How to Set the SWR on a Wilson 5000 Antenna
By Adam Quinn
Before you begin using your CB radio, it is important to adjust your Wilson 5000 antenna to a working SWR level. The SWR, or standing wave ratio, measures the impedance mismatch between the antenna and radio. When the ratio of the antenna and radio impedance, or resistance to electrical flow, is significantly higher than 2:1, the radio's efficiency will diminish. The system can be balanced by lengthening or shortening the antenna. When the SWR is within operating range, the radio will transmit at optimal power.
Park your vehicle in an open space, and close the doors. If an amplifier is installed to the CB radio, turn it off during the testing. Insert the antenna whip into the mast mount.
Connect the radio to the transmission jack on the SWR meter using the jumper cable. Connect the antenna cable to the antenna jack on the meter.
Set the radio to channel 20. Flip the SWR meter switch to "FWD." Press and hold the transmit button on the CB handset. Turn the "Set" knob until the needle on the meter lines up with the set mark. Release the transmit button. The radio is calibrated.
Flip the SWR meter switch to "Set" or "SWR." Set the radio to channel 1, press the transmit button, and record the needle reading. Perform the same procedure for channels 20 and 40, recording the readings.
Adjust the antenna's length, based on the meter readings. If the reading on channel 1 was less then channel 40, then the antenna must be shortened by lowering the whip further into the mast mount or trimming 1/4 inch from the bottom of the whip. If the reading on channel 1 was greater than channel 40, then the antenna must be lengthened by raising the whip inside the mast mount or purchasing a longer whip.
Adjust the antenna by small increments, and perform the SWR testing until the readings are below 1.5 on each channel.
Remove the SWR meter, and reattach the antenna to the radio.
- If the SWR reading is 3.0 or higher, do not use your radio until the antenna has been properly grounded and tested for continuity.
Adam Quinn has been writing since 2008. His articles have appeared in the "Journal of Humanistic Psychology." Quinn holds a Master of Social Work from the University of Washington in Seattle, where his focus of study was counseling combat veterans with post-traumatic stress disorder.