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2m mobile antenna suggestions?
#1
I want to hard-mount a 2m antenna on my little 92 Sentra. I'm considering putting it in the middle of the roof, or the middle of the trunk lid (gonna keep this car a while). Anyone have suggestions on brand, mount, mount location, coax, and 1/4 or 5/8 wave?
~Carl
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#2
In theory, the center of the roof should give you the best ground plane for an antenna. From a technical standpoint anyway. It also has the advantages of getting the antenna up higher in the air and getting the main radiation pattern off your body. That being said, it likely is a little more work to get a piece of coax up there, and any hole in a roof will be a possible site for water intrusion, especially if you have a bigger antenna with an NMO mount and no spring.

I recently put a 2 m / 70 cm antenna on my '04 F-150 and put it on the roof and haven't had anything bad to say about it... except that the antenna is high enough that it tends to smack stuff. I'm considering putting an antenna spring under it to try and help protect it, my roof, and the NMO mount tying it all together. I get great reception and transmission range off it, however.

In summary, here are some things to consider:
  • How easy is it to get the head liner out of your car to install an antenna on the roof? You'll need to drill holes up there, which means a drill and drill bit, etc.
  • How easy is it to get coax from wherever-you-mount-your-radio all the way to the trunk? To the roof? This may include removing internal trim pieces if you want to really hide and protect the cables.
  • How sturdy is the roof on the car? How sturdy is the trunk lid? If you only have a thin piece of unsupported sheet metal for the surface, you are going to get a lot of flexing and wobbling out of a bigger antenna with more chances for messing up the roof/trunk or the mount you put in the roof/trunk. In my experience, the lip-style mounts are sturdier than mounting directly through the sheet metal of a roof or trunk lid, unless there is some reinforcement in there that you can use to your advantage.

In my opinion, mounting to the center of the roof will give the best results... but it takes a little more work to get it up there and do it right. Not a lot... but a little. The trunk is easier to get to, but the antenna won't perform as well. You've also got the added bonus of "If I DO have a leak in the trunk, it won't be as bad as a leak in the roof, but I'll likely notice the leak form the roof well before the trunk leak".

As for 1/4 wave vs. 5/8 wave... I have no real input there. I've owned both (5/8 wave mag mount 2m and 1/4 wave dual band NMO mount), but the gain figures on the two antennas and their installations and attached radios were so different that making a comparison between them would be almost impossible. I'll let someone else chime in there.

Also please excuse the mess of this reply... I'm tired, so I've probably rambled and not presented my thoughts very well.
W0ULF 2011+
ex KF7RJU 2011-2011
ex KC7YNP 1997-2007
Rigs: Heathkit RX-1 Mohawk Receiver and HX-10 Marauder Transmitter, IC-7410 Base HF w/AH-4, IC-2720 Mobile Dual Band, IC-V8000 Go-Bag 2m, IC-2820 base 2m/70cm (That goes to Field Day or goes in the other truck when I'm driving it), Kenwood TH-75A and Icom IC-92AD HTs.
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#3
I would go with 5/8 wave for a lower take off angle! Ive never cared for drilling a hole in my roof. Good bracket for the trunk lip would be my choice!
Those who plan and prepare, endure the weather!!
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#4
Will the antenna placement, in relation to the stereo antenna affect TX/RX performance?
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#5
I dont with mine even running a 100 watts! But mine are like 6 feet apart!
Those who plan and prepare, endure the weather!!
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#6
Having another element within a wavelength or so is going to change your overall antenna pattern. Think about it this way: turn a Yagi on its side, it looks a whole lot like your AM/FM and Ham antennas. What will that pattern look like? Will it effect things significantly? I can't tell you without modeling the system.
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#7
I've had great results using a Radiallarson dual band 5/8s NMO mount antenna mounted to the edge of my hood using the available gutter mount. The radiation pattern isn't perfect, but I normally can't notice any difference and have great coverage. It's attached directly to the fender, so a lots easier to deal with than attaching to trunk or hood.

Sent from my ADR6400L using Tapatalk 2
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