Dilshan R Jayakody’s Web Log

USB Morse Keyer is a microcontroller-based auto keyer project with following features: USB / straight key / iambic key inputs. Support for both standalone and USB operating modes. 64-character USB typeahead buffer and 6-character Morse key typeahead buffer. Support 5, 10, 15 WPM. 6-page message memory. 1W Audio output. Audio and PTT output interfaces. 32 character display  Final view of the USB auto keyer. The USB interface of this unit is designed to work with most of the operating systems. It emulates a virtual serial terminal to transfer keystrokes to the keyer. In most of the operating systems, this interface works without installing any additional device drivers. To submit keystrokes user can use any serial terminal software such as PuTTY , Hyper Terminal , Minicom , etc. This keyer is designed to work with 7V to 16V DC input voltage. The most recommended working voltage is 9V. The bottom side of the USB auto keyer. To reduce the dimension of the P...

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-...