Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m

T i m wrote:
Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m

My other satellite boxes have an output which you can feed into another
reciever, can't remember if my Sky box has it though. Have a look on
the back of yours.

On Sun, 29 Jan 2006 17:56:49 GMT, T i m wrote:

Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m


You'll need at least a dual LNB, otherwise you'll find that there are
a lot of combinations of channels on the two boxes that won't work.

The first stage of tuning is done by the LNB, and it will need to work
in one of four different modes depending on what channel the box tries
to display. If two boxes need two different modes, you're knackered
with a single LNB.

Cheers,

Colin.

On Sun, 29 Jan 2006 18:52:47 +0000, Colin Stamp
wrote:

On Sun, 29 Jan 2006 17:56:49 GMT, T i m wrote:

Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m


You'll need at least a dual LNB, otherwise you'll find that there are
a lot of combinations of channels on the two boxes that won't work.

The first stage of tuning is done by the LNB, and it will need to work
in one of four different modes depending on what channel the box tries
to display. If two boxes need two different modes, you're knackered
with a single LNB.

Ah, thanks (vertical / horizontal polarization n that?).

When I installed 15 of so Maspro systems for the friends / family
(some years ago now) they used some 'figure of 8' cable with the co-ax
for the video and a pair for the polarizer. It seems it's all done via
a single co-ax now?

All the best Colin ..

T i m

On 29 Jan 2006 10:01:22 -0800, wrote:


T i m wrote:
Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m

My other satellite boxes have an output which you can feed into another
reciever, can't remember if my Sky box has it though. Have a look on
the back of yours.

Ah, I don't actually have Sky myself but a general question that came
out of a conversation I was having with a mate earlier.

It was sorta along the lines of 'if we are running cables through the
(soon to be sealed (as in access)) roof gap should we run one or two'
... ;-)

All the best ..

T i m

On Sun, 29 Jan 2006 20:38:14 GMT, T i m wrote:

On Sun, 29 Jan 2006 18:52:47 +0000, Colin Stamp
wrote:

On Sun, 29 Jan 2006 17:56:49 GMT, T i m wrote:

Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m


You'll need at least a dual LNB, otherwise you'll find that there are
a lot of combinations of channels on the two boxes that won't work.

The first stage of tuning is done by the LNB, and it will need to work
in one of four different modes depending on what channel the box tries
to display. If two boxes need two different modes, you're knackered
with a single LNB.

Ah, thanks (vertical / horizontal polarization n that?).

When I installed 15 of so Maspro systems for the friends / family
(some years ago now) they used some 'figure of 8' cable with the co-ax
for the video and a pair for the polarizer. It seems it's all done via
a single co-ax now?

All the best Colin ..

T i m

Yep. There's the two polarizations, and also two frequency bands, so
four combinations in-all.

The box signals which polarization it wants by varying the LNB
power-supply voltage, and it changes the frequency band by sending a
22KHz tone up the co-ax.

Cheers,

Colin.

On 29 Jan 2006 10:01:22 -0800, wrote:

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

Two cables from the LNB. Voltages and tones are used to switch between
hi/lo band and vertical/horizontal polarisation. Bit tricky to do within
one cable.

My other satellite boxes have an output which you can feed into another
reciever, can't remember if my Sky box has it though. Have a look on
the back of yours.

The Sky box has two RF outs that you can use to feed other TV's but
everything gets the same signal, no wtach one Sat station on one TV
another sat station on a different TV.

--
Cheers
Dave. pam is missing e-mail

On Sun, 29 Jan 2006 17:56:49 GMT, T i m wrote:

Hi All,

If you wanted to have two boxes from one Sky digital mini dish (?)
would you need two LNB's (or a dual LNB) and two feed cables or do
they do summat clever (splitting the cable indoors etc) these days?

All the best ..

T i m


The Astra 2 satellite transponders operate such that LNBs need to be
switched into four possible settings in order to achieve access to all
channels. The frequency band is divided into two (high and low band)
and vertical and horizontal polarisation is used as well.

The Sky Digiboxes signal the choices to the LNB through a combination
of voltage and tone signalling through the cable.
Thus, as you select channels from the EPG, the correct combination is
set up on the LNB to pick the right frequency range and polarisation.

More generic DVB-S receivers usually offer a choice of this and a
digital signalling method called DiSEqC

This signalling arrangement is the reason that you can't use simple
splitters for satellite connections as you would for a TV antenna.

There two basic solutions that can address this if you want more than
one receiver.


a) Dual LNB. This is essentially similar to the single LNB that
you have already but with two separate outputs, each individually
controllable. For this one, you have to home run the CT100 cable to
each satellite receiver position from the dish.
There are four-receiver versions of this known as Quad LNBs - however,
4 is the limit. Both will work with the Sky Minidish.

b) Multiswitch. This is an electronic switching unit which is
usually fitted inside the house and sits between the receivers and the
LNB. A specific type of LNB known as a Quattro (not to be confused
with Quad) is used. These have four outputs with one carrying one of
the four combinations (i.e. Vert. Low band, Vert Hi Band, Horiz Low
Band, Horiz High Band). Thus the multiswitch has all combinations
available. It understands the voltage and tone or DiSEqC signals
from receivers and switches through the appropriate LNB output. There
is some amplification to compensate for the signal losses. Think of
it like a matrix. The advantage with this approach is that you can
have quite a lot of outlets if you want the flexibility of more than
two receivers, or more to the point, more than two outlets.

Most multiswitches also have an option to include signals from
terrestrial antennas as well by having a 5th input. This is
essentially a cabling convenience for if you want to distribute this
as well. At the outlet positions, you fit a two or three way filter
to separate the satellite signals from terrestrial.

The basic switches are not that expensive - e.g. an 8 way Triax one is
about £100. http://www.satellitesuperstore.com/multiswitch.htm


They can be larger in terms of ways and also inputs. For example, I
have a Spaun multiswitch with 9 inputs and 12 outputs (expandable if I
wanted it). This has the ability to take inputs from two satellite
dishes and deliver to the outputs. I have an Astra 2 (Sky) dish
(slightly larger than the standard one) and a larger motorised dish
which can be directed to most satellites with some level of footprint
over the UK (Atlantic to quite a way East). The switch can select
which dish should be used for a given selected programme from the EPG
using DiSEqC signalling. AFAIK, the Sky boxes don't use this, so the
default is arranged to be the fixed Astra 2 dish. I then have a
DVB-S receiver which is able to both select the dish to be used and
drive the positioner on the movable dish. Thus one can select which
satellite and which programme from the EPG.

Personally, I like to be able to watch news and documentary programmes
from other European countries, although most people probably don't.
Another simpler solution for that is to fix two LNBs onto one dish
based on the principle of the different positions of the satellites in
space.

Quite a lot of choices depending on what you want to achieve and how
flexible you want it to be.






--

..andy

On Sun, 29 Jan 2006 21:43:58 +0000, Andy Hall
wrote:

snip interesting stuff

Quite a lot of choices depending on what you want to achieve and how
flexible you want it to be.

Indeed there are!

Thanks very much for all the answers guys and especially to Andy for
all the extra info (and I understood it!) ;-)

I think the dual LNB'svia two cables into two boxes is the solution to
my post but the other options may be of interest in the future .. ;-)

I love 'kit' and some of my most enjoyable moments have been unpacking
and neatly installing a few hundred grands worth of someone elses gear
into 19" racks and making all the pretty lights flash .. (mainly voice
/ data datacomms lan / wan). ;-)

those were the days ... sigh

All the best ..

T i m

On Sun, 29 Jan 2006 23:15:02 GMT, T i m wrote:

On Sun, 29 Jan 2006 21:43:58 +0000, Andy Hall
wrote:

snip interesting stuff

Quite a lot of choices depending on what you want to achieve and how
flexible you want it to be.

Indeed there are!

Thanks very much for all the answers guys and especially to Andy for
all the extra info (and I understood it!) ;-)

I think the dual LNB'svia two cables into two boxes is the solution to
my post but the other options may be of interest in the future .. ;-)

I love 'kit' and some of my most enjoyable moments have been unpacking
and neatly installing a few hundred grands worth of someone elses gear
into 19" racks and making all the pretty lights flash .. (mainly voice
/ data datacomms lan / wan). ;-)

those were the days ... sigh

All the best ..

T i m

Another thought!

If either of the boxes are Sky+, then you'll need extra LNB outputs -
Sky+ boxes need two LNB feeds each.

Cheers,

Colin.

On Sun, 29 Jan 2006 23:22:38 +0000, Colin Stamp
wrote:

On Sun, 29 Jan 2006 23:15:02 GMT, T i m wrote:

On Sun, 29 Jan 2006 21:43:58 +0000, Andy Hall
wrote:

snip interesting stuff

Quite a lot of choices depending on what you want to achieve and how
flexible you want it to be.

Indeed there are!

Thanks very much for all the answers guys and especially to Andy for
all the extra info (and I understood it!) ;-)

I think the dual LNB'svia two cables into two boxes is the solution to
my post but the other options may be of interest in the future .. ;-)

I love 'kit' and some of my most enjoyable moments have been unpacking
and neatly installing a few hundred grands worth of someone elses gear
into 19" racks and making all the pretty lights flash .. (mainly voice
/ data datacomms lan / wan). ;-)

those were the days ... sigh

All the best ..

T i m

Another thought!

If either of the boxes are Sky+, then you'll need extra LNB outputs -
Sky+ boxes need two LNB feeds each.

Cheers,

Colin.


True.

For Tim's application, using a Quad LNB is probably the best option,
with the fourth cable run into the loft (if nowhere else) for future
use.


--

..andy

On Sun, 29 Jan 2006 23:37:04 +0000, Andy Hall wrote:

For Tim's application, using a Quad LNB is probably the best option,
with the fourth cable run into the loft (if nowhere else) for future
use.

I agree, fit a quad the you have at least two spares for future
expansion. 8 output LNBs are available (need an adapter for a sky wok
though) but that's one heck of a bundle of cables. Much better to go
quattro and switch if you think that number of outlets is likely to be
required.

eBay seems a reasonable source of LNBs, just got a new Thomson quad for
under 12 quid delivered.

--
Cheers
Dave. pam is missing e-mail

On Mon, 30 Jan 2006 00:22:15 +0000 (GMT), "Dave Liquorice"
wrote:

On Sun, 29 Jan 2006 23:37:04 +0000, Andy Hall wrote:

For Tim's application, using a Quad LNB is probably the best option,
with the fourth cable run into the loft (if nowhere else) for future
use.

I agree, fit a quad the you have at least two spares for future
expansion. 8 output LNBs are available (need an adapter for a sky wok
though) but that's one heck of a bundle of cables. Much better to go
quattro and switch if you think that number of outlets is likely to be
required.

eBay seems a reasonable source of LNBs, just got a new Thomson quad for
under 12 quid delivered.

Hmmm,

So, if he wants 2 x Sky digital boxes he'll need a 'quad' LNB?

I assume the '+' gives the ability to record a chan in the background
so there are two tuners (decoders?) in there and hence the two feeds
required?

Two Sky + boxes = 4 cables (2 to each box). ?

All the best ..

T i m

On Mon, 30 Jan 2006 07:37:03 GMT, T i m wrote:

On Mon, 30 Jan 2006 00:22:15 +0000 (GMT), "Dave Liquorice"
wrote:

On Sun, 29 Jan 2006 23:37:04 +0000, Andy Hall wrote:

For Tim's application, using a Quad LNB is probably the best option,
with the fourth cable run into the loft (if nowhere else) for future
use.

I agree, fit a quad the you have at least two spares for future
expansion. 8 output LNBs are available (need an adapter for a sky wok
though) but that's one heck of a bundle of cables. Much better to go
quattro and switch if you think that number of outlets is likely to be
required.

eBay seems a reasonable source of LNBs, just got a new Thomson quad for
under 12 quid delivered.

Hmmm,

So, if he wants 2 x Sky digital boxes he'll need a 'quad' LNB?

Yes. Or at that point, a multiswitch starts to make more sense.

I assume the '+' gives the ability to record a chan in the background
so there are two tuners (decoders?) in there and hence the two feeds
required?


Yes. In essence, it's two receivers, but the operation is pretty
much seamless and hidden behind the EPG and remote.

Two Sky + boxes = 4 cables (2 to each box). ?

Yes.

With a multiswitch, you would still need two cables from the outputs
of course.


All the best ..

T i m

--

..andy