Note
Ham Radio, Sep 1971, p. 86.
QST, Oct 1971, p. 140.
QST, Jan 1972, p. 151.
Ham Radio, May 1972, p. 117.
Appears to be the first programmable electronic keyer.
The Curtis EK-402 keyer had four quadrants of 64-bit programmable memory. They were selectable in three banks (quadrants three and four were linked together). The programmable messages had a delay and repeat function. The EK-402 had an internal AC supply. A 9 volt battery retained programmed messages when the key was disconnected from the AC line.
BASIC POINTS
Instantly programmable and reprogrammable message memory
Instant transfer between manual and program keying
Exact speed and weight match between manual and automatic keying
20 character memory in three contest groups
Automatic variable repeat cycle
SPECIFICATIONS
256 bit MOS read/write message memory
1–30 second memory repeat cycle
8–50 WPM calibrated speed
Iambic keying, paddle or squeeze key
Variable character weight
Perfect dot memory
Built-in sidetone and speaker
External volume and pitch controls
Reed relay output keys any kind of transmitter
17 ICs, 6 transistors, 20 diodes