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stefantalpalaru / w_scan2

w_scan fork (channel scan tool which generates ATSC, DVB-C, DVB-S/S2 and DVB-T/T2 channels.conf files)
GNU General Public License v2.0
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DVB-T2 frequencies zero #41

Closed jamieburchell closed 6 months ago

jamieburchell commented 2 years ago

Hey

I'm seeing what I believe to be incorrect output from w_scan2 for DVB-T2 frequencies:

https://pastebin.com/raw/WSLhYheh

[CHANNEL]
    DELIVERY_SYSTEM = DVBT2
    FREQUENCY = 0
    BANDWIDTH_HZ = 0
    MODULATION = QAM/AUTO
    TRANSMISSION_MODE = AUTO
    GUARD_INTERVAL = AUTO
    HIERARCHY = NONE

Here's a file I cobbled together from an existing one "uk-Saddleworth" with revised frequencies as determined by TV signal information from a tuned Samsung TV. Feeding this file in to Tvheadend I receive all expected SDTV and HDTV services:

https://pastebin.com/raw/4MDbUHXr

stefantalpalaru commented 2 years ago

What was the command?

jamieburchell commented 2 years ago

What was the command?

Sorry, it was ./w_scan2 -cGB -5 -vvvv

stefantalpalaru commented 2 years ago

Try to increase the lock timeout with -t 2 (default is 1, goes up to 3).

jamieburchell commented 2 years ago

The first time I ran the command with -t2 it found nothing, which was odd.

Second and third time that seemed to have worked. Not sure why I still have an entry with a zero frequency.

[CHANNEL]
    DELIVERY_SYSTEM = DVBT2
    FREQUENCY = 0
    BANDWIDTH_HZ = 0
    MODULATION = QAM/AUTO
    TRANSMISSION_MODE = AUTO
    GUARD_INTERVAL = AUTO
    HIERARCHY = NONE

[CHANNEL]
    DELIVERY_SYSTEM = DVBT
    FREQUENCY = 474000000
    BANDWIDTH_HZ = 8000000
    MODULATION = QPSK
    TRANSMISSION_MODE = 8k
    GUARD_INTERVAL = 1/32
    HIERARCHY = NONE

[CHANNEL]
    DELIVERY_SYSTEM = DVBT
    FREQUENCY = 498000000
    BANDWIDTH_HZ = 8000000
    MODULATION = QPSK
    TRANSMISSION_MODE = 8k
    GUARD_INTERVAL = 1/32
    HIERARCHY = NONE

[CHANNEL]
    DELIVERY_SYSTEM = DVBT
    FREQUENCY = 522000000
    BANDWIDTH_HZ = 8000000
    MODULATION = QAM/16
    TRANSMISSION_MODE = 8k
    GUARD_INTERVAL = 1/32
    HIERARCHY = NONE

[CHANNEL]
    DELIVERY_SYSTEM = DVBT
    FREQUENCY = 554000000
    BANDWIDTH_HZ = 8000000
    MODULATION = QAM/64
    TRANSMISSION_MODE = 8k
    GUARD_INTERVAL = 1/32
    HIERARCHY = NONE

[CHANNEL]
    DELIVERY_SYSTEM = DVBT
    FREQUENCY = 626000000
    BANDWIDTH_HZ = 8000000
    MODULATION = QPSK
    TRANSMISSION_MODE = 8k
    GUARD_INTERVAL = 1/32
    HIERARCHY = NONE

# North West
[CHANNEL]
    DELIVERY_SYSTEM = DVBT2
    FREQUENCY = 641833000
    BANDWIDTH_HZ = 8000000
    MODULATION = QAM/AUTO
    TRANSMISSION_MODE = AUTO
    GUARD_INTERVAL = AUTO
    HIERARCHY = AUTO
jamieburchell commented 2 years ago

I ran it with -t3 and get different looking results, more like the file I cobbled together.

# North West
[CHANNEL]
        DELIVERY_SYSTEM = DVBT
        FREQUENCY = 570000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = AUTO

[CHANNEL]
        DELIVERY_SYSTEM = DVBT
        FREQUENCY = 554000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/64
        TRANSMISSION_MODE = 8k
        GUARD_INTERVAL = 1/32
        HIERARCHY = NONE

[CHANNEL]
        DELIVERY_SYSTEM = DVBT2
        FREQUENCY = 0
        BANDWIDTH_HZ = 0
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = NONE

[CHANNEL]
        DELIVERY_SYSTEM = DVBT2
        FREQUENCY = 0
        BANDWIDTH_HZ = 0
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = NONE

# North West
[CHANNEL]
        DELIVERY_SYSTEM = DVBT
        FREQUENCY = 594000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = AUTO

# North West
[CHANNEL]
        DELIVERY_SYSTEM = DVBT
        FREQUENCY = 618000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = AUTO

# North West
[CHANNEL]
        DELIVERY_SYSTEM = DVBT
        FREQUENCY = 666000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = AUTO

# North West
[CHANNEL]
        DELIVERY_SYSTEM = DVBT
        FREQUENCY = 690000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = AUTO

# North West
[CHANNEL]
        DELIVERY_SYSTEM = DVBT2
        FREQUENCY = 642000000
        BANDWIDTH_HZ = 8000000
        MODULATION = QAM/AUTO
        TRANSMISSION_MODE = AUTO
        GUARD_INTERVAL = AUTO
        HIERARCHY = AUTO
stefantalpalaru commented 2 years ago

Could be signal level. Do you have an amplifier you can try?

jamieburchell commented 2 years ago

I don't, but it's line of sight to the transmitter and when I check the signal strength of the various muxes I'm getting between 75% - 82%. Is that good? I don't have any TV reception issues here.

andimik commented 2 years ago

Hint: a grep for "0 kHz" (with space at the beginning) finds 81 results in the logfile.

And what about other_frequency=0 (0)? See new transponder: (QAM_64 f = 0 kHz I999B8C34D0T8G32Y0 (9018:12330:20544)) 0x405A

And I'm missing 177500 kHz in the list although there was something logged.

Is the +/- 167 kHz offset a problem?

stefantalpalaru commented 6 months ago

Closing this old issue, because I cannot replicate it and it seems related to signal strength or tuner sensitivity.