What can cause erratic changes in SWR readings?

Tags: feedline

• The transmitter is being modulated.
• A loose connection in an antenna or a feedline.
• The transmitter is being over-modulated.
• Interference from other stations is distorting your signal.

What happens as the frequency of a signal passing through coaxial cable is increased?

The greater the surface area of a conductor, the lower the resistance, and vice versa – small surface area means higher resistance. As signal frequency increases the skin effect becomes more pronounced. That is, the “depth” within the conductor through which currents flow becomes reduced as frequency increases.

Why is it important to have a low SWR in an antenna system that uses coaxial cable feedline?

Why is it important to have a low SWR in an antenna system that uses coaxial cable feed line? SWR or Standing Wave Ratio is a measure of how well an antenna system matched to the transmitter and is an indication of efficiency. A very bad SWR can also damage your transmitter.

How do I know if my SWR meter is bad?

How to Identify a Faulty SWR Meter

1. Be dead as a doorbell. No movement. Ever. This is definitely a defective meter.
2. Always peg to the far right when the mic is keyed, with adjustment of the CAL dial failing to move it leftward.

How does 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.

What is the approximate bandwidth of a VHF repeater FM phone signal?

Between 10 and 15 kHz
The answer to Technician Class question T8A09, “What is the approximate bandwidth of a VHF repeater FM phone signal?” is “C. Between 10 and 15 kHz.”

What is the electrical difference between RG58 and RG8 coaxial cable?

RG8. RG8 is a thicker 50 ohm cable, at 12 AWG, that can provide a stronger signal than RG58. It is mainly used for amateur radio. There is also a version called RG8X, which is thinner at 16 AWG but provides similar signal quality.

What does an SWR of 4 1 indicate?

What does an SWR reading of 4:1 indicate? Loss of -4 dB.

What connects your transceiver to your antenna?

In a wireless communications or broadcasting antenna system, the feed line connects the antenna to the receiver, transmitter, or transceiver. There are three types of antenna feed lines, also called RF transmission lines, commonly used in wireless systems. …

How do I test SWR?

To run a test, simply connect your radio’s coaxial and antenna cables to the indicated ports on the meter. When you set the meter for calibration and activate the radio transmitter, you’ll see a number indicating the strength of the signal being broadcasted. SWR is typically only tested on mobile or base installations.

How do I choose the right coax for my ham station?

It is of importance when making decisions about getting the right coax for your Ham Station to understand that there are trade-offs that have to be considered between transmitter power, antenna gain, coax loss, erp, and your total Ham Station system performance. Your bank account may also enter into the equation like most Hams.

Will Power lines interfere with my ham radio?

If you think that a problem in the power lines near your home is the reason for interference in your ham radio, never attempt to fix it on your alone. You should always contact your local power company. Aside from being extremely dangerous for you to do so, it is also against the law.

Is it possible to have a clear ham radio signal?

If you are an amateur ham radio operator then you would want nothing else than to have a clear signal whenever you power up your rig. However, that is not always the case most of the time. It is even impossible for you to switch on your radio without experiencing the noise of varying degrees.

What is the difference between a CB radio and a ham radio?

Ham radio operators also have a wider choice when it comes to frequency bands they can use. The CB radio, on the other hand, can only use a 27MHz band. Because of the frequency restriction, it also greatly reduces the applications that CB radio can be used for.