Very poor suppression

Two devices bought this week. Both work OK but the problem is that their power supplies being of the switch mode kind push out lots of annoying RF at frequencies between 100khz and around 20mhz. One of my hobbies is listening to the short waves and even medium and long waves, so its all a bit depressing to find that in order to continue both items need to be off. One, the DVD has the psu inside its box and the on off switch does not seemingly turn off the psu, which whines away at various places in the spectrum, but the True Call cal screening device, although it works fine puts out a nasty load of birdies quite close together which move as you do various things on the unit or remotely, and have a 50 hz buzz on them for good measure. I may ask the company if they know of a source of old fashioned psus for it as it has a very tiny right angled plug on the end of the wall wart wire. Life is just getting very depressing when you consider how long we have been making switch mode devices, surely we should expect better by now! Brian

Reply to
Brian-Gaff
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You need the Aulterra Whole House Neutralizer as mentioned in one of the recent Russ Andrews threads

Reply to
alan_m

Yeah, those cheap Chinese switchers are a menace. You need a linear supply you reckon? Try these:

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Reply to
Cursitor Doom

You could try looping all the connections to it through large ferrite toroids as near to the case as you can get them. The mains lead is probably the most critical.

Replcement wall-warts are easily and cheaply available. You may even have a suitable one laying around.

Another option might be a better radio aerial, so the radio can run with the AGC lower, and not amplify the interference so much.

Reply to
Andrew Gabriel

Be aware that all new ones are switched mode these days. Get an old heavy one.

they're better in that they're cheaper.

or put the PSU in an earthed biscuit tin, with ferrites & caps on in & outputs.

NT

Reply to
tabbypurr

Reply to
The Natural Philosopher

I doubt one could retro fit anything to anything to cope with this. the components need to be in the power supplies and in some cases the design is so bad that the little transformer saturates and makes things much worse as everything has sharp edges and lots of harmonics. The dvd is a cheap Panasonic, but it sounds very good, though I've not managed to work out how to play a cd yet without it muting between tracks as if you had select the tracks manually, not just let it play the whole cd. Annoying on some classical sound effect and segway type material.

the True call looks like a coommon Chinese type wall wart to me. Brian

Reply to
Brian-Gaff

I firstly need a talking meter to find out what the voltage and polarity is though. On the Panasonic dvd, I think a switch may have to be purchased for the plug end, as no way will I be delving in there,and besides, its probably not just the psu, but the various circuits in the player, but when one considers the cost its bloody amazing that it sounds so good. It also placys files on ramsticks and cds as well as rewritable cds, an everything else except blue rays and is multi region. Brian

Reply to
Brian-Gaff

The aerial is outside and it would be hard to get it much further away than it is.

Of course today, another idiot has installed over the mains internet, so now we have clicking noises whining sounds and very strange warbles. Must be a person fairly close with a the powerline adaptor. Its almost getting to the point where the only people who can listen are those in huge places devoid of human habitation with the gear running of batteries.

Down the road from me is a factory which makes and refurbisheds machine tools. When we drive by in a taxi his radio is obliterated by a severe whining noise. Nobody cares it seems. Brian

Reply to
Brian-Gaff

Surely to god there's someone in your area who could do this for you? If you're visually impaired there should be some support available, I'd have thought?

Reply to
Cursitor Doom

I share your pain, bro. Plus I have to inspect signals down to -120dBm! :(

Reply to
Cursitor Doom

You could try putting ferrite chokes onto their PSU cables - it might help a bit by preventing the RF having an aerial lead to radiate from.

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(Cheaper from proper components suppliers but MOQ applies)

Reply to
Martin Brown

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