ARRL HB 93 CHP 29 FIG.19
Description: The article originally appeared in December 1991 QST. This is a digital voice storage project using the ISD1020 IC by Information Storage Devices and stores up to 20 seconds of 2.7 KHz bandwidth voice. The project is set up to store and play back four different messages with a total length of 20 seconds. The article also explains how several boards can be cascaded to increase the message length. Also uses a 4001, a 78L05, and two transistors.
ARRL HB (88-91) CHP29 FIG.19, (92-94) CHP 29 FIG 3
Description: This is built on a 3.5" x 2.5" pc board. The article originally appeared in June 1988 QST. The circuitry consists of two 4017s, a 4070, and a 4093 IC. The side tone circuitry is not included on the board.
Description: This project adds the capability to send CW directly from the old AT/XT keyboards. The circuit uses an 87C751 PIC processor that is available programmed from the author. The circuit uses an 87C751, two transistors, 7805, and a relay to interface to the radio and has an on-board sidetone monitoring. This is one of the neatest projects for sending CW since the invention of the Keyer.
Description: This is a PIC processor based CW code reader than uses the audio from the receiver. The decoded CW is displayed on a LCD matrix display. The circuit uses a 4093, an NE567, a 78L05 and a programmed PIC processor.
Description: This is a simple keyer circuit using the 16F84 PIC processor. The circuit uses the 16F84 with RC timing, 78L05, 2N222 keying transistor, and has side tone to drive a small speaker. The board to assemble the circuit is 1.5" by 1.25". The PIC program is given in the article.
(FAR CIRCUITS NO LONGER HAS ANY OF THE 8044ABM CHIPS)
Description: This is simple Ibamic keyer using the Curtis chip that is available from MFJ.See www.mfjenterprises.com