Hello All,
I have today encountered a new source of QRN, which proved to be quite
baffling.
On Spectrogram, it looked like a series of vertical twisted ropes of varying
thickness, then a band of general noise and mush, the whole thing repeating
on a 5 minute cycle. Strength was enough to obliterate all but the strongest
signals.
Rotating the Rx loop did not null out the QRN, suggesting a very local
source. Unlike washing machines which can have a very similar effect, the
interference persisted for hours. I was stumped until my YL suggested the
newly-installed Xmas tree lights! These were of the type that can be set by
means of a control box to give a variety of flashing sequences. Sure enough,
switching them off killed the QRN, and you get a different pattern for each
sequence. Fortunately, on the "steady lights" setting there is no problem,
which helps alleviate the QRN from my young daughter when the lights are
out!
Regards to all
Paul G4MD
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