Last Modified: January 20, 2012
Contents: Caveats; Basics; Mounting Option; Home Brew; Avoidances; Odd & Ends;
As I mention in the VHF Options page, the roof of a vehicle is a very good place to mount a VHF antenna. However, all new vehicles come equipped with side curtain SRS devices, commonly called airbags. They typically are mounted along the edges of the headliner including the rear seat area if there is one. The wiring to these devices may be routed through any one (or more) of the roof pillars. Extra care is required when installing antennas in vehicles so equipped. If you are the least bit apprehensive about your installation, seek professional help from your dealer. In any case, you should have a copy of the service manual. Typical examples are in the $70 range, and easily pay for themselves when problems arise.
The same advice should be applied to mounting of hardware. As we'll learn, the top of the dash isn't an ideal mounting location, and either is the headliner area. The reason is, some folks mount speakers on or near the headliner and/or on the headrest supports. Both of these ares are within reach of the side airbags, and thus should not be used.
Today's vehicles don't have a lot of room to mount amateur transceivers of any size, and some are so cramped for space, you have to use extraordinary means to mount just the remote head safely. As I point out in my Safety article, there are a few things to avoid. One of those is the top of the dash. While inviting, and maybe even handy, there is a very good reason why, as shown in the right photo (click to open full size). Note the piece of padded dash literally ripped away by the force of the deploying air bag. If a remote head had been mounted within the air bag's reach, it too would have been tossed asunder. Remember, when they deploy, they accelerate at speeds up to 200 mph! Anything is their way, or attached to them, will be propelled asunder, and perhaps directly at you! It is safety hazard which can't be ignored, as this movie clearly shows.
You might remark that you would have to be an idiot to mount a radio atop an SRS, but I have seen exactly that! In one case, directly in the center of the steering wheel, and the amateur in question was bragging about how handy it was!
So, whatever you do, whatever radio you use, regardless of any remote head it may or may not have, it should be mounted away from all safety devices (SRS), and not be in a position to interfere with any of the vehicle controls, no matter how minor they may be. The best mounting locations are below the center line of the dash, and towards the driver's side to avoid the passenger side airbag. These points cannot be over emphasized!
The Photo Gallery depict how others have installed their radios and heads, and have avoided most of the pitfalls.
With the aforementioned in mind, you have a few options. But first, you have to decide how you're going to get the job done. Are you going to use a commercial mount, or perhaps a home brewed one? Let's cover a few points here before we go on.
When I speak of mounts, I'm not talking about the ones shipped with your new transceiver. No matter who made the radio, the supplied (usually at extra cost) mounting brackets are rather brief. They're certainly not universal, but just a basic bracket which can be used to mount the remote head (if there is one), and/or the main body. As long as the mounting surface is flat, and you have lots of available space, they'll do just fine. We all know this is not the norm.
If you're a DIY (do it yourself) kind of guy, just about every decent hardware store carries DIY aluminum. All manner of rod and bar, flat and square, angled or what have you, is available. You can bend it, form it, drill it, and even tap it to suit just about any mounting situation. Unfortunately, not all of us have enough hand tools to fashion such a mounting bracket. Thankfully, adroit manufacturers have come to our rescue (I cover home brew later on).
There are a few companies who specialize in mobile mounts. Ram Mounts is one of them, and they have a very good selection aimed at us amateur radio operators. Their web sites offers a plethora of examples. The photo at left is just one of many.
Ham Radio Innovations makes a variety of mount specifically designed for each model, HF and VHF alike. It is like having a custom made one without the hassle. The one shown at right is their Icom IC-7000 mount, but models are available Yaesu as well. If you don't see your specific radio on their web site, send them and e-mail with your specific needs.
Doug Johnson, W9IIX, has two different lines of mobile mounts, and enough accessories to go with them to mount just about any amateur transceiver. His e-mail address and telephone number are listed on his web site.
Gamber-Johnson, is most likely the largest manufacturer of mobile mounts in the world. Just about every police, fire, governmental, or allied safety organization uses them exclusively. While Ram Mounts' products (and most others) are universal, Gamber-Johnson's are designed for specific vehicles. Next time you see a parked police vehicle, look inside. The chances are you'll see a G-J mount.
Gamber-Johnson also make a first-rate, lockable slide mount replete with a coaxial QD good for up to 512 MHz. Cheap CB slide in mounts aren't much good above 50 MHz, and I don't know of any that are lockable.
In 
addition, Panavise, Havis, and Jotto Desk all make customized radio mounts for just about every vehicle you can name. Standard model prices vary from as little as $20, to as much as $200. Large custom mounts can run into the thousands.
This is Lido Mounts LM300 goose neck mount. What's unique about it is, it bolts to existing seat rail mounting bolts, which make it very secure, and transferable.
There is another aspect of mobile mounts every user should be aware of, and that is the attachment methodologies used. While I'll agree there are some spring clamp mounts, and some rare-earth magnet mounts that are very secure, the really safe method is to use a bolt! This applies to the actual mount, and to the device being held by the mount.
Tac-Comm specializes in what could be called portable mounts. They're unique as they can be stacked, although that is hard to see in the photo. A quick scan of their web site will show you a myriad of configurations. What struck me about them, they could easily be adapted for hump mounting. While few vehicles today have accessible humps, this is a decent alternative for those that do. The basic price of each module is $60, and there are top covers, front protection covers, and even carrying handles!
The modules themselves are expandable, with literally hundreds of mounting hole combinations. It is a niche product perhaps, but they're well made for whatever purpose you put them to.
Commercial mounts are not inexpensive. If low cost is an objective, the the next section is for you.
I like to think every amateur has enough tools and wherewithal to make whatever brackets they need. However, this pie-in-the-sky notion isn't reality. If you look over my Install article, or the Photo Gallery, you'll see all matter of home brew brackets holding everything from antennas, to remote heads, batteries, and more. Some of them were fashioned by the amateurs themselves, and some had the help of a machine shop and/or welding shop. No matter, if you designed it, it is yours, and that fact makes it a home brew project. I can't speak for you, but I get great joy (and pride) in making all manner of brackets, and even electronics that I install in my vehicles.
At left are a few examples of home brew brackets made out of DIY aluminum. Not all were successful, and that's part of the fun. The bracket on the left was used to mount a 1 Farad cap which I don't use any more. The one on the right secured one end of an SG235 Auto-coupler. The one in the middle didn't work like I thought it would. In fact, I remade the bracket three times before I got it like I wanted.
The bracket shown at right is made out of fiberglass reinforced Delrin®. Its dielectric strength goes beyond 1 GHz. One nice thing about Delrin®. it can be worked with normal woodworking tools. It drills well, but for holes over 3/8 inch, you should use a Forstner®. or spade bit. If you thread it, use a bit one number smaller than recommended, and back out often! And I wouldn't use fine thread sizes either. In other words, treat it like soft aluminum, and go slow! Delrin®. is also very slick (nearly as slick as Teflon®), and is easily melted. You also have to be careful as it 'snatches' easily, so clamp your work!
The white plastic in the photo is natural Delrin®. It is available in sheets, rods and tubes. It can be purchased from dozens of sources, and in several different formulations, but not all are RF transparent. Here is a site which lists the various properties of some of the more popular plastics. Although the chart (near the bottom of the page) lists dialectic properties in volts per mil, this figure is not in itself an indication that any given plastic will be RF transparent. If in doubt, ask, as most plastic suppliers have such information readily available.
One often recommended method is to place a sample in the microwave and turn is on for a few seconds. That may indeed work, but you have to be very careful. Some forms of PVC will explode into flames after just a couple of seconds. Personally, I just ask.
Another fine RF transparent plastic is Noryl®. It comes in both plain and fiberglass reinforced versions. It is very dark gray (almost black) in color, and is twice as expensive as Delrin®. A one inch thick slab, twelve inches square is about $200. One of the reasons it is so expensive, is the formulation necessary to make is as strong as it is. In fact, there are few plastic with greater strength. Like Delrin®, it is easily shaped and cut, and it threads better than aluminum.
By the way Professional Plastics sells all kinds of remnants in just about every kind of plastic imaginable. For example, a 25 pound box of Delrin®. remnants sells for $75 plus shipping. The pieces are at least 3"x3", and vary in thickness. The box I ordered had seven pieces larger than 6"x6", and most of it was 3/4 and 1 inch material. There was even a few pieces of rod and tubing. It is a home brewer's delight, and worth the money. They don't always have remnants, so it pays to give them a call even though they are shown on their web site.
The point I'm trying to make here is simply this; brackets can be made from a variety of materials. I've seen one very well made bracket fashioned from ironwood (Olea Laurifolia). It was nicely shaped, drilled, tapped, and finished in gloss black lacquer. With brass hardware, it looked right at home in a 2001 Bentley!
What ever your level of expertise is, a home brew project can bring a lot of satisfaction. Besides, it keeps you out of the spouse's hair for a while.
There are a few things I think amateurs should stay away from when installing radios, and remote heads. These include double-sided sticky tape (or any type of tape), loop and hook (Velcro®) fastening material, magnets (believe it or not), or any kind of spring, bungie cord, rubber band, or wedged in blocks of wood. Think about this.
"If Velcro is so good, why don't automobile manufacturers use it? I think this mounting technique shows the loyalty of a car's owner, actually. It demonstrates a level of dedication towards the preservation of their cars to such an extent that they would rather risk injury or death, rather than drill any holes. My hat is off to them." Mark K5LXP, Albuquerque, NM.
I should mention that some things we use, can be safely attached with Velcro®. A microphone hanger comes to mind. Just remember, if you want it to stay put during a crash, it shouldn't weigh more than a couple of ounces. Even then, the more square inches of material, the better.
Some forms of the double-sided tapes are used by vehicle manufacturers to attach all matter of things together. However, the tape they use is made from industrial grade adhesives. Once they're stuck on, they stay stuck! If you know how much of your vehicle was put together using this stuff, you might be surprised. They even use "pin-cushion" fasteners to hold down trim pieces inside of vehicles. If you've ever looked inside a crashed vehicle, you'd know all of trim typically flies off. One could argue that it is designed to do that, but a four ounce piece of trim is one thing, and three pound remote head is another! The safest method is always one that uses screws, nuts, and bolts. If you need to have a removable radio, then invest in a slide mount.
The propensity of some amateurs to mount additional cooling fans blowing on their transceiver's heat sink, shows a lack of understanding about thermal dynamics. While it might make the owner warm, and fuzzy (pun intended), it is an inane practice. All transceiver manufacturers publish operating temperature guide lines for their various models. If you're exceeding the published limits, adding additional cooling isn't going to help much. Remember too, it is always best to mount transceivers where they can get an adequate flow of air all around the chassis. Part of this strategy is to mount the transceiver using the supplied mounting bracket, rather than flat against any surface especially carpeting!
Clearly, some mounting methods are far-less effective and secure than others. The essential element in any method you choose, is safety. If it is easy for you to remove (Velcro® for example), then a crash will remove it, no matter how secure you assume it is. For example, I was recent shown a very clean install of an IC-7000 in a Volvo S40. The head mount was properly attached by using existing screws in the lower dash. The problem was, the remote head was held onto the mount with a magnet, albeit one of those insanely powerful neodymium ones. The proud owner demonstrated how secure the head was by trying to pull it off. Well, all I did was slide the head sideways about and inch, and off it came! This just proves that some things look and sound good in theory, but are poor in practice. It pays to think safety!
I've seen cup holders used a lot, but most of the time only friction holds them in place. A much better alternative is to remove the rubber insulator at the bottom of the cup holder, and screw down the mount. When trade-in times comes, just remove the mount, replace the insulator, and no visible holes!
There are a few extras worth mentioning. High voltage lacquer is available from any good hardware store. The stuff is truly amazing. When properly applied, its insulating properties exceed two kilovolts per mil. From experience, its insulating properties extend well into the VHF spectrum. Its only drawback is, it will discolor and/or damage some plastics, and paints. Make sure you read the label instructions.
Don't use car polish on anything with RF around it. The majority of car polishes are conductive which speaks volumes. Further, the stuff can seal in moisture just as good as it seals it out. Every single ballmount I have had fail, did so because it had car polish on it. If you have to protect your antenna and/or mount from the ravages of weather, use RainX. Just remember, it too can discolor some plastics, so exercise care.
Don't forget grommets. If a wire goes through a hole, it should do so through a grommet. Sometimes, in the case of firewall penetration, this allows fumes and moisture to get into the cabin. I've seen just about everything used to seal grommets including RTV, plumbers putty, and coax seal. Everyone of these has some drawback. The best stuff I've seen is made by 3M (Lord, what isn't?). It is called Strip-Caulk®, but most folks call it Dum Dum. You can buy it at most auto parts stores. Although it is gooey, it can be removed even years later. What little residue it has is easily removed with denatured alcohol.