washing machine blues(or, you spin my head round)

[Zorba]

Sorry I couldn't think of a better title. I was at a customers house sorting an alignment problem with a shared 4.2m dish,where there was a problem receiving True Movies. I told them about another job I went to a few days earlier where the cordless phone was knocking off True Movies.
Well,this customer tells me that their channels go off when the washing machine is on. Of course I laughed,politely but they both swore that it happens when on spin,so I said I have to see it happen so that I can post it on thge Sat forum.
So the wife programs it to spin and we are sitting there watching BBC while it starts spinning and its one of those machines that gradually build up the spin speed. We did see the odd break up on bbc,which could have been blamed on the cloudy weather and the husband switched over to sky news but that was fine.A couple of minutes later the machine went into full spin and then lo and behold,bbc went to no signal ! I tried sky news and that was off also. I wouldn't have believed it if I didn't see it. I connected my spectrum analyser to the sat cable but didn't notice any interference or spikes. The husband said something about the motor spinng at highj speed caused electromagnetic interference at high frequencies.
Anybody else ever seen this happen ?

 

[Topper]

I cannot give details of a satellite receiver application but in view of some of the crap cheap motors around these day I cannot say I am surprised with what you relate. Even in the days of the first Scalextric cars one had to have a small cap across the two terminal to reduce interference. I have a situation at home with my office sized electric shredder which stops the TV display on my PC in its tracks for the duration of the shredding. Em radiation is everywhere, yours is a good example of the type of swamping that can take place.

 

[Channel Hopper]

On one communial system (with a combined IF/TV distribution amp) I have seen certain channels drop off when the corridor lights are on.

When the analyser is connected on full screen you can just see an oscillation of the whole band of frequencies, very much like a wave rolling up the band, and only about 1 dB difference in signal, but enough to cause disruption.

The cure was to re-route the incoming wires from the fixed polarity LNB
onto the wall opposite the main mains wiring, even though it was already about 9 inches away on the cable tray.

 

[trigger]

Nice one.

Something else I can use as an excuse when I can´t get it to work - "well its obvious mate, its the washing machine innit - honest - I read it on tinternet!!!"

 

[Robbo]

I think I would be tempted to try a mains filter on it, the interference may be getting through from the mains supply.