[mythtvnz] dvbv5-scan 22KHz tone support

[OpenMedia]

> 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