The term Noise Temperature has two rather simple yet distinct meanings in the RF community. This article focuses on its use as a measurement of noise power, whereas another post will explore how it relates to wireless link performance. Conceptually, Noise Temperature is not much different than other temperature scales we are familiar with (Celsius, Fahrenheit). … Read more
As a rule of thumb, antenna gain is the measure of how well an antenna converts RF power from a transmitter to an electrical signal at its output terminals. Distance is generally referred to as transmission line loss or the attenuation of RF signals over a given amount of cable. There is certainly some correlation between … Read more
Ever turned on your walkie-talkie and a very odd and annoying sound come through? This is radio squelch.What does “Squelch” mean?Squelch is the noise reduction system of a Walkie-talkie. The squelch level is used to control unwanted background noise and prevent false triggering from noise when no one is transmitting. It’s important to set the squelch … Read more
There are a number of different types of walkie talkies on the market that offer various features. The two most common types of walkie-talkies are Family Radio Service (FRS), and General Mobile Radio Service (GMRS). For many years FRS was considered a low power short range system, while GMRS was thought of as high power long … Read more
The first thing we need to understand is how radio waves can transmit speech. The answer comes in the form of electromagnetic radiation. It works like this: human speech is converted into vibrations that travel through the air at a certain frequency, which we hear as sounds. How do Walkie Talkies Work?A walkie talkie picks … Read more
The term AC power system is due to the fact that it uses alternating current. The term DC power system is because direct current flows in a single direction only and there is no alternation of polarity.Alternating Current – ACDirect Current – DCWhat does AC Stand For?AC stands for alternating current which is the type … Read more
CB Radio has 40 channels with CB radio frequencies ranging from 26.965 to 27.405 MHz. Channels are generally spaced 10 MHz apart. The frequencies are listed in the table below. I have included different sets of channels used by people in various countries around the world. As you can see, these CB radio channels overlap each … Read more
To help make it easier, I break down what a CB radio repeater is, how they work, and the benefits of having one. Let’s get started:What is a CB Radio Repeater?A CB radio repeater is a type of radio setup that can extend the range of your communication signal while using a mobile or base … Read more
GMRS and CB are virtually identical as far as how they operate on the air, the only difference is one must have a license and pay fees to the FCC in order for legal operation. As such one can hack (“mod”) a standard FRS or CB walkie talkie or handheld transceiver into a powerful multi-user capable … Read more