Terrestrial card versus satellite card and recording multiple channels

[rowladar]

Hi,
I currently have a VU+ Duo 2 with a satellite card (and two sat cables) that allows me to record two channels at once. I am building an extension and want to put another box in the extension.
I know I can get the same channels via freeview and via freesat and I was wondering if I go with a freeview terrestrial card (as it is easier to get to my terrestrial aerial), can I record multiple channels at once with just one coaxial cable, or do I need a coax cable for every channel I want to record (like I do with the sat cable - Yes, I know about unicable but that is not an option for this build?)

many thanks,

Rowladar.

[Huevos]

All terrestrial channels are on one band and polarisation so only one cable is needed. The twin DVB-T card only has one input cable socket.

[abu baniaz]

With one Terrestrial tuner, you can record all the channels on one multiplex/transponder, not just one channel. So you will be able to record all the channels from two multiplexes/transponders

Most Vu Terrestrial tuner cards are twin tuners. They have one socket/input and have an internal splitter.

Unlike universal LNBs, you can split a Terrestrial signal. Wire does not have to come direct from aerial for every tuner.

[rowladar]

With one Terrestrial tuner, you can record all the channels on one multiplex/transponder, not just one channel. So you will be able to record all the channels from two multiplexes/transponders

Most Vu Terrestrial tuner cards are twin tuners. They have one socket/input and have an internal splitter.

Unlike universal LNBs, you can split a Terrestrial signal. Wire does not have to come direct from aerial for every tuner.

Hi Abu,
I struggle with some of this terminology... I don't understand the relationship between multiplex, transponder, and channels. Could you explain?

I guess the good news is that I can use the one coax cable from the loft and split it to the four tv's in the extension and stick a box on the end of one of them for my games room :)

[Trial]

Hi,
on one frequency (Transponder) several channels/services are broadcasted. In SD it was around 6-8 and in HD 3-4 channel on one transponder. So if you chose your recordings well even your old Duo2 can record 3, 4, 5 or even more programs at the same time. You can check on several transponder tables like lyngsat which channels are on the same transponder. The same is valid for cable.

Ralf

[Huevos]

Channel = one single service, e.g. BBC One.
Multiplex = a group of channels packed onto one transport stream.
Transponder = a piece of hardware on the satellite that receives a signal on one frequency and retransmits it on another (i.e. uplink and downlink).

[adm]

Hi Abu,
I struggle with some of this terminology... I don't understand the relationship between multiplex, transponder, and channels. Could you explain?

I guess the good news is that I can use the one coax cable from the loft and split it to the four tv's in the extension and stick a box on the end of one of them for my games room :)



Satellite
Satellite channels are carried on transponders and each transponder has a number of TV channels. If you go to
https://www.lyngsat.com/Astra-2E-2F-2G.html
which shows which TV channels are carried on each transponder

For instance the first transponder in that list has
Sky UK
Channel 4 London
Channel 4 South & East
Channel 4 Midlands
Channel 4 North
Channel 4 Scotland
Film 4 UK
More 4 UK +1
E4 UK

Each of the satellite tuners in your box can only tune into one of these transponders at any one time. So if it tunes into the one above you can watch/record Film 4 UK BUT also record at the same time any (all) of those other channels such as More 4 UK +1. If you have two satellite tuners then you can tune into two different satellite transponders and have the availability of all TV channels on those two transponders.

The Gotcha is that not all channels on the transponder may be free to air and require a subscription and/or when you created a TV channel list you may/will have selected a region and if you live in Scotland the software on the box will probably select Channel 4 Scotland and hide Channel 4 London, Channel 4 South & East, Channel 4 Midlands and Channel 4 North from your channel list. If you use the box's facility to create a Freesat channels list or even the Sky Free to Air option all the channel that will require a subscription will be hidden in your channel list and you should only see the channels that don't cost money to watch.

With a universal LNB attached to your dish you need one cable from the LNB for EACH of your tuners - two tuners, two cables.

Terrestrial
The same idea applies to terrestrial TV reception via an aerial but instead of transponders call them MUXs (Multiplexers). In general all the TV stations on Freeview are carried on 6 MUXs. In some parts of the country there may be a limited number of MUX but for the purposes of this post assume the main UK transmitters carry all Freeview TV channels.

The TV channels carried on each MUX can be found at
https://www.1a-aerials.com/wp-content/uploads/2015/10/Freeview-MUX-channels.pdf
(maybe a bit out of date)
The MUXs are called BBC A, BBC B, D3&4, ARQ A etc. and you can see from the list that each carries up to a couple of dozen TV and radio channels.

Each terrestrial tuner in you box can tune into any one of the MUXs, but only one at any one time. You can watch any of those TV channels and record all of the others on the same MUX. With one terrestrial tuner in a box you wouldn't at the same time be able to record anything on the other 5 MUXs. With two terrestrial tuners in a box you can tune into two different MUXs and have all the TV channels available to you on those two MUX.
Unlike satellite where its possible to select, say, a London regional TV program in Scotland on terrestrial TV you haven't got that choice - the broadcasters will only have London regional TV on transmitters near London and Scottish regional TV on Scottish transmitters.

With an aerial its possible to split the aerial down-lead with a cheap £5 (or less) splitter to feed two tuners.

[ccs]

I use the Belmont freeview transmitter, and the HD channels for bbc1, bbc2, itv, ch4, and ch5 are all on the same mux, so you can record all of those HD channels at the same time, even with just one tuner. 2 or more tuners will give you lots more options, I've got 3 twin tuners !!!

Check which transmitter you're on, it will probably be the same.

Sent from my SM-G998B using Tapatalk

[adm]

I guess the good news is that I can use the one coax cable from the loft and split it to the four tv's in the extension and stick a box on the end of one of them for my games room :)

In theory yes but you lose more signal signal level the more ways you split
A good quality two way passive splitter has a typical insertion loss of 4.7dB (each output = approx 0.58 of the input voltage)
A good quality three way passive splitter has a typical insertion loss of 7.0dB (each output = approx 0.45 of the input voltage)
A good quality four way passive splitter has a typical insertion loss of 8.5dB (each output = approx 0.38 of the input voltage)

If you have a strong output from your aerial then possibly you will not have problems.

[ccs]

I use a Wolsey variable gain powered signal booster rather than a splitter.
Setting the gain to zero should have no signal loss on any of the outputs.

Downside is they're not cheap.

Sent from my SM-G998B using Tapatalk

[rowladar]

thanks Abu and everyone else - it is a lot clearer to me now.