Last weekend I was sitting at my QTH station trying to chase POTA CW stations. My current QTH antenna setup consists of a multi band fan dipole (cut for 10, 20, and 30 meters) mounted in my attic, which works, but it’s certainly not as good as a 200 foot tower with a beam and rotor. So I was having varying levels of success. It also happened to be the weekend of the monthly SKCC Weekend Sprintathon (WES), and at one point I heard a station calling “CQ CQ WES” at 599, and wanted to answer him. Problem was, I typically use iambic paddles as my primary key, and I didn’t want to answer him without switching to my straight key (since that’s pretty much the whole point of SKCC). I took five minutes and switched my keys around and was able to have a QSO, but shortly afterwards I thought “wouldn’t it be great if I could have two keys hooked up to this radio, that way I could quickly switch back and forth if a situation called for it?”. This thought prompted me to create the morse key switcher that this post talks about.

There’s actually nothing terribly complicated about any of this design, and it took about 30 minutes or so to put together. My primary QTH rig is an IC-7300, but I use an external keyer already (an Ultra PicoKeyer) since that gives me an easily accessible knob to turn my speed up or down, and easily accessible buttons to access the memories. Plus I’ve found that keyers can be very slightly different from each other, and it’s nice having an external one that I can get comfortable with and then take elsewhere if I want.

Since I already use an external keyer, my IC-7300 is always in straight key mode, even if I’m using paddles. So the proposed switch would just have to be able to switch various mono inputs into one input for the radio. I say switch, but it’s actually simpler then that. If we just run a bunch of mono inputs in parallel with each other, from the radios perspective it can just key down whenever it sees any of those keys close to ground. A picture of my thoughts is included below.

key_bus_schematic.jpeg

Like I said, not a crazy idea at all. Basically we just need a bunch of mono jacks all run together in parallel. I happened to have a bunch of panel mount 3.5mm jacks on hand from an old project, so I set about to work immediatelly.

For the enclosure, I picked a small enclosure that I happened to have on hand. Don’t judge me.

key_bus_internal.jpeg

So the design is pretty simple, just get a bunch of mono jacks, and separately run the tips and sleeves parallel with each other. If you were trying to make use of the radios internal keyer this would be a much more difficult design. I added inputs for three keys in case I want to hook another key up in the future (like a WinKeyer for instance), and I tried to keep everything symmetrical for asthetic reasons. I’ve been switching back and forth between my paddles and my straight key for a week now, and it’s been working great!

key_bus_finished1.jpeg

key_bus_finished2.jpeg