In this video, I’ve tuned both the Tecsun PL-880 and PL-660 to All India Radio on 9,445 kHz (transmitted from Bengaluru, India, some 8,800 miles away).
Thanks to an image of a (prototype?) PL-880 keypad posted on the Tecsun PL-880 Yahoo Group–an excellent group you should join, by the way–I’ve discovered that if you press and hold the number 6 on the PL-880 keypad, it engages the hidden DNR function. I assume DNR is an acronym for “digital noise reduction.”
I engage the PL-880 DNR feature in this video and compare with the PL-660 audio. Again, apologies for quality as this was made using my iPhone.