Mobile 2m antenna mounts

[Jamie Lahowetz]

I was shopping for antennas and antenna mounts for my new (ebay) ICOM IC-V8000 and a question came up. What kind of mounts do you use? mag-mount or an actual mount? Where is the best place to mount an antenna for our hobby? Also can you recommend any antennas or other equipement you have found useful.

 

[Jim Southard]

Congrats on the V8000... that's the rig I use and it's been a joy.

The antenna and mount you choose might depend a little on what kind of car you have. I drive an SUV and I went with a mag mount on the roof, which I can say is somewhat problematic. Having a 5 ft. antenna on top of the car (at a height of about 6 ft.) is a hassle in drive thrus, and it probably also makes a pretty attractive target for lightning. Mounting it in the center of the roof provides a nice ground plane, though.

If you have no height limitations, then I'd say go for the best combination of high gain and manageable height that your budget allows. Be careful that if you do get a long antenna, that a mag mount can support it (mag mounts can usually only handle about a 60" antenna or so).

The mag mount is convenient in that you can easily take the antenna down if you don't want it out all the time. But if I had the chance, I'd get a trunk or lip mount. I believe (but I'm not sure and I could be wrong) that you'll get better antenna performance if you can use any mount other than a mag mount.

There are a lot of hams around here, so I'm sure you'll get lots of good advice. Good luck! 8)

Jim
W5YYZ

 

[Court Hubbard]

i just got into HAM radio stuff and recently puchased the Diamond 7500A antenna with the Diamond K550KM antenna mount. i have an SUV and decided not to go with the magnet mount. The K550KM is a luggage rack mount and it works great. i agree totally with jim, it depends on what kind of vehicle you have, your budget and how big of an antenna you are planning on getting.

 

[Jeff Snyder]

Remember that you want to try and put the antenna nearest the center of the vehicle (and highest) as possible. Again, as others have said, this largely depends on the type of vehicle you have and how much permanent modification you want to make on it. I recently redid my antenna system in my car, which included making a permanent mount for my Larsen dualband antenna. This constisted of drilling a hole in the center of the trunk and installing a simple NMO mount. I also re-ran RG8 cable through the car, instead of the more typical RG58. The results? I have noticed a significant performance increase! Stations come in more clear than ever (that's likely due to the much lower line-loss from the RG8 over the RG58). However, transmit is also quite a bit better...

Why the center of the trunk? The metal on the vehicle acts as the ground plane, so if there is a 'balanced' amount of metal on 'each side' of the antenna, then you'll get more omnidirectional performance. This is one of the downfalls from trunk lip-mounting an antenna on the side of the trunk... You'll more get energy directed forward and opposite/across the car (there's more metal in that direction) than rear and on the same side. Thus the benefit of mounting in the middle of the trunk...

In my opinion, the most important factor is putting the antenna as high as possible. For that reason, the middle of the roof is often the best location for an antenna, as it's both the highest spot on the vehicle, and it's as centered as possible. From field reports I've seen, it's signifcantly better to have a mag-mount in the middle of the roof than to have a permanent mount on the trunk. So that means location is more important (in the roof vs. trunk case) than mount type... The best mount option? Permanent mount in the middle of the roof... Then again, remember that when you're in the middle of nowhere, a long rod of metal on highest place on your vehicle also makes it a very good 'lightning attractor'...

 

[Tim Stoecklein]

Jamie, what kind of vehicle do you have?

For cars you can go with the magmount or a "lip" mount that would work well on the trunk.

I have a jeep liberty and I had my Diamond antenna mounted on the roof rack (basket) with what was essentially a "clamp" mount. Now I have a mag mount just because I am constantly throwing thing up on my roof like the basket or kayaks or whatever else, so I needed something I could move around with little effort.

The one thing I don't like about mag mounts is that it doesn't take much to scratch the paint if it gets moved around at all. On top of my jeep it's not much of an issue cosmetically, but it is still scratching.

One thing I like about my Diamond is that it can be layed down if I find myself in one of those pesky drive thrus or carwashes that have a clearance of less than 8 ft. It's a handy little feature to have.

I used to have a Larson window mounted antenna when I first got into radio a couple of years ago, had absolutely no problems with it. You just have to make sure you stay away from defrost wires, or windows that have other metals in them.

If you give us a little more information about the vehicle we could give you some more specific suggestions.

Tim

 

[Jamie Lahowetz]

My chase vehicle of choice, kind of, is a 1985 Toyota Camry. Its really reliable and has so many dents already put there by hail. Anyways, its really compact so im having trouble finding a spot to put the radio. A trunk mount might be a good way to go. I will post some pics if this will help you help me out. I have to get home first to take them so i will post them later.

 

[Alan Broerse]

antenna

Jamie...ditto on what Jim said...I love the V8000. My antenna is also a magnet mount that has withstood over 100 mph winds. I too drive an suv with 10 feet from the ground to the tip......McDonalds and sonic drive-thru dont like me much cause this tip drags the awning....no harm though. I dont like 6'5" parking garages though...knock the antenna over every time. My antenna is 6db gain and talks a large area, Im going to get a 2-3 db gain 24 inch or less tall antenna for the off season that would screw onto the mag base for about $10....there are options to choose from ...be wise to avoid buying junk or way toooo much stuff. Its easy to be a gadget/junk collector......Alan

 

[Jamie Lahowetz]

Here are some pics of my ride. Hope these help some:
[Broken External Image]:http://www.geocities.com/jlahowetz/0408130004thumbnail.jpg
[Broken External Image]:http://www.geocities.com/jlahowetz/0408130007thumbnail.jpg
[Broken External Image]:http://www.geocities.com/jlahowetz/0408130009thumbnail.jpg
also I am missing my regular radio FM antenna. This is just a thought but is there a way to use one antenna for both of these devices? even if you use one radio at a time.

 

[Tim Stoecklein]

Jamie, I think you're a good candidate for either a mag mount on the trunk or on top, or the lip mount on the trunk lid. As for mounting the radio.....I'm not terribly familiar with that radio, so I'll leave those comments to the users of that one. Good luck!

Tim

 

[Doug Lee]

Trying to use an antenna for both ham radio and broadcast recption could pose problems.

A 2M antenna would probably work for FM broadcast since the frequency ranges are close enough (144 to 148 for 2M and 92 to 108 for FM), but to keep your transmit signal out of your broadcast receiver, you'd have to use a device called a diplexer. I'm not sure if a diplexer is suitable for mobile operations, since I've only heard of them being used on repeaters and remote bases. You definitely don't want your transmit going into your receiver because of the damage it could do.

 

[John Erwin]

antennas

Jamie;

You've got lots of options there. A lot depends on how you want to use the car on/off season too. Mag mounts are easy to move/remove when you don't want them up, but often don't perform as well as their more permanent cousins (varies widely with model). Another problem I encountered with the mags (besides the scratching) was the tendancy for them to retain water under them; I would often check for this and dry if necessary. Perhaps not a problem if you're not worried about cosmetic issues.

I would personally go for a good trunk lip mount in your case; easy to mount and use, and the antenna still stays somewhat out of the way. Most models will allow you to easilly remove and store your antenna when not in use; check into a "blanking cap" that you can put on the mount when you do this. Keep in mind that this feature may also allow vandals/thieves to remove your antenna as well (I had this happen once).

I've seen diplexers advertised for vehicle applications (to use the same antenna for FM/ham). If I recall some reviews in the past, performance was not great with these setups. It may have been Grove that had the equipment, but I'm not sure..

Good luck with whatever setup you choose!

 

[Zach Bailey]

Re: antennas

Originally posted by John Erwin
Another problem I encountered with the mags (besides the scratching) was the tendancy for them to retain water under them; I would often check for this and dry if necessary. Perhaps not a problem if you're not worried about cosmetic issues.

Just caught this as I was browsing through. You might want to think about getting some sort of silicone-based caulk to put a bead around where the antenna interfaces with the car to avoid the water getting into there. Then, when you take the antenna off you should just be able to pull up the silicone-based caulk without removing the paint (as far as I know). I'm not an expert when it comes to caulk, but there's gotta be some kind out there that won't completely bond with your auto paint.

Just a suggestion - I'd ask at home depot or your equivalent.

Good luck,

-Zach

 

[John Erwin]

Re: antennas

Originally posted by Zach Bailey
You might want to think about getting some sort of silicone-based caulk to put a bead around where the antenna interfaces with the car to avoid the water getting into there.

Thanks for the tip Zach. That might work, there's some temporary peelable types of caulk that could be suitable, although a person might want to test it first somewhere to make sure there was no reaction with the paint. It might be prudent to ensure the seal is well done too.. thus a small problem might actually become worse if water has some way to sneak past the sealant.

In my case I simply elected to replace all my antennas with permanent type mounts, with the exception of the mag mount I use for WiFi and cellphone antennas; these are only used once in a while so not too much of an issue.