Many on the PL-880 Yahoo Group have been reporting “soft mute” or “noise gate” audio jumps that are heard when the PL-880 is tuned to a weak SSB signal.
SWLing Post reader, Tim, has a Tecsun PL-880 with firmware version 8819 (mine is 8820) that exhibits this soft mute behavior. Check out the following video where he uses the built-in attenuator to force the PL-880 to engage the soft mute. Tim notes that the sound quality of his $30 camera phone is poor, but I can still easily hear what’s happening:
There have even been confirmed reports of SSB soft muting in PL-880s with 8820 firmware. With that said, I have now spent hours trying to force my PL-880 to engage soft muting in SSB, but to no avail. My SSB copy is solid, regardless of signal strength, noise level, or adjacent signals (at 5, 10 or 15 kHz and much closer)–no muting at all in SSB.
While I’m very pleased with my PL-880, I would encourage many readers to consider waiting a couple of months before making the purchase. Many of the PL-880 early adopters have felt a bit like Beta testers–admittedly, I’ve felt this way as well–but with time, I imagine many of the 880 quirks will be ironed-out by Tecsun.
owl, this was AM, wasn’t it? Maybe Tecsun has fixed the mute chopper in version 8820 for AM (and AM sync), but has forgotten it for SSB. With 8820 the audio popper is definitely not there for AM and AM sync. But SSB with 8820 sounds pretty much the same as your recording.
I won’t be surprised that samples with firmware 8819 exihibit this problem. I discovered this issue on a version 8818 sample – after I turned muting to 00 I could still hear the on/off of muting on some very weak stations.
I then had some communciation with someone from Tecsun and he said Tecsun was aware of this issue which was related to the SL DSP chip’s soft muting function (this communication happenned to take place on 2013-11-13).
Here is my recording of the muting issue:
http://bbs.tecsun.com.cn/up_fls/2013111323282367123.zip
In view of this, I assume the issue should have been addressed with the release of version 8820. I wonder why this is still an issue on some samples. Maybe it is related to some other functionality/characteristics of SL DSP chips? I once browsed some part of the technical documentation for Si4714/15 and it is so complicated with so many default settings which might not be optimised for particular applications.