1 digital tuner, multiple channels simultaneous? (2 Viewers)

[Peter2]

Hi everybody,

A long time ago, there was a comparison table in the documentation with analog & digital tuners, which, for what I could understand pointed out that the biggest advantage with a digital tuner is that you can simultaneously record and watch different channels.
Since the documentation has been replaced by the wiki pages, this table does not exist anymore.

I'm a complete noob regarding digital tv and am considering a satellite dish so can someone comment on this please?

TIA!
P²

 

[craigparris1]

Hi Peter, without knowing exactly what the situation is in Belgium, I can only comment generally on what I know to be the case. In Australia, we have DVB-T format for digital broadcast, so I have 2 x DVB-T tuner cards in my MediaPortal machine. Each different broadcaster has its own MUX (group of channels) which it broadcasts (eg., we have channels called "2", "7", "9", "10", etc.). Within MediaPortal, it's possible WITH ONE CARD to watch multiple channels from the same MUX, but not multiple channels from different MUXes. So, for example, let's say channel "7" has 4 different digital channels on its MUX, and channel "10" has 3 different channels on its MUX - with ONE TUNER CARD I could watch/record all of channel 7's digital channels OR all of 10's digital channels, but I can't watch/record some "7" channels and some "10" channels.

If I want to watch/record some "7" channels and some "10" channels, I need TWO tuner cards to do this. Similarly, if I wanted to watch/record a combination of "7", "9" and "10" channels, I'd need THREE tuner cards.

As I say, this is the situation for me, in Australia, with free-to-air digital TV. I don't know how it differs with satelite or with subscription/pay TV - this could be different.

From my understanding, though, all of the digital broadcast formats work in essentially the same way, so I think that if you wanted some flexibility in being able to watch and record multiple channels simultaneously, you're going to need at least 2 tuners (maybe more, if you've got lots of channels to choose from).

Cheers,
Craig

p.s. if you're interested, I started a thread/poll last year (find it here) asking people about how many tuners they were using. You'll note that the majority are around 2, 3 and 4, with a handful having 5 or more!

 

[Vasilich]

just to add to what craigparris1 said - same situation is for DVB-S (satellite) - you can watch/record several channels simultaneously if they are in one group (for satellite those groups called Transponders and have same frequency, modulation, FEC etc.), so the possibility is really limited.

 

[craigparris1]

OK, just having a quick peek on Wikipedia seems to indicate that Belgium has a combination of DVB via cable and satellite, so I guess by what Vasilich is saying it's similar to my situation with DVB-T .... there'll be a certain number of different MUXes or transponders, and each tuner that you have will be able to lock on to one MUX/transponder at a time (thereby providing access to all of the channels on that particular MUX/transponder). If you want the ability to tune from different MUXes/transponders at the same time you'll definitely need more than one tuner

Cheers,
Craig

 

[Peter2]

Hi guys, thank you for your replies!
I'm thinking of subscribing to a local provider to be able to at least get the channels that are available on analogue/digital cable and IPTV so I guess that I need at least 1 LNB.

Vasilich: are these transponders what I 'know' as LNB's?

 

[craigparris1]

If it's cable, then it's most likely DVB-C (Wikipedia article here states that Belgium uses DVB-C) .... so "MUXes" will apply .... you'll need to find out how many different MUXes are used for your service, and then make a decision about the maximum number of different channels (on different MUXes) that you think you're ever likely to want to record simultaneously. That will tell you how many tuners you'll need.

 

[Peter2]

Well, we have DVB-C but only available by using a proprietary decoder so no go.
Then, we have IPTV over DSL, also with a proprietary decoder so not an option either.
There are also some DVB-T channels but very restricted.

Finally, there is a DVB-S2 provider and of course that's the way to go with a HTPC I guess.
They provide access to Astra 1 and Astra 3, that's all that I know.

 

[craigparris1]

OK, so you pretty much are in the same boat as Vasilich. The "LNB" you're talking about appears to stand for Low-Noise Block Down-converter, which is just a device that's part of the satellite dish. The "transponders" are then just the different frequency ranges that the various channels are being broadcast on.

I'm not really sure if Astra 1 and Astra 3 are just two individual transponders (meaning you'd get away with 2 tuners) ..... Vasilich, how many different transponders do you actually have with your satellite service?

 

[Peter2]

Just found this info through Satellite Finder / Dish Pointing Calculator with Google Maps | DishPointer.com

Most Popular Satellites in Belguim
1. 19.2E ASTRA 1H | 1KR | 1L | 1M | 1N | 2C
2. 13E HOT BIRD 6 | HOT BIRD 8 | HOT BIRD 9
3. 23.5E ASTRA 3A | ASTRA 3B
4. 5W ATLANTIC BIRD 3
5. 28.2E ASTRA 2A | ASTRA 2B | ASTRA 2D

I will have to investigate this a little further and get more familiar with the terminology/technology.
Since I'm looking to update my system HW, I was wondering what I needed as expansion slots and therefore my question about the abilities of 1 tuner.
I guess that there must be Belgian users here who have gone down this road.

 

[craigparris1]

I would think there would definitely be other users from Belgium out there.

Remember when looking at tuners, etc. that some devices have multiple tuners on the one device, so if it's an internal card it may still only need one slot. Of course there are external USB devices and the like as well, which may have multiple tuners within a single device also.

Have fun with it!

Cheers,
Craig