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PostPosted: Mon Oct 20, 2014 6:02 am 
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Joined: Fri Jun 27, 2014 4:20 pm
Posts: 211
I am almost done done !!! Some testing and then release. Something to be aware is that these usb dongles have different gain setting and different frequency response depending on the tuner.

_________________
Very proud user of Stereo Tool since 2010. Thanks Hans.

My radio station
http://amradio.ddns.net


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PostPosted: Mon Oct 20, 2014 10:12 pm 
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Joined: Fri Jun 27, 2014 4:20 pm
Posts: 211
Here it is.
https://www.dropbox.com/sh/naccq5dv8joj ... p1TOa?dl=0
Now this is a "modulation monitor" in gnu radio. It has RF FFT, MPX FFT, L/R Phase Scope, L and R Channel FFT and L-R FFT.
I am in no way a programer (or a dsp guru).

Known problems :

1)Stereo Separation
2)And when the sql is set to -100 and noise is picked up the FIR filter after the demod locks up.

Thank You all. I am waiting for suggestions and bugs. V4 to be expected.

_________________
Very proud user of Stereo Tool since 2010. Thanks Hans.

My radio station
http://amradio.ddns.net


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PostPosted: Sun Oct 26, 2014 5:52 pm 
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Joined: Wed Aug 20, 2014 9:32 am
Posts: 231
Location: Poland
Quote:
Meanwhile I ordered another USB dongle receiver - will give it a go and check if the results are similar to those obtained using the one I've got.
And this is it: http://notonlytv.net/p_lv5tdeluxe.html

Works great. This particular piece I got has quite accurate frequency measuring - no 10kHz shift:


Image

@ mpex2006km: I'll try to test the soft as soon as I get it to work on windows or perform linux install on one of my spare machines.


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PostPosted: Sun Nov 02, 2014 1:12 pm 

Joined: Sun Jan 04, 2009 2:54 pm
Posts: 158
Location: Finland
I made a Python script that opens rtl_fm with certain parameters to make it output MPX which then routes them to VAC and to any software that likes 192kHz audio input like MPXtool and RDS Spy. Of course you can't change frequency with rtl_fm when running but it's quite lightweight setup. Requires PyAudio and Python 2.x (whatever suits you and PyAudio).
Code:
import subprocess
import pyaudio
import socket

p = pyaudio.PyAudio()


FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 192000
CHUNK = 2048


# Audio device selection >
print "Choose OUTPUT device by typing corresponding number."
print "If you try to choose input device, it will end up in error."
for i in xrange(p.get_device_count()):
    print str(p.get_device_info_by_index(i)["index"]) + " " + p.get_device_info_by_index(i)["name"].encode("cp850", "replace")

while 1:
    try:
        dev_index = int(raw_input("Device number: "))
        try:
            output = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True, frames_per_buffer=CHUNK, output_device_index=dev_index)
        except:
            output = None
            print "Error! False output device!"
    except:
        print "Error! Type a number corresponding to output device!"
        output = None
        
    if output != None:
        break


#output = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True, frames_per_buffer=CHUNK)

cmd = "rtl_fm.exe -f 93.1M -s 192000 -g 15 -F 9" # Here's the commandline, f is frequency, g is gain, s is samplerate, F is some filter thing, not sure.
sp = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=False)

while 1:
    output.write(sp.stdout.read(2048))



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PostPosted: Fri Nov 07, 2014 8:38 am 
User avatar

Joined: Wed Aug 20, 2014 9:32 am
Posts: 231
Location: Poland
Quote:
I made a Python script that opens rtl_fm with certain parameters to make it output MPX which then routes them to VAC and to any software that likes 192kHz audio input like MPXtool and RDS Spy. Of course you can't change frequency with rtl_fm when running but it's quite lightweight setup. Requires PyAudio and Python 2.x (whatever suits you and PyAudio).
Code:
import subprocess
import pyaudio
import socket

p = pyaudio.PyAudio()


FORMAT = pyaudio.paInt16
CHANNELS = 1
RATE = 192000
CHUNK = 2048


# Audio device selection >
print "Choose OUTPUT device by typing corresponding number."
print "If you try to choose input device, it will end up in error."
for i in xrange(p.get_device_count()):
    print str(p.get_device_info_by_index(i)["index"]) + " " + p.get_device_info_by_index(i)["name"].encode("cp850", "replace")

while 1:
    try:
        dev_index = int(raw_input("Device number: "))
        try:
            output = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True, frames_per_buffer=CHUNK, output_device_index=dev_index)
        except:
            output = None
            print "Error! False output device!"
    except:
        print "Error! Type a number corresponding to output device!"
        output = None
        
    if output != None:
        break


#output = p.open(format=FORMAT, channels=CHANNELS, rate=RATE, output=True, frames_per_buffer=CHUNK)

cmd = "rtl_fm.exe -f 93.1M -s 192000 -g 15 -F 9" # Here's the commandline, f is frequency, g is gain, s is samplerate, F is some filter thing, not sure.
sp = subprocess.Popen(cmd, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT, shell=False)

while 1:
    output.write(sp.stdout.read(2048))


So... looks like you are able to run it in Windows ;) Looks like this weekend I will have more time so maybe I'll give it a go and finally do some testing.


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PostPosted: Sun Feb 07, 2016 7:03 pm 

Joined: Tue Jan 26, 2016 11:34 pm
Posts: 54
Location: Jugoistočna Srbija
A few pics of Serbian radio stations, made by my friend in Belgrade.
http://i.imgur.com/CfMVtq5.jpg
http://i.imgur.com/eVxceMN.jpg
http://i.imgur.com/vlffj4C.jpg
http://i.imgur.com/Pxdh6Et.jpg
Video will soon follow!


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PostPosted: Sun Feb 07, 2016 10:02 pm 
User avatar

Joined: Wed Aug 20, 2014 9:32 am
Posts: 231
Location: Poland
I'm pretty sure you set bandwidth to 192 kHz, while more accurate would be 150 (2x75). That's why the pilot on your screens has only 5% and modulation looks low.


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PostPosted: Sun Feb 07, 2016 10:43 pm 

Joined: Tue Jan 26, 2016 11:34 pm
Posts: 54
Location: Jugoistočna Srbija
The screenshots are not mine.
Anyway the levels look normal to me. The first screenshot (91.8) shows a station slightly overmodulating, the second screenshot (92.5) shows a station that looks OK modulation-wise, the third station (94.9) is undermodulating, but the station is a part of a national network and volume levels vary between transmitters. And the last screenshot shows the modulation of a public radio station broadcasting on 95.3 not using any compressors and limiters.


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PostPosted: Mon Feb 08, 2016 2:56 pm 

Joined: Tue Jan 26, 2016 11:34 pm
Posts: 54
Location: Jugoistočna Srbija
New screenshots:
http://www.rtvforum.net/thread-59-post- ... #pid168052
Edit: About the bandwidth change - he says it's impossible, and that the only options are 192, 96 and 48 kHz.


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PostPosted: Mon Feb 08, 2016 3:59 pm 

Joined: Mon Feb 08, 2016 3:55 pm
Posts: 3
Location: Belgrade, Yugoslavia
Hello everybody!

I'm "the guy" who made those screenshots posted above. Unfortunately I don't have (or I can't see it) an option for 150kHz bandwidth, here is a screenshot from HDSDR:

Image


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