Hi Chris,
my neighbour has exactly the same problem with
me transmitting on 137 kHz. The touch-switch sensor electronics are
integrated with a switchmode power supply in a small
plastic box. The sensor works by applying an unstable RF signal
to the metal shaft of the lamp, and detecting any voltage change using a
wide.band detector. Unfortunately it is also creating some interference with LF
reception.
Our compromise was to insert an extension
cord with a physical on-off switch, and she accepted not being able to use
the lamp during my transmit sessions. The best solution would probably be
to replace the built-in touch-switch power supply by a conventional iron
transformer.
Best 73,
Markus (DF6NM)
Sent: Thursday, March 10, 2016 4:10 PM
Subject: LF: Touch switched lamp influenced by lf/mf
transmission
Dear all,
my neighbour uses a very expensive lovely designer lamp switched by a
four step touch switch. Unfortunately that switch follows keying of my mf
transmitter. Is there somebody having experience with that kind of
malfunction?
The distance to the antenna feeding point is approximately 16m (ANT
voltage app. 2.5kV). I tested a chain of eight common mode chokes in series to
the affected lamp (mains separation of more than 100kOhms at the desired
frequency). That showed improvement in sensitivity but the switch did not work
anymore during transmission. The most effective solution is replacing the touch
switch by a normal dimmer.
Are there better ideas to keep in use the original touch
switch?
73, Chris
dl7saq
