Bulletins from the Pacific Packet Radio Society - page 089

To All

For your information, the text of the ARRL's Petition for Rulemaking to the FCC to permit AMTOR (CCIR Rec. 476-2) in the Amateur Radio Service is quoted below.

73, Paul, W4RI

Before the
Federal Communications Commission
Washington, D.C. 20054

In the Matter of )
Amendment of Part 97. 69 )
of the Commission's Rules ) RM-4122
Regarding Radioteleprinter )
Codes Authorized in the )
Amateur Radio Service. )


The American Radio Relay League (the League), the national non-profit organization of Amateur Radio Operators in the United States, hereby respectfully requests that the Commission amend Section 97.69 of its Rules to permit transmission by amateurs of the digital teleprinter code specified in Recommendation No. 4762(1978) of the International Radio Consultative Committee (CCIR), known in the Amateur Radio Service as "AMTOR," in the amateur high-frequency bands. In support of its request, the League 1/ states as follows:


1. AMTOR is an automatic request-repeat radioteleprinter system which conforms to the standards of CCIR Recommendation 476-2. 2/ That standard was developed for the commercial maritime service, and has come to be known commercially under the trade name Sitor. To avoid confusion, AMTOR was coined as a term to describe amateur use of the method. Basically, a radioteletype station utilizing AMTOR transmits data in blocks of three characters, pausing after each to obtain from the receiving station either an acknowledgement or instructions to re-send. Microprocessor circuitry is gene rally used to automate the process. Because data transmission and acknowledgement alternate in a time-sharing manner, duplex frequency utilization is unnecessary. Both receiver and transmitter operate on the same radio frequency.

2. Perhaps AMTOR's greatest benefit is, by definition, reliable, error-free copy at the receiving teleprinter, and the certainty of the sending operator that the data has been received correctly. The automatic "hand-shaking" technique of AMTOR transmissions allows reliable communication even under marginal

Click for Original Graphic Image of this page.

Previous Index Next