How is the Comet CA-2X4SR antenna?

[dosw]

Reviews for this antenna seem to be generally very good. It comes in two versions: the PL-259 version, and the NMO version (CA-2X4SRNMO). Both versions are foldable. The antenna is marketed as broad multi-band, with a pretty wide VHF frequency range, and a wide UHF frequency range: 

 

• Dualband: VHF and UHF 140-160 MHz / 435-465 MHz
• VSWR: Less than 2:1 / Gain: 3.8/6.2dBi / Max Power: 150W FM

 

My question is how does it perform at 467.5500-467.7250. It's supposed to achieve <2:1 SWR at up to 465MHz, but 467.7250 is almost 3MHz outside of that spec.

 

My MXTA26, mounted on my vehicle, gets a 1.4:1 SWR in the 462.xxxx range, and 1.1:1 SWR in the 467.xxxx range. So it's almost impossibly good for working repeaters, as far as mobile antennas go. How does the CA-2X4SR compare?

 

https://www.amazon.com/Comet-Original-CA-2X4SR-140-160-435-465/dp/B00HVGQZ9G

 

My Laird/TE B4505CN (5dbi) is in the 1.15-1.35:1 SWR range across the 426.xxxx and 467.xxxx range. And the HYS SDN1-T (3dbi) is in the 1.1-1.3 SWR range throughout the 462.xxxx and 467.xxxx frequencies, also when mounted on my vehicle.

 

 

[WRYZ926]

The 2x4SR is an excellent antenna and works very well on 2m, 70cm, and GMRS. I run one on my Honda Pioneer 500 SxS along with a 20 watt radio. The highest SWR reading on the three bands is 1.8 which is good to go. I am using the Midland magnet mount with the antenna on an expanded metal rack.

[kidphc]

Reviews for this antenna seem to be generally very good. It comes in two versions: the PL-259 version, and the NMO version (CA-2X4SRNMO). Both versions are foldable. The antenna is marketed as broad multi-band, with a pretty wide VHF frequency range, and a wide UHF frequency range: 
 

• Dualband: VHF and UHF 140-160 MHz / 435-465 MHz
• VSWR: Less than 2:1 / Gain: 3.8/6.2dBi / Max Power: 150W FM

 
My question is how does it perform at 467.5500-467.7250. It's supposed to achieve SWR at up to 465MHZ, but 467.7250 is almost 3MHZ outside of that spec.
 
My MXTA26, mounted on my vehicle, gets a 1.4:1 SWR in the 462.xxxx range, and 1.1:1 SWR in the 467.xxxx range. So it's almost impossibly good for working repeaters, as far as mobile antennas go. How does the CA-2X4SR compare?
 
https://www.amazon.com/Comet-Original-CA-2X4SR-140-160-435-465/dp/B00HVGQZ9G
 

First it's a heavy stiff antenna, part of the reason it is broadband.

Marc and myself, as well as others could not get the swr into a manageable number in the upper gmrs regions. Other have had it lower than 1.7. Not me, it was floating closer to 2.5 in the mid of the band.

It heard well, but was starting to be iffy on transmit. I got good audio reports.

I don't know about Marc, but mine was on a hood mount. So that certainly doesn't help with the ground plane.



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[WRYZ926]

I just remembered that I checked the SWR with the SxS parked inside the garage. I am sure the metal garage doors and metal door tracks affected the SWR reading. SWR on the GMRS repeaters was no higher than 1.8 for 467 MHz while the SWR for 462 MHz, 2m and 70cm was all around 1.2 to 1.4. 

20 minutes ago, kidphc said:

First it's a heavy stiff antenna, part of the reason it is broadband.

Ys it is. I ended up getting the spring base for my 2x4SR.  https://www.dxengineering.com/parts/cma-ca-spr

The spring did not effect the SWR readings.

[kidphc]

I just remembered that I checked the SWR with the SxS parked inside the garage. I am sure the metal garage doors and metal door tracks affected the SWR reading. SWR on the GMRS repeaters was no higher than 1.8 for 467 MHz while the SWR for 462 MHz, 2m and 70cm was all around 1.2 to 1.4. 
Ys it is. I ended up getting the spring base for my 2x4SR.  https://www.dxengineering.com/parts/cma-ca-spr
The spring did not effect the SWR readings.

Nope it doesn't. I have had mine fold over before the spring did anything on a solid whack..lol



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[wrci350]

It's long, it's stiff, it's ugly, and I still haven't figured out how to make it fold!

But ... I was using it on a magmount on top of the roof of my crew cab truck and had a good SWR on GMRS and MURS as well as 2m, 1.25m, and 70cm amateur frequencies.  The only place it went above 2:1 was at the very bottom of 70cm although it was between 1.5:1 and 2:1 on the entire band.

It worked well for me ... but it's long, it's stiff, it's ugly (did I say that??), and I now have a permanent NMO mount on my truck and I'm using a Larson NMO2/70SH which is only 19" long (less than half as long as the Comet) and actually has a *better* SWR not only on 2m/70cm but also on GMRS and MURS.  It IS a unity gain antenna which may be good or bad depending on the terrain.

And it's nice to be able to go through a drive-thru without taking my antenna down!

[kidphc]

To fold, grab a meaty part pull up, then try to fold it over. Go slow it's fairly stiff the first couple of times.

The hinge has been known to fail over time.

Another thing get extra grub screws. They are really only designed to used once. But go through clean them with isopropyl alcohol and blue loctite them. They have been also know to loosen up overtime.

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[WRUU653]

I had considered getting this very antenna but ended up with another Comet antenna the SBB-5 NMO and I have been very happy with it and while I can’t speak to the CA-2X4SR specifically I wouldn’t hesitate to get another Comet antenna. 

[SteveShannon]

2 minutes ago, WRUU653 said:

I had considered getting this very antenna but ended up with another Comet antenna the SBB-5 NMO and I have been very happy with it and while I can’t speak to the CA-2X4SR specifically I wouldn’t hesitate to get another Comet antenna. 

That’s what I have also. 

[Lscott]

What kind of SWR do you get with the SBB-5 antenna on the Ham bands, MURS and GMRS? I'm still looking for a 1/2 wave ground independent antenna I can use for Ham, MURS and GMRS. I need something that will work on my luggage roof rack rail mount. The CA-2x4SR is a 5/8 wave design which requires a GOOD ground plane, which I don't have with the mount I'm using.

https://forums.mygmrs.com/gallery/image/473-close-up-of-mobile-mount/?context=new

https://forums.mygmrs.com/gallery/image/471-mobile-mount-with-antenna-rear-view/

https://forums.mygmrs.com/gallery/image/472-mobile-antenna-install-side-view/

Old installation on my Jeep.

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

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

 

[dosw]

Mine arrived today. I tested it on my vehicle; at 462.xxxx and 467.xxxx it produced SWRs between 1.1-1.35:1. It was better than expected. Mounted on a magnetic mount on my super-sketchy window air conditioner it produced SWRs between 1.01 and 1.3:1 in the 462&467 range, and 1.01-1.5:1 in the VHF range. I haven't tested fars yet, but really I don't need to. It's going to be just fine for my needs.

 

It's so true that this is a big, heavy, ugly antenna, by some definitions of ugly. I don't mind it.

 

I also tested it on both MURS and GMRS frequencies mounted on a camera tripod with a GPK-01 ground plane kit. With the kit its SWR at MURS frequencies was still 1.1-1.3;1. And at GMRS frequencies things got a little worse, like 1.7-1.8:1. Without the GPK-01 ground plane kit, mounted on a camera tripod, it was more like 1.7-1.8:1 in the VHF range, and 2.4:1 in the GMRS range.

 

Great antenna. I'm glad I got it.

 

At some point I'd like to do a shootout of the antennas I've collected: MXTA13, MXTA25, MXTA26, HYS SDN1-T, Laird TE B4505CN, and this CA-2X4SR-NMO antenna. If anyone has parameters or methodologies they'd like to see, let me know. I can toss the GPK-01 ground plane kit into the mix as well, if we want. For mounts, I have that kit, plus a hood lip mount (positioned such that I have at least seven inches of vehicle body steel all around), and a magnetic mount.

[WRUU653]

3 hours ago, Lscott said:

What kind of SWR do you get with the SBB-5 antenna on the Ham bands, MURS and GMRS?

1.0 on 146.520, 1.25 on 446.000, 1.83 on 151.940, 1.86 on 462.562, 462.550 and 462.725, and 2.38 on 467.625 

Here is what I am using for a mount. It bolts on with the hood hinge bolts.  It isn’t mounted as high as you have but it works and I have no complaints. 

Edited June 20 by WRUU653
Typo

[Lscott]

Thanks for everyone who responded. I might pick one of these up to experiment with it. The SWR numbers look encouraging.

[Lscott]

For testing I’ve used a section of sheet metal about 36 to 40 inches square from the local hardware store specifically to simulate a ground plane when using a magnet mount. This way I don’t need to drag crap outside for testing. I can do it in the basement. The sheet metal section is about the area of a passenger vehicle roof. It’s big enough for a VHF through UHF antenna.

https://forums.mygmrs.com/gallery/image/306-220-mhz-antenna-scan/?context=new

I’ve also used some brass rods bent at a 45 degree angle for a cheap home made ground radial kit. The rods were held in place using a stainless steel hose clamp around a short SO-239 barrel adapter. My antennas are typically using a UHF mount.

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

 

[marcspaz]

On 6/18/2024 at 12:06 PM, kidphc said:

First it's a heavy stiff antenna, part of the reason it is broadband.

Marc and myself, as well as others could not get the swr into a manageable number in the upper gmrs regions. Other have had it lower than 1.7. Not me, it was floating closer to 2.5 in the mid of the band.

It heard well, but was starting to be iffy on transmit. I got good audio reports.

I don't know about Marc, but mine was on a hood mount. So that certainly doesn't help with the ground plane.



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Mine was on a hood mount, too, but I have run plenty of other antennas in the same spot with much better results. 

 

Overall, I would say that it's an OK antenna if you are primarily using it for Ham radio and occasionally use it on the 462 simplex frequencies. I was very disappointed with the SWR and performance on the 467 frequencies.

 

I ended up replacing it with an MXTA27, and then eventually with a Diamond NR-770, when not sharing my NR-7900 with my amateur gear.  All 3 antennas are much better performing on the 467 frequencies. 

[Lscott]

9 hours ago, marcspaz said:

I ended up replacing it with an MXTA27, and then eventually with a Diamond NR-770

What kind of match did you get on the Diamond? The NR-770 and the SBB-5 look like a clone of the other one. Might even come off the same assembly line with a different label?

[Lscott]

I did find the following on the NR-770 antenna. worth reading.

https://www.hamradio.me/antennas/diamond-antenna-nr770hbnmo-with-k515snmo-mobile-antenna-review.html

[marcspaz]

2 hours ago, Lscott said:

What kind of match did you get on the Diamond? The NR-770 and the SBB-5 look like a clone of the other one. Might even come off the same assembly line with a different label?

 

This is everything I have notes on...

@OffRoaderX I wanted to tag you in case you're interested in my results, too.

MXTA26

Freq in MHz - SWR

440 - 1.5

446 - 1.8

448 - 2.1

462 - 1.5

467 - 1.3

 

NR-7900

140 - 2.2

142 - 1.7

146.520 - 1.4

148 - 1.3

154 - 2.8

440 - 1.6

448 - 1.3

462 - 1.6

462 - 1.5

 

NR-770

140 - 1.8

142 - 1.5

146.520 - 1.4

148 - 1.3

154 - 2.6

440 - 1.1

446 - 1.1

448 - 1.2

462 - 2.1

467 - 1.5

 

SBB1

140 - 1.9

142 - 1.8

146.520 - 1.7

148 - 1.6

154 - 1.6

440 - 1.6

446 - 1.3

448 - 1.0

462 - 1.8

467 - 1.2

[dosw]

11 hours ago, marcspaz said:

 

Mine was on a hood mount, too, but I have run plenty of other antennas in the same spot with much better results. 

 

Overall, I would say that it's an OK antenna if you are primarily using it for Ham radio and occasionally use it on the 462 simplex frequencies. I was very disappointed with the SWR and performance on the 467 frequencies.

 

I ended up replacing it with an MXTA27, and then eventually with a Diamond NR-770, when not sharing my NR-7900 with my amateur gear.  All 3 antennas are much better performing on the 467 frequencies. 

You probably mean MXTA26, which is still my primary antenna on the vehicle. I'm using the Comet in a different application where I wanted dual-band without compromising tooooo much in GMRS. It's the first one that gets my antenna count in this application down to one.

 

If I had to rank the antennas I've tried on GMRS performance I would go with Midland MXTA26 (6dbi) > Laird TE B4505CN (5dbi, NGP) > Comet CA-2X4SR-NMO (6.2dbi) > HYS SDN1-T (3dbi) > Midland MXTA25 (3dbi) > Midland MXTA13 (2.1dbi). But that's just ranking how I sound from 3-miles away on simplex as well as some signal reports from distant repeater users.

Each of these have their own strengths. The MXTA26 is just a good solid antenna, 32 inches tall. The B4505CN is a pretty solid "no ground plane" antena. Good signal reports, good SWR without a ground plane. The 2X4SR is not bad at GMRS, and also good in MURS and Marine VHF ranges. The SDN1-T is only 17.7 inches long, and works pretty good for closer-in repeaters, not great over longer distances across the city. The MXTA25 is so compact and doesn't draw much attention, still working alright given its form factor, and the MXTA13 is perfect to keep in the glovebox or put on the packing list in case of an NMO mount failure. Lightweight, it travels easy.

[marcspaz]

I still have my CA-2X4SR...  I will probably sweep it again in a bit.  I don't have notes on the exact numbers or performance experience, just memories of disappointment.  I remember the main reason I changed it was because I was sitting next to a friend of mine and his mobile was receiving a station fairly well, that my radio didn't hear at all, and we have the exact same radio, the same mount, on the same year/make/model vehicle.  The only difference was the antenna.

[WRYZ926]

@marcspaz you did get good results with your Comet SBB1. I have a SBB1 NMO and the SWR on 462 and 467 are over 2.0 while 2m and 70cm are under 1.5

[marcspaz]

3 minutes ago, WRYZ926 said:

@marcspaz you did get good results with your Comet SBB1. I have a SBB1 NMO and the SWR on 462 and 467 are over 2.0 while 2m and 70cm are under 1.5

 

Hmmm  I wonder if it's mounting location or if the NMO version performs differently.  I've had great luck with it... though there is no obvious gain to it.

[WRYZ926]

4 minutes ago, marcspaz said:

 

Hmmm  I wonder if it's mounting location or if the NMO version performs differently.  I've had great luck with it... though there is no obvious gain to it.

No idea on that one. I have my SBB1 NMO mounted in the center of the roof on my 2023 Ford Escape using a Midland MXTA12 magnet mount. The Comet 2x4SR is using a Melowave magnet mount which is on the expanded metal rack on my SxS. I'll swap the antennas around to see if the mag mounts make any difference.

[marcspaz]

Quick note... with the exception of the Midland, my antennas are UHF mounts, not NMO.

So, you all should find some entertainment in this.  I just finished sweeping my Comet CA-2X4SR and on the the hood lip mount, the antenna does not work as well as on the thru-hole mount on the bed rail.

On the thru-hole mount on the pick-up bed, these are the current values.

140 - 1.5

142 - 1.2

146.520 - 1.3

148 - 1.3

154 - 1.5

440 - 1.6

444 - 1.7

448 - 1.5

462 - 2.1

467 - 1.9

 

The biggest deviations on the hood lip mount are seen in the MURS frequencies and in the GMRS frequencies.  The curve is much steeper and the center tuning moves down in frequency.

154 - 2.0

462 - 1.9 (improvement)

467 - 3.1 (worse by more than 1 unit)

 

So, it looks like the SWR is better on the VHF frequencies while using the Comet and better on the UHF frequencies using the Diamond.  I am fine with this since the NR-770 is being used on my Moto exclusively for GMRS.

[WRYZ926]

I just tested the 2x4SR versus the SBB1 on the Melowave magnet mount. Granted the SWR will be a little higher since I tested with the SxS parked inside the garage.

The 2X4SR was 1.8 at 467.600 and below 1.5 on 462.600. It was 1.6 or below on 2m and 70cm. The SBB1 was at 1.8 at 467.600 and at 2.5 at 462.600.

I then put the SBB1 back on my Ford Escape. Inside the garage, SWR was 1.7 or lower on 2m and 70cm. On 467.600 it was 2.2 and on 462.600 it was 2.8.

Again the low ceiling along with the metal garage door tracks and garage door opener being close to both antennas will affect the SWR readings and make them higher.

I then pulled the Escape out of the garage so that there was nothing close to the antenna. This was using the Midland MXTA12 magnet mount. SWR was 1.6 or below on 2m and 70cm. SWR at 467.600 was at 1.6 and at 462.600 it was 2.2

I can say with my non scientific experiment that the Melowave magnet mount works better than the Midland magnet mount. Both mounts are 3.5 inches in diameter but the Melowave is not as tall. I used my Rig Expert Stick Pro analyzer for testing.

For the OP, the 2x4SR antenna will work fine for 2m, 70cm, and GMRS.

PS: I tested both antennas with the Melowave mount on the expanded metal rack and also on top of the aluminum tool box (with steel plate attached). The SWR did improve with both antennas on top of the tool box. There was not a big improvement with the 2x4SR. The SBB1 had more improvement on top of the tool box. With the SBB1 mounted lower on the rack, the SWR at 462.600 was at 2.8 and at 467.600 it was 2.3.