Help with static issues on stream RTL-SDR

[2000nesman]

Hi all,

I come to you for assistance or guidance as I am very new to all of this. I'm trying to broadcast over on broadcastify on this page and its been a complete train wreck. I'm streaming to the site using a Raspberry Pi 3 B+ and a RTL-SDR dongle. I've managed to get Weather Band to play on it with good audio trying to test the stream audio as this frequency I want to broadcast isn't used 24/7. As soon as I switch to the frequency I want to broadcast (155.0925) it becomes solid static. I've tried adjusting all the levels under -p -l -g but nothing is working.

Also to note:
I did resort to before steaming to test it using rtl_test all came back good
I tested it locally with

rtl_fm -d 0 -M fm -f 162.474M | aplay

this had issues playing the audio back to me so I installed SOX
once I had sox I then used

rtl_fm -M fm -f 162.474M | play -r 32k -t raw -e s -b 16 -c 1 -V1 -

and this is where I figured out some of the levels that worked here but then would not work once broadcasting.

Here is my current configuration for 155.0925

/usr/local/bin/rtl_fm -d 0 -M fm -f 155.0925M -p 0 -l 10 -g 20 -t 2 -E pad -s 12k |
/usr/bin/lame -r -s 12 --resample 22.05 -m m -b 16 --cbr --lowpass 4 - - |
/usr/bin/ezstream -c /etc/ezstream_bcfy.xml > /home/pi/Desktop/bcfy.log 2>&1 &

Here is a picture of my setup if you need it.




Any help or guidance is greatly appreciated.

Thanks.

 

[vagrant]

It appears you have the squelch set to ten which is seems to low ( -l 10 )

The RR Wiki on this notes a setting of 65 ( -l 65 ), but that may be too much. I would stay to start it again at -l 20 and keep moving up in multiples of 10 until the static is gone. I would then change the configuration and move down in multiples of two, as you do not want to squelch out weak signals.

Now, if that signal is from one source and it is always strong when it does transmit, then you do not need to worry about backing it down once you are able to set the squelch. It will punch through.

I do not provide a stream using a Pi so I do not have a config to share. I am just familiar with that stuff and read the wiki.

 

[2000nesman]

It appears you have the squelch set to ten which is seems to low ( -l 10 )

The RR Wiki on this notes a setting of 65 ( -l 65 ), but that may be too much. I would stay to start it again at -l 20 and keep moving up in multiples of 10 until the static is gone. I would then change the configuration and move down in multiples of two, as you do not want to squelch out weak signals.

Now, if that signal is from one source and it is always strong when it does transmit, then you do not need to worry about backing it down once you are able to set the squelch. It will punch through.

I do not provide a stream using a Pi so I do not have a config to share. I am just familiar with that stuff and read the wiki.

So I did what you suggested. I did it locally first with the command

rtl_fm ... | play ...

found a good squelch level was 50 and it worked there was no static. ok so put it in the config and ship it off to the broadcast and it should work. Not so much, it still has the static in the stream.

 

[IAmSixNine]

you confirmed the weather channel sounds fine, so the set up is good.
If your getting static on the actual channel your trying to listen to then its either to far away, low power or something causing interference.
These dongles are not the best receivers since they are so wide band.
The next question that should be asked, what are you trying to monitor, where is it located relative to you?

 

[2000nesman]

you confirmed the weather channel sounds fine, so the set up is good.
If your getting static on the actual channel your trying to listen to then its either to far away, low power or something causing interference.
These dongles are not the best receivers since they are so wide band.
The next question that should be asked, what are you trying to monitor, where is it located relative to you?

Im monitoring dispatching for local town's fire department's. Nearest antenna is within 2 miles of me. I currently have the system switched to a laptop and am not having issues on it.

 

[a417]

Can I ask a silly question? I know you said you had "good audio" from the NOAA All Hazards TX, but the rtl_fm command is 162.474 - which is off frequency. NOAA is 162.400 to 162.550 mhz, in 25khz steps, which your tuned frequency wasn't. If you're getting a solid copy of the NOAA robot on 162.474 then you might want to go and try to calibrate your setup against it so that you are on frequency.

I've also noticed that you have not specified -g in the test setup with NOAA (defaulting to autogain), and your streaming setup is fixed to a -g 20 ...so you're apples to oranges there. Set the gain high and try again.

You need to get a completely static WORKING setup of the NOAA all hazards (or another known good transmitter), figure out your ppm offset so that you can effectively tune your rtl_sdr on the correct frequency, and then once you have EVERYTHING dialled in to work, the only thing you change is the frequency that you want to stream. Fewest moving pieces until you're solid.

 

[2000nesman]

Can I ask a silly question? I know you said you had "good audio" from the NOAA All Hazards TX, but the rtl_fm command is 162.474 - which is off frequency. NOAA is 162.400 to 162.550 mhz, in 25khz steps, which your tuned frequency wasn't. If you're getting a solid copy of the NOAA robot on 162.474 then you might want to go and try to calibrate your setup against it so that you are on frequency.

I've also noticed that you have not specified -g in the test setup with NOAA (defaulting to autogain), and your streaming setup is fixed to a -g 20 ...so you're apples to oranges there. Set the gain high and try again.

You need to get a completely static WORKING setup of the NOAA all hazards (or another known good transmitter), figure out your ppm offset so that you can effectively tune your rtl_sdr on the correct frequency, and then once you have EVERYTHING dialled in to work, the only thing you change is the frequency that you want to stream. Fewest moving pieces until you're solid.

I completely forgot to mention what my gain was so I tested it again.
This was WB

rtl_fm -M fm -f 162.475 -d 0 -g 30 -l 30 -p 0 -E pad -t 2 -s 24k | play -r 24k -t raw -e s -b 16 -c 1 -V1 -

and then took that and tuned it locally through my speakers first

rtl_fm -M fm -f 155.0925 -d 0 -g 30 -l 60 -p 0 -E pad -t 2 -s 24k | play -r 24k -t raw -e s -b 16 -c 1 -V1 -

I'll leave the feed up so you guys can get a true feel of the issue im having.
Farmingdale, Pittston, Randolph and West Gardiner Fire Departments Live Audio Feed

 

[2000nesman]

For reference the WB station I was using
NOAA Weather Radio WSM60

 

[a417]

I seldom run rtl_sdrs with less than 45 gain.

 

[2000nesman]

I seldom run rtl_sdrs with less than 45 gain.

Should my gain be higher? It sounded pretty decent through my speakers when it was at 30 gain

 

[a417]

bump it all the way up to max, can't hurt it to try...

 

[a417]

can you tune .550 from where you are? I can hear .475, but it may be too close to your residence so you are getting a REALLY hot signal into your front end - making it actually harder to fine tune your setup.

 

[zapman987]

Trying to do a similar thing, how are you piping from sox/play to broadcastify?