SSTV not working with 3 channel configuration (fixed in v1.822)
For some time now, I have noticed that the SSTV decoder in the Kiwi has been missing every SSTV transmission that has been received. I've been mostly listening to pirates in the 6900 range lately, but the other day, I left the Kiwi open on 14230 for about an hour and it didn't catch a single decode, despite watching and hearing some strong ones come through. Same with earlier today, watched a few strong SSTV signals go undetected. This is with the Kiwi on "more bandwidth" 3 channel config.
Other public Kiwis I was listening to, set to 4 channel mode, were decoding SSTV just fine.
Tonight, I transmitted some SSTV images myself. With the Kiwi set to 3 channel configuration, it didn't detect a single transmission. I changed the Kiwi to 4 channel config, and sure enough, it detected the transmission. Same with the Kiwi in 8 channel config. I repeated the test several times. The SSTV decoder never attempted to decode a transmission while the Kiwi was in 3 channel configuration.
I'm currently running v1.821 with Debian 11.11.
Comments
I don't think generally there is a problem. Below is a 3-ch Kiwi-2 running v1.821 and it seems to work. Check the admin log tab. If you have messages like the following (parity fail or too many Hz off) you may not have good enough Kiwi frequency calibration to be decoding the SSTV VIS code correctly. And you will get no images without a properly decoded VIS code at the start.
SSTV: VIS 48 (0x30) @ +36 Hz
SSTV: Parity fail
I have nothing in the log for SSTV failure.
I just noticed that when in 3 channel config, there is no "waiting for signal" indicator, and the test button is shaded out. Where in 4 and 8 channel configs, it shows "waiting for signal" and the test button works.
Kiwi set to 3 channel config:
This is also the case with a couple of other Kiwis running 3 channel config, including the ScratchMoney Kiwis in Louisiana. I just watched a couple of strong signals do undetected on there too.
Kiwi set to 4 channel config:
This is on a KiwiSDR 1. SSTV was working (in 3 channel config) a couple of months back, never had a problem with it until recently. Feeding the Kiwi audio into an external SSTV decoder program still works.
The "Test" button is disabled because it is a file recorded at 12 kHz. So it won't work when the Kiwi is in 3-ch 20.25 kHz mode.
I tried the ScratchMoney Kiwi and did get the "waiting for signal" message on both of them. I'd really like to see your browser's Javascript console when the "waiting" message is missing.
Ah, I do get a Javascript error when I try it on yours. Let me look into that.
Okay, I see what's wrong. It's because I'm an idiot.
Will be fixed in the next release..