Dear Topbanders,
I have used my 160m full size dipoles 4SQR over 3 years already. The one has
been working excellently all the time as TX antenna and RX one sometimes
too.
I found recently that when 4SQR switched to any direction ( 0-0, 1-0, 0-1,
1-1 ), except that one when all switching relays are de-energized ( 0-0 ). a
noise level into my receiver ( e.g. all 8 x Beverages 400m long in the
closest distance from Txing 4SQR 300m and 8Circle in the closest element
over 200m from 4SQR ) were both suddenly full of noise in level of S7.
I was thinking about a cause of the problem and finally found it. Due to
voltage on a long cable feeding 24V relays I had to use higher voltage 34V
and to regulate it by 7824 regulator: of course they were blocked by
appropriate capacitors on both input and output sides. Probably due to
sudden loss of capacitance of some of them the regulators have started a
circulate what course a noise. So I replaced 7824 by classic resistors - an
old fashioned method - set up 24V for relays and QRM totally disappeared.
My personals instruction is that simple is better and nobody would believe
that 7824 circuits could make so huge QRM by re-radiation from 4SQR to far
away Rxing antennas.
I hope that this sort of my experience could help somebody if meets similar
problem in future.
73 Jarda OK1RD / OK7XX from remote controlled QTH
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