Tune to an AM broadcast station and zero-beat the signal (fine tune it until the signal has no SSB distortion and voices/music sound natural)
If the last two digits of the frequency are not “00”, this means there is some display deviation
Simply press and hold the [SNOOZE] button for about one second or so to calibrate the last two frequency digits, which will show “00” when successful.
I will try this procedure later today by re-calibrating my PL-880.
Dan has also noted what many others have–that the PL-880 “is sensitive to both power levels, and time in the powered on state, and will vary by some hz up and down the bands
no matter what one does to zero at any particular point.”
Tecsun PL-880 owner, Patrick, has made a video showing how to calibrate SSB on the PL-880. In the video, you can hear what it sounds like to zero-beat an AM carrier. Patrick writes:
Some people reported their PL-880 wasn’t properly calibrated in SSB (off-frequency).
Here is a simple tip to calibrate your TECSUN PL-880 for zero-beat operation (SSB mode) : either tune to USB or LSB, say 500 Hz off-frequency (603.05 USB for example, if you wish to calibrate your radio on 603.00, or 602.95 LSB).
PRESS and HOLD the 0 button of the keypad.
Look at the UPPER RIGHT corner of the display, where stands the clock and S/N ratio. A 2-digits number is BLINKING as well as the Hz digits of the tuned frequency.
RELEASE the 0 button, and properly adjust the FINE TUNING. You will probably have to slightly tune, de-tune and re-tune before calibration is perfect. Play a bit with it to understand how it works … (the change is effective AFTER you press again the 0 number to validate the value).
Do the same for both USB and LSB modes.
Check the tone when tuned to xxx.95 USB and xxx.05 LSB. They should sound exactly the same.