In Review: The PK-3 Keyer from Jackson Harbor Press
The ARS Sojourner
It was not always so. The first keyer I built was the WB4VVF Accu-Keyer, which required something like six 14-pin chips, an AC power supply and a hefty box in which to carry it all. We thought it was a pretty nifty device at the time, rather compact when compared to the tube clunkers of the day.
Since then keyers have shrunk and their capabilities have grown. The Super CMOS keyers marked a quantum jump in keying technology. One chip, numerous features, several memories and peanut power consumption made them an unbeatable combination. My CMOS Super Keyer II is probably over ten years old and is still my keyer of choice for contest work.
But tiny built-in keyers are now the chips of choice for portable work. No need to carry along an extra box when the keyer is already in the rig! At last count there were seven rigs in the N6GA collection with internal keyers - a 38 Special (Tick), Norcal 40 (KC-1), Small Wonder SW-40 (KC-1), an SST (KC-1), a Sierra (KC-2), a Norcal 20 (Tick) and a Red Hot 40 (PK-3).
Never heard of a PK-3? I hadn't, either, until I saw it mentioned on QRP-L. The PK-3 is an 8-pin PIC-based keyer that is an exact drop-in match for the Tick. The words that caught my eye were "pot speed control." I enjoy the usefulness and small size of the Tick keyer chip, but for contest operating I really miss a knob for controlling my speed. Having a knob to crank on is especially useful in QRP contests where you can encounter a wide range of code speeds. I like to answer a station at the same speed at which he is calling, and with a knob I often end up adjusting my speed as I'm making my call.
The PK-3 is sold by Jackson Harbor Press and contains an amazing number of features for such a tiny little package. The instructions for operation run about 6 pages. Inputting commands to the keyer involves a push of the "Keyer" button on the radio in conjunction with a squeeze of the appropriate dot or dash paddle. I know I'll never remember all the commands, so I copied the command menus and had them laminated so I can carry them around like little cheat sheets.
For speed pot operation you need three external parts, a 100k ohm pot, a 1K ohm fixed resistor and a .01 uF capacitor. These items need to be connected to Pin 2 of the chip. I planned to use the PK-3 in my Red Hot 40, which is designed with Pin 2 of the keyer chip grounded. To avoid lots of delicate surgery, I chose to insert the chip with Pin 2 "flying", that is, with it bent up in the air while all of its siblings are inserted in the appropriate holes just vacated by the Tick. I soldered a Molex pin on the end of the wire coming from the speed pot, then slipped it over Pin 2 of the chip.
The only difficult decision of the whole procedure is where to locate the speed pot. I chose an empty space on the front panel, but then had a tough time applying drill bit to that nicely anodized red faceplate. The result is a slightly more cluttered look, but I'll get used to it.
Meantime, I can now crank my speed up and down to my heart's content. As an added bonus, the PK-3 offers an auto character space feature, which I got used to with both the Accu-Keyer and the CMOS Super Keyer.
I feel truly spoiled.
Jackson Harbor Press, RR1, Box 91C Washington Island, WI 54246
http://jacksonharbor.home.att.net
jacksonharbor@att.net
* * * * * * * * * * Cam Hartford, N6GA, an avid QRPer, homebrewer and outdoorsman, is a contributing editor to The ARS Sojourner. He lives in Claremont, CA.