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Amateur Radio Antennas - For discussion of all amateur band designed antennas and related accoutrements. This includes base, handheld, mobile and repeater usage. For commercial antennas on the amateur bands please use Commercial Radio Antennas below.

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Old 06-29-2017, 12:36 PM
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Default Antenna for flat-bed truck

I'm also a new guy and came here looking for recommendations on an antenna setup. My truck has a flat bed with headache rack and I do not have the same clearance requirements that the OP has. So my question is, given two choices, would it be better to put an L bracket on the hood or put the L bracket on my headache rack. Advantage of headache rack seems to be higher elevation and potentially less interference, but slightly spaced away from hood and perhaps reducing ground plane? Advantage of the hood mount option would be a better ground plane, but I'm not sure that will actually be the case. I will eventually put in a proper roof mount, but was looking for something quick to be up and running and was hoping someone would have some advice on application.
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Old 06-29-2017, 2:49 PM
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I don't think either one will be "quick" compared to doing it right. Routing the coaxial cable is the hard part. Drilling a 3/4" hole for the NMO mount on the cab roof doesn't take any more time than drilling the holes to support the L-bracket on the fender or headache rack.

However, given the two options, go for the headache rack.
There's a couple of good reasons:
1. Getting the RF energy away from the vehicle occupants. Running a 50 watt or more radio that close to the driver or passengers is not a good idea. Lots of amateurs do it anyway and will tell you "it doesn't matter", but on the professional side we do take steps to reduce RF exposure to vehicle occupants. Fender mounts on the front of vehicles are usually avoided for this reason. Also, in the olden' days, noisy ignition systems and radios didn't always play well together.
2. Putting the antenna down on the fender doesn't provide a very good ground plane. While it does have a ground, it's lopsided and will make for a funny radiation pattern.
3. The antenna on the fender often can result in unwanted reflections from the cab. If the antenna is too close to the metal structure of the cab, either on the front fender or on the bed rail, it can detune the antenna.
4. The higher the antenna, the farther off the radio horizon is. In other words, the higher the antenna on the vehicle, the better it'll work. While it may only be a 3 foot difference, there's no need to make things any worse.
5. Routing the coaxial cable through the pinch point of the hood, through a hot engine compartment where it may be exposed to chemicals, and then trying to get it into the cab doesn't make a lot of sense if you've got an alternate location that will actually work better.

Where the fender mounts work well is for people with garage clearance issues. Other than that, it comes down to what the owner wants it to look like, or is just being lazy (no offense intended). Sure, some are very happy with them even with the drawbacks. Not everyone has the skill to do a permanent install on the cab, however, it will never work better than a roof top install.

On the flip side….
Getting the antenna up high on the headache rack will put the antenna out in the open where it'll work better.
It will be at a higher risk for tree branch strikes, but if you do the install correctly and use a quality antenna, this shouldn't be an issue.
The ground plane is less than ideal, but it won't be lopsided in just one direction, IF it's mounted in the center of the headache rack.
Cable routing will require (maybe) some additional cable, but it will likely be easier. Look for access holes under the cab. All the trucks I've owned have had several.

As for the antenna….
Don't go cheap. You may save a few dollars with a Tram or Browning antenna, but you'll pay for that in the long run. I've looked at these antennas at trade shows, and they are not high quality. I talked to one of their guys, and he had very little knowledge about the antennas and had no clue who made them or where.
For a few bucks more you can get a name brand antenna that will easily outlast your truck. I'm running Larsen antennas that are nearly 30 years old.
Laird, Anntenex, Comtelco and MaxRad are all good brands.
Same goes for the mount. Get a good one and you won't regret it. Installed properly it'll outlast the life of your truck. I've got 25 year old vehicles here at work driving around with NMO mounts on the roof that still work just fine.

Choosing the correct antenna is important, too. Depending on what band or bands you want there may be several options.
For the fender or headache rack installs where there is a less than ideal ground plane, think about a half wave antenna. They do not require a ground plane to work properly, but they will work better with one.
Most other antenna designs require a ground plane under them in all directions for proper performance.
If you get the half wave now, you'll have no issues when you do transfer it over to the permanent mount on your roof.

If your needs require a dual band antenna, it limits your options. Again, stick with the name brands. Avoid the "Amateur" brand antennas. They are not better than the commercial antennas and are often marketed using gimmicks. You don't need gimmicks, you need a good reliable antenna.
And, in many cases, the commercial brand antennas can be cheaper that the gimmicky amateur/hobby grade stuff.

Last edited by mmckenna; 06-29-2017 at 2:53 PM..
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Old 06-29-2017, 3:31 PM
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Thanks mmckenna. I'm new to the hobby, new to the forum, and I've read enough on here to know that I hoped you might answer :-) Your time and explanation are greatly appreciated.

I'll look into the permanent mount a little more seriously before proceeding. Funny, you felt that the cable wiring is the hardest part and I'm more worried about how to pull out the metal ceiling liner in my 85' GMC Sierra so I can get access to a hole I would drill in the roof than I am routing some coax from my headache rack and up through the cab. You've definitely given me some things to think about.

Also, thanks for the extra advice on the antenna. You caught me just in time to cancel an order I placed on amateur antennas so I could order the commercial variants you recommended.

Thanks again!
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Old 06-29-2017, 3:41 PM
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Always happy to help….


OK, older GM truck….
Often installers will drop the dome light and look up to see if you can see the outer skin of the cab roof. While this will put the antenna near the rear edge of the cab, it's an option.

With an NMO mount, you don't have to have direct access to the under side. They are designed to be installed "blind". You will have to push the cable to where you can access the path to the radio. Sometimes this is easy, sometimes it requires some time with a straightened out coat hanger to grab the cable.
My truck is a 2011 F150, and both antennas were installed in this "blind" fashion.

You just have to be 100% sure you are not drilling into a cross member, wiring or something else that won't get along with the hole saw.
Also, as for the hole saw, avoid the hardware store hole saws designed for wood. Preferably get the hole saws designed for NMO installs. They have a depth limiting feature that will help reduce the chances of punching through the headliner. They'll run $30 or so, but it's worth it.
If that's not an option, DeWalt makes a nice 3/4" hole saw designed for metal. Those work just fine if you are careful when it starts to punch through.

Shouldn't be too much of an issue, though, probably tens of thousands of that era GM pickups out there with antennas installed in them for public works type use, tow trucks,utilities etc.


As for the antenna, if you can tell me what band or bands you intend on operating on, I may be able to provide some suggestions.
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Old 06-29-2017, 3:54 PM
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Excellent!

Not sure on bands yet. Still being new, and not certain what will work best in my terrain, I was thinking dual band antenna for most flexibility for when I eventually make a decision. I know it won't be a complete comparison, but I have a dual band handheld that I thought I would plug into the antenna to at least test before committing to one band or another on a mobile unit. I live in a remote area of WY so not much in terms of radio clubs in my area but I'm noticing a few service trucks in the area with antennas now that I am learning and thought I would flag someone down for suggestions.

I'm presently a GMRS license holder and intend to get my technicians license.

Tx is intended to be primarily local 5 mile range, though hitting a repeater if one is available would be desirable in an emergency situation. It is my firewood (summer) and plow (winter) truck, so having the ability to communicate to other family members in the meadows up in the mountains is desired.

That may not really help, but at least gives some context.
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Old 06-29-2017, 4:16 PM
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Originally Posted by ManUtdWY View Post
Excellent!

Not sure on bands yet. Still being new, and not certain what will work best in my terrain, I was thinking dual band antenna for most flexibility for when I eventually make a decision. .
The NMO mount on the roof gives the most flexibility for different antennas. And the better groundplane.

I run a 18" VHF/UHF antenna, you probably do not need some overgrown long hammie thing.
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Old 06-29-2017, 4:27 PM
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OK, that's a good mix…

The service trucks you see would likely be running on commercial radio systems, so they won't be much help. Unlikely the guys in the trucks will have any knowledge of the actual band or systems they talk on. They are just end users, not technicians. Wouldn't hurt to ask, but you might just get a blank stare.

In the hills, VHF is a better performer than UHF, so the 2 meter band will -likely- be a better choice, but it really depends on who is around you and what they are using. In my area (Central California Coast) I've got a lot of hills around me. I have a Polaris Ranger UTV I use in the mountains of California and Nevada. We used GMRS for a while, with commercial radio and proper antennas, and it worked well, however VHF works better.

Nothing wrong with going dual band. I'd recommend the Larsen NMO-2/70. Solid antenna, will last you decades and will cover the 2 meter and 70 centimeter amateur radio bands.

You can certainly run GMRS on there. In fact, you could get a GMRS mobile with a UHF antenna on the roof and add a dual band amateur mobile later on with a dual band antenna on the roof. That way if your family doesn't want to get their amateur license, they can use GMRS. I did something similar for years, GMRS for family, amateur for everything else.

It will require two radios, in most cases, though. Most all amateur radios do not have the proper FCC certifications to be legally used on GMRS.
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Old 06-29-2017, 4:32 PM
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Quote:
Originally Posted by cmdrwill View Post
The NMO mount on the roof gives the most flexibility for different antennas. And the better groundplane.

I run a 18" VHF/UHF antenna, you probably do not need some overgrown long hammie thing.
Excellent advice.
Skip the "hammy" hobby grade antennas. You don't need that sort of headache in your life. There is nothing magical about them that creates better performance than a commercial antenna. Build quality and materials on a name brand, quality commercial antenna is way better.

And don't let ANYONE talk you into anything other than an NMO antenna. NMO mounts are THE industry standard for professional 2 way radio systems. Once you install an NMO mount, you can change antennas to your hearts content, everything from CB, amateur, GMRS, commercial, cellular, XM/Sirius radio, GPS, etc, all with one mount type.
The amateur hobby has been slow to adopt NMO mounts, and instead rely on proprietary mounts or coaxial connectors that were never intended to support an antenna. They are in no way superior to the NMO standard mount, and in some cases, can lock you into the low end amateur grade antennas.
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Old 06-29-2017, 4:43 PM
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Quote:
Originally Posted by cmdrwill View Post
The NMO mount on the roof gives the most flexibility for different antennas. And the better groundplane.

I run a 18" VHF/UHF antenna, you probably do not need some overgrown long hammie thing.
Good recommend there. That's a Comtelco A1531A. Good antenna. I use these, though in the black version.

RFWIZZ sells them at a fair price, and I've purchased several of these, and others from them.
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Old 06-29-2017, 6:12 PM
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Originally Posted by mmckenna View Post
OK, that's a good mix…

The service trucks you see would likely be running on commercial radio systems, so they won't be much help. Unlikely the guys in the trucks will have any knowledge of the actual band or systems they talk on. They are just end users, not technicians. Wouldn't hurt to ask, but you might just get a blank stare.

In the hills, VHF is a better performer than UHF, so the 2 meter band will -likely- be a better choice, but it really depends on who is around you and what they are using. In my area (Central California Coast) I've got a lot of hills around me. I have a Polaris Ranger UTV I use in the mountains of California and Nevada. We used GMRS for a while, with commercial radio and proper antennas, and it worked well, however VHF works better.

Nothing wrong with going dual band. I'd recommend the Larsen NMO-2/70. Solid antenna, will last you decades and will cover the 2 meter and 70 centimeter amateur radio bands.

You can certainly run GMRS on there. In fact, you could get a GMRS mobile with a UHF antenna on the roof and add a dual band amateur mobile later on with a dual band antenna on the roof. That way if your family doesn't want to get their amateur license, they can use GMRS. I did something similar for years, GMRS for family, amateur for everything else.

It will require two radios, in most cases, though. Most all amateur radios do not have the proper FCC certifications to be legally used on GMRS.
Thanks again. Looking for setup on UTVs for group family travel as well, so that would be a great way to proceed and is largely why I went ahead with the GMRS license to begin with.
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Old 06-29-2017, 6:13 PM
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Good recommend there. That's a Comtelco A1531A. Good antenna. I use these, though in the black version.

RFWIZZ sells them at a fair price, and I've purchased several of these, and others from them.
Thank you for clarification of model on that photo and for the recommendation. I will look into this one as well.
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Old 06-29-2017, 6:24 PM
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Originally Posted by ManUtdWY View Post
Thanks again. Looking for setup on UTVs for group family travel as well, so that would be a great way to proceed and is largely why I went ahead with the GMRS license to begin with.
I'm using commercial VHF radios set to 2 meter amateur radio frequencies. Half wave VHF antenna mounted on the roll cage.
Works really well, and on the trails out this way it's really easy to get separated. Adding radios to our UTV's has made life a whole lot easier.
You can do the same with GMRS just as easy.

If a radio can last mounted on a UTV and the antenna takes frequent tree branch strikes and it all still works, you can be sure you've got a good setup.
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Old 06-30-2017, 8:03 PM
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Thank you for clarification of model on that photo and for the recommendation. I will look into this one as well.
Yes, A1531A, the photo came out sort of fuzzy. You can call Kathie at Comtelco and let her know you want antenna for Ham bands. They also drop ship for some of my 'customers'. Not all antenna disturbers have the Ham band range in stock.
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Old 06-30-2017, 10:10 PM
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Originally Posted by mmckenna View Post
I'm using commercial VHF radios set to 2 meter amateur radio frequencies. Half wave VHF antenna mounted on the roll cage.
Works really well, and on the trails out this way it's really easy to get separated. Adding radios to our UTV's has made life a whole lot easier.
You can do the same with GMRS just as easy.

If a radio can last mounted on a UTV and the antenna takes frequent tree branch strikes and it all still works, you can be sure you've got a good setup.
My dad just bought a new to him Artic Cat side-by-side. I've been hoarding an Astro Saber AVA for that specific application (unless I see something out of GME anytime soon). I may actually install a flexiwhip over the brake light and see how it does.

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Old 07-01-2017, 2:43 AM
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30-40MPH hitting tree branches and it's doing well.
An adapter would be a good solution. I picked up a used CDM-750 for $75.00 and it's worked well. I bought a remote head kit, installed the RF deck in the glove box where it's safe. Control head is tucked under the dash where it's safe. So far, dust, mud, snow, hail, rain, 10F - 100F+ and no issues.

I do use an external speaker with it, mounted under the dash. Even at speed with a full face helmet, no issues hearing it.
I ran a portable with mic/speaker in my helmet for a while, but this works much better.
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Old 07-01-2017, 8:41 PM
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You ALWAYS want to use a half wave antenna when you have less than a quarter wavelength of groundplane in all directions

The Larsen NMO270B is hard to beat
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Old 07-01-2017, 10:50 PM
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You ALWAYS want to use a half wave antenna when you have less than a quarter wavelength of groundplane in all directions

The Larsen NMO270B is hard to beat
The NMO-270b isn't halfwave though. The OP would need to work hard to find a good half wave dual band antenna.

Personally, this is exactly why I mount my antennas through the roof with a proper ground plane around them whenever possible. Reduces the need to find specialized antennas for the application. With a full sized truck, it's not hard to do.

As for the Polaris Ranger, the roll bar mount makes the ground plane odd shaped, so I won't rely on that as a ground plane. For a single band radio, it's easy enough to do.
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Old 07-01-2017, 11:58 PM
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The NMO-270b isn't halfwave though.
You sure about that?

Larsen's own sales literature says that the NMO2/70B is a "Center Loaded 1/2 λ" on 2m. The length and gain are sorta consistent with a 1/2 wave antenna.
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Old 07-02-2017, 12:21 AM
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My dad just bought a new to him Artic Cat side-by-side. I've been hoarding an Astro Saber AVA for that specific application (unless I see something out of GME anytime soon). I may actually install a flexiwhip over the brake light and see how it does.

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Old 07-02-2017, 1:04 AM
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You sure about that?

Larsen's own sales literature says that the NMO2/70B is a "Center Loaded 1/2 λ" on 2m. The length and gain are sorta consistent with a 1/2 wave antenna.
And what's the UHF side?
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