Two way spliter Passive to allow sky magic eye

roboughton · 26 Jun 2016

Hi all I am looking for a solution to a little issue I have. I have never been able to get good DTV reception so have always used sky in the main room of the house and then used the RF out with magic eye in all other rooms and also DTV (all be it intermittent/naff signal)

Now as the main TV aerial from outside went to the sky box and then back up via RF2 it caused naff signal but did allow us to use sky in each room via magic eye so worked fine. Now the kids want to be able to watch something different in other rooms so I need to fix the bad signal issue. If I remove the sky box then we have no problems DTV is good signal and no break in picture.
Put sky box back in and the issue start.

I have a Labgear 12 Way Diglink Amplifier in the loft if I put the aerial direct to that DTV works perfect in all rooms, but If I want the RF2 and the aerial I have to use a splitter as only one IN on the Labgear so I need one that is passive to allow the magic eye to work (the ones I have tried dont work).

I could sketch up my setup if required.

Any ideas?

flameport · 26 Jun 2016

Not clear where this splitter thing is being installed, and it certainly isn't required.

For Sky via RF in all rooms, then this:

For no sky, then the aerial connects directly to the amplifier.

roboughton · 26 Jun 2016

Whenever i plug the aerial to the sky it degrades the signal to much (I have tried two sky boxes)

Sureitsoff? · 26 Jun 2016

have you checked the cable from the sky2 output to the loft amp as it sounds as though that could be the problem

roboughton · 26 Jun 2016

Sureitsoff? said:
have you checked the cable from the sky2 output to the loft amp as it sounds as though that could be the problem

Both cables to and from the loft box work fine

If I put Ariel in out of sky box to the TV directly all is fine with DTV

Rf2 from sky box works fine as it distributes about the house

If I link the two together then again DTV works fine.

I think I am going to ditch sky and go to talk talk TV anyway so at that point I wont be sending RF2 back up so I can just put the main aerial into the Labgear box.

If anyone knows of a splitter in the meantime please let me know.

Lucid · 26 Jun 2016

From your descriptions it could be a problem of too much signal strength just as easily as too little quality. The Sky box boosts the strength (power) of the signal to help cope with the extra cable length run going from RF2 Out to a distribution amp. The distribution amp does the same thing. If the signal direct from the aerial is already very strong then the extra amplification from both the Sky box and your distribution amp could be tipping things over the top.

Fortunately there are some simple tests you can do to help diagnose what's going on using the signal meter built in to most Freeview TVs. (You'll have to either look through the tuning menus or consult the manual to find references to the Quality and Strength display.) If it turms out that too much signal is the problem then the fix is equally simple and relatively cheap too.

At this point it's useful to understand that Quality is the most important facet of digital TV signal. Ideally Quality should be in the 80+% range, or if your meter reports Poor/Weak/Moderate/Good/V.Good/Excellent then you're looking for the reading to be in whatever the upper two categories are. e.g. Good/V.Good or V.Good/Excellent. The level for Signal Strength is far less important. Strength is simply how 'loud' the signal is. A signal with 100% on the Strength display but only 30% on Quality is simply loud garbage. Boosting doesn't improve Quality, it only affects Strength. 50-60% on the Strength scale is usually plenty for decent reception so long as Quality is high.

Start off with the TV aerial coax connected directly to the lounge TV. Bring up the Quality and Strength display on the TV. If you're seeing strength at 80~100% and Quality in the 80~100% range too then you can easily afford to reduce the Strength level. You do this with a device that you buy called an attenuator. It is simply like a volume control for signal level. There are two types; fixed attenuators are available in a variety of different values i.e. 3dB, 6db, 12db, 24dB. The higher the number then the greater the effect. These are useful if you already know how much signal level reduction to apply and you want something that won't drift over time. The other type is a variable attenuator. This is simply an attenuator with a control knob for the adjustment level. Typical ranges for these are 0~20db or 0~25dB. You can fit one of these to a TV or signal cable then adjust the level while watching the TV Q and S display. The only catch with these is that the level can drift a little after a while. Have a look at this page for examples of both types http://www.satcure.co.uk/accs/page15a.htm
http://www.satcure.co.uk/accs/page15a.htm
If you buy an attenuator you can then fit it and adjust the signal level to compensate for the boost added by the Sky box and the aerial distribution amp. To do this all you need is to find the Q and S display on some other TV in the house.

There's one other thing to look at which often gets overlooked; and it's what channel the Sky box is using for the RF2 Out signal. The thing is it is very easy to think of the analogue output from a Sky box and bbeing completely independent of the digital TV broadcasts for Freeview. After all, you have to switch the TVs from analogue to digital tuners and back, so the signals must be separate, right?

Well , no. They inhabit the same frequency range. Those who complain of unusually poor results from RF2 often have their Sky box set to output at a frequency very close to- or the same as- one of their local transmitter frequencies for Freeview. There's a quick fix for that. Adjust the Sky box to use a frequency somewhere in the 61-68 range.

roboughton · 27 Jun 2016

Lucid said:
From your descriptions it could be a problem of too much signal strength just as easily as too little quality. The Sky box boosts the strength (power) of the signal to help cope with the extra cable length run going from RF2 Out to a distribution amp. The distribution amp does the same thing. If the signal direct from the aerial is already very strong then the extra amplification from both the Sky box and your distribution amp could be tipping things over the top.

Fortunately there are some simple tests you can do to help diagnose what's going on using the signal meter built in to most Freeview TVs. (You'll have to either look through the tuning menus or consult the manual to find references to the Quality and Strength display.) If it turms out that too much signal is the problem then the fix is equally simple and relatively cheap too.

At this point it's useful to understand that Quality is the most important facet of digital TV signal. Ideally Quality should be in the 80+% range, or if your meter reports Poor/Weak/Moderate/Good/V.Good/Excellent then you're looking for the reading to be in whatever the upper two categories are. e.g. Good/V.Good or V.Good/Excellent. The level for Signal Strength is far less important. Strength is simply how 'loud' the signal is. A signal with 100% on the Strength display but only 30% on Quality is simply loud garbage. Boosting doesn't improve Quality, it only affects Strength. 50-60% on the Strength scale is usually plenty for decent reception so long as Quality is high.

Start off with the TV aerial coax connected directly to the lounge TV. Bring up the Quality and Strength display on the TV. If you're seeing strength at 80~100% and Quality in the 80~100% range too then you can easily afford to reduce the Strength level. You do this with a device that you buy called an attenuator. It is simply like a volume control for signal level. There are two types; fixed attenuators are available in a variety of different values i.e. 3dB, 6db, 12db, 24dB. The higher the number then the greater the effect. These are useful if you already know how much signal level reduction to apply and you want something that won't drift over time. The other type is a variable attenuator. This is simply an attenuator with a control knob for the adjustment level. Typical ranges for these are 0~20db or 0~25dB. You can fit one of these to a TV or signal cable then adjust the level while watching the TV Q and S display. The only catch with these is that the level can drift a little after a while. Have a look at this page for examples of both types http://www.satcure.co.uk/accs/page15a.htm
If you buy an attenuator you can then fit it and adjust the signal level to compensate for the boost added by the Sky box and the aerial distribution amp. To do this all you need is to find the Q and S display on some other TV in the house.

There's one other thing to look at which often gets overlooked; and it's what channel the Sky box is using for the RF2 Out signal. The thing is it is very easy to think of the analogue output from a Sky box and bbeing completely independent of the digital TV broadcasts for Freeview. After all, you have to switch the TVs from analogue to digital tuners and back, so the signals must be separate, right?

Well , no. They inhabit the same frequency range. Those who complain of unusually poor results from RF2 often have their Sky box set to output at a frequency very close to- or the same as- one of their local transmitter frequencies for Freeview. There's a quick fix for that. Adjust the Sky box to use a frequency somewhere in the 61-68 range.

I will check out your advice. I have sky box set to a dif channel setting as the original one was getting interference.

I will report back later this week when I get chance.

Sam Gangee · 14 Jul 2016

You need this: https://www.amazon.co.uk/dp/B01DAHBTHM

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Two way spliter Passive to allow sky magic eye

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