Here is a consolidated version of the Hidden Feature List for the Tecsun PL-880.
Thanks to Thomas over at The SWLing Post for publishing all of the hacks in one list.
Function | Key | What to do | Radio State |
Synchronous Detection | USB/NORM LSB/NORM | Hold button in until change occurs. One push to change back. | ON |
Muting Threshold for AM/SSB, also sets FM Threshold on some versions | 9 | Select mode to adjust first (AM, SSB, FM). Press and hold, then adjust with either tuning knob. Press 9 again when done to save. | ON |
DNR (Automatic adjustment of bandwidth, etc?) | 6 | Press and hold till display says 'ON' and again for 'OFF'. | ON |
Display Firmware Version, and date | AM/BW | With radio OFF: press and hold until display turns on. Then press and hold again to get firmware. Press one more time for date | OFF |
FM De-emphasis | 5 | Press and hold to toggle between 75 (USA) and 50 (Europe) | ON |
Line-Out Level (only works on FM?) | 7 | Press and hold till current level begins flashing. Adjust with either tuning knob. Press again to save | ON |
Adjusting Seconds on Clock | 8 | With radio off, press and hold, and then adjust seconds | OFF |
Calibrating on AM (MW) | Snooze | Tune a strong MW station. Turn on SSB mode (USB/LSB). Move fine tuning till zero-beated and pitch matches non-SSB. Press and hold the snooze button till correction value appears in display, then press snooze again to save. | ON |
USB/LSB Calibration | 0 | PRESS and HOLD the 0 button. Look at the UPPER RIGHT corner of the display. A 2-digits number is BLINKING as well as the Hz digits of the tuned frequency. RELEASE the 0 button, and adjust the FINE TUNING. Tune, de-tune and re-tune before calibration is perfect. Play a bit with it to understand how it works. Change is effective AFTER you press 0 again. Do 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. | ON |
Forcing External Antenna on MW/LW | Several | Visit http://goo.gl/AXSgMI for instructions and video | ON |