BUYING A RADIO
Compliments of Firestik® Antenna Company Technical Support Team
Copyright © 1996 Firestik® Antenna Company
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THE RADIO PURCHASE Over the years we have gravitated to simplicity. It stands to reason that the more features the radio has, the more problems you can have. Since the FCC regulates power output of production CB radios, what separates a $200 radio from a $70 radio is not much more than "bells and whistles". It is not uncommon for a person with an inexpensive radio and a thoughtfully installed and tuned antenna system to enjoy performance that far exceeds the fellow with the $200+ radio and a mediocre antenna or questionable antenna installation. Insofar as performance is concerned, it is the antenna that makes the difference, not the radio. RADIO FEATURES Every radio has a few common features, a dial or switch for changing channels, an on/off/volume control and a squelch control. If the radio has PA capabilities, a switch to go from the radio function to the PA function will be present. There is one additional feature that we like in a CB, and that is "RF gain." RF gain is a receive only adjustment that allows you to control incoming signal strength when strong signals are present and over-powering. Once we find a radio with those features, we are done shopping. Radios with the basic features are generally compact and it is easy to find a nook or cranny to place them. If your true intent is functionality, bigger does not mean better (and chrome does not make a radio perform better). As you move up in price range, you will find features such as ANL (automatic noise limiter). When this feature is turned on, the receiver (not the transmitter) is attenuated to cut out lower level noises on the airwaves. Keep in mind that the radio does not know the difference between a hissing sound or your friend saying "Come back! I need help" from a marginal distance. The ANL is okay for short distance communications, but then again, we prefer to just use the squelch and allow the radios receiver to have the capacity to gather up all that it can. As far as built-in SWR/power meters are concerned, we prefer that the antenna system be tuned and tested with an external meter. Our confidence in the accuracy of the built-in meters is, at best, weak. The most valuable part of having an internal SWR meter is to offer the user the ability to spot-check the antenna system. That is, after it is set up and functioning, random checks will point out possible flaws that might occur because a coax cable got pinched, a connector came loose or the antenna hit something that may have caused damage. For more about SWR, read the SIDEBAR ON SWR at the end of this article. One of our least favorite add-ons that started showing up in CB radios is weather band reception. Weather information is typically broadcast from major metropolitan areas and at a fairly low power. You do not have to travel far to be out of range. Your chance of getting current information is much better from a vehicle installed AM/FM radio. We would much rather see those interested in these frequencies put the money towards a mobile scanner that will pick up the weather bands and much, much more. And if you want to maximize the features, a dedicated antenna is a better option. SIDEBAR ON SWR The primary function of an SWR meter is to gauge the radios output potential and compare that to the antenna systems ability to absorb the radios maximum output potential. It is a simple process. First the antenna system is isolated from the transmitter and the user activates the radio transmitter by "keying up" the microphone. A calibration control allows the user to "swing the needle" to the meters calibration line. Once calibrated, a switch is repositioned and the meter opens a gate for the energy to enter the antenna system. The resulting "number" indicates how much of the radios potential is being absorbed and radiated by the antenna system. The more the better. Please take note that when we say "antenna system" we are not just talking about the antenna itself. The SWR meter "sees" everything beyond the antenna connection as one unit. Bad coax and/or connections, improperly installed mount components, poorly located antennas, insufficient counterpoise and untuned antennas can and will create conditions that will prevent the antenna system from absorbing and radiating the radios energy. The SWR meter "sees" the whole picture. If you do not gain anything else from this article, at least note that ALL antennas MUST be tuned to the transmitter after installation. The chance that a non-tested system is going to work properly is very slim. There are several articles in our library that offer more detail on SWR and we encourage you to read them. |
Updated: 2023.12.05