Thanks for all the suggestions.
Let me give you a few more details. I recently complicated matters, which
seems to have exacerbated the problem. Instead of using the rotary switch
on the RCS-4, I am now controlling over WiFi with an ESP8266 driving
relays, which then apply the correct voltage on the RCS-4 bias-tee (+13,
-13, 17 AC). So I have the relays in the control box, and the relays
switching the antennas. One nice thing about using my own ESP software is
that I was able to confirm that the arc is happening on the make, and not
the break. The new relays in the control box are Tongling JQC-3FF-S-Z. You
can buy a set of 8, mounted on a PC board, for next to nothing from eBay,
Amazon, etc.
As an experiment, I'm going to take the control voltage off the bias-tee
and run it independently, since I have some spare wires out to the
switching box.
73,
Steve, N2IC
On Tue, Feb 22, 2022 at 8:55 PM Allan Zadiraka <ajzadiraka@gmail.com> wrote:
> While I totally agree with the comments on the poor performance and life of
> the contacts on open frame relays, my experience with noise from relay
> switching has been that it is usually a failed snubber capacitor or diode
> across the relay coil. Occasionally, especially with rotary switches, the
> cause has been arching on the switch contacts.
>
>
> zeke ab8ou
>
>
> On Tue, Feb 22, 2022 at 5:07 PM Grant Saviers <grants2@pacbell.net> wrote:
>
> > 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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