QRPGuys Mini Keyer V2 – $15
The QRPGuys Mini Keyer V2 is a very small basic through hole component design keyer to use externally with your rig, or mount in a small chassis to use with your existing paddle. Small in size 2.00”W x 1.625”L x 1/2”D, 22 grams (.78oz.), it can stand alone or mount by the two stereo jacks mounted on the board, by drilling two 1/4” dia. holes in a chassis or box 1/2” apart. It is powered from an onboard lithium CR2032 battery (not supplied), drawing only 1mA active, 1uA standby, virtually the shelf life of the battery. The message and programming switches are board mounted with operators long enough to protrude thru the top cover of a box or chassis. There is an onboard piezo speaker for rigs without side tone, which can be jumper disabled for those rigs that do, and connections for an external speaker. The dit/dah/right/left selection header is jumper selectable on board. The keyer has adjustable speed from 6WPM-45WPM in 31 increments. The speed setting is stored in the PIC EEPROM, so it is not lost if you change the battery. There are two programmable memories at (63 and 55 characters), continuous playback mode (beacon), and a 30 second “Tune” mode, that can be stopped by tapping the paddle.
The PIC16F628A program is in the public domain and available for modification. The PIC chip is in a socket, not locked, and can be easily reprogrammed. We use 3.5mm jacks for connection to your rig and paddle. The tools required are a soldering iron with a small tip, rosin core solder, small side cutters, and can be built in an hour. On a difficulty scale of 1 to 5, 5 being the most difficult, this is rated at 2.