Jul 17, · I will show you how to calibrate and use a simple SWR meter. Great information for new HAMs who are trying to learn the makingoz.com: I forgot to mention, you. Aug 17, · Standing wave ratio can be very important when using a transmitter. If the level of standing waves is too high then it can either damage the transmitter or.
Last Updated: January 13, References. This article was co-authored by our trained team of editors and researchers who validated it for accuracy and comprehensiveness. There are 18 references cited in this article, which can be found at the bottom of the page. This article has been viewed 11, times. Learn more Knowing how to find your radio's SWR value is important, as it allows you to adjust the antenna for optimal reception. Ykutube Avoid testing your radio in a garage, carport, or other enclosed space where the surrounding usw may have a distorting effect.
This image may not be used by other entities without the express written consent of wikiHow, Inc. Conduct your test at least 20 feet hw.
Ask anyone in your immediate vicinity to stand a minimum of 20 feet ohw. You can pick up an SWR meter from any major electronics store or CB radio specialty shop, as well as online.
Disconnect the antenna and coaxial cables from your radio. A standard coaxial cable is a thick black cord with a screw-on barrel head. Antenna cables tend to be slightly thinner, and may be designed to attach to metrr separate external antenna piece.
To remove them, simply unscrew them and pull them free from their respective ports. This port will be located either on the side or back of a standard SWR meter. Part 2 of Locate the power button or switch on a digital meter to activate the unit. Most newer SWR meters feature a central power button on the face of the device. On some models, you may find a power switch on the side or back of the unit's casing. Turn the calibration dial usee analogue meters to the indicated zone.
You must set analogue meters for calibration manually. Keep turning the dial until the needle on the display window comes to a stop against the far right edge of the area highlighted in red. Set your radio to how to use a swr meter youtube 1. Turn the channel dial on the radio interface to the left, or press and hold the down arrow button under the display until you reach channel 1.
This is the signal that your SWR meter will be measuring. As you move the switch, the needle on the window display will jump to the position corresponding to the SWR value for that channel. Write down this number for future reference. As long as the how to cover a fart you see is below 2, though, it means that your radio and antenna are calibrated properly.
The reading will ue as soon as you let go. Repeat the process on channel The closer they are, the more stable the signal. Ideally, the numbers should be within a few decimal places of one another. However, this is not a necessary step. Make adjustments to your radio or antenna as needed.
Most often, a short or grounding issue is to blame. This is a highly technical project that you shouldn't attempt without the necessary knowledge and experience. Include your email address to get a message when this question is answered. Understanding how to check antenna calibration is a crucial part of operating a CB radio.
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Typical set-up for SWR meter
Apr 04, · How to use an SWR meter. How to use the SWR meter. Actually using the VSWR meter is very easy, but a few simple steps may help the first time user. When using the VSWR meter to measure the performance of a new antenna or where the VSWR may not be know, it is wise to use a low power and a clear channel. With these concepts in mind the following procedure may be useful.
Understanding how to use a SWR meter is relatively easy, but sometimes knowing how to interpret the results and their limitations enables far more to be gained from using a VSWR meter. There are many different SWR meters that are available, often aimed at the CB and amateur radio markets. Some very low cost items are available, but sometimes it may be better to pay a little more and obtained a better quality instrument. Current and voltage standing waves are set up when power is reflected from a mismatch, and often their is a focus on the voltage elements.
When looking at how to use a VSWR meter, most instructions are fairly vague, often just detailing which connector is to be connected to the antenna and which connector to the transmitter. The basic set-up for a VSWR meter is as shown in the diagram below. The VSWR meter is connected in the feeder from the transmitter to the antenna. Typically it is located at the transmitter end of the feeder for convenience, and so that the actual VSWR as seen by the transmitter can be monitored.
Again for convenience these are often placed near the transmitter. It is often more convenient to place an ATU close to the transmitter as having a remote one often means getting power to it and also weather-proofing it and this adds significant cost. When an ATU or antenna matching and tuning unit is added to the set-up, the system shown below is normally used.
This is normally the most critical point to monitor the VSWR because high VSWR levels can damage the power amplifiers if no protection is incorporated, or it can result in the protection circuits backing off the power. However it is found that if the coax feeder can withstand the higher voltages and current as a result of the poor antenna match, and the feeder loss is not too high, then the system will work well.
When using the VSWR meter to measure the performance of a new antenna or where the VSWR may not be know, it is wise to use a low power and a clear channel. With these concepts in mind the following procedure may be useful. There is no general pass or fail mark when measuring VSWR. VSWR is measured as a ratio, i. Often VSWR meters will have a red calibration above and this is probably the maximum you would want a transmitter to run with.
A maximum of would be better to prevent damage to the transmitter if it does not have protection on the output circuitry. Check the transmitter handbook in case there are guidelines on the maximum VSWR that the unit can work with. But in reality there are no hard and fast rules. In general, the lower the better, but there will be very little difference in signal at the receiver between a VSWR of and Unfortunately these requirements do not coincide and therefore it is necessary to understand what happens and how the VSWR measurements and readings can be distorted.
The main issue is the feeder loss that is always present to a greater or lesser degree. This can have a major effect on the VSWR readings that are seen. Any feeder loss absorbs power in both directions, and a high level of feeder loss can mean that the reflected signal is much reduced. It is reduced as a forward signal to the antenna, and then again as a reflected signal back to the transmitter.
This means that an antenna with a poor match and a very high VSWR may appear as being fine at the transmitter because the signal is reduced on its way to the antenna, and even thought he same percentage of power is reflected, it is the same percentage of a smaller amount.
This means that with a feeder that introduces a high loss the VSWR can seem good at the transmitter, but at the antenna itself it may be very poor. As an example take the example of a transmitter transmitting watts through a feeder with a loss of 3 dB.
This means that only 50 watts reaches the antenna. If the antenna has a poor match and the resulting VSWR is , i. This is further attenuated by 3 dB meaning that only 15 watts reflected power is seen at the transmitter. The reflected power has been attenuated by 2 x 3dB, i. Understanding how to use a VSWR meter is normally very easy. A few simple steps is all that is required to connect it and set it up. Once this has been done, then it can be left in circuit if needed.
In many instances it is good to leave a VSWR meter of some form in circuit so that checks can quickly be made, and if there are any intermittent faults, these can be flagged up very quickly. Shopping on Electronics Notes Electronics Notes offers a host of products are very good prices from our shopping pages in association with Amazon.
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