Testing a SWR Meter

While rarely the cause of high SWR readings, a defective SWR meter can wreck havoc on your SWR troubleshooting efforts. The easiest way to test for a defective meter is to use a second meter for testing, and compare the results to the first meter. If it's convenient to borrow a meter from a friend, or you have a 2nd on on hand, fantastic. However, most people don't have access to a treasure chest of back-up meters. In that case, please refer to our notes below:

If using an external SWR meter

A defective external SWR meter will often do one of two things. It will either:

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

In either case, you likely have a faulty meter that needs to be replaced. In some instances, the SWR meter CAL/REF switch may be wired backward, which we've seen on rare occasions. To test for this, you'll want to measure SWR in the following manner, which simply reverses the standard REF and FWD switch positions:

1. With the meter correctly hooked-up to radio and antenna, set the switch to the "REF" postition
2. Turn the SWR Calibration knob fully counter clockwise
3. Key the microphone and while continuing to depress the talk button, adjust the calibration knob so that the needle touches the "SET" mark on the meter
4. When the needle reaches the "SET" mark, flip the switch to "FWD"

If this procedure produces what looks like a reasonable SWR reading, it is a good indication that the SWR meter was wired backward. This faulty wiring won't affect the accuracy of the SWR reading, and a good reading achieved with this method can be trusted. Despite the accuracy, you may want to replace the meter as the reversed switch may cause confusion down the road.

If using an internal SWR meter

Unfortunately, SWR meters built into radios have a reputation for being somewaht finicky. While they more often than not are good enough to perform a basic antenna tune, they tend to be much more unreliable than even the most basic external meter. If you have gone through all the previous troubleshooting steps, found no problems, and your built-in SWR meter is STLL alerting you to SWR above 3.0, you should try to get your hands on an external meter to double-check the readings. Frequently in these circumstances, it's the on-board meter that is to blame.The same rule applies for an on-board "Antenna Warning Light" that refuses to turn off despite what you believe to be a correct installation. Test the SWR with an external meter. If the SWR is within an acceptable range, you likely have a malfunctioning on-board meter and warning light.

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