Analogue Passthrough Issue (again!)

[etyek78]

Hi all,
Sorry to begin yet another rambling variant on the age-old Analogue Passthrough question that seems to pop up on here once every few months, but I wonder if anyone can give me some advice so I can sound like I know what I'm talking about when on the phone to NTL support?

Basically, for the last two years I've had a particular NTL digibox (model and make unknown, never bothered to check!) that *doesn't* output the analogue terrestrial channels from the NTL feed itself. This hasn't been a problem, as we have a rooftop aerial anyway and it's no bother to plug it into the digibox's Antenna In socket (in fact, this is a bonus as it allows us to have both NTL and Freeview on the same TV without interference - see the first of two attached images).

However, during a heavy storm last week, signal on the terrestrial channels suddenly became really weak when sent through the digibox, but fine when plugged straight into the TV itself (this suggests to my untechnical mind that the Antenna In on the digibox has blown, either randomly or due to some lightning-related issue during the storms).

Anyway, I phoned up NTL to log the fault, only to be 'almost' turned away as they claimed they aren't responsible for any issues related to the analogue signal, and furthermore that there is no such box that doesn't output the analogue channels itself and requires an external aerial to do so. However, I convinced them to send an engineer to investigate, sure that he would know immediately that such a digibox does exist and how to either fix or replace it immediately.

Unfortunately, the engineer arrived and immediately declared that the digibox should not under any circumstances be connected to the aerial because it definitely outputted the analogue terrestrial channels itself, and any poor signal quality issues I was now having were due to interference between NTL box and aerial (despite the previous two years of interference-free viewing).

He then swapped digiboxes and set about rewiring my setup (see the second attached image - note that he's somehow linked it so that the VCR and NTL box aren't connected and can't tape from NTL!) so I would be free of this 'interference' problem (without actually checking to see if the old digibox DID actually output the analogue channels), and now I have a different model digibox that does indeed output analogue channels with no need for an aerial, which means I can no longer watch both NTL and Freeview on the same TV, as the two signals clash (I could use SCART to avoid an RF signal clash, but would rather avoid this due to my Dad not knowing his SCART from his elbow, and also the Freeview box is in a different room to the NTL box and would require a long SCART cable trailing round the house).

OK, rambling story over, here's where I'd like the assistance of the good people on this forum:

1) Does anyone know the model number(s) of the NTL digibox that DOESN'T output the analogue terrestrial channels?

2) Am I entitled to ask for such a box, or do NTL's contractual obligations end at merely supplying any digibox, regardless of analogue capability?

3) Can anyone technically minded rewrite the above in such a way that it doesn't sound like the babblings of a know-nothing technophobe?

Any advice would be much appreciated!

[Rob]

to Cable Forum

I don't know about various ways of doing the analogue passthrough on the ntl digi boxes, however what you require can be done without needing passthrough. I have something similar, but just without the freeview.

I'll try an post some wiring diags once I've had a prod around

[SMHarman]

Doesn't the freeview signal and the NTL DTV signal occupy the same frequency range? Thus combining will cause interference.

The NTL coax does have C1-4 in analogue form (and some others)
__________________

Could you take the COAX out from the NTL box and connect to that your roof aerial signal? Then you will have a decoded NTL channel and Freeview signals and analog thrutheairwaves in that coax, this could then be distributed.

NTL Cable
|
NTL Box
|
COMBINER -- Roof Aerial
|
Splitter
| | |
TV1, TV2 (freeview box), VCR

[Rob]

Having re-read your orignial post, I'm now a little confused, and not so sure this can be done, easily with the current kit. Both the ntl and freeview STBs are allowing passthrough of the terrestrial channels (BBC1 & 2, ITV1, Ch4 & Five). Both will be slightly out of sequence yet use the same frequency.

You don't indicate the area in which you are, some have different choices of STB than others. I've currently got the Samsung STB, and mine is not doing a passthrough for the terrestrial channels. The PACE box I had before that too did not offer such a facility (lots of PACE models though and don't know which I had), but the old analogue cable STB I first had (through Nynex now swallowed into the ntl group), had a passthrough adaptor.
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The wiring issue, as it now stands between the NTL STB, VCR and TV 1 is easy to resolve so you can record to the VCR. I suspect you can work that out:

by coaxial
NTL STB > VCR > TV1

by SCART:
NTL STB #2> TV1 SCART #1
NTL STB#2 > VCR in #1
VCR out #2 > TV1 SCART #2 (assumes tv has two scart sockets)

[etyek78]

Oops, apologies for not mentioning my location. I'm in Warwickshire and get my analogue terrestrial signal from Sutton Coldfield, meaning I have the following from the aerial:

UHF 40 (BBC2), 41 (DTT Mux 1), 43 (ITV), 44 (DTT Mux 2), 46 (BBC1), 47 (DTT Mux A), 50 (Ch4), 51 (DTT Mux B), 52 (DTT Mux C) and 55 (DTT Mux D).

I don't have the NTL analogue frequencies to hand at the moment, but from memory at least two of them were the same as some of the above.

I'm fairly certain you're right in saying that the aerial and cable analogue signals will interfere no matter how the current equipment is wired up, which is why I've given up rewiring and am instead trying to get a replacement NTL box that doesn't output analogue channels (and will therefore allow me to reenable the connection setup shown in my original diagram from my earlier post).

The question is, does anyone know of a specific model number that I could ask for?

[matt_hunter3]

I read once that, some people forced a coax from an ntl line and sky one, QVC, the box and some others all from their tv with no Reciver!