Unable to get clean audio

[ZL1LAC]

I have been trying so hard to be able to record and stream a clean audio signal with no luck what so ever and it's driving me COMPLETELY NUTS!

No matter what I do I either get buzzing or some humming sound and distorted audio.

Where is my config. `tau = 100; devices: ({ type = "rtlsdr"; index = 0; gain = 16;

mode = "scan";

sample_rate = 2.4; centerfreq = 141.400; channels: ( { freq = (141.400); labels = ("EAS"); modulation = "nfm"; outputs: ( { type = "icecast"; server = "icecast.server.example.org"; port = 8080; mountpoint = "stream.mp3"; name = "EAS"; genre = "EAS"; description = "EAS"; username = "source"; password = "mypassword"; send_scan_freq_tags = false; }, { type = "file"; directory = "/home/pi/radio"; filename_template = "EAS"; } ); } ); } );`

What the heck am I doing wrong?

[szpajder]

First of all:

• don't put parentheses around freq value. It's not a list, its a single value, so it should be just freq = 141.000;
• don't set centerfreq to the same value as freq. Shift it at last a couple tenths of kilohertz either side (for example 141.450 would be a good value).
• no correction value has been specified. Are you sure your dongle does not need frequency correction?
• gain = 16 might be a little low, unless your signal of interest is very strong or you are using an external amplifier or a directional antenna.
• labels parameter does nothing unless mode is set to scan.

[ZL1LAC]

Freq value changed, centerfreq changed.

No correction from what I have been testing in SDR sharp. gain = 16 yep correct, the repeater is only a few miles away from me.

[spotter-ssol]

Can you post an audio sample?

[ZL1LAC]

Only a small one but you can hear the hum. EAS_20190917_17.zip

[szpajder]

Nothing wrong here, I guess it's https://en.wikipedia.org/wiki/CTCSS ?

[ZL1LAC]

You cant hear that hum?

[szpajder]

I can hear it, and I have given you a link where you can read what it is.

[ZL1LAC]

Yeah, it does use CTCSS and the value of it is 186.2. Would be cool to remove that noise.

[ZL1LAC]

Resolved after looking into CTCSS here. By adding the following to my config. lowpass = 2500; highpass = 150; squelch = 50;