Changes to ARRL "Rule 1.12" regarding contests above 50 MHz



On July 16, 2010 during ARRL Board of Directors meeting, changes were made to the General Rules for ARRL Contests Above 50 MHz. Previously, rule 1.12 read:

"Above 300 GHz contacts are permitted for contest credit only between licensed amateurs using coherent radiation on transmission (for example, LASER) and employing at least one stage of electronic detection on receive."

The rule now reads:

"Above 300 GHz, contacts are permitted for contest credit only between licensed amateurs using monochromatic signal sources (for example, LASER and LED) and employing at least one stage of electronic detection on receive. LASER usage is restricted to ANSI Z136 Class I, II, IIa, and IIIa (i.e., output power is less than 5mW)." Note: The current FCC rules allow operation - with certain restrictions - an all frequencies above 275 GHz even though many references and contest rules refer to the older "...above 300 GHz" allocations.



As noted, the changes allow sources of light other than lasers to be used - including LEDs. This wording could also be taken to also allow various types of gas-discharge lamps - perhaps even filtered multi-line emitters. It does seem to disallow direct use of broadband "thermal" sources such as tungsten lamps, however.



Allowing the use of noncoherent light sources such as LEDs allows other types optics to be utilized (e.g. non diffraction-limited) which can be used to greatly increase the exit aperture of a transmitter, decreasing the power density and thus the potential hazards to the operators and others that might encounter the beam while simultaneously increasing the total amount of power one can radiate safely.



Keep in mind that the above rules apply ONLY to ARRL contests and shouldn't limit one's imagination: If you wish to conduct experiments using techniques or gear that doesn't fall within the scope of the rule, feel free to do so safely! It is with such experimentation that new techniques are developed and perhaps, one day, may be included in the rules!



Comment: As of the time of writing this the rules covering VUCC contacts still specify the use of coherent light.