[mythtvnz] dvbv5-scan 22KHz tone support

[Stephen Worthington]

On Fri, 20 Dec 2024 20:22:41 +1300, you wrote:

>> On Fri, 20 Dec 2024 13:22:35 +1300, you wrote:
>>
>>>Anyone tried to use dvbv5-scan  to scan Optus D10 on a Sky Dish recently?
>>>
>>>I can't find any decent examples, but it looks like "-S 1" will activate
>>>DISEqC support for 22KHz tone.
>>>
>>>Just trying to run some test scans of Optus D10 ahead of the big switch
>>>over, and I'm not sure if my ​Matchmaster 10mm-dda28 is getting in
>>>the way.
>>
>> With dvbv5-scan, I do not think it has a blind scan option - it only
>> works from the multiplex data in its config files.  The relevant one
>> in Ubuntu 24.04 is:
>>
>> /usr/share/dvb/dvb-s/Optus-10-156.0E
>>
>> but that does not contain any of the new Sky multiplexes.  You would
>> have to add them manually.
>>
>> I have been able to run blind scans using DVBViewer (Windows payware)
>> via a SAT>IP connection to my DVB-S2 tuners running under minisatip. I
>> had to change the minisatip LNB settings manually to force the 22 kHz
>> tone on, as there are no LNB settings that actually match my fairly
>> standard Sky dish.  So I changed this option:
>>
>> -L *:10750-10750-99999
>>
>> to this:
>>
>> -L *:10750-10750-00000
>>
>> and restarted minisatip.  What this does is specify the LNB local
>> oscillator frequencies for the low and high oscillators both as 10750,
>> and the changeover frequency between low and high to be 0, so that the
>> LNB will be set to use the high local oscillator.  Switching to the
>> high local oscillator with the default ("Universal") type of LNB is
>> done by turning on the 22 kHz tone.  With my Sky dish, it does not
>> actually have low and high LNB local oscillators.  Instead, it seems
>> to have only one local oscillator, and uses the 22 kHz tone to select
>> the second throat that is pointed at 156.0E.  The first throat is
>> pointed at 160.0E.
>>
>> So if you can get any scanning software to generate the 22 kHz tone
>> somehow (maybe via a DISEqC option), that would be better than what I
>> am doing by fooling around with the LNB settings.  But if not, then
>> you should be able to do it with the LNB settings the way I am.  If
>> your dish works the same way mine does.
>>
>> Note to everyone - if you send 22 kHz to your Sky dish from a DVB-S/S2
>> tuner while your Sky box is recording, or you are recording via
>> MythTV, you will be switching throats and the current recordings will
>> fail.  Make sure to only do it when the dish is not being used, and to
>> switch the 22 kHz tone off when finished testing.
>
>Thanks Stephen
>
>I never had any issues using tone with the old DVB-S centric dvbscan, but
>I can't get S2 based tools to work correctly

Try using w_scan2, a fork of w_scan that has been updated:

https://github.com/stefantalpalaru/w_scan2

For my dish, there is an undocumented format for the -l parameter I
can use, so this works for me to scan the current D3 satellite using
my spare DVB-S2 tuner (7):

w_scan2 -fs -sS160E0 -l10750,10750,99999 -a7

To scan Optus 10, I will be trying this (when my dish is free):

w_scan2 -fs -sS156E0 -l10750,10750,00000 -a7