What Does A Very High SWR Reading Mean?

How do you lower the SWR on a dipole antenna?

To raise the frequency of minimum SWR, trim the antenna shorter.

Cut each of the dipole’s segments by equal amounts so that the two halves maintain equivalent lengths.

If the minimum SWR is minimized at a higher frequency than desired, you must lengthen the wire segments..

Why the SWR goes higher when I use an amplifier?

if the swr meter is connected between the output of the amp and the antenna this rule applies. using more power than necessary to obtain a set meter reading will result in higher swr readings.

What is the best height for a CB antenna?

Generally, the higher the antenna is above ground, the better it will perform. Good practice is to install your vertical antenna about 5 to 10 feet above the roof line and away from power lines and obstructions. Remember that the FCC limits your antenna height to 60 feet.

How do I know if my CB antenna is bad?

Testing for a Defective CB AntennaUsing your multimeter, touch one of the probes to the metallic end of the antenna. For fiberglass antennas, this will usually be the tunable tip on the antenna’s end. … Touch the other probe to the metallic threads at the end of the antenna. … As you maintain contact with both probes, measure the circuit’s resistance.

What causes high SWR reading?

One of the most common causes of high SWR readings is incorrectly connecting your SWR meter to your radio and antenna. When attached incorrectly, readings will be reported as being extremely high even if everything is installed perfectly.

What does high SWR mean?

Short. The most common cause of a high SWR is an antenna shorted to ground. There are two places a short can occur in a CB antenna system, in the coax and in the antenna stud.

What SWR is too high?

For instance a SWR too high (over 3:1) all over the band can be an indication of a bad part or junction, poor ground or poor location. An SWR too low over the whole band (1:1 for all 40 channels) can indicate a low efficiency antenna or lossy component.

What does an SWR reading of 4 1 indicate?

What does an SWR reading of 4:1 indicate? Loss of -4 dB. Good impedance match. Gain of +4 dB. Impedance mismatch.

Does a CB antenna need to be grounded?

Ground Your Antenna Mount If you’re using a standard CB antenna (i.e., anything except a no ground plane, or NGP, kit), you’ll need to make sure your antenna mount is solidly grounded to the vehicle’s chassis. A bad ground will result in an un-tunable antenna and sky-high SWR levels.

What does an SWR reading of 1 1 mean?

What does an SWR reading of 1:1 mean? The best impedance match has been attained. An antenna for another frequency band is probably connected. No power is going to the antenna.

What affects SWR?

There are many things other than the antenna that can cause high SWR. SWR meter readings take into consideration the antenna, the coaxial cable, the mount, the mounting location, the vehicle and objects in the antennas near-field environment.

Is it OK to coil coaxial cable?

It is recommended that you use as little coaxial cable as you can. … Less is more with coaxial cables. Also do not coil the coaxial cable as this can cause signal loss. Instead let the cord lay uncoiled if at all possible.

Does SWR affect reception?

Simplified answer: There is no relationship between SWR and receive performance. … SWR is a measure of the impedance mismatch between your antenna and transceiver. Whether transmitting or receiving, a higher SWR correlates with a less efficient coupling of energy between the transceiver and antenna.

Can I use 75 ohm coax for CB?

RG-59 and RG-6 are 75 Ohm coaxial cables designed for cable television applications, they tend to have wide frequency response and low line loss. … You can use these cables with a 50 Ohm amateur radio antenna system, but because of the impedance mismatch, your SWR will be a little higher.

How do you adjust the SWR on a CB radio?

Turn the radio to channel 1. Key the microphone (depress the button and hold it). Turn the knob on the SWR meter labeled “SET” or “ADJUST” until the needle reaches the setting position at the end of its range. While still keying the microphone, flip the switch on the SWR meter to the “REF” or “SWR” position.

What is an acceptable SWR reading?

What is a good SWR reading ? The best reading possible is 1.01:1 (46dB return loss), but usually a reading below 1.5:1 is acceptable. Outside the perfect world a 1.2:1 (20.8dB return loss) is spot on in most cases. To ensure an accurate reading, it is best to connect the meter at the base of the antenna.

Does coax length affect SWR?

“the length of the feedline will not change the swr it will change the apparent reading depending on what wave length you read the swr at. . just as adding a signifigant length of coax, the resultant loss will look like a lower swr.”

Can high SWR damage a radio?

High SWR can reflect enough power back into the radio to create enough heat to cook the final RF transistor. It isn’t usually an immediate failure, it takes some time for that heat to build up and do damage.

Is a longer CB antenna better?

Choosing the Optimal CB Antenna Length Yes, taller/longer is better for range of distance when it comes to an antenna and the optimal antenna length is 1/4 wavelength. That translates to 102 inches (8.5 feet), too tall to be practical for most mobile applications.

Does SWR change with power?

SWR really doesn’t increase with power. It’s always the same.