HD Freesat PVR boxes - Quad LNB required?

B

BT52

Guest
Are the twin tuner recorder boxes going to follow Sky's lazy method of twin tuner requiring a twin cable feed, or will they do it properly using a single cable feed like a Freeview PVR does and splitting it within the box.

Ie. Will the recorder boxes have twin tuners enabled with a single LMB or will I need to change my Sky dish to a quad LMB? (I have no interest in keeping Sky when I switch).
 

gavan

Novice Member
Are the twin tuner recorder boxes going to follow Sky's lazy method of twin tuner requiring a twin cable feed, or will they do it properly using a single cable feed like a Freeview PVR does and splitting it within the box.

Ie. Will the recorder boxes have twin tuners enabled with a single LMB or will I need to change my Sky dish to a quad LMB? (I have no interest in keeping Sky when I switch).

This has got to be a joke post, right?
 

nwhitfield

Novice Member
It's not "lazy" - it's necessary because, unlike a terrestrial aerial, a satellite LNB is not a passive device.

Signals from a satellite can be "high band" or "low band" and either vertically or horizontally polarized. The LNB receives a signal from the receiver to set it to one of the four possible combinations, depending on which transponder has been selected. It can only be in one mode at a time.

It will then ONLY be able to receive other signals in that same band and with the same polarization. If you simply looped through to the other tuner, you would only be able to record or watch those other signals - and anything requiring any of the other 3 combinations of settings would be unavailable.

So, a second LNB connection is a necessity if a satellite box is to be able to freely select any channel at the same time on each of its tuners. You can't just split inside the box, as with a terrestrial signal.

There are some solutions to use a single cable to deliver two feeds but they're not widely used, and not recommended for performance, either.
 

munkeectr

Novice Member
^^^ Damn, I was beaten to it by a few minutes ^^^

Satellite technology does work the same as Freeview - therefore what you want isnt possible..

A single LNB will only receieve about a quarter of the available channels at a time - therefore if you've only got a single LNB and a PVR you most likely wouldn't be able to record the channel you want.. as it would depend on the channel that your watching.

A Dual or above LNB is the only solution for a Satellite PVR - So a twin run off cables it going to have to be.
 

Boon72

Active Member
^^^ Damn, I was beaten to it by a few minutes ^^^

Satellite technology does work the same as Freeview - therefore what you want isnt possible..

A single LNB will only receieve about a quarter of the available channels at a time - therefore if you've only got a single LNB and a PVR you most likely wouldn't be able to record the channel you want.. as it would depend on the channel that your watching.

A Dual or above LNB is the only solution for a Satellite PVR - So a twin run off cables it going to have to be.

a quad LNB is used by SKY+ as each cable is a feed to a tuner allowing the recording of 1 channel with the ability to watch another. the other 2 unused conections on the LNB are for other connections to be used with other boxes ie multi room. so you could have 1 sky+ and 2 normal sky boxes using all 4 connections on the quad LNB
 

gavan

Novice Member
Are you joking about joking? I dont think you want to put people off asking questions.

I have never really thought about it but excellent clear responses.

Thanks.
Even the most basic search for information on Google would have yielded the fact that it's an LNB and not an LMB :rolleyes:

And it wouldn't have taken too much reading to figure that we have Dual LNBs for dual tuners because that's the way the technology works.

I don't think we are expecting Einstein levels of knowledge for people to at least understand that a dish/LNB combo is not the same as an aerial antenna for conventional TV.

Is it really too much to expect people to do basic levels of reading about the subject before asking irrelevant questions?
 

dodgyd

Member
Totally disagree gavan, where is one to go to find the answers to the already asked stupid questions? Why it's forums of course, and now someone has dared to ask a 'stupid' question, it's here with documented answers to help us avoid asking the same question in future (you can search this site from Google).

Dave.
 

TeeDoubleUDee

Novice Member
Totally disagree gavan, where is one to go to find the answers to the already asked stupid questions? Why it's forums of course, and now someone has dared to ask a 'stupid' question, it's here with documented answers to help us avoid asking the same question in future (you can search this site from Google).

Dave.
Quite agree - we all have to learn the basics at some time and where better than these forums. I have at a great deal of help from posters on AV-Forums and have answered simple questions myself from "newbies" as my knowledge has increased :nono:

TWD
 

gavan

Novice Member
Totally disagree gavan, where is one to go to find the answers to the already asked stupid questions? Why it's forums of course, and now someone has dared to ask a 'stupid' question, it's here with documented answers to help us avoid asking the same question in future (you can search this site from Google).

Dave.
Read the post again:

Are the twin tuner recorder boxes going to follow Sky's lazy method of twin tuner requiring a twin cable feed, or will they do it properly using a single cable feed like a Freeview PVR does and splitting it within the box.

Doesn't look like an honest question to me, just an attempt to make a smart comment. I'm no fan of Sky but if you're going to take a pop at someone then at least get your facts straight first..... In that context, the post was so inane (especially with the repeated use of 'LMB') that I thought it had to be a joke or a troll.
 

Gadgetcity

Novice Member
The "lazy" thing was funny, but it was right to ask the question. When New Zealand freesat (called freeview :)) was launched they only used one transponder for a bit so you only needed one cable for dual tuners. Some boxes even had an output to allow daisy chaining of boxes AND you could get Sky as well. They have since added H and V polarity channels, but it still means that BT52's original question was very sensible.

@Gavan: You are right about googling 'LMB' though. Made me giggle. But asking if it was a joke did come across as a bit rude IMHO.
 
A

AVdavid

Guest
Read the post again:

Are the twin tuner recorder boxes going to follow Sky's lazy method of twin tuner requiring a twin cable feed, or will they do it properly using a single cable feed like a Freeview PVR does and splitting it within the box.

Doesn't look like an honest question to me, just an attempt to make a smart comment. I'm no fan of Sky but if you're going to take a pop at someone then at least get your facts straight first..... In that context, the post was so inane (especially with the repeated use of 'LMB') that I thought it had to be a joke or a troll.
You should have your senoir member status revoked and be put on a stiff ban maybe 3 days or so for being so rude and unhelpful.
MODERATORS deal with him

Dave
 

Chilly Willy

Active Member
This has got to be a joke post, right?
What the **** is this any way to answer a question gavan

Are the twin tuner recorder boxes going to follow Sky's lazy method of twin tuner requiring a twin cable feed, or will they do it properly using a single cable feed like a Freeview PVR does and splitting it within the box.
This question has been on my mind too. I do not have Sky, but I have V+ which has three tuners inside the box.

Ie. Will the recorder boxes have twin tuners enabled with a single LMB or will I need to change my Sky dish to a quad LMB? (I have no interest in keeping Sky when I switch).
Since I do not know what a single LNB/LMB or a quad LNB/LMB is - DOES THAT MAKE ME STUPID TO GAVAN?

I look for the advice from members of this forum so as I can work out what the requirements for my system would be.

Is it possible to have two PVR boxes and one non PVR box linked to a quad LNB? If not is there something else I could use?

It's not "lazy" - it's necessary because, unlike a terrestrial aerial, a satellite LNB is not a passive device.

Signals from a satellite can be "high band" or "low band" and either vertically or horizontally polarized. The LNB receives a signal from the receiver to set it to one of the four possible combinations, depending on which transponder has been selected. It can only be in one mode at a time.

It will then ONLY be able to receive other signals in that same band and with the same polarization. If you simply looped through to the other tuner, you would only be able to record or watch those other signals - and anything requiring any of the other 3 combinations of settings would be unavailable.

So, a second LNB connection is a necessity if a satellite box is to be able to freely select any channel at the same time on each of its tuners. You can't just split inside the box, as with a terrestrial signal.

There are some solutions to use a single cable to deliver two feeds but they're not widely used, and not recommended for performance, either.
Many thanks nwhitfield and the other members who have given me some of their wisdom.
 

jason1wood

Well-known Member
i agree with the question asked, as i had the Sky engineer at my apartment to fit HD but he mentioned i only had 1 feed installed, so thought this was quite a good post as i never knew anything about dual feeds.

Gavan, senior member?????
 

nwhitfield

Novice Member
A quad LNB only has four outputs, and so you'll only have unrestricted channel choice for four tuners - and between two twin tuner PVRs and a single box, you have five tuners. (Assuming you are using twin tuner PVRs; little point these days in a single tuner one).

There are octo LNBs, which would give you eight outputs, so you'd have three spare. A quick bit of googling suggests a price of around 70-80 quid, compared to 25-30 for a quad.

However, if you do a bit of thinking, there are other solutions, depending on the equipment and how you use it.

First, if any of your boxes have an LNB out then you could piggy back one box on something else, depending on the layout of your home, and how you watch. For instance, main PVR in the living room, probably where most recording will be done - so give that two feeds direct from the dish.
You then have three things that need a feed, and only two feeds left.

If you'd unlikely to record often on the second PVR, then you might get away with putting just one feed into it - some will work like that. Or if the standalone receiver has an LNB out port, connect the standalone direct to the dish, and the output to the second tuner on the second PVR, with the first tuner on that PVR direct to the dish; you'll then be restricted in that you can only do dual recording on the second PVR when the standalone box is switched off. Or you could connect the standalone receiver to the LNB out from the second PVR's second tuner, and only be able to watch on that box when the second PVR isn't in use.

That's all a bit fiddly for wiring, of course.

Other alternatives - the 8 way LNB (and loads of cables coming through a hole in your wall), or a four way LNB, plus a multiswitch.

What's one of them? Remember back at the beginning, I explained there are four possible combinations of High/Low and Vertical/Horizontal for an LNB? There is a special type of LNB - usually called a Quatro rather than a Quad - that, instead of four independent outputs, has one for each of the four possible settings. You connect this to a multiswitch (which is a bit like an aerial amp for terrestrial), which has several outputs - again you need one output for each tuner, so at least five in your case.

The multiswitch then looks at what each tuner is requesting (high band, horizontal and so on) and connects that tuner to the appropriate signal from the LNB. So you only have four cables coming in, and can have lots of receivers. This is typically the way it's done in blocks of flats, but of course the multiswitches aren't that cheap; 5 in 8 out will be about 70 quid (the extra in is for a standard TV aerial, which it will distribute too).

You can see some examples here

Nigel.
 

Chilly Willy

Active Member
Thanks Nigel, once again you have helped out in letting me know what I need, but most of all how to avoid the pitfalls. I know we are getting several steps ahead of what is presently available at the moment but it does mean that I can do some future planning.

Again many thanks


Will
 
You should have your senoir member status revoked and be put on a stiff ban maybe 3 days or so for being so rude and unhelpful.
MODERATORS deal with him

Dave
What the **** is this any way to answer a question gavan



This question has been on my mind too. I do not have Sky, but I have V+ which has three tuners inside the box.



Since I do not know what a single LNB/LMB or a quad LNB/LMB is - DOES THAT MAKE ME STUPID TO GAVAN?

I look for the advice from members of this forum so as I can work out what the requirements for my system would be.

Is it possible to have two PVR boxes and one non PVR box linked to a quad LNB? If not is there something else I could use?



Many thanks nwhitfield and the other members who have given me some of their wisdom.
I can fully see where Gavan is coming from, the OP inferred he/she had a lot of knowledge on the subject and was having a pop at the "lazy" methods applied by Sky. Making it sound like Sky and everybody using quad LNB's is daft and has got it architecturally wrong....

Besides these forums are for discussion aren't they, so if you give some, better take some...And if you are lucky you learn...
 
I can see two ways of interpreting the OP's question

First as a straightforward question from someone who is from a background of DTT or cable and little knowledge of satellite AND an anti-Sky bent.

Second from someone who knows of single cable satellite distribution technology and is being sarcastic about current Sky and freesat use of old technology. For further info on single cable systems see here
http://www.ftacom.com/UploadImages/UNICABLE (V080807).pdf.

Rereading the OP I tend to the first from his use of LMB instead of LNB
 

Silas Greenback

Standard Member
You should have your senoir member status revoked and be put on a stiff ban maybe 3 days or so for being so rude and unhelpful.
MODERATORS deal with him

Dave
I found this post rude and unhelpful, if the original poster (if real??) has bothered there lazy ass, they could have looked around on other threads on the forum and found the answer to there questions.

Like Gavan Said, how about goggle?

Gavan is entitled to his Views, There are far too many posters in this forum, in my view, that are too lazy to do any research for them self's and just ask a question and demand a reply.

How may times have you recently seen the question "would a sky dish be ok for receiving freesat"?

The forum is just a reflection or real life, do you expect in real life, to ask questions to anybody with Impunity?

Sooner or later you are going to meet a smarter person than you, who thinks your dumb, and a dumber person than you who thinks your clever!

Thats just life!

I thought, the original post was crass, and Gavan comments made me laugh!
 

vex

Novice Member
Even the most basic search for information on Google would have yielded the fact that it's an LNB and not an LMB :rolleyes:
Actually, either is correct and as well as a LNC.

The commonly used LNB stands for Low Noise Block although in the early days of residential satellite reception they were referred to as Low Noise Converters (LNC) and Low-Noise Modulation Blocks (LMB).

Technically they are Low-Noise Modulation Block Converters! But it is a bit long winded to use daily!

HTH

V.
 

Digiman

Active Member
In the title he called it an LNB so it was as typo really. I see a lot of typos and crass spelling mistakes. Take note Silas before somebody has a pop at you.

While there maybe too many stupid unresearched questions on this forum, this one was not one of them. There are forums like Doom9 where you need a phd just to post but as far as I know AVforums welcomes all, the technical and the not so technical.
 

Silas Greenback

Standard Member
In the title he called it an LNB so it was as typo really. I see a lot of typos and crass spelling mistakes. Take note Silas before somebody has a pop at you.

While there maybe too many stupid unresearched questions on this forum, this one was not one of them. There are forums like Doom9 where you need a phd just to post but as far as I know AVforums welcomes all, the technical and the not so technical.

Yes Like I said "Sooner or later you are going to meet a smarter person than you, who thinks your dumb, and a dumber person than you who thinks your clever!"

looks like sooner rather than later for me! I have fixed my spelling now thanks, it was early morning.....
 

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