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S.O.S —SHOWING OFF THE SEQUENCER

Contemporary Design Execution
by Robert P. Bisey

Start ý The History ý Interfacing ý Interface Board Circuit Descriptions ý The Microcontroller Board • Program Logic • Software • Code Transmission Protocol • Something Old, Something New..• Sources and PDF

In this era of highly sophisticated modes of digital communication, the ongoing furor concerning the use of Morse code in contemporary amateur radio practice and the recent amateur license restructuring that sharply reduced the proficiency requirements for this elementary mode of radio communication calls into question the validity for developing a Morse code sequencer. Despite arguments as to the legitimacy of Morse code, it still finds its use in amateur radio service, specifically in person-to-person amateur shortwave communications and in repeater stations, which are automated, unmanned relay stations presently operating in various VHF, UHF, and microwave allocated amateur radio bands.

The use of such repeaters greatly extends the limited communication range of small hand-held battery-operated transceivers by affording a means of amplifying and retransmitting the weak transceiver signal at a higher power level on a nearby offset transmit frequency. The FCC specifies that such unmanned relay stations must periodically transmit the amateur radio call sign assigned to the station. Presently, either an automated voice-synthesized announcement or a short Morse code message using a Morse code sequencer is sent to fulfill this requirement.

The sequencer also can be used to alleviate the tedium experienced when participating in Amateur Radio Field Day activities. Throughout the year, the Amateur Radio Relay League (ARRL) sponsors contests to see who can accumulate the most contacts with other stations within a specified time period. During this period, the continuous wave (CW), Morse code segments of the low-frequency amateur bands are thick with hundreds of CW stations frantically competing with each other to accumulate the most contacts.

Each time a station sends an invitation to transmit message (CQ), the station call sign also must be transmitted to facilitate two-way communication. Many hours at the Morse code key or electronic speed keyer, transmitting the same message ("...CQ CQ CQ DE WA2DJH WA2DJHý," for example), can become quite tedious. Encoding such a message in the sequencer makes this task considerably easier because the amateur operator only has to tap the transmit/test button on the sequencer to transmit the pre-coded message.

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