Mouse Keyer
This CW keyer was a kit given out with registration to Ozarkcon, a QRP & homebrewing convention held in Joplin Missouri. The kit is based on the Norcal keyer chip, and since I had already built a couple of keyers with that chip, I was fairly familiar with it. At Ozarkcon, the kits were entered in a building contest, so I thought it would be neat to build the keyer into a unique package. At first I was just going to use an Altoids box, but I got to thinking what I'd use for paddles. I had heard of others using an old computer mouse as a set of paddles, so decided to try that since I had several old mice laying around. Eventually I wondered why it would be necessary to have the keyer in a separate enclosure when the board was small enough that it should fit into a mouse. I then had the idea to put the keyer board & 9V battery into the mouse and have a self-contained unit.
The board included with the kit is a Pittsburg-style board. This means the kit is built Manhattan-style, but the board has the lands etched into it, rather than glued to it. The kit went together quickly and worked the first time it was turned on. I just needed a good mouse to put it in.
I had several computer mice in my junk box, some of them working, some not. The challenge was finding one that had enough room to mount the board & a 9V battery, plus one that would allow easy use of the buttons. I finally found one that would work and took the guts out of it. I carefully removed the mouse buttons from the rest of the pc board by cutting them off with a Dremel tool, so I had the three buttons on one piece of PC board. This was glued to the bottom half of the mouse enclosure once I had soldered wires to the PC traces. The left and right buttons were wired up as the dit & dah, while the center button was wired up as the keyer's function button. When the top half of the mouse is placed over the bottom half, the buttons line up and work just as they did when it was a computer mouse.
Originally when I built the kit, I connected a superbright LED to the chip's output. It faced out the front of the mouse and flashed in sequence to the CW that was being sent. This was neat to look at but I wanted to use the keyer to key a radio. The keyer kits given out at Ozarkcon were just like the Norcal keyer kits with one exception. The Ozarkcon kits were meant to be used as audio CW keyers only and not for keying a radio, so part of the circuitry was left out. However, the only missing parts were a resistor, a transistor, and a capacitor, which were easily found in my electronic supplies. I added the extra circuitry to the keyer, and after removing the LED and replacing it with the mouse cord, I had a working keyer. I used a subminature toggle switch I salvaged from an old PC board as the power switch and added a small LED next to the switch as a power indicator.
I wondered if it would be difficult to key the keyer using the mouse buttons, but found that it works just fine. I wired the buttons so that I would key dits with my middle finger, and dahs with my index finger. I felt that would be easier to get used to rather than the other way around, since normally with paddles the dahs are sent with the index finger and dits with the thumb. This way keeps the dahs being sent with the index finger so that it's less confusing when switching between the mouse keyer and a set of paddles.
The mouse keyer is a good portable keyer and goes with me when operating portable. With it I don't have to pack a keyer and separate set of paddles since it's all conveniently located in one package. It should be noted that since the picture taken above, I have modified the mouse keyer by installing a 3.5 mm stereo jack in parallel with the mouse buttons. This allows me to connect a set of paddles and operate the keyer with them if I get tired of clicking mouse buttons. The 3.5 mm jack is installed just behind the on/off switch.