AIRWAYS COMMUNICATION SERVICE 



805 



three telephone channels above and three below the calling wave, or a 

 total of six channels. Assuming that a beacon requires a channel 

 width of but 300 cycles, there are altogether for marine and airport 

 use one hundred beacon channels in the band 285-315 kcs. 



Fig. 3. Cabin Laboratories of the Monoplane. 



The band reserved for beacons is already partly occupied by marine 

 beacons, and near the coast difficulty may arise in finding clear channels 

 for airport beacons. Although it is probable that, by a proper geo- 

 graphical distribution of frequencies, there may be worked out without 



