What is SWR and SWR CAL on a CB Radio?

Something most newbies struggle with understanding is SWR on a CB radio. SWR is essential to any CB set up as it helps the equipment run to its full potential. It enables users to match the antenna to the signals being transmitted. In simple words, the right SWR reading can help you get the best transmission range. Keep in mind; a high SWR reading without proper antenna tuning can cause poor transmissions, or worse, may even damage the radio’s output transistors. Therefore, to get peak CB performance, it’s critical to know all about SWR calibration or SWR CAL.

This article explores the importance of SWR and how you can calibrate SWR on a Citizen band radio.

What is SWR on a CB radio?

SWR refers to “Standing Wave Ration,” which shows the power ratio reflected to the antenna lead. Therefore, its primary aim is to help match the antenna to the transmit signals. Using the SWR meter, you allow the antenna to work on the radio frequencies you’re operating on. Most CB units have an in-built meter for testing the device’s antenna system. It’s an essential feature to ensure efficient running. But why is it so important?

First, it helps to check if the antenna system, including the antenna, mount, and coax, is installed correctly. Second, the SWR reading also helps find out if the antenna is reflecting greater power. In simpler terms, if the SWR reading comes high, it means the antenna is wasting power, which may eventually damage your equipment. As a result, the device’s performance will suffer. This happens because of power not leaving the antenna correctly, which in return feeds the output power back to the radio. Therefore, an optimal ratio is closer to the 1:1 standing wave ratio. Hence, strive for a low SWR reading as it means a longer-lasting and well-performing CB radio! Given how vital both factors are, it’s best to look for equipment that supports SWR Cal.

Why is SWR Cal important?

When more output power is reflected to the radio via the feed line, it hampers the signal output. According to the FCC guidelines, your CB is restricted to 4-Watts of RF power. SWR Cal on CB helps prevent losing power that the antenna may be reflecting. When your radio’s SWR meter shows a high reading, it simply means a loss of output, which will cause poor signals and distortion. This can also be quite damaging to the radio equipment, as the power being sent back to the system can cause heat build-up. Most product warranties often do not cover damage to the output transistor and can generate several bucks for repair or replacement.

CB radios with SWR Cal

Cobra 29LTD

The Cobra 29 LTD is one of the best professional CB radios on the market today. It entails all the essential travel and emergency features, such as access to Instant Channel 9, antenna warning indicator, 40 channels, switchable noise blanker, and RF gain. Most importantly, it offers SWR calibration that helps you optimize your device performance.

Texas Ranger TR-199MKI

If you’re on the lookout for a heavy-duty mobile CB radio, then check out the Texas Ranger TR-199MKI. This classic design, 40-channel CB, is an underrated device. It is designed, keeping professional users in mind. Its controls include RF gain, Squelch, SWR calibrate, tone control, S/RF meter, and ANL. The expert design, along with the premium audio quality, makes it ideal for on-the-road communications.

Cobra 29 LX

Like the Cobra 29 LTD, 29 LX is an excellent CB that offers a range of features that make the overall communication experience quite pleasant. Its key features include a built-in SWR meter, NOAA weather channels, radio check diagnostic, and antenna warning indicator. It also features SWR calibration, which allows the calibration of the 29 LX’s antenna system for maximum performance.


SWR Cal CB radio is the best equipment you can get to achieve optimal performance. It helps you check if the antenna system works appropriately. Furthermore, it also enables you to measure any power being lost or reflected into the radio. Increased power being reflected can cause heat build-up and may damage your equipment. Therefore, this reading is critical to maintaining a healthy and long-lasting CB radio. Cobra radios, particularly 29 LTD and 29 LX, feature an SWR Cal knob to help you get peak CB performance.