Question about Freesat signals
 

"Steve Terry" wrote in message
...

Or for less cost you could put up 2 dishes, each with a quad LNB
to give you those 8 outputs
Or one dish with an octo LNB.


A multiswitch is only worth bothering if you want more outputs
or can't put up more than one dish
Yes, although there are now some multiswitches that need no local power
supply. They get all their power from the receivers.

Bill

Question about Freesat signals
 

"Bill Wright" wrote in message
...
"Steve Terry" wrote in message
...

Or for less cost you could put up 2 dishes, each with a quad LNB
to give you those 8 outputs

Or one dish with an octo LNB.

Bloody fiddly sockets thou and more than double the price of a dish and quad
LNB

A multiswitch is only worth bothering if you want more outputs
or can't put up more than one dish

Yes, although there are now some multiswitches that need no local power
supply. They get all their power from the receivers.
Bill

That's handy, makes for a simple community aerial system,
and getting cheaper all the time

Steve Terry

Question about Freesat signals
 

"Steve Terry" wrote in message
...
"Bill Wright" wrote in message
...
"Steve Terry" wrote in message
...

Or for less cost you could put up 2 dishes, each with a quad LNB
to give you those 8 outputs

Or one dish with an octo LNB.

Bloody fiddly sockets thou and more than double the price of a dish and
quad LNB
Yes, they are really only a solution if you are not wanting to fit two
dishes. I think they'll get cheaper though.


A multiswitch is only worth bothering if you want more outputs
or can't put up more than one dish

Yes, although there are now some multiswitches that need no local power
supply. They get all their power from the receivers.
Bill

That's handy, makes for a simple community aerial system,
and getting cheaper all the time
Problem are that for communal systems you still have to earthbond, and of
course there's the need to add terrestrial. These switches attenuate
terrestrial signals severely. They are really only suitable for one-dwelling
systems with no terrestrial.

Bill

Question about Freesat signals
 

In article ,
Paul Ratcliffe wrote:
On Sat, 22 Aug 2009 16:06:18 +0100, Tony wrote:

You can't generally mix satellite and terrestrial raw signals on the
same cable

Of course you can.

likely they would interfere.

They use completely separate frequency bands. It is not "likely". It is
completely unlikely.

but remember that the LNB acts as a frequency changer. What is fed from
the LNB is at uhf. this could (and has in the past) interfere with
terrestrial signals

--
From KT24

Using a RISC OS computer running v5.11

Question about Freesat signals
 

On Sun, 23 Aug 2009 00:35:26 +0100, charles
wrote:

You can't generally mix satellite and terrestrial raw signals on the
same cable

Of course you can.

likely they would interfere.

They use completely separate frequency bands. It is not "likely". It is
completely unlikely.

but remember that the LNB acts as a frequency changer. What is fed from
the LNB is at uhf. this could (and has in the past) interfere with
terrestrial signals

Yes, you can get out-of-band crap from the LNB but it is not in the
normal range of frequencies used for real signals and, as Bill says,
the rubbish should be filtered out before combining.

Supplementary question
 

Can someone please explain the point of the "loop out" socket on my FTA
satellite receiver?

Given that the receiver evidently switches the single LNB in my set-up
into one of four possible modes, it seems to me that a daisy-chained
receiver (say in another room) would only have access to (roughly) one-
quarter of the channels, as determined by the first receiver.

Would control signals from the second receiver be sent back through the
loop connection and change the mode of the LNB? Can the "loop out"
serve any useful purpose?

--
John Legon

Supplementary question
 

On 23/08/09 10:37, John Legon wrote:

Can someone please explain the point of the "loop out" socket on my FTA
satellite receiver?

Allows another satellite receiver to be used (e.g. in a bedroom) so long
as the one with "loop out" is switched off.

Question about Freesat signals
 

On Sat, 22 Aug 2009 18:05:53 +0100, "R. Mark Clayton"
wrote:


"Peter Duncanson" wrote in message
.. .
On Sat, 22 Aug 2009 15:28:54 +0100, ChrisW
wrote:

I am confused about satellite TV signals. With DTT I feed the signal
from one aerial into a distribution amplifier and the signal and all
channels are then available to any of the amps distribution points. I
am told that for satellite one needs a separate LNB for each TV set -
dual and quad LNBs seem to be common. I was planning to feed a single
Freesat signal into the Sat input of a suitable distribution amp and
was expecting the Freesat signal to be available at all distribution
points and to be available wherever I had a suitable decoder.

In what way is my understanding wrong? Is it that only one channel at
a time is available on any one LNB? If this is the case, would that
same channel be available on any decoder in the setup? How can one
combine Freesat signals with DTT in a home distribution system?

Two tricks are used to maximise the bandwidth from the satellite two your
dish.

1. There are two bands of ~1GHz each. These are mixed down to a single band
between ~1GHz and 2Ghz (which is about the limit of what you can get down a
cable).

2. The signals are sent in horizontal and vertical polarity, without the
polarity the channels would overlap somewhat and you would get adjacent
channel inteference. Only one polarity can be sent down the wire at once.

Essentially the receiver tells the LNB which band and polarity it wants (by
volts and tones). In a multi-switch all four are sent from the dish to the
switch and the selection is made inside the switch.

Have a butcher's on Wiki.


The way to do it is with a Multiswitch fed by a Quattro LNB. Note
"quattro" not "quad".

Depends on your switch - the latest EMP Centauri can cope with either.

Emerging technology is going to use fibre to send the whole lot down a
single fibre.

I think it's already emerged:

http://www.triax.co.uk/Products/Fibr...cal%20LNB.aspx

Apparently quite expensive at the moment
--
Cheers

Peter

Question about Freesat signals
 

snip


Emerging technology is going to use fibre to send the whole lot down a
single fibre.

I think it's already emerged:

http://www.triax.co.uk/Products/Fibr...cal%20LNB.aspx

Well I would say it was still emerging.


Apparently quite expensive at the moment

Not half, but expect this to change and to be able to cascade the LNB's.

--
Cheers

Peter

Question about Freesat signals
 

"Bill Wright" wrote in message
...

"Steve Terry" wrote in message
...

Or for less cost you could put up 2 dishes, each with a quad LNB
to give you those 8 outputs
Or one dish with an octo LNB.


A multiswitch is only worth bothering if you want more outputs
or can't put up more than one dish
Yes, although there are now some multiswitches that need no local power
supply. They get all their power from the receivers.

Bill


That is pushing - if only one receiver is on (or configured to provide LNB
power in standby) then you have to power the switch and any LNB in use down
one cable...