Club Torque Spring 2021

LET’S TALK TECHNICAL

LET’S TALK 2-WAY RADIOS PART TWO

Words: Chris Wyatt Images: Stock footage

In part one we talked about the

to connect to each other. Design and mounting of these things is an exacting science but many modern “off-the-shelf systems” have built-in features such as ground plains to correct for poor installation. I’ve seen many aerials on MX- 5’s that my professors some 50 years ago would have said were impossible. Let’s just say that you should try it out and see if it works. (I am going to get a bit technical for a minute so if you are not interested just go to the specifications advertised for aerials one of the least understood is “gain” which many think of as being the higher the better. It refers to the pattern of transmission created by the aerial design. I don’t want to bore you with next paragraph). There are many

drawings of these but think of a giant ball with the centre being the aerial and the skin being the limit of transmission. Let’s flatten the ball a little and call that a standard (3db) aerial, as we go up and down hills the ball tilts but the receiving radio stays in range. If we flatten the ball significantly (6- 8db) on a flat road we get much longer range but go down hill and suddenly nothing. That’s why 4WD vehicles have huge high gain aerials as they tend to drive on long flat roads but when they are crossing mountains are usually close together. Most handheld radios have an aerial designed to be as efficient as possible at all angles but because of that tend to have a shorter transmission range than those fixed to the car body.

pleasure we get from communicating with our car friends whilst we are driving. Now that we know all about the obvious things like the law, different types of radios and how we use them let’s make the more detailed technical stuff simpler. Aerials (antennae etc.) These are the magic things that convert the electrical signal in the transmitter into radio waves that travel through space to another aerial which converts radio waves back into electrical signals at the receiver. That’s already starting to sound complicated so let’s just say that they are the part of the system that lets two radios (transceivers)

32 | Club Torque - SPRING 2021