Advice on splitter

Dardania

Hi there,

I recently upgraded my folks to UPC Digital+ from Analogue, and they have since gotten broadband from UPC also. When trying to distribute channels to other points in the house, my father got this splitter from a wholesaler:

http://yhst-18278607509093.stores.yahoo.net/pico-0093.html

however even with only 4 devices plugged in, blocking has started appearing on the Digital+ DVR, and the reception on the other points is weak enough. Clearly I reckon the splitter isn't up to the job - the 11dB split loss figure sounds quite ominous.

Would this splitter do a better job? I understand from searching around here that UPC like to pass through a DC level, so its important to have that funtion:

http://cgi.ebay.ie/Antiference-FS-409-Low-Loss-4-Way-Splitter-5-2250MHz_W0QQitemZ170361456966QQcmdZViewItemQQptZUK_ConEle_SatCableFreeview_RL?hash=item27aa558946&_trksid=p3286.c0.m14

steveon

A splitter like the one you arre using is reducing the signal too much, you would be better off purchasing a powered distribution amplifier ...expect to pay between 40 to 60 euro for a proper one....available in most electrical stores such as maplin etc.

U should not reduce the signal going to the digibox, at the back of most boxes there is a spare output that will send out the analog tv channels

Dardania

Thanks for that steveon although I'd prefer a passive solution than to use an active amplifier - don't amplifiers inhibit cable modems from uploading data? Also, the split location woul be difficult to get power to...

I think I remember seeing a yellow sheet a few days after UPC installed digital+ / then the modem that listed the signal levels when they eliminated the split (they had a straight-through connector, thereby knocking out all the other TVs in the house) - I must have a look for it and see if I can use that to calculate what max attenuation I can introduce in a split.

watty

Ordinary TV amps don't work properly on cable. There are too many channels. Also modem (and possibly the DVR) need a 5MHz to 65MHz band in the opposite direction (not a DC pass).

You need UPC to fit an extra outlet(s). They have the correct components.

More than a two way splitter is too much loss. That 8 way splitter needs a 12dB Cable Trunk Amplifier driving it (which has two sets of diplex filters for the upstream band and an optional 5Mhz to 65MHz upstream amplifier). The best an 8 way Splitter can be is 9dB. Since 3 levels of split are needed and each may waste 1dB that's why it's nearly 12dB loss, 11dB would be good for an 8way. A 2 Way will be nearly 4dB and 4 way nearly 8dB. A perfect split is 3db.

That splitter reduces the signal to 1/30th. A TV distribution amplifier will overload with the number of channels on cable and cause distortion and cross modulation between the channels. TV aerial signals are at a lower level and have 1/10th to 1/20th the number of channels. A cable amplifier for the same per channel signal level needs to be able to handle nearly 30 times power level.

It may even contravene your T&C to fit additional outlets/split signal yourself.

Dardania

watty wrote: »

Ordinary TV amps don't work properly on cable. There are too many channels. Also modem (and possibly the DVR) need a 5MHz to 65MHz band in the opposite direction (not a DC pass).

You need UPC to fit an extra outlet(s). They have the correct components.

More than a two way splitter is too much loss. That 8 way splitter needs a 12dB Cable Trunk Amplifier driving it (which has two sets of diplex filters for the upstream band and an optional 5Mhz to 65MHz upstream amplifier). The best an 8 way Splitter can be is 9dB. Since 3 levels of split are needed and each may waste 1dB that's why it's nearly 12dB loss, 11dB would be good for an 8way. A 2 Way will be nearly 4dB and 4 way nearly 8dB. A perfect split is 3db.

That splitter reduces the signal to 1/30th. A TV distribution amplifier will overload with the number of channels on cable and cause distortion and cross modulation between the channels. TV aerial signals are at a lower level and have 1/10th to 1/20th the number of channels. A cable amplifier for the same per channel signal level needs to be able to handle nearly 30 times power level.

It may even contravene your T&C to fit additional outlets/split signal yourself.

I hear what you're saying RE UPC having the correct components etc to do the split, and that the current splitter is causing too much attenuation, but what I'm concerned is that UPC will try to charge an additional rental per month for supplying the cable split.

From reading their T&Cs on http://www.upc.ie/pdf/UPCTermsAndConditions.pdf

they mention this, which may refer to their distribution cable, rather than final internal circuiting:

9.3 From the time we deliver the Equipment to you until you return the Equipment to us
you must take reasonable care of it. You must not and must not allow anyone else (other
than our representatives) to add to, interfere or modify the Equipment in any way and the
splitting of lines and or cable by you is strictly not allowed. As well as any other rights we
may have, such action may result in our suspending the Services, terminating the
Agreement and/or our retaining the whole or a part of any deposit.

However later on in the T&Cs they refer to:

9.7 You are responsible for ensuring that the Equipment is at all times kept safely and
properly used and in this regard you agree:
(i) While the Equipment is not in use, electricity supplied to it is not turned off and that it
remains in the standby/rest mode;
(ii) That you shall not dispose of or deal with any of the Equipment in any way by, for
example, trying to sell it or hire it to anyone else, or by putting it up as security for a loan,
mortgage or charge, or allow any of the Equipment to be seized under any legal
process. You shall not move the Equipment to another location without our prior written
consent;
(iii) That you shall not remove, tamper with or obliterate any words or labels on the
Equipment; and
(iv) That you shall take proper care at all times to prevent the loss or theft of the
Equipment.

which suggests that "equipment" refers to set top boxes etc...

What equipment do UPC use to split the incoming cable supply to 4 outlets? When they do it, do they have to make any alterations to their cable trunk amplifier? cause if they don't surely I can match their specs

watty

You're an expert on Cable TV?

UPC can use an additional feed from the main Trunk tap if the signal level is too low.

It's likely at most you can fit a two way splitter (3.5dB to 4dB loss per port, 5MHz to 862MHz, DC not needed). I've designed distribution systems for entire apartment blocks/Hotels. Doing it properly does require some knowledge.

Contact UPC. It's UPC's service. If they think you have to pay an additional rent for additional outlets they can decide this as it's their service and all setboxes and Modems are theirs.

I'm locking the thread as it serves no useful purpose.