Best mobile ham/gmrs antenna

[WRWE744]

I know this is probably a lot to ask, but I am a new ham, with GMRS contacts I would like to keep in touch with. What is the best mobile (car) antenna for 2 meter/70cm and GMRS?

[WRQC527]

37 minutes ago, WRWE744 said:

I know this is probably a lot to ask, but I am a new ham, with GMRS contacts I would like to keep in touch with. What is the best mobile (car) antenna for 2 meter/70cm and GMRS?

First, welcome. Second, GMRS and 2m/70cm antennas are not really interchangeable. A 2m/70cm dual band antenna works fine for ham radio but won't tune properly for GMRS, and vice-versa. It's unlikely you'd find an antenna that will cover all three frequency ranges. 

[KAF6045]

22 minutes ago, WRWE744 said:

I know this is probably a lot to ask, but I am a new ham, with GMRS contacts I would like to keep in touch with. What is the best mobile (car) antenna for 2 meter/70cm and GMRS?

A diplexer (presuming you are trying to use a dual-band radio) splitting VHF from UHF, a 2m whip, and a commercial wide-band UHF whip spanning ~400-470MHz (and that probably doesn't get any better than 1.5:1 SWR mid-range).

Pretty much any dual-band Amateur antenna is going to be narrow-band with terrible SWR on GMRS frequencies. 440MHz is ~3x 146MHz, so is a harmonic frequency. 465MHz comes in at 3.2x 146MHz, not harmonically related (though 465MHz is close match for MURS 4&5 -- coming at at 155MHz when MURS is 154MHz on the high channels, around 152 on the lower three). https://www.rfwireless-world.com/calculators/RF-Harmonics-Calculator.html

[WRWE744]

17 minutes ago, WRQC527 said:

First, welcome. Second, GMRS and 2m/70cm antennas are not really interchangeable. A 2m/70cm dual band antenna works fine for ham radio but won't tune properly for GMRS, and vice-versa. It's unlikely you'd find an antenna that will cover all three frequency ranges. 

 

15 minutes ago, KAF6045 said:

A diplexer (presuming you are trying to use a dual-band radio) splitting VHF from UHF, a 2m whip, and a commercial wide-band UHF whip spanning ~400-470MHz (and that probably doesn't get any better than 1.5:1 SWR mid-range).

Pretty much any dual-band Amateur antenna is going to be narrow-band with terrible SWR on GMRS frequencies. 440MHz is ~3x 146MHz, so is a harmonic frequency. 465MHz comes in at 3.2x 146MHz, not harmonically related (though 465MHz is close match for MURS 4&5 -- coming at at 155MHz when MURS is 154MHz on the high channels, around 152 on the lower three). https://www.rfwireless-world.com/calculators/RF-Harmonics-Calculator.html

So in that case, what is my best option for a regular dual band amateur antenna?

[WRQC527]

Just now, WRWE744 said:

 

So in that case, what is my best option for a regular dual band amateur antenna?

That's a question with a ton of answers. It depends on what kind of vehicle, what the vehicle is made of (aluminum, fiberglass, etc), what kind of mounting options (magnet mount, lip mount, drilling into the roof, etc), where you park (garage, outside), what kind of driving (on or off off road with lots of overhead branches or wide open desert), etc. Pretty much everyone here will tell you something different, not because they're right or wrong, but because their use-case is unique. I run a Diamond AZ504 on my van because it (barely) fits in the garage and it works very well where I am in Southern California. Many others use taller antennas because they have more gain. It all depends on what works best for you.

[wrci350]

1 hour ago, WRWE744 said:

I know this is probably a lot to ask, but I am a new ham, with GMRS contacts I would like to keep in touch with. What is the best mobile (car) antenna for 2 meter/70cm and GMRS?

Comet CA 2X4SR

It's advertised as "140-160/435-465 MHz" but I just went out to my truck and swept mine and the SWR is about 1.75:1 on the 467 MHz repeater inputs, which is certainly acceptable.  It's a gain antenna, but it's kind of ugly and 40" high, which pretty much rules out drive-thrus for sure!

Larsen 150/450/800

I also sometimes use the Larsen 150/450/800 commercial antenna on my truck.  I'm probably going to switch to it later this week so I'll sweep it if I get a chance, but it should be fine on 2m/70cm/GMRS too.  It's unity gain but it's also only 16.5" high.

[WRFP399]

Tram 1181?

[jeffsimmons1960]

I just ordered a Nagoya UT-72 that they claim works both bands, along with an Anytone AT-778UV dual band, as I'm going for my amateur license this month. Obviously, I don't have any experience with them, I just went by reviews and YouTube. Hope this helps. https://www.youtube.com/watch?v=TSQszkFH3G4

[marcspaz]

Over the past few years, I have tried just about every commonly discussed antenna available in the US.  I literally have 8 or 10 antennas sitting in my office and garage right now, and 4 more in/on the truck.

 

Anecdotal I know, but the absolute best antenna I have used for 2m/70cm/GMRS is the Diamond NR-7900a.  It's rated for 300w/250w and, 3.7/6.4 gain.  Real-world, it far out-performs my dedicated MXTA26 GMRS antenna, which is the best dedicated GMRS antenna I have used.  Not only is the range the best and able to handle the most power, the SWR on 146.52 is 1:1, on 446 it's 1.3:1, on 462 it's 1.6:1, and on 467 it's 1.5:1. 

 

The Diamond NR-770 is a close second. The power ratings are a little lower at 200w/200w, the gain is a little lower at 3.0/5.5, and the SWR is the same everywhere but 462, where it's a little higher... 2:1.  It's 1.4:1 on 146, 1.1:1 on 446, and 1.5:1 on 467 (which is where I spend most of my time).  The slight sacrifice in performance benefits does yield a smaller, thinner, lighter antenna that is more discrete.  However, I still prefer to use the NR-7900.

[Lscott]

1 hour ago, marcspaz said:

Over the past few years, I have tried just about every commonly discussed antenna available in the US.  I literally have 8 or 10 antennas sitting in my office and garage right now, and 4 more in/on the truck.

 

Anecdotal I know, but the absolute best antenna I have used for 2m/70cm/GMRS is the Diamond NR-7900a.  It's rated for 300w/250w and, 3.7/6.4 gain.  Real-world, it far out-performs my dedicated MXTA26 GMRS antenna, which is the best dedicated GMRS antenna I have used.  Not only is the range the best and able to handle the most power, the SWR on 146.52 is 1:1, on 446 it's 1.3:1, on 462 it's 1.6:1, and on 467 it's 1.5:1. 

 

The Diamond NR-770 is a close second. The power ratings are a little lower at 200w/200w, the gain is a little lower at 3.0/5.5, and the SWR is the same everywhere but 462, where it's a little higher... 2:1.  It's 1.4:1 on 146, 1.1:1 on 446, and 1.5:1 on 467 (which is where I spend most of my time).  The slight sacrifice in performance benefits does yield a smaller, thinner, lighter antenna that is more discrete.  However, I still prefer to use the NR-7900.

I tested a Diamond CSB7900 and the match wasn't that good.

A Diamond SG7500A tested OK on the Ham bands but not good for MURS or GMRS. Maybe with some tweaking It might work.

https://forums.mygmrs.com/gallery/image/283-sg7500a-swr-scans-2jpg/

The only antenna I have that works great on Ham, MURS and GMRS is my old trusty Comet CA-2x4MB. Unfortunately they don't make them any more. I have two, one is new in the original packaging. The other one the fold over spring is shot so I have the antenna is permanently fixed in the upright position. Otherwise it still works fine, but it's a huge monster, about 5 feet tall.

https://forums.mygmrs.com/gallery/image/282-ca-2x4mb-scansjpg/

https://forums.mygmrs.com/gallery/image/259-ca-2x4mb-jeepjpg/

 

[Lscott]

17 hours ago, wrci350 said:

Comet CA 2X4SR

It's advertised as "140-160/435-465 MHz" but I just went out to my truck and swept mine and the SWR is about 1.75:1 on the 467 MHz repeater inputs, which is certainly acceptable.  It's a gain antenna, but it's kind of ugly and 40" high, which pretty much rules out drive-thrus for sure!

I recommended one of these to a work buddy for GMRS. He mounted it on the driver's side fender of a pickup truck near the roof pillar. The match was reasonably good on the UHF GMRS frequencies. I've attached the scans I did with it mounted on his truck.

Being a 5/8 wave antenna it needs a GOOD ground plane to give acceptable SWR across it's operational range.

Antenna Scan Results (CA-2x4SR VHF TRUNK LIP MOUNT).pdf Antenna Scan Results (CA-2x4SR UHF TRUNK LIP MOUNT).pdf

[marcspaz]

Honestly, I don't know if it's just my antennas, but I have a CA-2x4SR both in NMO and UHF style and they both kinda suck. The SWR is fine everywhere except on 462 MHz frequencies. But they just don't seem to perform well compared to some of my other antennas. Like, to the point that I don't use either of the anymore. 

 

At one point, they were my favorite, for reference. 

[wayoverthere]

3 hours ago, Lscott said:

Being a 5/8 wave antenna it needs a GOOD ground plane to give acceptable SWR across it's operational range.

Antenna Scan Results (CA-2x4SR VHF TRUNK LIP MOUNT).pdf 287.06 kB · 3 downloads Antenna Scan Results (CA-2x4SR UHF TRUNK LIP MOUNT).pdf 287.12 kB · 4 downloads

That fits pretty well with what I remember from when I tested mine (mag mounted, center of roof of single cab  compact truck). i generally aim for 1.5 or less, and i want to say 1.3 was about the worst i saw testing with a swr meter, not vna.

it does seem to give up a little in exchange for that wide bandwidth though...judging on use, the sbb5 seems to do as well on the fender as the 2x4 did on the roof.

[Lscott]

42 minutes ago, marcspaz said:

Honestly, I don't know if it's just my antennas, but I have a CA-2x4SR both in NMO and UHF style and they both kinda suck. The SWR is fine everywhere except on 462 MHz frequencies. But they just don't seem to perform well compared to some of my other antennas. Like, to the point that I don't use either of the anymore. 

 

At one point, they were my favorite, for reference. 

I discovered the antenna is sensitive to the mounting location and type of mount. I've attached a zip file of some other  tests I did with different mounting locations and types of mounts, like magnet - ground radials etc.

This was one of the better mounts and location in a home office setting inside a room.

https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/

 

CA-2x4SR Antenna Tests.zip

[marcspaz]

15 minutes ago, Lscott said:

I discovered the antenna is sensitive to the mounting location and type of mount. I've attached a zip file of some other  tests I did with different mounting locations and types of mounts, like magnet - ground radials etc.

This was one of the better mounts and location in a home office setting inside a room.

https://forums.mygmrs.com/gallery/image/268-ca-2x4sr/

 

CA-2x4SR Antenna Tests.zip 2.81 MB · 0 downloads

 

That image has a great looking setup!  Ill check out the ZIP when I get home.

 

[Lscott]

1 minute ago, marcspaz said:

 

That image has a great looking setup!  Ill check out the ZIP when I get home.

 

The antenna is screwed into a really short UHF barrel adapter and the other end has a length of RG-8 coax coiled up then reduced to a short run of RG-58. The whole thing is attached to a sawed off clothing display rack I found in the trash. A stainless steel hose clamp is used to hold it on the end of the tube along with 4 brass rods, about 1/16 inch diameter and approximately 19 inches long, bent down at roughly a 45 degree angle for a ground plane.   

[WRWE744]

16 hours ago, jeffsimmons1960 said:

I just ordered a Nagoya UT-72 that they claim works both bands, along with an Anytone AT-778UV dual band, as I'm going for my amateur license this month. Obviously, I don't have any experience with them, I just went by reviews and YouTube. Hope this helps. https://www.youtube.com/watch?v=TSQszkFH3G4

I'm new to ham and I don't have an SWR meter, but I decided to go ahead and try my Nagoya UT-72G that is tuned for GMRS. I have hit a repeater over 12 miles away on 2 meter with no issue, and the guys on the other end said I sounded loud and clear.

[Lscott]

57 minutes ago, WRWE744 said:

I'm new to ham and I don't have an SWR meter, but I decided to go ahead and try my Nagoya UT-72G that is tuned for GMRS. I have hit a repeater over 12 miles away on 2 meter with no issue, and the guys on the other end said I sounded loud and clear.

You should check the match on it before running high power. While you can hit a remote repeater OK on 2M the antenna is trimmed for the MURS band on VHF. The antenna would be too short. A high SWR could cause overheating and final amplifier stage failure. Many radios recommend the SWR not to exceed 2:1, which if they have a protection circuit will reduce output power to save the finals above that limit.

[WRQC527]

Odd. The Nagoya Ut-72G shows up as a dual-band in some places, but just GMRS in other places, including its own packaging. 

[Bande1]

On 4/4/2023 at 5:49 PM, WRQC527 said:

Odd. The Nagoya Ut-72G shows up as a dual-band in some places, but just GMRS in other places, including its own packaging. 

theres 2 different ones. a GMRS and a dual band. if it says 72G its the GMRS version.

 

THIS antenna is the absolute best dual band I have found that isn't ridiculously tall. It beats the living snot out of a UT-72 for not much more and makes the Nagoya look like a toy from walmart. (it does in fact tune up to 467mhz decently)

https://www2.randl.com/index.php?main_page=product_info&cPath=2_1200&products_id=38572

if height or cost isn't an issue go with this

https://www2.randl.com/index.php?main_page=product_info&cPath=2_1200&products_id=30318

 

attached is the Jetstream antenna next to a diamond MR-77 (same size as UT-72) to see how much taller it is.

[wrci350]

On 4/3/2023 at 4:46 PM, wrci350 said:

Comet CA 2X4SR

Larsen 150/450/800

So I swept both of my mobile antennas yesterday.  The SWR readings on the Larsen are actually better than on the Comet which doesn't really surprise me since it's designed to be a wide bandwidth antenna (you trade gain for bandwidth).  Here are the max SWR readings on five different bands.  Either one would be just fine for 2m/70cm ham, MURS, or GMRS.  I found it very interesting that the Comet also had very low SWR on 220.

Antenna	2m	1.25m	70cm	GMRS	MURS
Larsen 150/450/800	1.35	4.1	1.8	1.6	1.25
Comet CA-2x4SR	1.15	1.23	2.15	1.68	1.46

On 70cm, the Comet SWR starts at just under 2.15 at 430 MHz, dips to 1.5 at 435, back up to 1.95 at 443 and down to 1.55 at 450.  Not optimal, but under 2:1 from 431 to 450 MHz.  I can post the graphs if anyone is interested.

 

[gortex2]

I run the larsen on all my vehicles. Its the best all around antenna I have found for all the bands you asked about as well as public safety bands I operate on. 

[Sshannon]

1 hour ago, wrci350 said:

So I swept both of my mobile antennas yesterday.  The SWR readings on the Larsen are actually better than on the Comet which doesn't really surprise me since it's designed to be a wide bandwidth antenna (you trade gain for bandwidth).  Here are the max SWR readings on five different bands.  Either one would be just fine for 2m/70cm ham, MURS, or GMRS.  I found it very interesting that the Comet also had very low SWR on 220.

Antenna	2m	1.25m	70cm	GMRS	MURS
Larsen 150/450/800	1.35	4.1	1.8	1.6	1.25
Comet CA-2x4SR	1.15	1.23	2.15	1.68	1.46

On 70cm, the Comet SWR starts at just under 2.15 at 430 MHz, dips to 1.5 at 435, back up to 1.95 at 443 and down to 1.55 at 450.  Not optimal, but under 2:1 from 431 to 450 MHz.  I can post the graphs if anyone is interested.

 

I would be interested in seeing the graphs.

[wrci350]

Comet CA-2x4SR

[wrci350]

Larsen 150/450/800