Ham Amateur Radio Technician Practice Exam 2026 - Free Technician Practice Questions and Study Guide

In amateur radio, RTTY (Radio Teletype) is a popular mode of digital communication that transmits text over radio waves. The most common frequency shift used for RTTY emissions in the amateur HF bands is 170 Hz.

This shift refers to the difference in frequency between the mark and space tones used in RTTY transmission. A narrower frequency shift, like 170 Hz, allows for more efficient use of bandwidth and helps prevent interference with adjacent signals. This standard is commonly adopted for the 45.45 baud rate used in amateur RTTY operations.

The other choices represent frequency shifts that are less frequently used in the amateur bands. Larger shifts can be found in other digital modes or in other communications contexts but are not typical for amateur RTTY transmissions. By sticking with the standard of 170 Hz, operators can ensure better compatibility and smoother communication across the RTTY community.