Mystery Interference... Solved.

[PJC58-Hythe]

I am very lucky in that I do not normally experience interference on MW, but the other day I switched on one of my valve battery portables to listen to Gold while working - I live about 3 miles as the crow flies from a 500W Gold Tx so normally get good reception However I noticed a general 'mush' so I tuned over the entire waveband and also tried LW and it was all over the place. Strangely enough it was much less prevalent on SW.

Knowing something must be causing this I walked around the house with the portable and it seemed pretty much the same wherever I went so I wasn't able to pinpoint it.

Today I had to change some sockets in the kitchen and consequently had to kill the power downstairs, at the same time I switched on the portable and the mush was still there, so I switched off the power upstairs just to see if it made any difference, and it dissapeared

To cut a long story short I tracked it down to a 'wall wart' switching PSU which was powering a digibox. It turned out the PSU wasn't faulty but there was a fault in the digibox (a leaky electrolytic) causing the PSU to go into current limit!

What has shocked about this is how MUCH interference this was generating, and I assume propogating via the house wiring acting as an antenna.

I don't know if anyone else has had a similar experience?

Peter

[Coastwatch]

I once had a "whir whir" type noise on every band including VHF right up to the Marine band, the best way I can describe it is like the noise you get from the child's toy made from a circle of card with two holes threaded with a loop of string that you pull open and close with the hands to make the disc spin and whir.

Turn's out this coincided with me upgrading to a (Wanadoo/Orange) WiFi "Live Box", this has an internal fluorescent lamp that oscillated from full brightness to off and bright again. This illuminated the large 'W'

To find it I isolated the mains which proved I was the source, I then Isolated every wall switch till I discovered it was the "Live Box", fortunately there was a button on the underside to switch the feature off.

Newer boxes do not have this feature now. I wonder if they realised the problem.

Cheers n Beers,

David........

[Skywave]

Yes, David: that's just another example which again causes me to wonder if the manufacturers of such electronics products do actually test them for EMC Compliance. Mind you, it is 'interesting' that that feature is no longer fitted.

Al.

[Coastwatch]

Originally Posted by Skywave

Yes, David: that's just another example which again causes me to wonder if the manufacturers of such electronics products do actually test them for EMC Compliance. Mind you, it is 'interesting' that that feature is no longer fitted.

Al.

I doubt it Al, in this case, the light was purely cosmetic and the interference extended out to 2 houses away . when the box eventually failed the replacement had no internal light though the button was still there.

It would be interesting to see if other members on Orange have these earlier Live boxes from Wanadoo and do they have the same interference or was my box a rouge one.

Cheers n Beers,

David.....

[Skywave]

Originally Posted by Coastwatch

. . . or was my box a rouge one.
David.....

A rouge box from Orange . . . I like it! (Sorry - couldn't resist!)

Al.

[marconimen1901]

I think that the Wanadoo/Orange Live Box was a one off issue, as I had one of these with no such problem on many and various radios.

Mine also failed in the end and was replaced by a non illuminated model.

DAVID