The SWR cannot be changed by rotating this knob. The SWR function allows you to determine the SWR or "match" of the antenna system and transmitter on a specific channel. The entire process must be performed whenever you want to know what the SWR is on a different channel. The SWR/CAL
button toggles the meter between the CALIBRATE and SWR modes.
Set the radio to CH1. Press the SWR/CAL
button. The radio CAL(ibrate) mode is now selected. Press and hold the mic PTT (or push to talk
) button. Rotate the SWR knob as needed to adjust the meter indicator until it is on the SET mark
on the dial. The meter is now calibrated for this channel.
While still holding down the mic PTT, press and release the S/RF SWR CAL button to the SWR setting to read the SWR on the meter.
This entire process should be done for Ch 20 and Ch 40. You must go through the CAL procedure for EACH channel before attempting to read the SWR.
Changing the SWR requires that the antenna be lengthened or shortened until such time that the SWR can be reduced no further. Typical SWR across the band may be:
CH1 - 1.5:1, CH20 - 1.1:1, CH40 1.5:1
CH1 - 2.2:1, CH20 - 1.7:1, CH40 2.3:1
The "dip" in SWR on CH20 is typical, as the antenna is the perfect length on only one channel - it will be come slightly too long or slightly too short as you tune up or down from CH20. The further away from CH20 you go, the poorer the SWR will be. You can "slide" the dip to any channel you prefer - say CH8. If you tune for lowest SWR on CH8, You might see CH1 with a 1.2:1 SWR, CH8 at 1.1:1 SWR and CH40 at 2.5:1. All are acceptable - sort of. Many manufacturers say up to 2.5:1 or even 3.0:1 matches are ok, There's no reason a quality antenna can't be tuned for optimum SWR in the middle of the band (CH20) to have less than a 2.0:1 SWR on CH1 or CH40, unless there is a ground issues or bad cable / antenna / connection somewhere.
You can view the manual here
. I hope this helps & good luck!