[mythtv-users] Big Myth system (2-3 satellite receivers + capture devices, 5 tvs, Samsung DLNA) ?

Nick Rout nick.rout at gmail.com
Sun Oct 9 20:20:29 UTC 2011

On Mon, Oct 10, 2011 at 7:06 AM, linux guy <linuxguy123 at gmail.com> wrote:
> On Sat, Jul 30, 2011 at 2:22 AM, Simon Hobson <linux at thehobsons.co.uk>
> wrote:
>> Linuxguy123 wrote:
>> >Aside: my home is wired funny.   Most rooms have a single coax from the
>> >utility room to the TV locations, supposedly for cable.   Almost all the
>> >TV locations also have a Cat5 feed from the utility room.
>> >
>> >My satellite system requires 2 coax feeds from the LNB to the receiver
>> >in order to view HD content.  I'd have to rewire the entire house to get
>> >2 coax feeds to everyplace we want a TV.
>> Not true - you need two LNB feeds to allow two tuners (ie get the
>> "watch one, record another" facility). The HD signal comes down
>> exactly the same cable as an SD signal.
>> Some devices can be told not to use both tuners (for situations like
>> you describe) which will allow all the functionality - but restricted
>> to what can be done with one tuner instead of two. Eg, you can still
>> record something while watching something else, you can still pause
>> live TV, etc - but you can't watch one thing live while recording
>> something else, and you can't record two things at once.
>> Technically, there is a halfway house supported by some - by
>> splitting the LNB feed you can still have two tuners BUT the second
>> can only access the same band and polarisation as the first (roughly
>> a quarter of what's available).
>> The reason for this is, unlike terrestrial where the whole spectrum
>> of usable signals comes down the cable together, on satellite some of
>> the tuning is done in the LNB. The LNB (Low noise Block Converter)
>> shifts the received signal from something very high in frequency
>> (well up into microwave territory) down to something that will travel
>> reasonably well in a coax cable. It can select one of two bands (low
>> and high), and also select by polarisation (horizontal and vertical).
>> Thus only about 1/4 of the possible signals are ever present on the
>> coax at any time, and so you can't split it without significant
>> compromises.
> Update.
> I checked into this.  Any system using the Motorola HDPVR 630 needs 2
> satellite feeds to run all the channels on the receiver.  You cannot use a
> switch or a splitter.
> If you run 1 feed to this receiver, you will not get all the channels.
> Ditto for the older 530.
> The Motorola HD 605 will run on 1 satellite feed, but it doesn't do PVR.
> I have used 2 tuner receivers in the past that would run 1 tuner on 1 feed
> just fine.  But not the 530 and 630.
> Moral of the story... if you want to use a satellite service that uses the
> Motorola 530 and 630 boxes, you need to run TWO (2) coax feeds to every TV
> location.

I assume your satellite provider encrypts channels and therefore you
need an stb? If not, simply get some dvb-s cards.

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