[mythtvnz] Re: Best type of splitter for Sky + MythTV DVB-S

[Hadley Rich]

On Mon, 05 Feb 2007 18:11:44 Daniel Williams wrote:
> This is purely based on my experience from getting things working for me
> with the switch to D1, but its capable of tuning both H+V at the same time.
>
> I have both SKY + Myth working at the same time on the one LNB / Dish.
>
> My setup:
> Sky Dish + Dual Head LNB
> There is a splitter in the ceiling, which passes power on both ports.
> This was installed by sky.
> The mythbox wall outlet also has a splitter (this was a little future
> proofing for when I get the next DVB card), one port which is power
> pass, the others aren't.
> DVB Card : Skystar2
> Mythtv doesn't set any Disqec stuff, so it's just using the default 160E
> Lnb of the dual head. The other head is set for 156E, and won't pick up
> D1 AFAIK - it's there as a backup incase the sat that Sky uses dies like
> B1 did last year.
>
> When TVNZ was on B1:
>
> Mythtv was not plugged into the power passing port, worked fine, Sky +
> Myth co-existed nicely.
>
> When TVNZ moved to D1:
>
> Changed the polarity in Myth, mythtv still broken.
> Unplug SKY the sky decoder, mythtv still broken
> Changed mythtv to be plugged into the power pass port, Mythtv working
> (stupid me LNB needs some power).
>
> Now, I was intrigued what would happen if I plugged the Sky decoder back
> in, so I just did it (mentally thinking of the 'I have no idea how the
> decoder broke' line to use to Sky if the decoder died).
>
> To my surprise everything works. I did a little tinkering to find what
> combination worked for me, and only came up with one.
>
> In short -
> If both Mythtv + Sky are sending power to the LNB, then everything works
> fine.  There is a little flicker (<1sec) on sky reception when mythtv
> tunes the DVB card, but it is perfectly watchable on Sky + Mythtv AT THE
> SAME TIME.

That's very interesting and a little odd. It sounds like I've got the same LNB 
as you and the same all power pass splitter (from Sky) but I can't seem to 
tune to horizontal without losing signal on the Sky box.

If I issue `dvbtune -f 1733000 -s 22500 -p h -tone 0 -m` then the Sky box will 
go to the rain fade screen instantly and then if I tune back to vertical with 
`dvbtune -f 1921000 -s 22500 -p v -tone 0 -m` then it comes right again 
instantly.

May I ask what the settings are that you have in Myth for the DVB-S card (LNB 
type, frequencies etc.)?

hads

-- 
http://nicegear.co.nz
New Zealand's VoIP Supplier