my understandinf of lnb/unicable/fbc - needs correction.

[satteliter]

I'm trying to understand the various components before switching from sky. At the minute, I have a Sky dish with quad output.

I am hoping to switch to Gigablue UHD UE 4K for my main box. This has 2 sat inputs but 8 tuners/demodulators. I've read up on how to assign them to input etc.
My understanding which may need correcting:
All channels hit the satellite dish and the lnb. Previously (pre-unicable), each wire carried 1 quadrant of the signals down the cable to the box (high/low, vertical/horizontal). Each of these quadrants consist of multiple transponder frequencies. [Maybe it's only all channels on the 1 transponder frequency that are all sent down?]
When switching channels, the sat receiver box looks up the corresponding transponder frequency for a channel and the sends a signal to the lnb to send the corresponding quadrant of channels/specific transponder frequency of channels?

Unicable 1 sent 4 of these (quadrants or transponder frequencies?).
Unicable 2 sends 32 of these.

If I had a sat box like the gigablue uhd ue(2 physical inputs/8 tuners/modulators), then each of these tuners decodes a unique transponder frequency. Which means if FTA KU sat channels come in 4 quadrants, then 4 tuners/demodulators would be enough to decode all quadrants and thus record multiple channels from the output of each tuner/demodulator. All channels from 1 transponder frequency would be decoded by a single tuner/demodulator at once so the box could in theory record all channels from that one transponder frequency at the same time.

Is this correct?
Does the existing sky(non Q) lnb send a single quadrant of channels or a single transponder frequency of channels?
Does unicable 2 send (up to) 32 quadrant of channels or (up to) 32 transponder frequency of channels?
Does each demodulator on the gigablue box decode all channels on a transponder frequency or just the single channel requested. e.g. If i record BBC1 HD, does the tuner just find and decode that single channel or does it decode all the channels on that transponder frequency and then just send the decoded BBC1 HD to whatever record process is running?

Thanks in advance for answers.

[abu baniaz]

If you wanted to use all 8 demodulators on an FBC tuner unit independently, you will have to use a unicable LNB/switch and assign them a unique SCR.

You can only use one transponder per demodulator(tuner). Whether that is unicable or universal LNB.



Unicable 1 sent 4 of these (quadrants or transponder frequencies?).
Unicable 2 sends 32 of these.

They don't send frequencies from the satellite. They are communication frequencies between LNB and receiver/tuner.

A unicable 1 LNB will usually have 4 user bands (although capable of more)
A unicable 2/jess LNB will usually have 24 or 32 user bands (although capable of more)

However number of user bands you have will determine how many devices/tuners can communicate with LNB. So, a unicable 1 LNB will allow you to set 4 demodulators/devices independently.




All channels from 1 transponder frequency would be decoded by a single tuner/demodulator at once so the box could in theory record all channels from that one transponder frequency at the same time.
If i record BBC1 HD, does the tuner just find and decode that single channel or does it decode all the channels on that transponder frequency and then just send the decoded BBC1 HD to whatever record process is running?

It is receiving, not decoding. All receivers with any LNB will allow you to access the services on that one transponder. Even a Dreambox DM 500, 250 Mhz , single tuner, about 12 years old will do that.

Best you treat Unicable LNBs/switches and FBC tuners separately. It will be easier to understand and not mix up. Trying to understand both together just complicates things. You have actually added wideband into the mix. Enigma2 has not been coded to use it.

If you think about FBC tuners as tuners with "shared connections", it is easier to get head around albeit simplified.


More info here:
https://wiki.openpli.org/Unicable_/_Jess

[satteliter]

OK so I think(!) that means that the 8 demodulators are assigned their own Userband and thus can each receive 1 unique transponder and this transponder can be from any of the (low/high, V/H) quadrants.

So if I get the Gigablue with 8 demodulators & unicable 2 then FBC doesn't really come in to play as each demodulator has it's own userband to request and receive a transponder anyway so it doesn't really matter whether or not FBC is on the box as the tuners will get sent what they want from the lnb (and not just from a single quadrant)?

[JonMMM]

OK so I think(!) that means that the 8 demodulators are assigned their own Userband and thus can each receive 1 unique transponder and this transponder can be from any of the (low/high, V/H) quadrants.

So if I get the Gigablue with 8 demodulators & unicable 2 then FBC doesn't really come in to play as each demodulator has it's own userband to request and receive a transponder anyway so it doesn't really matter whether or not FBC is on the box as the tuners will get sent what they want from the lnb (and not just from a single quadrant)?

No it does matter with out the FBC tuners to get the eight demodulators you would need 8 tuners in the receiver.

[BrokenUnusableAccount]

I think it's confusing because FBC stands for Full Band Capture but it doesn't, at least from the point of view of somebody just wanting to use it, mean what it sounds like.
It effectively just means there are 8 tuners (inside the one FBC tuner) than can each tune to any transponder frequency that is coming in to that FBC tuner.
So from the user point of view it ought to be called 8 transponder capture.
Full Band Capture refers to how it works internally.

[abu baniaz]

FBC tuner is on receiver. Unicable LNB is the LNB. They are different devices. Treat them differently and separately and you won't get confused. Start off with unicable.

A unicable LNB does not do the switching that a universal LNB does. Whatever transponder data is requested by a connected tuner will be sent to it.

[abu baniaz]

No it does matter with out the FBC tuners to get the eight demodulators you would need 8 tuners in the receiver.
This is wrong.

An FBC tuner is a tuner unit with 8 demodulators/tuners. This is comprised of two tuners with physical connections (usually referred to as root tuners). The two root tuners can send signal source to each other. The other 6 tuners/demodulators can also be sent signal source from either of the root tuners.

If you have a unicable device, you can allocate the available SCRs to the tuners/demodulators so they communicate directly with LNB. If you do not have a unicable LNB or run run out of SCR, the tuners without assigned SCR will work in loop-through mode.


People understand easily that some twin terrestrial tuners are two tuners with one physical connection on one card. They are still two tuners. So similar principle.

An FBC cable tuner is eight separate tuners/demodulators with one physical connection. Only Vu+ do these.

[satteliter]

Right. My understanding was FBC captures the entire quadrant of (High/Low, H/V) thus the name. It can also do a loopback to the 8 demodulators (so as to make use of the full band capture abillity)

As Unicable just send specific transponders (and not the quadrant), the 'full band capture' of FBC isn't really used, but the loopback of all received signals is still used to run through to all 8 demodulators who then receive whatever transponder they requested on the specific user band frequency they're set up for.

[abu baniaz]

As Unicable just send specific transponders (and not the quadrant), the 'full band capture' of FBC isn't really used, .

Your understanding will be hampered so long as you talk about two different things as if they are the same. Forget FBC tuners for now and get your head around unicable first. Don't even think about FBC tuners until you are comfortable with Unicable.

[abu baniaz]

Universal LNB:
Receiver sends a signal/voltage. It will then be locked into high/low vertical/horizontal plane. LNB is "locked" in this position and one transponder will be accessible to the tuner. All the channels on that transponder will be accessible to the one tuner. You can record/view/stream as many services/channels as you want subject to being FTA/decryption restrictions.

A universal LNB cannot be shared across different by using a splitter because you can't have one tuner request high and another request low. (I'm not mentioning pot luck method of power pass splitters)

A universal LNB with four ports is in essence four separate LNBs.

Unicable LNB (non programmed):
Tuner says I want to access X frequency from the satellite. This one transponder frequency is made available to the tuner and sent on the SCR channel/frequency.
If a unicable LNB has 32 SCR channels/frequencies. It can communicate with 32 devices/tuners simultaneously and provide them access to whichever transponder they want. It can be the same transponder that other devices are requesting or anything that the receiver wants.

A unicable LNB has only one physical connection. You can use a splitter to connect the LNB to multiple tuners so they can request what they want. They will remain independent.

[Huevos]

There is no such thing as a quadrant. That is something someone made up.


I think it's confusing because FBC stands for Full Band Capture but it doesn'tYes it does. It is tuned to the whole band between 950 and 2150 MHz, whereas a conventional tuner is tuned to a single frequency.

Also, the demuxes are not part of the tuner. If I remove all the tuners from my Ultimo4k it still has the same 23 demuxes.

A Unicable device should not be called an LNB (Low Noise Block converter) because it is not a block converter. Instead, it converts single, individually requested frequencies.

In reality, FBC just means a single tuner matrix that can monitor multiple frequencies at one time (e.g. 8 in the case of Vu and GB).

[JonMMM]

This is wrong.

An FBC tuner is a tuner unit with 8 demodulators/tuners. This is comprised of two tuners with physical connections (usually referred to as root tuners). The two root tuners can send signal source to each other. The other 6 tuners/demodulators can also be sent signal source from either of the root tuners.

If you have a unicable device, you can allocate the available SCRs to the tuners/demodulators so they communicate directly with LNB. If you do not have a unicable LNB or run run out of SCR, the tuners without assigned SCR will work in loop-through mode.


People understand easily that some twin terrestrial tuners are two tuners with one physical connection on one card. They are still two tuners. So similar principle.

An FBC cable tuner is eight separate tuners/demodulators with one physical connection. Only Vu+ do these.


OK

With unicable 2 LNB alone, you can connect to a splitter and feed to as many tuners as you have (within reason) but you need the physical tuners.

With FBC tuners (sat) and a universal LNB you can connect to 2 transistors and record stream upto 8 channels from those 2.

With Both Unicable 2 and FBC you can record / stream upto 8 channels from any transponder from the one receiver, and if you put a splitter in can add other receivers (the last bit about adding other receivers I am unsure about?)

[abu baniaz]

If you are using a universal LNB with an FBC tuner, you still have 8 tuners. The fact that you cannot set the leaf tuners does not mean they are not tuners.

A tuner with access to an LNB gives you access to a transponder/frequencies, not channels/services. Don't restrict yourself to 8 channels/services. I got to about 30 channels using a universal LNB on my GB UE 4K.

[BrokenUnusableAccount]

Who deleted my post?

[Huevos]

Who deleted my post?
I did. It was off topic.