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Will Freesat PVR require 2 inputs?

Jonson

Active Member
Does anyone know if forthcoming freesat Pvrs will need 2 inputs for multiple recording/playback (like sky plus/sky hd)?

If so I'm knackered 'cos I rent a flat with only 1 satellite input :(
Unless anyone knows any get-around for this too??

TIA
 

BrianMc

Active Member
Does anyone know if forthcoming freesat Pvrs will need 2 inputs for multiple recording/playback (like sky plus/sky hd)?
Yes - for exactly the same reason!

Noone (yet!) knows if it can in any way adapt (at lessor functionality) with
one feed.
 

theo cupier

Active Member
Yes - for exactly the same reason!

Noone (yet!) knows if it can in any way adapt (at lessor functionality) with
one feed.

Is that definitely, documented fact?

I only ask because - as an owner of a Humax 9200T Freeview PVR that uses internal circuitry to send the signal to each tuner. It doesn't have multiple aerial inputs. Similarly my BT Vision Freeview PVR box only uses a single external aerial feed.

I had assumed that a Freesat PVR would work in the same way. Why not?
 

davemurgatroyd2

Distinguished Member
Is that definitely, documented fact?

I only ask because - as an owner of a Humax 9200T Freeview PVR that uses internal circuitry to send the signal to each tuner. It doesn't have multiple aerial inputs. Similarly my BT Vision Freeview PVR box only uses a single external aerial feed.

I had assumed that a Freesat PVR would work in the same way. Why not?

Basically because you only get about a quarter of the channels available being sent down from the lnb (bit in front of dish) to the receiver - which quarter is down to control signals sent from the receiver to the lnb at any one time. So a satellite receiver requires a completely independant cable from the lnb and a seperate output from it to each tuner to give total use to each one. You can split the signal BUT the second tuner would only have access to approx 25% of the channels available. Beasically this is all down to the frequency bandwidth of satellite broadcasts ( a spectrum over 3 GHz wide between roughly 10 and 13 GHz which the lnb [Low Noise downconvertor Block] down converts to frequencies a cable can carry) and the capabilities of cheap easily obtainable and fittable cable which carries a frequency spectum between one and two GHz, you then have to factor in vertical and horizontal polarised signals - again which of these the lnb sends down to the receiver is controlled by the signals. So to sum up you have four possible groups of signals coming down the cable high frequency band vertical polarisation, high freq horiz polarity, low freq vert polarity and finally low freq horizontal polarity. To carry all those signals down one cable would mean an horrendously thick cable and for very limited cable lengths only.

Freeview/DTT is operating at frequencies roughly up to 1 GHz and still requires good quality cabling. (All figures very roughly rounded) This is also why satellite has so much more bandwidth available compared to DTT.
 

theo cupier

Active Member
Thanks for that, I understand a LOT more now. Oh well, if only my old Sky dish didn't have to be installed right up on the chimney to get line of sight. That's a bit tedious.

Does anyone know if the Freesat standard installation cost includes awkward situations like really high dishes or if it includes multiple LNBs for PVR boxes?

Incidentally, what happened to the original Dave Murgatroyd?
 

ched

Active Member
Is that definitely, documented fact?

I only ask because - as an owner of a Humax 9200T Freeview PVR that uses internal circuitry to send the signal to each tuner. It doesn't have multiple aerial inputs. Similarly my BT Vision Freeview PVR box only uses a single external aerial feed.

I had assumed that a Freesat PVR would work in the same way. Why not?
With a tv aerial it just receives the radio waves broadcast. But on a satellite dish the lnb (bit that sticks out on the dish) receives either a horizontal or vertical signal. This is done by a 12v switching signal being applied by the sat receiver. So to be able to record one channel and watch another you may need a vertical and a horizontal signal simultaneously. Thats why you need 2 feeds from a dual or quad lnb.

On Sky+ the system (as you know) has major problems with only 1 feed from a dish. But freesat may ( I dont have any info to back this up) have been designed to overcome not having 2 dish feeds. It is possible and hopefully bbc/itv read the forums and realised how many people can only have 1 sat feed.

Fingers crossed you will get recording capability on a freesat PVR with 1 feed when they are released.
 

bearing

Standard Member
Is that definitely, documented fact?

I only ask because - as an owner of a Humax 9200T Freeview PVR that uses internal circuitry to send the signal to each tuner. It doesn't have multiple aerial inputs. Similarly my BT Vision Freeview PVR box only uses a single external aerial feed.

I had assumed that a Freesat PVR would work in the same way. Why not?

The reson that the Satellite PVR needs two feeds is down to the way satellite signals are transmitted, they are sent down as both a horizontal and a vertical feed. In a standard satellite receiver the box automatically signals to the LNB to switch between H or V depending on which channel is selected.

But with the PVR it may be that you want to watch a channel that is Vertically polarised and record another which is Horizontally polarised, but because the two opposing signals can't travel down the same cable(actually they can, but I'll come to that) the need for two cables becomes necessary.

There is a way of utilising just one cable this is done by the use of a piece of equipment called a Stacker/De stacker which as the name suggest stacks the two signals and sends them down the single cable, the installation still needs the use of a quad LNB with two cables entering the Stacker and two cables exiting the de stacker at the receiver end.
 

JH4

Well-known Member
"To carry all those signals down one cable would mean an horrendously thick cable and for very limited cable lengths only."


The throughput of these signals is not dependent on the cable thickness.
 

davemurgatroyd2

Distinguished Member
Incidentally, what happened to the original Dave Murgatroyd?

My original ID but I lost my password and didn't still have access to the email address I signed up with (but I have since found the original password and could use either ID)
 

davemurgatroyd2

Distinguished Member
"To carry all those signals down one cable would mean an horrendously thick cable and for very limited cable lengths only."


The throughput of these signals is not dependent on the cable thickness.

It would to make a wave guide for the microwave frequencies to send them down - perhaps cable is the wrong description more of a tube.
 

FlyingSquirrel

Standard Member
Thanks for that, I understand a LOT more now. Oh well, if only my old Sky dish didn't have to be installed right up on the chimney to get line of sight. That's a bit tedious.

Does anyone know if the Freesat standard installation cost includes awkward situations like really high dishes or if it includes multiple LNBs for PVR boxes?

Incidentally, what happened to the original Dave Murgatroyd?

I think you probably need to read each installer's small print.

The Comet blurb said something along the lines of a standard installation being up to the height accessible by a 'standard' ladder or something similar.

Might be worth enquiring with some local satellite installers how much to have a quad/octo LNB attached to your exosting dish.
 

Lakeuk

Active Member
With certain devices (mainly pc based) it is possible to record more than one channel from one satellite connection so long as they're on the same mux - still limited but still better than just one channel.

I currently regularly record BBC1/2/3/4 at the same time from one satellite connection.

I've just got a tv card for my PC that supports dual dvb-s and dual dvb-t which in theory could record 16 channels at the same time (not sure is PC has the bandwidth to record 28Gb per hour)
 

Stephen Neal

Distinguished Member
There are also other solutions beginning to become available that allow multiple tuners (I think up to 8) to be fed from a single down link cable from an LNB. This is done by each receiver being given a slot of RF space, and each receiver requesting a particular chunk of H or V spectrum (not the full Hi or Lo band) by a more complex data sequence, and a much more intelligent LNB that has 8 separate tunable local oscillators.

Not widespread yet - but being supported by SES Astra I believe as a solution to running multiple PVRs and receivers from a dish without having to run lots of cables from the dish.
 

jeffgoodwin

Standard Member
I thought the manual of the Humax box said you need two inputs. I quote


Connect the cable from your satellite dish to2. Connect a cable from the LNB 1 OUT to theLNB 2 IN connection
• If connecting with a single cable using loopthrough you will have limited functionalityWhile recording a channel you will be limitedto the second channel you can view. Visit"http://www.humaxdigital.com/freesat"]Welcome to HUMAX for further
information
• When using a Motorised System, SCD Antenna (also known as Unicable), or SMATV please connect thecable to LNB 1 INI am still waiting for my satellite installer to come up with the Humax box, they seem as rare as the old rocking horse stuff
 
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