Glass Mount

[XTS5000wellesleywv]

All, hopefully I won’t get too much hate for this but I’ll accept it nonetheless. I’m trying to install my VHF Motorola XTL5000 O3 configuration in my 2018 Audi Q7.

Given I won’t be transmitting much, I figured a glass mount antenna would suffice and that I’d mount it either on the glass directly behind the sunroof or on the back side windows. When the sunroof is fully retracted, there is a few inches of glass window remaining that is free and clear of obstruction, that would allow me to properly mount the antenna and route the cabling on the inside.

Here’s my question: I don’t have a ton of experience with glass mount antennas- only regular NMO. Am I wrong to assume mounting on the sunroof would be the best spot for RX in particular? I’m only wondering as I’ve never seen it done this way.

Thanks so much!! Antenna is: Tram 1191 Dual Band

 

[MTS2000des]

You can't have any metallic tint or anything on the glass surface (including defroster or AM/FM antenna wire). FWIW, these are truly compromised antennas, especially on VHF, so if your XTL is a HP, make sure you turn both HI and LO power down to no more than 50 watts. They aren't very broadband either.
These were the rage back in the early days of cellular and worked okay on 870MHz for 3 watt cellular radios. On VHF/UHF...if I absolutely had to, one step above a mag mount.

 

[mmckenna]

Ditto what he said.

We had an old Chevy Malibu (Captains take home car) at work that someone decided to do a VHF high power XTL.

It'll work, but clean/clear glass. They are half wave on their tuned frequency, sometimes loaded to shorten them a bit, but they are not low profile by any stretch of the imagination.

The antenna you mentioned is ham radio tuned, so don't expect much performance.
If you just need VHF, the Larsen KG-144 would be an option that would be tuneable outside the ham bands.

 

[XTS5000wellesleywv]

Thank you both for that information. Obviously this is not an ideal situation…

Do you have any other recommendations as to how I can Mount without any holes? I also have a lip mount that I was going to try to put on the lip of the hatchback but unfortunately it did not fit. I’d mount on the hood but to be honest, I would rather not deal with going through the firewall.

As I mentioned, I’ll almost never transmit and certainly never above 50watts (yes… this is a 110w radio but that’s just what I have). I guess I’m looking for the antenna configuration that will provide the best RX at 159.9Mhz in analog, and also a few frequencies in the 154-156 range in digital.

 

[mmckenna]

Many of us hate magnetic mounts, but they do have their place. If drilling a hole is out of the question, then you've only got a few options.
Benefit to the ma mount is that you can put the antenna in a location that better suits the ground plane requirements. Trunk lip mounts often put the antenna offset on the ground plane.

A simple NMO mag mount with a quarter wave antenna might be a good solution.

There are other options, but for easy installation, glass mount, trunk lip mount and mag mounts are common. Anything else would need to get pretty creative.

 

[popnokick]

Tram has several models of glass mount antennas. The 1191 you referenced is cut for Amateur Radio use. A better choice if your interest is VHF only (159 mHz) is the 1189.

 

[XTS5000wellesleywv]

Many of us hate magnetic mounts, but they do have their place. If drilling a hole is out of the question, then you've only got a few options.
Benefit to the ma mount is that you can put the antenna in a location that better suits the ground plane requirements. Trunk lip mounts often put the antenna offset on the ground plane.

A simple NMO mag mount with a quarter wave antenna might be a good solution.

There are other options, but for easy installation, glass mount, trunk lip mount and mag mounts are common. Anything else would need to get pretty creative.

It’s been a little while since I checked, but unfortunately I don’t think the Mag Mount works either; the small portion of metal roof behind the sunroof on the car is not very magnetic. I did use a mag mount on a VW Alltrack that I used to have- worked pretty well for what I needed

 

[XTS5000wellesleywv]

Tram has several models of glass mount antennas. The 1191 you referenced is cut for Amateur Radio use. A better choice if your interest is VHF only (159 mHz) is the 1189.

Very good idea- I’ll take a look at it now

 

[mmckenna]

It’s been a little while since I checked, but unfortunately I don’t think the Mag Mount works either; the small portion of metal roof behind the sunroof on the car is not very magnetic. I did use a mag mount on a VW Alltrack that I used to have- worked pretty well for what I needed

OK, so that's out.

Glass mount or finding a lip mount that will fit your application sounds like your best options.

If it has a shark fin type antenna, there may be some choices there, but that usually impacts satellite/GPS/AM/FM stuff.

 

[ElroyJetson]

I use a mag mount because I'm far too likely to change my setup before long and I'm very averse to drilling holes in cars that belong to me and not some department or agency. If someone else owns it I'll turn it into swiss cheese and enjoy it, if that's what they want.

I've also found that I can get a very favorable SWR match with a good mag mount. I can move the antenna around and find a good spot, without leaving holes to fill. For my purposes this works just fine.

 

[XTS5000wellesleywv]

OK, so that's out.

Glass mount or finding a lip mount that will fit your application sounds like your best options.

If it has a shark fin type antenna, there may be some choices there, but that usually impacts satellite/GPS/AM/FM stuff.

I do have a shark fin! What are the options there?

 

[a417]

I do have a shark fin! What are the options there?

pull the shark fin out, use the pilot hole there for a nice 3/4in punch, and put an NMO mount there.

-- proud "Team Punch-the-hole" member.

 

[kayn1n32008]

pull the shark fin out, use the pilot hole there for a nice 3/4in punch, and put an NMO mount there.

-- proud "Team Punch-the-hole" member.

I did that on my VW Jetta. It was just a blank, as I didn't have the nav package in my car. It was surprising a clean look with the EMWave wide band 1/4 wave.

 

[GlobalNorth]

I've seen someone take a shark-fin antenna, paint it a very dark shade of grey, and mount it to the underside of a rear bumper assembly. No height, lousy transmit pattern, possible damage to the antenna from road debris, sloping curbs and drives, etc.

On the other hand, 4 or 5 of them along the rear underside of an Audi bumper would look like aero diffusers on a rally car and you could run multiple antennae.

 

[mmckenna]

I do have a shark fin! What are the options there?

I doubt they make a replacement for an Audi, but here are some options. Maybe adding a second one wouldn't look out of place:

Products - Covert Operations - Page 1 - STI-CO

sti-co.com

Products - Covert Operations - Page 1 - STI-CO

sti-co.com

Several other manufacturers make similar antennas. Keeping AM/FM/Satellite/GPS working may be a challenge. Some of the antennas include GPS and cellular in them, but satellite might be a challenge. If you use those things, adding a hidden satellite antenna might be require to restore the service.

 

[sefrischling]

Hood mount?

 

[XTS5000wellesleywv]

Hood mount?

Is there a way to do that without going through the firewall?

 

[sefrischling]

Is there a way to do that without going through the firewall?

Not that I know of, but the firewall already has a hole for your cables to come into the cabin, so its easy.

 

[APX8000]

We used Sti-co glass mounts and they are crap. The Sti-co Shark-fins work great....I have one for my 8500. The only problem though is people taking the whip off so "its more covert." And they wonder why they go OOR or have reduced or no reception or can't get out.

Mine is mounted in the factory hole. I took the factory antenna and mounted it inside the rear hatch to maintain good time radio and GPS. Wifi/BT antenna inside rear window.

 

[RadioGuy7268]

I would mount an antenna inside the trunk before I'd try to run a glass mount antenna for VHF. I'm serious. Glass mount at VHF frequencies is about the worst possible solution. If you can run a 1/4 wave wired sideways under the bumper cover it's better than a glass mount.