Maximum Length Of Coax?

[Spearmint]

I’m not sure if this has been answered before so forgive me if it has.

Does anyone know what the maximum length of coax one can use for Foxtel IQ?

We’re having Foxtel IQ installed shortly and I going to run the cables because of the shoddy workmanship we had done in our last place. What I’m proposing is running dual coax up to one room in my house where the projector is and then back from there to the family room which is where the Foxtel will probably be 90% of the time. The reason for doing it this way is because the connections for the projector are hidden away in a cupboard whereas the family room they will be on show.

The run will be approx 55M all up each coax with a double join in each coax for the link, with this create problems for the signal?

PS I also realise that every join has the potential of ~3dB loss.

[cyril]

I seem to remember that Foxtel have a max cable length of 48.5meters. However I have often put runs in (not for Foxtel) that are a fair bit longer than that with no issues. Assume a loss of 2-3dB/10meters with RG6 when calculating overal losses. So 50meters is 15dB, so way 20dB with all connectors taken into account. Most LNB's will deliver around 75-78dBuV all depends on model and individual LNB, so that leaves 58dB which is still acceptable.

Why dont you have the installer, install the IQ at the projector room (which I assume is less than 48m) and just leave it there, he need not know what the extra cables going to the Family room are for, or what your intentions are, then sort it out once he is gone.

Alo have you thought of other options, is there a midwayish point in the ceiling space or under floor where you could mount a pair of change over switches. You can get LBand IF switches that have a seperate 12V drive pin, use a pair of these, one for each feed from the dish, and have one set of outputs going to the HT room and the other to the family room. Normally have no power going to the switch (ie family room pos) and when you what to put the IQ in the HT room then just have a plug pack that is wired to the switch to change it over.

Here is an example, http://www.adigitallife.com.au/product_inf...mp;resultpage=1

This would cut down on total cable length as you dont have to take the cable to the HT room then back again to the Family room. Once again, I would just have the install to one point, then make your changes once the installer has left.

Obviously all of this is outside the T&C of Foxtel, so if a problem arises due to this extra cabling etc then you are on your own, but I guess you are old enough and ugly enough to sort through that .

Cyril

[Spearmint]

Thanks Cyril, you’re a Gentleman and a Scholar.

~SNIP~

but I guess you are old enough and ugly enough to sort through that .

Cyril

Ahh I see you’ve been talking to my wife.

[Spearmint]

I would just like to add the reason for wiring the way I have. When I built, I installed the Clipsal Starserve system through out the house with the main point being behind the built in rack for my HT room. The problem is the Clipsal modulators are only mono, to send the signal all around the house is okay for video, however the audio is mono. If I can find a good stereo modulator then the problem should be fixed.

[llama_boi]

Alternatively (and more expensively) get a multiswitch like this. Then all four points can be active with no switching required and it also amplifies the signal a little to make up for the long cable lengths.

If you get a second outlet (third really due to how iQ works) then Foxtel supply a multi-switch with the install. Dont know what they're charging for installing a second outlet these days but is might be worth getting one connected then disconnected. Just another option for you to ponder I guess...

[cyril]

Yeah a multi switch is the correct method, but if you are not using both sites simulateousy then its a hell of a lot dearer. However if in future you may get a second decoder then it makes sense.

Cyril

[Spearmint]

Thanks llama, for the information.

So from this I take it the reason for the dual inputs is one is vertical and the other horizontal and the multiswitch supplies the power to the LNB’s, will this then only require one input into the IQ box or two? I’ll order a switch tomorrow, just trying to figure out how to connect it to the IQ box.

[cyril]

You will require that the switch connectst to both inputs of the LNB and each outlet to the IQ is treated as seperate feed. Basicaly each tuner of the the IQ must be able to select what ever pol it wants. Thus a Multiswitch allows this. The multi switch will force one input to be hPol the other Vpol thus allowing each reciver to select either.

Therefore you will have a dual output LNB connected to the inputs of the multiswitch. The switch will force one intput Hpol, and one Vpol. Depending on what voltage each reciever applies to each input of the multiswitch depends on what pol is supplied to that receiever.

Cyril

[llama_boi]

...will this then only require one input into the IQ box or two?

You'll still need to hook up a cable each (2 cables) from the multiswitch to the iQ box.

[Spearmint]

Switch is on order should be here tomorrow or the day after.

Thanks for the update guys, so from your posts I leave LNB power enabled (I guess it can be disabled) in the STB, this will then select which LNB it requires via the switch which in effect locks both LNB’s to one polarity each? I take it then it won’t matter which STB input either coax goes into since the switch will select the appropriate LNB for the signal required.

PS which is exactly what Cyril has said in his post?

[cyril]

Yep you got the idea, the switch will force each of its two inputs to 13V on one and 18V on the other, then as each STB or Tuner outputs either voltage then the appropriate input port will be switch to that STB/tuner.

Cyril

[Spearmint]

Thanks so much for the help!

I’ll let you know how the installation goes.

[Spearmint]

The Johansson MS34 Multiswitch has arrived, I thought it would have its own power pack, but obviously is powered via the STB. Certainly makes it easier to mount these in hide away places.

Now just have to wait for the Foxtel Man…

[Spearmint]

The install is done… the IQ signal test says 68 and 66 dB so I guess that’s not too bad. Obviously it should be a bit better in the HT room being a shorter run and fewer connections.

Hooked up the component lead and yes some improvement over composite but not as big a difference as say the DVD player. I noticed the audio is better out of the digital out, so I’m guessing the on board DAC’s are rather average.

[cyril]

66-68dBuV is fine, although the Pace decoder signal level readings are not that accurate. What is important is that its well above the minimum and the BER/Quality reading is in the green as BER/Quality are a more accurate reflection of recieved C/N.

Did the installer put it all in place or did you fit it after he left. If he did install it did he have any issues with you suppliing your own bits.

Cyril

[Spearmint]

66-68dBuV is fine, although the Pace decoder signal level readings are not that accurate. What is important is that its well above the minimum and the BER/Quality reading is in the green as BER/Quality are a more accurate reflection of recieved C/N.

Did the installer put it all in place or did you fit it after he left. If he did install it did he have any issues with you suppliing your own bits.

Cyril

Yes the BER is in the green.

All the installer said to my good lady, “this is not the way Foxtel like things done, but we try to please the customer”. They basically fitted the dish, connected the box to the wall plate which was already fitted off, fired up the STB, tuned it in, and left in a very short space of time.

I think they could see it wasn’t a doggy install, plus the use of Belden coax and Cat5e, I guess they thought well we’ll give it a run. Anyway they had no problems so I guess it made for an easy for them as well.