Power quality HF noise bursts 2vp-p

[UKMeterman]

Hi,
I have a megger power disturbance analyser in a collegues house, it is showning HF noise bursts of up to 2vp-p at about 5 to 10 times a min. What are the normal causes of these? The mains voltage is in spec.
Thanks

 

[MarkieSparkie]

Most likely originating from a switched mode power supply in a computer, TV or other audio/visual equipment. Some modern white goods also using SMPS now. What's the frequency of the individual HF burst? If its >20KHz then suspect SMPS as the source. This is assuming you don't have any high power radio, TV or radar transmitters (particularly military/RN/RAF) close to the house, or a radio HAM or illegal CB in close proximity.
Sweeping the rooms with a detuned MW radio may be a quick way of locating the offending source.

 

[UKMeterman]

Hi,
Thanks for that, the analyser in question is the PDA1 of 1989 vintage and so only states there has been a HF noise event no frequency display or anything else, all the events get printed on a till roll. The house is about 6 miles from Brize Norton and 3 miles from Oxford Airport. I have suggested trying outlets on different circuits and turning the other final circuits off.