Reasonably changing existing SAT/cable connection botch work

Yes, the reason was a switch from cable to satellite due to a change of ownership. Additionally, at one spot where there was previously a maximum of one outlet, 2 SAT connections were needed, so a new cable had to be pulled anyway. I suspect that is why they decided to simply ignore the old installation. But of course, it is also possible that there were additional problems due to distance and cable quality. Thanks for the hint. I hadn't really thought about that yet.

Of course, I have to test it. But for that, I would first need to know how I should connect it. That was actually the question.

I obviously have to test it. But for that, I would first need to know how to connect it. That was actually the question.

I would put proper new connectors on everything. Replace as much of the old stuff as possible. I think you need F-connectors and F-couplers.

Otherwise, your plan sounds feasible, as far as I understand everything. Maybe a sketch would help so we can all visualize it. For example, it’s unclear to me whether the satellite stuff is also in the attic or somewhere else entirely.

Difficult to draw. The satellite dish is on the garage. The new cables were simply laid on the outside wall or from outside under the roof and a hole was drilled at the required spot. The old wiring (Kabel-HÜP) comes from the other side of the house and goes up to the attic from there. There was an 8-way splitter there and the cables go back down to the old cable connection boxes. Unfortunately, although they are sometimes in empty conduits at the bottom, on the attic side they partly still come out of the plaster without conduits. So replacing them is not really possible for most of them.

Old cable connection is no longer used. The wiring for it went from the HÜP up to the attic and there via a distributor down to several rooms. The cables/sockets still largely exist but are no longer connected.

Classic case of a former distribution network for terrestrial antenna reception, where the signals were fed from top to bottom into trunk line(s) and later switched to cable.

I am currently renovating and want to optimize that. I want to stick with the sat connection for now, but also want to keep the option open to switch to cable someday.

Meanwhile, the bandwidth used for cable has been extended in a first step from 862 to 1006 MHz and overlaps with the satellite IF, which starts at 950 MHz. The previously common joint feed of cable and sat signals can also fail because the installation partner of the KNB refuses the feed due to missing/insufficient grounding and equipotential bonding of the satellite antenna.

Can I even use the same type of distribution for sat/cable? (apart from the fact that I can operate multiple devices via cable on a star distributor and via a star wiring on a quad LNB only one device would be usable, that’s clear to me).

The described frequency collision can only be avoided with certain Unicable matrices. For laypersons without practical experience, who have to absorb comparably simple antenna-technical knowledge from forums, the qualification of the I is not assessable.
According to DIN 18015 series, cable should only be installed internally in apartments as star distribution and for a long time only in pullable empty conduits. The simplest solution at this property would be to feed the cable signals completely separately from the sat star lines from bottom to top into the old series distribution or better into new high-shield cables. The pass-through sockets then have to be reversed in flow direction or replaced.
Only antennas that are located, including their cables, within safely defined facade areas are exempt from grounding with at least 16 mm² Cu AND class H = 100 kA lightning current-resistant connectors (and main equipotential bonding) according to DIN EN 60728-11 (VDE 0855-1). Even with satellite antennas that are "passively" protected by facades, a potential equalization of the cable shields may still have to be performed.

"Classic" case of a former distribution network for terrestrial antenna reception, where the signals are fed from top to bottom into trunk line(s) and later switched to cable TV.

Yes, I think so too.

In the meantime, the bandwidth used for cable TV has been expanded in a first step from 862 to 1006 MHz and overlaps with the satellite IF, which begins at 950 MHz. The previously common combined feeding of cable TV and satellite signals can also fail because the installation partner of the KNB refuses the feed-in due to missing/insufficient grounding and lightning protection of the satellite antenna.

Thank you very much for the explanations – of which, unfortunately, I only understood half, but I think it still brings me one step closer to the solution.
I probably expressed myself awkwardly with the "use of the same distribution for Sat/Cable." I do not want to use Sat+Cable, but possibly switch from Sat to Cable at some point. To what extent is this frequency overlap a problem? Then I can just separate the lines to the antenna and should not have the described problem with antenna grounding, right?

In the first step, it is primarily about (if possible) using the old laid cables to bring the Sat signal to the outlets. That is, of course, limited because I only have one quad LNB. That is clear. Is there, for example, a way to connect one output of the quad LNB to the old star network – so that I can then connect a device to one of the outlets and the others remain unused? Or is it basically not possible to connect several (unused) outlets to one LNB line?
The other three LNB lines will be connected directly to outlets that do not go through the old distribution. I could continue to use these if I reactivate the cable connection.
Assuming that works, then I would also have to disconnect the LNB on the roof and connect the cable connection? In that case, one could even use all outlets (3x separate SAT outlets and the old outlets with cable TV)?

I probably expressed myself clumsily with the "use of the same distribution for Sat/Cable". I do not want to use Sat+Cable, but possibly switch from Sat to Cable at some point.

This is a completely different situation than a Sat and BK transmission over a distribution network. This misunderstanding could have been avoided with much less text through a simple sketch.

Is there, for example, a way to connect one connection from the Quad-LNB to the old star network - so that I can then connect a device to one of the outlets and leave the others unused? Or is it generally not possible to connect multiple (unused) outlets to one LNB line?

THINKING!

In terrestrial old installations, tree networks/main lines with several pass-through outlets were common, and star lines to stub/single outlets (types?) were rare exceptions. Star lines only became popular with broadband cable connections.

In norm-compliant installation of the Sat antenna, the LNB lines should already be included as close as possible to the building entry in the mandatory equipotential bonding even for old buildings. If this protection against electric shock was implemented according to the standard, this is a possible interface for BK feed-in. What is missing must be retrofitted, whereby the connection of the (still) Sat star lines could also take place further inside.

In a renovation, it should not be an unsolvable problem to lay a high-shield cable according to Class A+ between HÜP -> 1st earth block -> house connection amplifier -> 4-way splitter or distributor -> 2nd earth block and to connect the whole assembly with at least 2.5 mm² Cu (for protected installation) or at least 4 mm² Cu (unprotected) to the main grounding bar of the mandatory equipotential bonding also required in every old building.

The correct dimensioning of the amplifier and adjusting it so that all subscriber outlets comply with the standard signal level window according to IEC 60728-101, as well as installing modern compression or self-install connectors, is already not so trivial without practical experience and equipment.