Can I combine an analogue cable feed (UPC) with an aerial in my attic

jumbone

Can I combine an analogue cable feed (UPC) with an aerial fed in my attic in order to tune all the 15 odd analogue UPC channels and the Saorview OTA channels. This would be combined in the attic and would only serve a computer in an upstairs bedroom. How would I prevent interference on the other UPC points in the house?

simple.
Just get a distribution amplifier to feed the bedroom only and source the existing bedroom upc feed into it and saorview so as the new output from that is a new feed containing both of those to the bedroom only.
Nothing goes near the other tv points.

watty

You need a filter or the UHF digital and Broadband on UPC will wipe out your TV aerial signal.

Try a VHF/UHF diplexer as a combiner.

lucernarian

There's a fair few analogue channels in Band IV though. I'd suggest a UHF combiner that cuts off at Ch. 50/52. Once the "up to Ch. 50 side" can accept VHF on its input, it shouldn't interfere with UPC reception. This only works in the greater Dublin area however and a couple of other spots.

Surely upc aren't broadcasting a digital signal on ch 54 so no interference on that unless they are?
What else do you want to filter?

Are the upc analogue mostly on vhf? Theres none of them on 54.
It's been a while since I've had anything to do with messing with upc analogue so I'm not clear on what channels may interfere with what.
I'm presuming vhf channels will pass through unhindered.

Is upc broadband on a uhf channel?

lucernarian

Assuming UPC don't use any frequencies above about 700MHz, which they don't for analogue, a combiner for (VHF up to Ch. 50 UHF) and (Ch. 52 to 68 UHF) on the other leg would allow UPC customers in Dublin to combine their cable TV and DTT on the one lead/distribution system within a house.

The only complication is finding a UHF combiner that will pass through VHF Bands 1-3 and that hyperband section around 200-400 MHz on the "lower-pass" leg. E.g. no Tetra filters etc.

A combiner would be fine actually and the cheapest if you get the mix right and don't cut down signal on a upc analogue that you want to watch or on saorview ch 54
Whats needed here is the list of channels that upc use for analogue and the uhf channel they use [or whatever frequency] for broadband.
If theres no interference,the distribution amp is simple but more expensive.
I'm reckoning ,no matter what you do,you will degrade signal from upc when you add a combiner though regardless of how carefull you are in following instructions or sourcing one with specefic cut off channels.

The best person to ask,who sells them and who would have than level of local knowledge probably would be Tony from satelite.ie

watty

Deleted User wrote: »

Surely upc aren't broadcasting a digital signal on ch 54 so no interference on that unless they are?
What else do you want to filter?

Are the upc analogue mostly on vhf? Theres none of them on 54.
It's been a while since I've had anything to do with messing with upc analogue so I'm not clear on what channels may interfere with what.
I'm presuming vhf channels will pass through unhindered.

Is upc broadband on a uhf channel?

UPC broadband downlink and digitalTV are IDENTICAL DVB-C signals. 8MHz channel spacing. One has multiplex data and one multiplexed TV.
Some old cable is only to 560MHz. Most upgraded areas are upto 872MHz, Ch68
EVERY 8MHz channel from 110MHz to 872MHz can be in use for any mix of Broadband (DOCSIS) Channels, Digital TV Multiplexes or a single Analogue channels.

UPC will be upgrading 100% of cable areas to 872MHz.
The Broadband uplinks (800kHz, 1.6MHz, 3.2MHz or 6.4MHz TDMA channels) replace band I TV. They can in theory be from 5MHz to 65MHz.

DOCSIS 2.0 uses up to only one downlink 8MHz channel (2MHz to 8MHz possible by varying symbol rate and model of cable modem or SW on DSP based modems) per modem. About 48Mbps shared to whatever number of modems. DOCSIS 3.0 is used to go above 25Mbps per user by allowing up to 5 x 8MHz channels on a modem! (125Mbps typical per user, several users per haps multiplexed)

The newest Cable TV boxes and Modems can work up to 1200MHz. Used on short coax on HFC (Hybrid Fibre Cable) systems.

DVB-t might use 16QAM or 64QAM. Satellite QPSK (like 4 QAM). Cable can use 256QAM or even 1024QAM. That's a lot more capacity per channel. Satellite uses from 12.5% FEC (Big dish for Feeds) to 50% FEC (small DTH dish). Cable might run at 10% FEC.