Radio Broadcast (May-Oct 1926)

RADIO BROADCAST ADVERTISER 267 Frequency Channels Used by All New Stations, Including Broadcasters, are Assigned Wavelengths According to this hist 'HEN a new radio station commences operation, it is assigned a definite frequency (or frequencies), this latter figure being allocated depending upon the type of service etc., from bands already decided upon. The list printed below gives these bands, and was drawn up at the Fourth National Radio Conference, and only differs slightly from that drawn up at the previous conference. Wavelength allocations by the Department of Commerce are based upon the information contained in this list. An important matter treated by the Conference Committee was the utilization of the frequency bands above 2000 kilocycles (below 150 meters). Certain additional services have been placed in some of these bands, as will be noted from the list. Special thought was given to the application of the ultra-high frequency bands to beam and amateur services, but, as it will be noticed, no bands have as yet been specially put aside for the transmission of photographs by radio. It was concluded that certain of these channels should be available for experimental work other than beam transmission, and the allocations were accordingly modified in that respect. The Committee stated that the allocations above 2,000 kilocycles (below 150 meters) must be considered to some extent temporary or experimental. A question of primary interest to the broadcast listener was also dealt with. This was relative to a proposed extension of the present band of frequencies used for the broadcasting service. It was fully recognized by the Committee that such an extension would result in a certain amount of relief of the present congested state of affairs, but it was not found feasible to make any extension without encroaching upon the major wave band used by the amateurs. Many present-day receivers too, would be unable to tune down to the extended wave band, so no alterations to the present band are put in force, nor are any such alterations likely. KILOCYCLES 95-120 120-153 125 153-165 155 165-190 175 190-230 230-235 235-285 245 275 285-500 300 315 343 375 410 425 445 454 500 500-550 550-1,500 1,500-2,000 2,000-2,250 2,250-2,300 2,300-2,750 2,750-2,850 2,850-3,500 3,500-4,000 4,000-4,525 4,525-5,000 5,000-5,500 5,500-5,700 5,700-7,000 7,000-8,000 8,000-9,050 9,050-10,000 10,000-11,000 11,000-11,400 11,400-14,000 14,000-16,000 16,000-18,100 18,100-56,000 56,000-64,000 64,000-400,000 400,000-401,000 3,156-2,499 2,499-1,960 2,399 1,960-1,817 1,934 1,817-1,578 1,713 1,578-1,304 1,304-1,276 1,276-1,052 1,224 1,090 1,052-600 1,000 952 874 800 731 706 674 660 600 600-545 545-200 200-150 150-133 133-130 130-109 109-105 105-85.7 85.7-75.0 75.0-66.3 66.3-60.0 60.0-54.5 54.5 52.6 52.6 42,8 42.8-37.5 37.5-33.1 33.1-30.0 30.0-27.3 27.3-26.3 26.3 21.4 21.4 18.7 18.7-16.6 16.6-5.35 5.35-4.69 4.69-0.7496 0.7496-0.7477 TYPE OF TRANSMISSION CW and ICW CW and ICW CW CW and CW and CW and CW and CW and CW and Phone CW and CW and ICW ICW ICW ICW ICW ICW ICW ICW CW and ICW CW and ICW CW and ICW CW and ICW CW, ICW, spark CW, ICW, spark CW and ICW CW, ICW, spark CW, ICW, spark, phone. CW, ICW, phone. Phone CW, ICW, phone Government only Marine and aircraft only Government Point to point, marine, and aircraft, only. Government Point to point and marine only Government Government only University and college experimental only. Marine only Government do Marine and coastal only Beacons only Government only Marine only Radio compass only Marine only do Government Marine only Calling and distress, and messages relating thereto, only. Aircraft and fixed safety of life stations. Broadcasting only Amateur only Point to point Aircraft only Mobile and Government mobile only. Relay broadcasting only Public tol! service. Government mobile, and point-to-point communication 'by electric power supply utilities, and point-to-point and multiple-address message service by press organizations, only. Amateur, Army mobile, naval aircraft, and naval vessels working aircraft, only. Public toll service, mobile, Government point to point, and point to point public utilities. Relay broadcasting only Public toll service only Relay broadcasting only Point to point only Amateur and Army mobile only Public toll service, mobile, Government point to point, and point-to-point public utilities. Relay broadcasting only Public toll service only Relay broadcasting only Public service, mobile, and Government point to point. Amateur only Public toll service, mobile, and Government point to point. Experimental Amateur Experimental Amateur Non exclusive. Do. Do.' Do. Do. Do. Do. Do. Do. Do. Do. Do. 'Ice patrol, broadcasting, etc. ^ Tested and approved by Radio Broadcast SUPER-EMISSION RADIO TUBES Excel in All Characteristics Standard Types Power Amplifiers Type 200 Power Detector JOBBERS DEALERS A few territories open for exclusive distribution Write "Nj>w for Details CABLE SUPPLY CO. INC. Sales Offices 907 Broadway New York