with a dual band gain antenna.
A little better, but not worth the hassle from what I have tried.
Dual band antennas are MUCH more rigid and tend to get bent or broken pretty easily. Or break the mount.
If you are going to mount ANY antenna, I recommend an NMO mount.
And once you have the mount, trying the NMO-Q "tunable" (cut to length) is a pretty inexpensive thing to try.

 

[fschoenheit]

Gotcha, thanks again!

 

[mmckenna]

If you really need gain, then you'd want two separate antennas and a diplexer. That gives you some flexibility by letting you choose which UHF and which VHF antenna you want based on your needs. However, you'll need two antenna mounts with sufficient separation to make it work well. By saying "I plan on mounting an antenna forward of the third brake light." I really hope you are doing a permanent NMO mount, and not one of the third brake light mounts. Those really come with a lot of drawbacks and should be avoided if at all possible.

But don't assume you need more gain. Adding antenna gain comes with tradeoffs.

More gain is achieved by focusing the radiation pattern at the horizon. That works well in some cases. In very mountainous areas where repeaters or other radio user may be far above or below you, focusing that RF at the horizon can work against you.

The 1/4 wave VHF antenna can work well as mentioned above. But remember, the antenna needs sufficient ground plane under it to work properly, and third brake light mounts do not give you a good ground plane. (RF ground plane and a DC ground are different things).

If you really plan on using UHF frequently, you may want to go with either the diplexer and separate antennas, or do a single mount and a multiband antenna.

For a quarter wave, one of these two antennas would be my recommendation. I spec these at work and have installed a lot of them. Never had a failure. Both these brands (EM Wave and Larsen) make public safety antennas. They'll outlast your truck and the three trucks after that. These are products that you can pass down to your grandkids:

EM Wave EM-MX0108-FT 108-960 MHz Tunable, VHF UHF Broad Band Quarter-Wave Mobile Antenna

EM Wave EM-MX0108-FT 108-960 MHz Tunable, VHF UHF Broad Band Quarter-Wave Mobile Antenna

theantennafarm.com

Larsen NMOQC 136-512 MHz Field Tunable Two Way Radio Antenna NMO Mount

Larsen NMOQC 136-512 MHz Field Tunable Two Way Radio Antenna

theantennafarm.com

If you want to run a multiband antenna to get squeeze out some better performance on UHF, I'd recommend one of these. Again, I use these frequently at work and never had an issue:
I spec these out on our police vehicles:

Larsen NMO150/450/758 Tri-band Mobile Antenna covers 150-174, 430-520 & 750-870, 100 Watts, Length 16.5 in, NMO Mount, Spring Base, Solid Black

Larsen NMO150/450/758 Tri-band Mobile Antenna covers 150-174, 430-520 & 750-870, 100 Watts, Length 16.5 in, NMO Mount

theantennafarm.com

I ran this one on my personal truck for a few years:

EM Wave EM-M43002 Tri-Band 150-162/450-490/763-870 MHz Mobile Antenna - 17.7 in - NMO - Spring Base

EM Wave EM-M43002 Tri-Band 150-162/450-490/763-870 MHz Mobile Antenna - 17.7 in - NMO - Spring Base

theantennafarm.com

Couple of good options that will work well and last a long time.

If you really think you need the extra gain, then one of these would be a good option:

VHF UHF 150-154/ 450-465 MHz Dual Band Mobile Two Way Radio Antenna NMO

Larsen NMO150450C 150-154/450-465 MHz VHF/UHF Dual Band High Gain Mobile Antenna - 37.25 inches - NMO

theantennafarm.com

 

[fschoenheit]

Wow, more great advice! My F-250 is a crew cab with an aluminum body. I wasn’t going to use a third brake light mount, they’re way over priced. My plan was to mount it forward of the third brake light. My questions is how far forward? Center of the roof? I’ve also seen a couple forms talking about the aluminum roofs are so thin that the nmo mounts tend to wear out and oblong the hole but I’m not sure if that’s factual. Maybe use an adhesive metal plate and magnetic nmo mount?

 

[jeepsandradios]

I had 6 NMO mounts in my F150 and ran a lowband and CB antenna (Larsen) and never bent the roof. a properly installed NMO will be fine. I'd move it closer to center, however dead center there is a rib so verify befre dropping the mount. Personally for your intended use you can probably get away fine with a VHF antenna and know that uhf will be a sacrafice. Ideally yes a dual band would be ideal. I run the Laresn on my work trucks and have been happy with it but I know a few folks switching to the EM Wave with good results.

 

[mmckenna]

Wow, more great advice! My F-250 is a crew cab with an aluminum body. I wasn’t going to use a third brake light mount, they’re way over priced. My plan was to mount it forward of the third brake light. My questions is how far forward? Center of the roof? I’ve also seen a couple forms talking about the aluminum roofs are so thin that the nmo mounts tend to wear out and oblong the hole but I’m not sure if that’s factual. Maybe use an adhesive metal plate and magnetic nmo mount?

Not a problem on those. I ran a 2018 F350 crew cab for years with a permanent mount NMO. Plus a 2017 work truck, and recently a 2025. I've done a bunch of these trucks….

For the antenna to work at it's full potential, you want at least 1/4 wavelength at your lowest operating frequency of ground plane in all directions under the antenna.
For your 151MHz frequencies, that's around 19".

On my 2018, I measured forward 25 inches from the rear of the cab roof. Measure from the point where the third brake lamp meets the roof:

25" forward of that is what worked on the 2018. Should be the similar for your truck:

That'll give you the ground plane the antenna wants at your lowest frequency (even if you decide to get your amateur radio license, you'll be good).

I can guarantee you that the body panels on these trucks are not thin. Whoever said that has never installed an antenna on one. I've done a bunch of these trucks with the aluminum bodies, starting in 2017, and just did a 2025 a few months back. Most of those trucks have spent quite a bit of time off highway. My work truck has been run up and down a lot of miles of overgrown site access roads. The 2017 work truck has had a lot of low tree branch encounters, including one that bent the headache rack, but did zero damage to any of the several antennas on the roof.
My own 2018 F350 went through a low parking garage that resulted in the antenna spring taking a permanent bend, but again, zero damage to the roof.

Anyone that has installed on one of these trucks will tell you that the grade aluminum they use is thick and pretty hard. It takes longer to drill these aluminum body trucks than any of the steel body Chevy's. A properly installed NMO mount will not "oblong" the hole, sounds like someone didn't follow the installation instructions.
Glued on steel and mag mounts are going to cause you a lot of long term issues.

 

[fschoenheit]

Thank you very much, I’ll post pics once I complete my install!