Does such an antenna exist?

[SvenMarbles]

I'm curious if there is a good quality base antenna with high gain that is GMRS and dual bands with MURS? I've found LMR antennas but the VHF is a few MHZ high for the PS fire band. I'm trying to just have 1 antenna on my mast and I use both services regularly..   

[warthog74]

The Comet GP-9NCA is probably the best you'll find specifically tuned for murs/gmrs. It's not cheap though.

[WRYZ926]

Here are a few options I found that does both MURS and GMRS. 

Comet GP-9NCA $210

Comet GP-6NC $150

The GP-9NC is 16' 6" long and the GP-6NC is 10' 2" long. For comparison the Comet CA-712EFC is 10' 5" long but is not tuned for MURS

There are other antennas but most are listed at only going up to 465MHz.

[SvenMarbles]

Shortly after posting this I did find the GP9NCA. I’m considering it. My only hang up is that it’s a complete beast of an antenna. I’ll need to guy my mast if I stick that thing on top of it. Also I like to keep my antennas sort of discreet from the curb view as well. But the gain and dual banding that it does fits exactly what I am looking for. I guess that’s just what an antenna of those parameters needs to be lol. 
 

The GP6NC has that same issue with the VHF side being a bit above MURS. Maybe it’s still usable? IDK. Anyone ever put one on a VNA? Is the 151-154 still in the neighborhood of 1.5?
 

[MarkInTampa]

29 minutes ago, SvenMarbles said:

 

The GP6NC has that same issue with the VHF side being a bit above MURS. Maybe it’s still usable? IDK. Anyone ever put one on a VNA? Is the 151-154 still in the neighborhood of 1.5?
 

Here's a sweep I just did on the GP-6NC per your request...

 

[WRYZ926]

I will throw out one other option if you don't mind using a mobile antenna for your base station. The Comet 2x4SR mobile antenna will cover all of the MURS and GMRS frequencies. The down side to using a mobile antenna is that you will need to install it onto some type of metal ground plane for the best results. A large cookie sheet works well for this.

Comet 2x4SR-NMO $69

The 2x4SR is only 40" long. It is listed at only going to 465 MhZ but I can tell you from personal experience that it works fine on GMRS repeater channels (467 MHz). I am using one on my SxS and the SWR is 1.8 at 467 MHz and 1.2 at 462 MHz.

There are other options from different brands that list 465 MHz. I can't tell you how well they will or will not work since I have not tried any of them.

[WRYZ926]

From what @MarkInTampa just posted, I would say that the Comet GP-6NC will work great for you. A SWR of 1.8 or less is just fine for any band/frequency.

Sometimes people get hung up on chasing after the perfect SWR. Most of us are guilty of that. But anything 2.0 or less is fine.

[MarkInTampa]

1 minute ago, WRYZ926 said:

From what @MarkInTampa just posted, I would say that the Comet GP-6NC will work great for you. A SWR of 1.8 or less is just fine for any band/frequency.

Sometimes people get hung up on chasing after the perfect SWR. Most of us are guilty of that. But anything 2.0 or less is fine.

The GP-6NC is tuned about as good as it gets for GMRS. SWR of 1.02 at 462.5MHz and 1.05 at 467.5MHz. Also usable across most of the 70cm band. I've also got a GP-9NC but was disappointed with it. It worked a bit better in the VHF bands but a bit worse on UHF. Don't know if its my terrain, height of antenna (30ft), big oak tree near the antenna or what so put the GP-6NC back as UHF is a bit more important to me than VHF.

Here's a sweep of the GP-6NC from 430MHz to 470MHz:

 

[WRYZ926]

8 minutes ago, MarkInTampa said:

The GP-6NC is tuned about as good as it gets for GMRS. SWR of 1.02 at 462.5MHz and 1.05 at 467.5MHz. Also usable across most of the 70cm band.

One definitely can't complain about those SWR readings.

I don't use MURS so I concentrate more on antennas that work well for 2m, 70cm, and GMRS. From your posts, the Comet GP-6NC looks to be a very good antenna for MURS and GMRS

24 minutes ago, MarkInTampa said:

I've also got a GP-9NC but was disappointed with it. It worked a bit better in the VHF bands but a bit worse on UHF

I wonder if it was just your antenna or if all of the GP-9NC antennas are that way. I have a standard dual band GP-9 that does well for 2m, 70cm, and GMRS. I have not tested it for MURS.

[SvenMarbles]

2 hours ago, MarkInTampa said:

Here's a sweep I just did on the GP-6NC per your request...

 

Oh that really isn’t bad at 151.94 (our neighborhood channel). I wonder if I’d actually get that after my install and coax though.. you know how it is..

[SteveShannon]

5 minutes ago, SvenMarbles said:

Oh that really isn’t bad at 151.94 (our neighborhood channel). I wonder if I’d actually get that after my install and coax though.. you know how it is..

The addition of coax typically reduces the measured reflected power, resulting in a lower observed SWR.

[MarkInTampa]

4 minutes ago, SvenMarbles said:

Oh that really isn’t bad at 151.94 (our neighborhood channel). I wonder if I’d actually get that after my install and coax though.. you know how it is..

All my measurements above were done with 50ft of LMR400 cable and the antenna up 30ft for what it's worth.

 

[SvenMarbles]

3 hours ago, MarkInTampa said:

Here's a sweep I just did on the GP-6NC per your request...

 

 

Thank you for doing that scan. It really informs what I might choose to do..

[SvenMarbles]

Just now, MarkInTampa said:

All my measurements above were done with 50ft of LMR400 cable and the antenna up 30ft for what it's worth.

 

That's literally my setup. 50 ft run of LMR400 on a mast very similar to that..

[MarkInTampa]

18 minutes ago, SvenMarbles said:

That's literally my setup. 50 ft run of LMR400 on a mast very similar to that..

It's actually a 2" or 2.5" (can't remember) aluminum 35ft sectional flag pole. I thought by clamping it to the side of the house it should be able to handle the wind load of the antenna without much of a issue without guy wires. The mast is located directly behind my radio and during high winds I could hear it creaking a bit and it swayed a bit more that I wanted. It was really bad when I had the GP-9 on it. I guyed it with some outdoor rated paracord from DX Engineering and it's been great since then. It's pretty easy to put up or take down (one man job), just loosen the clamp on the house and remove/add sections.