Will magic eye work with my setup?

glent12

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Hi

I currently Have a setup like this

MAIN ROOM SKY HD>
RF2>
CABLE TO WALL SOCKET>
WALL SOCKET TO AMP/SLITTER IN LOFT>
2 CONNECTIONS TO WALL POINST IN ROOM 1 + 2
Both room get the picture from Main Room.

its worked fine for sometime, letting the kids watch cartoons in such in bed.

We had multi room set up in ROOM3 , long story short box is dead and sub is cancelled.

If I fit magic eye to the BOX in MAIN ROOM, can I control it in ROOM 3, Will ROOM 2 and 1 still get a picture?

Sorry its not clear, uber tired:hiya:
 
Let's make it just a bit mehr clear.;)
That now reads "3 CONNECTIONS TO WALL POINST IN ROOM 1 + 2 + 3" - right?
If so then you can put a "magic eye" between the incoming cable and the TV in any room.
Whether that's to one room, two, or all three, it or they should send control back to the Sky machine.
The "magic eye" is not connected directly to "the BOX in MAIN ROOM".
 
Oh ok super embarrassed, that makes sense.


I assumed one part of magic eye connected to RF2 directly
 
That's OK, as there's a lot of mythology out there about how these things work, and it's easy to get wrong ideas about what they do and what the cable that they're connected to does.
For sending the current Sky channel, and Freeview too if thst's connected to the Sky machine, you have a cable from RF2 Out to an extension TV, or to a distributor with cables to more than one TV.
When you want to introduce a "magic eye" you take the cable out of the extension TV and put it into the new device, which has a short length of cable that you now connect to the TV.
The "eye" itself is a little IR receptor that connects into the device, so that the control goes back down the cable directly into the Sky machine.
You can see how the setup works from the pictures of these examples: Sky TV Links.
 
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This will work IF:

The amplifier in the loft has DC Pass or Sky Link or whatever else they choose to call it.

and ALL of your tv wall plates do NOT have isolating capacitors built into them.

If either of those are not satisfied, the tv links won't work because they need a DC path back to the sky box.
 
This will work IF:

The amplifier in the loft has DC Pass or Sky Link or whatever else they choose to call it.

and ALL of your tv wall plates do NOT have isolating capacitors built into them.

If either of those are not satisfied, the tv links won't work because they need a DC path back to the sky box.

My experience was slightly worse than this. I fitted a wall plate and the link stopped working. But taking the wall plate apart, it's just a plastic box and two pieces of elaborately folded tinned steel, each of which has a screw connector ant one end and is folded into the outer and inner socket contacts at the other. Nothing in there to cause any problem as far as I could see, but it just wouldn't work. So I just put a coax plug on the end of the cable instead and all is fine. Except it looks a mess now with a cable just poking through a hole in the wall.
 
My experience was slightly worse than this. I fitted a wall plate and the link stopped working. But taking the wall plate apart, it's just a plastic box and two pieces of elaborately folded tinned steel, each of which has a screw connector ant one end and is folded into the outer and inner socket contacts at the other. Nothing in there to cause any problem as far as I could see, but it just wouldn't work. So I just put a coax plug on the end of the cable instead and all is fine. Except it looks a mess now with a cable just poking through a hole in the wall.

some wallplates have a capacitor on the pcb that stops the dc voltage from getting to the eye (a capacitive wallplate)

either fit a wallplate that has dc pass, or put a blob of solder across the capacitor legs on the soldering side of the pcb to short it out and the dc path is restored
 
I've never seen them called that. They are "isolated" (having capacitors) or "non-isolated".

I was using a "generic" term I had seen before and stuck in my head

I had no idea what the correct term was, so am glad to see that you have now identified for me what the actual terms are
 
Thanks, I understand that, but still don't know why my wallplate won't work. It contains no capacitor or indeed circuitry of any kind (apart from the two metal strips I described above).

I can only conclude that it must, as Martin suggests, be lack of DC continuity. Especially as the red tell-tale on the eye box did not come on with the wallplate, but did with the coax plug.
But without such continuity I'm surprised that I still got a perfect picture (well, as perfect as analogue gets).
 
Thanks, I understand that, but still don't know why my wallplate won't work. It contains no capacitor or indeed circuitry of any kind (apart from the two metal strips I described above).

I can only conclude that it must, as Martin suggests, be lack of DC continuity. Especially as the red tell-tale on the eye box did not come on with the wallplate, but did with the coax plug.
But without such continuity I'm surprised that I still got a perfect picture (well, as perfect as analogue gets).

just buy a new "non-isolated" wallplate that is magic eye compatible and problem solved
 
But without such continuity I'm surprised that I still got a perfect picture (well, as perfect as analogue gets).

A capacitor doesn't have to be a physical component. At UHF frequencies, two copper tracks, which are adjacent to each other or on opposite sides of a Printed Circuit Board, will form sufficient capacitance to pass the signal with minimum attenuation. But, with an insulator in between, no DC can pass.

Free Beginner's Guide to Electronics eBook
 
OK Martin, thanks. So this must mean that in effect I had a bad connection preventing a DC signal, but the video signal still managed to pass via induction? (Bearing in mind my original description of the "device" in question at post #6; it really does contain nothing apart from two metal strips. There is certainly no PCB!)
 
OK Martin, thanks. So this must mean that in effect I had a bad connection preventing a DC signal, but the video signal still managed to pass via induction? (Bearing in mind my original description of the "device" in question at post #6; it really does contain nothing apart from two metal strips. There is certainly no PCB!)

It's not by induction any sort of capacitance will pass an ac current. The larger the frequency the lower the impedance. The tiny capacitance in between two parallel tracks isn't capable of passing much ac current but it doesn't need to.

Isolated walplates are required where one aerial is used to feed more than 1 property to prevent the potential transfer of dangerous voltages.
 
Here you go ...
 

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And again, without the cover.

Perhaps I should have said earlier that this is the cheapest piece of junk that could possibly claim to be a wall plate.
 

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That's because the email notification I received was "Here you go ...".
I was otherwise occupied at the time and it meant nothing to me, so it got trashed.

The photo is of a "surface mounted socket" and not a "wall plate", which explains why I couldn't picture what you were trying to describe. It looks as if it might be intended to provide a DC connection. However, there is no possibility of impedance matching or shielding, so it's a long way short of ideal.
 
Sorry Martin, didn't mean to nag at you, just wanted to bump the thread a little.

Yes, of course, it is a 'surface mounted socket' as you say. What I couldn't get my head round is how it could fail to provide a DC connection while still providing picture and sound. Odd.
 
Sorry Martin, didn't mean to nag at you, just wanted to bump the thread a little.

Yes, of course, it is a 'surface mounted socket' as you say. What I couldn't get my head round is how it could fail to provide a DC connection while still providing picture and sound. Odd.

IF you connect a 12V battery via a resistor to a large capacitor with a voltmeter across the capacitor the reading on the voltmeter will gradually rise to 12V as the capacitor is charged. If you then remove the battery and create a circuit the capacitor will discharge through the resistor in the same time it took to charge. Connecting an ac voltage to a capacitor in effect constantly charges and discharges it so you get a current through it, so capacitor once charged stops a dc current but will pass an ac current.

The impedance (equivalent to resistance in a DC circuit) of a capacitor is inversely proportional to the frequency so if you apply a 12V 1KHz signal to a capacitor you will get a current, if you double the frequency you get twice the current.
 
I'm sorry, are we at cross-purposes here? I have no problem with how capacitors work. My confusion was, and still is, how the device I fitted (pictured above) which has no capacitors, and minimal possibility for inherent capacitance, passed a video signal but not DC.
 
I'm sorry, are we at cross-purposes here? I have no problem with how capacitors work. My confusion was, and still is, how the device I fitted (pictured above) which has no capacitors, and minimal possibility for inherent capacitance, passed a video signal but not DC.

There was clearly an open circuit somewhere. The small capacitance at the break still passed the high frequency rf signal. Most likely place is an unsoldered centre core in a Belling Lee connector.
 

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