Protected and Smart
For some time I have been using a CAL-AV Mark 5 spring at the base of my monobander antenna system, and I recently acquired and added a second CAL-AV Mark-5 to the base of my gearmotor antenna.
The springs offered by CAL-AV come in various sizes depending on the antenna size and weight you plan on using it with, and I was very pleased when I found that their Mark 5 model was capable of handling my gearmotor antenna that weighs in at 6 lbs.
This CAL-AV Mark 5 military grade all stainless springs that I am using with the antennas mounted on my mobile are built in the US, and are no doubt the best quality springs I have ever used on my mobile.
The size of this all stainless steel spring is aprox 2” in diameter, and approximately 5” long, and weighs 2 1/4 pounds. The spring has a tinned copper braid strap, which is internally connected from one end to the other.
The spring has flats milled in place on the end caps, allowing for a wrench to be used without marring the finish of the spring, when installing the antenna mast, as well as the mounting of the spring.
When purchasing this spring, there are options available, one option allowing you to pass your run of coax through the spring. Of course the options come with a extra cost.
The spring requires 9 foot-pounds of torque for a 10 degree deflection. The torque is measured with a perpendicular load applied 36 inches above the spring base on my mobile.
The advantages of having a spring as part of the antenna has already proven itself, as I tried to drive in to my garage while my 17 meter monobander was in place on my mobile.
I became aware of the fact, by the noise of the antenna being pushed back at a 30 degree angle, and the fact that the coil was cutting a groove in the trim around the garage door opening.
I backed out, and the antenna stood back up tall and proud.
The only damage done, was to my ego!
Click on the photo for a closer look.....