ORIGIN OF 73 

Via Louise Ramsey Moreau, W3WRE and Charles A. Wimer KC8EHA 

The following is from Louise Ramsey Moreau, W3WRE: "The traditional expression "73" goes right back to the beginning of the landline telegraph days. It is found in some of the earliest editions of the numerical codes, each with a different  definition, but each with the same idea in mind - it indicated that the end, or signature, was  coming up. But there are no data to prove that any of these were used. 

"The first authentic use of 73 is in the publication The National Telegraphic Review and  Operators' Guide, first published in April 1857. At that time, 73 meant "My love to you"!  Succeeding issues of this publication continued to use this definition of the term. Curiously  enough, some of the other numerals used then had the same definition as they have now,  but within a short time, the use of 73 began to change. "In the National Telegraph Convention, the numeral was changed from the Valentine-type  sentiment to a vague sign of fraternalism. Here, 73 was a greeting, a friendly "word" between  operators and it was so used on all wires. 

"In 1859, the Western Union Company set up the standard "92 Code." A list of numerals  from one to 92 was compiled to indicate a series of prepared phrases for use by the operators  on the wires. Here, in the 92 Code, 73 changes from a fraternal sign to a very flowery "accept  my compliments,"which was in keeping with the florid language of that era. "Over the years from 1859 to 1900, the many manuals of telegraphy show variations of this  meaning. Dodge's The Telegraph Instructor shows it merely as "compliments." The Twentieth  Century Manual of Railways and Commercial Telegraphy defines it two ways, one listing as "my compliments to you"; but in the glossary of abbreviations it is merely "compliments." 

Theodore A. Edison's Telegraphy Self-Taught shows a return of "accept my compliments."  By 1908, however, a later edition of the Dodge Manual gives us today's definition of  "best regards" with a backward look at the older meaning in another part of the work  where it also lists it as "compliments." 

Editor Note -- Dodge's "The Telegraph Instructor" can be found at URL: http://artifaxbooks.com/afxrare/dodge.htm

"Best regards" has remained ever since as the "put-it-down-in-black-and-white" meaning  of 73 but it has acquired overtones of much warmer meaning. Today, amateurs use it more  in the manner that James Reid had intended that it be used - a "friendly word between operators." I hope that this helps you in some way.... 

73, Charles A. Wimer Amateur Radio Call:  KC8EHA Assistant Emergency Coordinator, Trumbull County (OH) ARRL Official  Emergency Station (OH)