Ham Radio Extra Class Practice Test 2025 - Free Extra Class License Exam Questions and Study Guide

The organization of JT65 contacts is based on alternating transmissions at 1-minute intervals, which allows for effective communication within the mode's protocols. In JT65, each contact consists of a series of structured transmissions where a station sends its information during a specific time frame. The standard timing for these transmissions is set so that each station alternates sending and receiving within these one-minute slots.

This method of timing is crucial for maintaining order and ensuring that both stations can decode the transmitted signals properly within the limited bandwidth available. The protocol is specifically designed to accommodate the weak signal conditions that JT65 often operates under, making the organized timing an essential part of successful communication in this mode.

The other options do not reflect the operational methodology of JT65. For instance, ACK/NAK packets are more relevant to data link layers and are not part of the timing structure in JT65. The idea of stations taking turns on alternate days or depending on lunar phases does not align with the structured transmission system that facilitates quick and reliable exchanges during a contact. This structured timing allows operators to complete effective communication even with low power and high noise levels.