This is one of those articles we feel compelled to post because of the number of problems that tech support receives on the subject matter. There are four primary components in an antenna installation, the antenna, the coaxial cable, the mount and the antenna stud. The "antenna system" can only be as good as its weakest link and since the antennas studs responsibility is to transfer the radios energy from the coaxial cable to the antenna, it's quality is extremely important to those looking for maximum performance.
In most cases, if your primary decision on a product is its price, you need to go into that buying experience understanding that you will most likely be sacrificing quality and performance. Purchasing antenna stud mounts is no exception to that statement. If you're going to use cheap coaxial cables and cheap stud mounts, you may as well use a cheap antenna. Radio waves are somewhat like water. If you put a high-pressure nozzle on a hose full of holes and without a gasket, the nozzle performance will be disappointing. But unlike water, you cannot see the leaking radio waves. Nonetheless, it happens.
Almost all cheap stud mounts will use insulators made with structurally inferior plastics with limited weathering resistance. In most cases, but not all, they can be identified by their color. Most of them are black. In short, there are production plastics and there are higher quality-engineering plastics. All insulators used in all Firestik antenna stud mounts are made with low moisture absorbing, high tensile strength, engineering thermoplastics that industry leaders specify for high load mechanical and electrical insulation applications.
Low quality SO-239 stud mounts (thread on coaxial type) can be difficult to identify in their package unless you know what to look for. Other than the inferior ring insulators that can be seen, the insulator between the lower housing and the center shaft will almost always be made of structurally inferior plastic. Those plastics lack structural integrity and often crack and deteriorate during normal use. Also, it isn't uncommon for the center shaft insulator to pull out of the housing when the part is tightened. Malfunctioning antenna studs can easily lead to damaged radio circuits.
What to look for …
1. On most of the cheap imported stud mounts the center shaft isn't plated. By not plating the center shaft they save money and you get performance affecting corrosion. So, always look at the bottom of the stud mount. If it is brass colored instead of being chrome plated, you can bet that it is a low quality stud mount.
2. If the circular shoulder washer (insulator) is black, it is most likely made from inexpensive, structurally inferior plastics.
3. Lastly, be aware that most imported stud mounts use zinc plated lock and flat washers and, in stud mounts made for use with ring terminal style coax connectors, the bolt will be plated steel. Being exposed to road grime, water and salts, they will rust in short order. All hardware used in Firestik stud mounts is stainless steel.
Posted April 14, 2017