Morse Code Beacon Keyer

Published:2013/3/7 3:07:00 Author:Ecco | Keyword: Morse Code , Beacon Keyer | From:SeekIC

This circuit stores a morse code message as bits in an EPROM chip, the message is sent to a relay which can key a CW transmitter. The keyer can output either a one-shot message such as CQ DX DE CALLSIGN , or a continuous message. The continuous mode is useful for making beacons for low power (QRP) and slow (QRSS) transmissions. A One-shot message can be controlled by pressing the start/stop buttons, a continuous message can be sent by turning on the free run switch. EPROMs other than the 2732 can be used if suitable changes are made to the address lines in the circuit. For larger EPROMs, just ground the higher order address input lines on the EPROM chip, and wire the appropriate chip select pins for outputs enabled and chip selected. It is also possible to store more than one message in different banks of a larger EPROM, for instance, if a 2764 part were used, the A12 address line could be used to select the upper or lower message. Note that the photo above shows a slightly different implementation of the circuit. A 5V power supply and a 555 timer sidetone oscillator have been added, the keyer relay has been removed and the EPROM is a 2716 type.



Reprinted Url Of This Article:
http://www.seekic.com/circuit_diagram/Basic_Circuit/Morse_Code_Beacon_Keyer.html

Print this Page | Comments | Reading(3)