Small signal, dry contact relays are made from different contact
materials than power relays made for higher voltages and currents. Any
fix that cleans them or removes the surface oxide that inhibits low
voltage signal transmission will likely be temporary. Plus the high
power relays are prone to generating noise and have a large bounce.
Except for mercury wetted ones, bounce is common on all relays.
Grant KZ1W
On 2/22/2022 13:41, Michael Tope wrote:
Steve,
Does the switch produce an S9 spike on any transition of the switch
(i.e. from position N to position N+/-1) or only on a certain subset of
switch transitions? That might provide a clue as to whether there is a
problem with one of the relays or the power supply that energizes them.
I am wondering if it could be a bad filter capacitor in the relay
control circuits or a bad DC blocking cap over on the switch end.
I am not convinced that dirty relay contacts could cause the noise
spike, but it is probably agree to clean the relay contacts anyway just
in case. W8JI recommended soaking a piece a paper in a liquid
hydrocarbon (I think he used Xylene) and then passing that paper between
the contacts of the relays in order to transfer any foreign material to
the paper without causing undue abrasion to the relay contacts. I've
done this and it has fixed the problem of an RCS-4 going deaf on receive
despite still working for transmit. For receive only applications you
might have to do it more often.
73, Mike W4EF...........
On 2/22/2022 10:04 AM, Steve London wrote:
I am using an Ameritron RCS-4 antenna switch to select between beverage
antennas. Recently, it has developed a bad case of relay bounce
causing an
S9 spike every time I switch between antennas. Any suggestions on how to
improve this ? Since it's only used for RX antenna selection, I'm
amenable
to replacing the relays with something else, although I have had issues
before with other relays due to no current going through the contacts.
Thanks and 73,
Steve, N2IC
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