Colin the wavy line you display as your QRM is almost certainly a
switched -mode power supply. the line at 1400 is a harmonic of the switching
frequency and this is modulated by 100Hz giving the sidebands. If you wind
out the bandwidth you may see other harmonics, the interval between the
central lines gives the switcher fundamental. This can help to identify it.
A note of the times it appears with respect to local human activity can give
a clue where it is. Altenatively a bit of DF with a loop aerial (always
useful to have at LF) might locate it. It might be one of your own family
devices or it may only occur when your neighbours are at home.
A little "detective work" can identify the source and often arrange a
replacement which is quieter.
Good Luck with it
Alan
G3NYK
----- Original Message -----
From: "Colin J Thomson" <[email protected]>
To: <[email protected]>
Sent: Monday, April 24, 2017 12:28 AM
Subject: LF: Thanks for all the LF reports
Hi MF/LF
I would just like to say thanks for all the reports on OP32 and WSPR on
136k
from a small QRP station this end.
Sadly due to QRM here I do not copy many stations.. See attached of the
QRM
that appears now and then.
73 Colin - G6AVK
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Fedora 25 (Twenty Five)
Registered Linux user number #342953
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