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RaspSDR / server

The web-888 web server code, Clone from kiwisdr with lots of changes
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Major problems with the signal-to-noise ratio #43

Open jimjackii opened 2 weeks ago

jimjackii commented 2 weeks ago

Hello,

I have a question for the experts where I can't find a solution.

There are 2 screenshots - 1x Web-888 and 1x an OpenWebRX installation with a SDRPlay RSPdx. A YouLoop with an amplifier is connected to both receivers. The antenna signal is distributed with an RF 2-way splitter with an attenuation of ~3.5dB. The distributor has a frequency range of 100 kHz - 60 MHz. The antenna hangs in an attic with some interference, which unfortunately cannot be avoided.

The reception of the RSPdx is OK so far. The signals can be recognised quite well on the waterfall and with little noise. The waterfall on the Web-888 is almost catastrophic in my view. There is a lot of noise and the voices are barely recognisable.

What could be the problem here? Is the input of the Web-888 possibly defective? Are there any other options for the Web-888 settings?

Thank you.

Regards, Steffen

Web-888: web_888_10m

OpenWebRX with RSPdx: owrx_10m

howard0su commented 2 weeks ago

Can you try to disconnect the antenna to see if the noise is picking up from antenna? Also, double check the power supply. The noise pattern is like EMI Interfere.

neil969 commented 2 weeks ago

just as an observation here.. I run an openWebRX+ and the WEB-888 too. The way that the OpenWebRX draws the waterfall is soooooo much "cleaner" than the Kiwi version. Regardless of how you adjust it, you will always be able to "see" less noise on the waterfall with OpenWebRX, so try to get the best you can on the waterfall on KiwiSdr first. Now you say you "There is a lot of noise and the voices are barely recognisable.", is that just on the waterfall, or can you also not "hear" them with your ears? My guess is that despite seeing all that noise, you will be able to listen to the signal just as well ( if not better!) on the Web-888/kiwi.

My experience is that it is actually much, much harder to "see" the signals on the waterfall with the Kiwi-SDR software than on the newer OpenWebRX, as the whole waterfall fft stuff in Kiwi is very much older.. There are many years of work in the OpenWebRX since the KiwiSDR was forked from it , and a LOT of it was the waterfall. If you zoom in on the area of the signal in KiwiSDR the average noise floor will drop in the waterfall and you will see the signals.

All that said - looking at your waterfall on the Web-888 , I would be looking hard at USB power supply - just try running it off a battery pack for a few minutes & see if the noise floor drops across the HF bands. I found running mine off the "shack" 13.8v supply through a "mount in the dash" type of USB adapter worked best for me. :) Sorry for the the rambling response, but I do see your issue and I have found that comparing the waterfalls like that is really comparing apples to oranges ;) ( I would give you screenshots from mine but I am away, and the WEB-888 refuses to map to a different port than my OpenWebRX - (there is an issue open for that here!)) M0KNC

jimjackii commented 2 weeks ago

Thanks for the tips.

Unfortunately, I haven't had time to experiment in the last few days.

I will check the noise without the antenna and also look for a better USB power supply. I've already tried a few power supplies (iPhone, Samsung, Xiaomi) and couldn't see any significant changes with the different power supplies. I will probably try an analogue transformer power supply (which is unfortunately hard to find).

It's true, the waterfall display in OpenWebRX+ is much better and it also seems to me that the signals on the Web-888 are somewhat easier to hear, despite the poorer waterfall.

@M0KNC Is it a problem that both OpenWebRX and Web-888 have the same internal port 8073? You can specify separate ports on the outside. Otherwise you could change the port in OpenWebRX in the file /etc/openwebrx/openwebrx.conf.

Regards, Steffen