Glass mount antenna on 4th gen 4runner with in glass AM/FM?

[Martinjmpr]

One of the "winter projects" I'd really like to do this year is to finally get my 2m mobile unit mounted in my 4runner (unless I decide to go all the way and get a dual band - which is what I'm leaning towards, actually.)
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My dilemma, though, is that I park the 4runner in a garage most of the time (actually all the time unless I'm on a trip somewhere.) That pretty much rules out a roof mounted antenna even though a center-roof mount would probably give me the best ground plane and the best all around coverage.
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I've used glass-mount antennas in the past and they seem to work fairly well, although I have to be honest I never really 'tested' them compared to other types.
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On the 4runner, the only windows I could put it on are the rear-most side windows, since all the other ones are on doors and roll down.
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The problem with using the glass mount is that the 4th gen 4runner uses "in glass" antennas on both sides (I think one side is AM and the other is FM) for the car radio instead of a mast-type antenna.
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Is there a reason to be concerned about putting a glass mount antenna on the same glass that carries the AM or FM antennas? I'm wondering if keying the mike at full power (I think mine is 35w but it might be 50w) could send a surge through the stereo and fry it or otherwise damage it.
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The only other places I can think of for a permanent mounted antenna would be on the front bumper (I have an aftermarket bumper) or on the hood/fender. The only issue there is pushing the antenna wire through the firewall. Also, although having antennas on the front bumper looks "salty", isn't that a really crappy place to mount an antenna? Not much of a ground plane at all, is there?
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For others with 4th gen T4Rs or similar vehicles with in-glass antennas, what are you using for an antenna?

 

[Kiddmen57]

Do you need to leave it on the vehicle 100% of the time? If you only need it for trips, then use a through he roof NMO mount and pick up one of the weather caps for the NMO. Then just install/ remove the antenna as needed.

If you need 100% permanent antenna then thats a different story. On my jeep I mounted a Larsen NMO-2/70 at the fender/ hood transition, drivers side, about 6-8" from the base of the A pillar using an NMO mount and L bracket. Its not as clean of an install as a through the roof would be on your rig. I have good reports for clarity on low power (5watts) to a repeater 12 miles away, even sitting in my garage, so this mounting location sure seems to work.

 

[Martinjmpr]

Do you need to leave it on the vehicle 100% of the time? If you only need it for trips, then use a through he roof NMO mount and pick up one of the weather caps for the NMO. Then just install/ remove the antenna as needed.

Ideally, yes, I want something that is always on the truck.

 

[java]

There is the option of lip mount on the rear hatch also.

IIRC HAM is not nearly as picky as CB on ground plane. There are folding antennas also.

 

[Martinjmpr]

Is that lip mount a universal or is it vehicle-specific? And can you mount it anywhere on the lip? It would be easier to wire something where I could run the cable through the truck body vs. running it though the firewall to the hood, but I'd want to mount it low enough that it would clear the garage door.

Of course, that begs the question: What works better, a longer antenna mounted lower or a shorter antenna mounted higher? Assuming the tops of the antennas are in roughly the same place am I right in thinking a longer antenna would probably work better, at least at lower (2m) frequencies (because a longer antenna would be closer to the wavelength of a 2m signal?)

 

[java]

Is that lip mount a universal or is it vehicle-specific? And can you mount it anywhere on the lip? It would be easier to wire something where I could run the cable through the truck body vs. running it though the firewall to the hood, but I'd want to mount it low enough that it would clear the garage door.

Of course, that begs the question: What works better, a longer antenna mounted lower or a shorter antenna mounted higher? Assuming the tops of the antennas are in roughly the same place am I right in thinking a longer antenna would probably work better, at least at lower (2m) frequencies (because a longer antenna would be closer to the wavelength of a 2m signal?)

Not my picture... But they are universal. I believe the commonly used ones are Diamond brand. And yes you can mount them lower. A local guy has his down by the bottom of the window with a taller whip.

 

[DaveInDenver]

I wouldn't go with one of those coupled-thru-glass antennas on the same windows as the AM/FM. Beside the chance to blow up the front end on the in-dash it probably wouldn't work through the glass anyway. In fact most of the glass in the 4Runner is probably passivated so would lend itself to poor coupling. A lip mount is the best option, that's what we had on our 2005. If you get the Diamond with the RG316 coax you can tuck it into the plastic trim at the end of the ceiling and run it down the passenger's B-pillar. Then you can mount the radio under the seat if you wish.

Height is probably more important than length of the whip, so I'd suggest mounting a lip mount on the rear hatch as high as you can and then use whatever antenna works best for your situation. A bumper mounted antenna is alright, but clear height is best.

 

[AlbanyTom]

I wouldn't do glass mount, either, for the reasons above. Plus, other than for undercover vehicles I've never seen a commercial glass mount install.

More important than height or length is being clear of the vehicle, in my view. Or in other words, the antenna should be on top of something, like the roof, hood, or rear deck, not beside anything. Imagine the antenna is an 18" ball, not a stick, and don't let the sides touch when it's mounted.

Commercial installs of VHF radios around here, for suburban type vehicles, are either on the roof or on the hood lip, like shown above on the Jeep.

I'm in a similar spot, as I park my xterra in a garage at home and work. I think I'm going to go with an NMO mount on the roof in front of the roof rack, and keep a flexible/stubby antenna on there most of the time, with a 1/4 wave whip tucked away for when I'm out and need the extra reach. Part of my reasoning is that this will give me a great antenna when I want it, and that the 25w I transmit with will be on the other side of a piece of steel from my head, not 2 or 3' in front of it. I'm not skittish about electricity, but I don't like beaming the signals through what few brain cells I have left if I don't have to. I think a 6" antenna or so will keep my clearance around 7' - that'll clear the work garage, and just 2 whacks a day for the house.

Tom

 

[Martinjmpr]

If you get the Diamond with the RG316 coax you can tuck it into the plastic trim at the end of the ceiling and run it down the passenger's B-pillar. Then you can mount the radio under the seat if you wish.

Which model of Diamond mount is that?

 

[DaveInDenver]

The K412S-NMO is the one I have, it's an NMO (obviously) base, dial on the side to adjust tilt and uses an Allen key to adjust the other direction.

http://www.universal-radio.com/catalog/hamantm/4032.html

They also make the K400, which you set both tilt and rotation with an Allen key. Either way you want to get the one that has RG-316 coax and an SMA connector. They included an SMA to PL259 adapter with it.

I dunno if it's Diamond or Comet that makes it, but there exist mounts with a stepped feedline, a short length of RG-316 that allows easy bypass of the hood or door but most of the length is RG-58. This is harder to conceal without actually removing trim pieces. I mounted the thing on the passenger's side of the tailgate, put a little loop in the coax zip tied to the lift cylinder and ran the coax along the edge of the ceiling by just pushing it into the trim. I use it now in our old Jetta wagon since we long ago had to sell the 4Runner but I kept the mount.

I'd go over to HRO (they're east of Quebec on Iliff, a little strip mall on the south side of Iliff, you'll see their antenna) and ask them. Just be sure you tell them you want the one with the full run of RG-316. That's the super thin coax. It's more lossy than even RG-58 but in this case it's IMHO worth it to make easy to install.

 

[Frdmskr]

Going back to the glass mount concept there are a great many reasons to avoid that scenario altogether. Not the least of which is the amazing level of loss there is going through glass which is in any way tinted (as most vehicle glass is).

Don't forget, drilling holes is not so bad. That first mount near the front hood may be the best idea of them all. I have had the clamp on mounts. They work and I did not have any fail. They do cut through the paint and leave a happy rust spot waiting to be. Drill the holes for the mount, have someone weld and screw it on (need RF and a mechanical back-up in case the weld breaks hitting a tree) and that should help.

Alternative, I take and unscrew the whip from the coil on the NMO270B when doing the parking garage thing. If not, well...I get quickly reminded to do so

 

[Tigglebitties]

Here's my setup. On a 2013 taco
I've got the hood mount brackets from someone on Tacoma world not sure where they came from but I've got my ham mounted on one side and CB on the other. We can argue electrical engineering and theory all day long, but fact is mine works perfectly fine and I regularly pick up people 20+ miles away. Our vehicles should be very similar. Simple setup and it doesn't sit much higher than my roof rack so it'll work for your garage.

 

[CaliMobber]

I vote for wither the hood mount or the diamond mount. Ive got some pics in my build for the diamond mount, So far its great. Its mounted on the rear hatch on the 4runner and seems to get out well.

Glass is a big no go.

 

[ebg18t]

I run a comet lip mount NMO with flexi comet antenna on the rear hatch door for my ICom dual band. The top of the antenna taps my garage door each morning and night but causes no issues since it's flexi. Been 2 years and still works excellent. Looks just like Java & CaliMobbers setups.