Tram 1126-B vs Midland MXTA25

[jsneezy]

I'm going to be adding a radio to a work truck, and because of the ladder rack, a roof mount won't work with the way the rack gets constantly loaded. I was thinking about doing a mount on the outside of the rack. I'm a little concerned about the lack of a good ground plane in that particular spot. I'm trying to keep the antenna as high as possible, without the possibility of signal being blocked by the cab or anything loaded up on top of the rack. At the same time, a 1/2 wave will be too tall. Would either the Tram or Midland antenna be better for this specific install, being that I do need it to be as low profile as possible, or am I better off looking for other options?

[marcspaz]

They are completely different antennas that serve different purposes, and both require a good ground-plan.

 

The Tram is a no-gain antenna, with a great pattern for hilly and mountainous areas, while the Midland is a high gain antenna, designed for use in areas that are relatively flat.

 

Regardless of what antenna you use, you have to be sure the element is clear of obstruction so it can work the best.

[SpeedSpeak2Me]

Without seeing what there is to work with in terms of clearance, it's hard to say.  If you are looking for low-profile antennas, I've had good success with Laird, but have never tested the salt & pepper shaker "ghost" antennas.  They do have both a 1/2λ no-ground plane, and a one that does require a ground plane.  The second one doesn't state the wavelength, but since it requires a ground plane I'm going to presume it is 5/8λ.  Both require an NMO mount.
 

No Ground Plane:
https://theantennafarm.com/shop-by-categories/shop-all/mobile-antennas/300-512-mhz-uhf/no-ground-plane-antennas/11440-laird-connectivity-etrab4500n-detail

Ground Plane:
https://theantennafarm.com/shop-by-categories/shop-all/mobile-antennas/300-512-mhz-uhf/phantom-disguise-antennas/8290-laird-connectivity-etrab4503-detail

 

 

[wayoverthere]

5 hours ago, SpeedSpeak2Me said:

 If you are looking for low-profile antennas, I've had good success with Laird, but have never tested the salt & pepper shaker "ghost" antennas. 

 

The other lairds I've used have been solid...the phantom, I just wasn't impressed. I hooked it up to an unlocked anytone at779uv and did some testing on 70cm (the UTRA4301S3N, rated for 430-490), mag mounted in the center of the roof of my truck. On mid power I was having trouble getting in readable to a repeater I can normally use on a handheld that's 30ish miles out on a 4000ft ridge. High power was usable.

Had no problems at similar power levels in the same location with a comet sbb1 (basically a mobile rubber duck) or the small signal stalk). Have also used the bb4303 with a handheld to the same repeater, no problem.

[SpeedSpeak2Me]

1 hour ago, wayoverthere said:

The other lairds I've used have been solid...the phantom, I just wasn't impressed. I hooked it up to an unlocked anytone at779uv and did some testing on 70cm (the UTRA4301S3N, rated for 430-490), mag mounted in the center of the roof of my truck. On mid power I was having trouble getting in readable to a repeater I can normally use on a handheld that's 30ish miles out on a 4000ft ridge. High power was usable.

Had no problems at similar power levels in the same location with a comet sbb1 (basically a mobile rubber duck) or the small signal stalk). Have also used the bb4303 with a handheld to the same repeater, no problem.

I would only use a ghost/phantom/pepper shaker antenna as a last resort.  I can't see them ever outperforming any kind of stick antenna.  That Comet is 16" (mobile) compared to 3.4", so that makes a big difference in propagation.

[wayoverthere]

16 minutes ago, SpeedSpeak2Me said:

I would only use a ghost/phantom/pepper shaker antenna as a last resort.  I can't see them ever outperforming any kind of stick antenna.  That Comet is 16" (mobile) compared to 3.4", so that makes a big difference in propagation.

I didn't have high expectations to begin with, but wanted to test it, since the next truck (whenever i get around to replacing mine) will be taller and thus more of a height issue. On the current, the signal stalk was just a little too long, and the comet gave me a little space to spare for the work garage

[jsneezy]

Basically, what I'm looking at is something like in this screenshot. Mine is custom made for the truck, with rectangular tubing rather than the round tubing like the one in this pic. The red circle shows roughly about where the antenna would be mounted, with the cable run along the underside of the rail with coax clips like a cable TV installer would use, then down the vertical at the front of the bed, in through a grommet I'll add to the back wall of the cab, then forward under the carpet to the radio. The reason I chose this location is partly because I can get better antenna height, no tie downs ever go near that spot, and nothing ever goes over the edge of the rack there. 

As for terrain, it's mostly going to be around Phoenix, so some spots with hills, and some flat, but not a whole lot of trees. The plan is to use half of a mirror/roll bar mount with the NMO attached to it, so I can set it so the NMO is flush with the top of the rack. I'll try to get a better picture of it later, for a better reference as to what I'm trying to do.

[SpeedSpeak2Me]

I think you'll be able to get by just fine with a 1/2 wave antenna.  They're good for flat terrain due to the way they propagate the RF (closer to horizon and flatter).  I have one on the back of my car due to limited space for not enough ground plane.  Do I sacrifice some performance?  Yes.  But it's a good compromise antenna that does what I need it to do, and can still work repeaters at 30-40 miles with it, with just 15w.

Question, would you still be having it on the roof of the truck's cab, or on the rack itself?  For ground plane It won't really matter since a 1/2 wave doesn't need one, but I'd hate to see the bottom quarter or half of the antenna (mast) itself sitting below the framework.  That'll hurt performance as well.

You've definitely got a challenging situation there.

[jsneezy]

I drive into a lot of low clearance areas, like parking garages and things like that. I typically only get enough clearance to get away with a 1/4 wave antenna in this situation. If it weren't for all the pipes and conduit on the ceilings, I could probably get by with a 1/2. 

I will be mounting to the side of the rack. I was considering taking off the shark fin on the front, since it's only for satellite radio, which I don't use, and putting an NMO there, but the rack and anything loaded on it would just be an obstruction. And it could potentially be broken off during loading. 

[nokones]

I would try using a Laird B4502N antenna that you can get from Arcadian Antenna. They have a warehouse in Phoenix and it would only take a day or two to get it. The B4502N is a base load NMO mount 1/2 wave non-ground plane 2.4 dB gain omni-directional antenna. If the antenna is properly trimmed for use on GMRS freqs ( tune for high 464-low 465 MHz freqs) the rod would be about 10 1/2" high/long.