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 <ajzadir...@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 <gran...@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 > > >> _____________ > > > > > > _________________ > > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > _________________ > > Searchable Archives: http://www.contesting.com/_topband - Topband > > Reflector > > > _________________ > Searchable Archives: http://www.contesting.com/_topband - Topband > Reflector > _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector