HD-1410 is quite popular iambic keyer which is manufactured around the 1970s by Heathkit . The original HD-1410 keyer is designed using 5 commonly available 74LS series TTL ICs and 8 transistors. Other than iambic operation it has an option to adjust sidetone frequency and support for (external) single-paddle key unit. In this project, we redesign the original HD-1410 electronic keyer with today's commonly available components. In this new design, the key components which we replace are transistors, diodes, and power supply section of the original HD-1410 circuit. Most of the NPN transistors in original design are replaced with KSP42 and KSP10 transistors, and all the PNP transistors are replaced with KSP92 transistors. To keep everything simple we also use the same TTL chip-set with this new design. PCB of modified Heathkit HD-1410 electronic keyer. Tested PCB layout for this new keyer is available in the project archive and this PCB layout is based on standard through-...
This blog contains electronic, amateur radio, and embedded system projects, which I did during my free time. Unless otherwise noted, all the articles and projects described on this blog are based on my original designs.