Tetra decoding

[paulania]

Follow up:
I as able to ear some traffic and identify three network in my area (1 Swiss and 2 Italian).
Now is time to switch to a dedicated computer running Ubuntu native, perhaps headless.

Ciao
Roberto

Hi. Be aware that Gnu Radio comes with this "volk_profile" utility, meant to perform some tests and determine the best settings based on your hardware. I never knew how much things could be improved with it, but they usually recommend you to use it after installing all your software.

Regards

 

[Arruba]

Hi. Be aware that Gnu Radio comes with this "volk_profile" utility, meant to perform some tests and determine the best settings based on your hardware. I never knew how much things could be improved with it, but they usually recommend you to use it after installing all your software.

Regards

Thank you! I'll try it.
Now I am in Genoa, and I don't see any Tetra transmission here. Perhaps a more in deep search will find someone.

Roberto

 

[tsapers]

Squeaking randomly on GSSI between same SSIs

I often see where calls on a specific GSSI would be perfect, and also Encrypted:Clear. GroupCall Clear Speech, and everything else indicating that it is not encrypted. The voice comes through perfect. Then some time later (next call) on the same GSSI with exactly the same non-encrypted scenario as above it would give me the "squeaks" for voice audio. This could be for example where control calls a mobile on the same GSSI, all fine, and when control replies it squeaks, or the same mobile replies and it squeaks. The conversation might go into a few iterations and then maybe not squeak again, only to squeak again on the next reply (or not). This all being on the same GSSI between the same 2 SSI's.

The above example is not specific to 1 GSSi, but multiple where one call might squeak and the next not. Or have a few calls not squeaking at all.
Signal strength and noise floor uploaded.
Anyone know what could be causing this?

 

[tsapers]

Squeaking randomly on GSSI between same SSIs

I often see where calls on a specific GSSI would be perfect, and also Encrypted:Clear. GroupCall Clear Speech, and everything else indicating that it is not encrypted. The voice comes through perfect. Then some time later (next call) on the same GSSI with exactly the same non-encrypted scenario as above it would give me the "squeaks" for voice audio. This could be for example where control calls a mobile on the same GSSI, all fine, and when control replies it squeaks, or the same mobile replies and it squeaks. The conversation might go into a few iterations and then maybe not squeak again, only to squeak again on the next reply (or not). This all being on the same GSSI between the same 2 SSI's.

The above example is not specific to 1 GSSi, but multiple where one call might squeak and the next not. Or have a few calls not squeaking at all.
Signal strength and noise floor uploaded.
Anyone know what could be causing this?

Further to this I have now see that when the above happens I have TXer field as 0 and the Timeslot field as blank in the Net Info window. Another observation, not related to the above, it seems that the demodulator only plays voice on TimeSlot3 with the odd selection of TimeSlot4 (but no audio). Never see anything for TimeSlot 1 or 2.

 

[j_renner]

Hi to all

I need an urgent help please.
I have an I&Q file from SDR# and I want to have the decoded output of that via Telive offline
The file is below;
https://www.dropbox.com/s/rg80mwmrauwl1v4/SDRSharp_20180120_161525Z_469900000Hz_IQ.zip?dl=0

I think I did the conversion from wav to csample file by "./rtl_sdr_converter" means that I have .csample file. Then I did the conversion for float and .bits but if I run "tetra-rx" there will be no output ? or where will the output be ?

sudo /home/ubuntu/osmo-tetra-sq5bpf/src/demod/python-3.7/tetra-demod.py -i /home/ubuntu/rtl_sdr-to-cfile/converted_tetra.cfile -o /home/ubuntu/rtl_sdr-to-cfile/converted_tetra.float -s 156250 -c 0

sudo /home/ubuntu/osmo-tetra-sq5bpf/src/float_to_bits /home/ubuntu/rtl_sdr-to-cfile/converted_tetra.float /home/ubuntu/rtl_sdr-to-cfile/converted_tetra.bits

-

sudo /home/ubuntu/osmo-tetra-sq5bpf/src/tetra-rx /home/ubuntu/rtl_sdr-to-cfile/converted_tetra.bits

and If I run this line it writes "EOF". It generates the .bits file but when I check EOF in tetra-rx.c, there is an error from my side ?

Thx,
WR

 

[klaus10000]

Callid zero and SSI zero

Hi all, in my recorded files, very often the callid appear to be zero. More, in other files some SSI is zero, one, two or all three.
Which are the conditions that lead to this behavior. Is there any setting I can change in order to fix this? Is there a way to have more info in order to catch the problem?
Best regards
Claudio

 

[deadite66]

Saw sq5bpf got an rsp1a from sdrplay, but has anyone got telive to work with one, tried changing the device argument but haven't had any luck.

 

[deadite66]

got things working, installed gr-sdrplay and used the appropriate source block and messed with the bandwidth and gain settings until things started to work.

 

[hamradionl]

TSSDR welcome back in the community bringing a new SDR# tetra plugin release
RTL-SDR russia

 

[sq5bpf]

I did a simple receiver to use telive with the SDRplay RSP-1A. To use it you must install gr-sdrplay first.

Either update telive and look in the gnuradio-companion/sdrplay directory, or get the flowgraph from here:
sq5bpf/telive

I'd be grateful for any comments. The flowgraph uses a 2Msps sampling, so it's easy to compare the performance with an rtl-sdr with the same sample rate. Try playing around with the AGC and other settings.

Other receivers (6-channel, headless etc) will be added in the future.

 

[hamradionl]

TSSDR introduce a new type Tetra Monitor, working with 1x -ore more independent tuners.
https://forums.radioreference.com/threads/tetramonitor-using-multiple-tuners.386883/

 

[tsapers]

##################################################
# Variables
##################################################
self.samp_rate = samp_rate = 1000000
self.first_decim = first_decim = 32
self.xlate_offset_fine1 = xlate_offset_fine1 = 0
self.xlate_offset1 = xlate_offset1 = -1000000
self.sdr_ifgain = sdr_ifgain = 21
self.sdr_gain = sdr_gain = 41
self.ppm_corr = ppm_corr = 0
self.out_sample_rate = out_sample_rate = 36000
self.options_low_pass = options_low_pass = 12500
self.if_samp_rate = if_samp_rate = samp_rate/first_decim
self.freq = freq = 431937500


With the above tetra.py sample.
If your CC was at 430.9375 (1Mhz below the freq above), what would one have to set the offset to? From what I understand one would put centre freq as 431937500 as above and then have offset at -100000 so that it will pick up the CC freq on 430.9375. Setting the centre freq higher will give the bonus of being able to cover 430.9375 to 432.9375 with the current samp rate of 1000000? Am I understanding this correctly?

 

[vselic]

Any news with voice decryption?

 

[rts47]

I was wondering if you have the updated 1 channel grc for telive ? (For gnuradio 3.8, i already have osmosdr working with this version of gnuradio)