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Old 23-06-2013, 19:22
DeelyBopper
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I'm not sure if this is the right place for this but hopefully is.

I have a Panasonic LCD TV in the living room which has built in Freeview (inc. HD).

Today I have added an old PC to the mix and stationed it behind the TV. Connected via HDMI.

I have an Edimax wireless USB dongle so that it can connect to my wireless.

I noticed when I have the PC on that BBC1 and BBC2 get 'scrambled'. The picture becomes unwatchable with a wavy image across the centre.

If I turn the PC off. The channels return to normal.

Is this normal? Not sure if its the PC too close or the wifi signal or something else.
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Old 23-06-2013, 19:57
Chris Frost
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Most likely cause is the PC's power supply. It is emitting Radio Frequency Interference (RFI) that is being picked up by the TV.

There are certain things that will make your TV more susceptible to RFI: Poor quality/cheap "freebie" or 1 shop aerial fly leads. They're thin and poorly shielded against RFI. Next, it's aerial cables that are coiled in neat little loops so as to keep the wiring tidy. This turns them in to a great RFI receiver.

The ultimate fix though is to replace the PC PSU with one that complies to UK emission standards.
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Old 23-06-2013, 20:04
DeelyBopper
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Most likely cause is the PC's power supply. It is emitting Radio Frequency Interference (RFI) that is being picked up by the TV.

There are certain things that will make your TV more susceptible to RFI: Poor quality/cheap "freebie" or 1 shop aerial fly leads. They're thin and poorly shielded against RFI. Next, it's aerial cables that are coiled in neat little loops so as to keep the wiring tidy. This turns them in to a great RFI receiver.

The ultimate fix though is to replace the PC PSU with one that complies to UK emission standards.
Thanks Chris.

I ought to move the PC away again to check (I'll do it tomorrow).

Why wouldn't my PSU comply with UK emission standards?

It's an Antec Earthwatts EA-380D.
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Old 23-06-2013, 20:05
Nigel Goodwin
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The ultimate fix though is to replace the PC PSU with one that complies to UK emission standards.
It 'may' already do so - it might be simply that it's too close to the TV, and the DTT signal levels at the TV are fairly low?.

But how would you find a PC PSU that complies with UK standards, assuming some currently don't - the CE stickers (which are supposed to guarantee such emissions) are self certified, and are placed on Chinese equipment with no testing whatsoever.
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Old 23-06-2013, 20:18
DeelyBopper
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It is quite close to TV. TV is in the corner but the unit is angled so that there is quite a big space at the free end. So I slotted the PC in that space.
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Old 23-06-2013, 21:45
Chris Frost
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I ought to move the PC away again to check (I'll do it tomorrow).
Moving it away is a good plan.

Why wouldn't my PSU comply with UK emission standards?

It's an Antec Earthwatts EA-380D.
When people come on with vague descriptions of their gear and their problems then the best we can do is take a best guess at the most likely cause.

At the point where I answered there was no info from you about the PC. "An old PC" covers a hell of a lot of ground. Your PSU might be fine in that it does comply but, as Nigel alluded, it might still too close to the aerial lead that some interference breaks through. So don't shoot the messenger when vague questions get vague answers. It's the start of a process, not a dash to the wrong finish line.
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Old 23-06-2013, 22:26
DeelyBopper
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Moving it away is a good plan.

When people come on with vague descriptions of their gear and their problems then the best we can do is take a best guess at the most likely cause.

At the point where I answered there was no info from you about the PC. "An old PC" covers a hell of a lot of ground. Your PSU might be fine in that it does comply but, as Nigel alluded, it might still too close to the aerial lead that some interference breaks through. So don't shoot the messenger when vague questions get vague answers. It's the start of a process, not a dash to the wrong finish line.
You seem to be getting all defensive for no apparent reason Chris.

I do very much appreciate your advice.

It was just a question Chris. You said to replace with a PSU that would comply with emissions.

The only thought that entered my head when I read that was 'why wouldn't it'. Not knowing anything about 'emissions' I assumed a retail PSU would meet standards etc.

I haven't 'shot the messenger' Chris. Like I said just a question. I ask a lot of them when I don't understand something.

To put what I have wrote into some context of it's intention. Note I am unarmed. I do not wish to shoot anyone.

In fact. Please read the above as if you saw me with a smile, and thankfulness emanating from my eyes.

I am going to add some for good measure.
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