What is better, one dual band 2m/70cm antenna or two singles?

[btu44]

Hope this isn't a question that has not been asked before (yes I tried a search). I'm close to getting my first mobile dual band transceiver. Pretty much narrowed it down to a ICOM IC-2730A but am considering the Yaesa FT-8900 for 6 meters. The radio will be in a lifted 4x4 truck so tree strikes are common. My usage is mostly scanning and some voice transmission.

I'm trying to decide on the best route for a dual band antenna setup. The truck already has a 10m whip mounted on the forward right side of the bed.
I plan to use Breedlove 2" NMO mounts in the center of the roof. The antennas I'm looking at are the Larsen NMO-2/70C for a dual band antenna. For the single bands I like the Larsen NMO-440C with a NMO-150BHW.

Here is how I'm judging each antenna system.
One dual band antenna has the positives of simpler install, less expensive and half the mount seals to leak. But they looks more fragile and may not perform as well as a single band antennas.

The two single band antennas may perform better and if one breaks at least I have the other band but there is much more expense. Two mounts, two antennas, a duplexer and two holes in the roof to leak, although here in California that has been an issue of late

What do you guys recommend? Is the performance gain of two single band antennas outweigh the cost and installation?

 

[BettysNephew]

Hope this isn't a question that has not been asked before (yes I tried a search). I'm close to getting my first mobile dual band transceiver. Pretty much narrowed it down to a ICOM IC-2730A but am considering the Yaesa FT-8900 for 6 meters. The radio will be in a lifted 4x4 truck so tree strikes are common. My usage is mostly scanning and some voice transmission.

I'm trying to decide on the best route for a dual band antenna setup. The truck already has a 10m whip mounted on the forward right side of the bed.
I plan to use Breedlove 2" NMO mounts in the center of the roof. The antennas I'm looking at are the Larsen NMO-2/70C for a dual band antenna. For the single bands I like the Larsen NMO-440C with a NMO-150BHW.

Here is how I'm judging each antenna system.
One dual band antenna has the positives of simpler install, less expensive and half the mount seals to leak. But they looks more fragile and may not perform as well as a single band antennas.

The two single band antennas may perform better and if one breaks at least I have the other band but there is much more expense. Two mounts, two antennas, a duplexer and two holes in the roof to leak, although here in California that has been an issue of late

What do you guys recommend? Is the performance gain of two single band antennas outweigh the cost and installation?

An Austin Antenna 500c Soft Top would likely hold up to any abuse limbs and parking garages could inflict.

 

[FatHam]

I've run a Comet CA-2X4SR on a similar truck for 5 years with zero regrets. The "tree strikes" that you mentioned are what kept me from punching a hole in the roof. I used a big mag mount on mine, so when the wife (it's never me) drives under a branch, it simply knocks it over rather than bending my roof.

You mention "scanning" and the 2X4 excels here. Very broad banded with reasonable SWR WAY outside what most single band antennas will deliver.

Plus, it's short!
http://www.universal-radio.com/catalog/hamantm/3907.html

 

[Captain Kilowatt]

The gain difference is negligible and the dual band antennas do work quite well. I also have been using the Comet CA-2X4SR and really like it a lot. It has a lift-and-fold over feature so you can simply lift up on it and flop it over if you need too without taking it off the vehicle. it was made to cover outside both the 2m and 70cm bands for Search And Rescue operators that are also hams hence the SR in the model number. Generally when working thru repeaters gain is not a big issue unless you are REALLY out in the boonies and the gain difference of going to a really long monobander is only around 2 extra dB anyway.

BTW do not let the addition of 10m and 6m in the FT-8900 sway your purchase. It operates FM only and unless you have either a 6m or 10m repeater locally or lots of friends on those bands 10 and 6m will be pretty useless except during the very rare band openings and even then you will want SSB instead of FM.

 

[vkrules]

personally I use a single 5/8 on 70 ,that works just nice as a quarter wave on 2 , mounted on a mag base in the middle of the roof.Plenty of good dual band ants on the market.

 

[milkman21218]

I've run a Comet CA-2X4SRB for a few years. And they are truly great antennas. They handle the weather and whacking tree limbs. But the best thing about them is they do perform very well. And I also run a Jetstream JTM-7505 it works very well. And only cost $35 at R&L Electronics It's the same as the Diamond SG-7500.

 

[btu44]

Thanks for the good suggestions. The Comet CA-2x4SRB sure is a cool looking antenna. I probably would not have considered it because it looks kind of 'bling' but it seems like the way to go.

Are you guys running the Comet with the optional spring?

I've never used a NMO mount before. Could it be considered a quick disconnect? If I'm busting through some heavy overgrowth on the trail, can I easily unscrew the antenna from the NMO?

Captain Kilowatt, I was really on the fence about the FT-8900. I think the Optima Mk3 covers 10 meter well and was looking at the FT-8900 for just 6 meters. I guess it's not worth the extra $150 to gain 6 meters.

 

[2RT307]

I have two dual banders. A Larsen 2/70 and a Comet SBB-7. Both work really well. Larsen is short, Comet is long. I use the Larsen with a mag mount for rental cars, and it does the job just fine.

73,
Brett

 

[2RT307]

I've never used a NMO mount before. Could it be considered a quick disconnect? If I'm busting through some heavy overgrowth on the trail, can I easily unscrew the antenna from the NMO?

The NMO is quicker than an SO-239. Thicker but fewer threads. And yes, you can easily unscrew it.

73,
Brett

 

[btu44]

For you guys running mag mounts, how are routing the coax cable into the vehicle?
When I've seen them on road the cable is usually in a door jam and has a kink in it.
Doesn't a kink or a collapse of a coax cause loss? Are you use a mag mount as a permanent mount? I herd they can be abrasive to the paint over time.

 

[Captain Kilowatt]

Most quality 2m/70cm antennas have the mount sold separately. You can buy mounts and coax cable assemblies that have a short section of really small diameter teflon coax cable that is really easy to run thru a door. It is also very tough so it will not crush easily.

 

[2RT307]

For you guys running mag mounts, how are routing the coax cable into the vehicle?
When I've seen them on road the cable is usually in a door jam and has a kink in it.
Doesn't a kink or a collapse of a coax cause loss? Are you use a mag mount as a permanent mount? I herd they can be abrasive to the paint over time.

Captain K answered the first part. And yes, they are abrasive to the paint. I've tried pantyhose, soft t shirt material under the mount, and still get a nice little ring on the paint. I consider it a red badge of courage... part of radioing. Permanent mounts are better, but have their cosmetic issues too.

73,
Brett

 

[binrat]

I have my dual band antenna mounted off of the lip of the front fender. Works very well and I don't have issues with trees etc and about the same performance as when it was mag mounted on the roof.

 

[Captain Kilowatt]

I have my dual band antenna mounted off of the lip of the front fender. Works very well and I don't have issues with trees etc and about the same performance as when it was mag mounted on the room.

Why would you mount your antenna on the "room"?

 

[binrat]

Why would you mount your antenna on the "room"?

Just starting my morning "please wake me up" coffee..