Radio broadcast .. (1922-30)

'!"• *!: '"','..: :'.' ii •: "I.:.1 * •!"! •••• ••III • ! ARTHUR PERKINS (2 APQ) Who goes with Commander Dyott to the River of Doubt to report by means of a battery operated short-wave transmitter the progress of the expedition. The receiver that will be used by Mr. Perkins is shown in this picture 'ITH the departure of Commander Dyott, of the Roosevelt Memorial Association Expedition, for the River of Doubt, in Brazil, RADIO BROADCAST adds another name to its list of those expeditions which are equipped with short-wave apparaus constructed according to specifications upplied by the Laboratory at Garden City. As generally chronicled in the press, it was on uly 24th that the Dyott expedition left New fork on its big adventure — to re-explore the liver of Doubt, up which Theodore Roosevelt aboriousiy navigated in 1914, before short-wave adio communication, as it is known to-day, was Ireamed of. With Dyott went two complete radio transmitters, a 25O-watt short-wave ransmitter built for RADIO BROADCAST by the Allan D. Cardwell Corporation, and a small jortable set operating from Eveready B bateries. It is intended that the 25O-watter, ogether with a suitable receiver (which was especially built for RADIO BROADCAST), be set up as a base station in a suitably located spot somewhere near the center of Brazil. This station will be under the charge of Eugene Bussey (2 CIL), of Yonkers, while the key of the small portable set, which will advance up the river with the expedition, will be "pounded" by Mr. Arthur ^erkins (2 APQ). The equipment used by Mr. Perkins was built by himself to RADIO BROADCAST specifications, with Hammarlund parts. At the time of writing, little can be told about schedules and wavelengths, as this depends upon restrictions imposed by the Brazilian government. It is probable, however, that the 7500kc. band (4O-meter band) will be used. The call signals, too, are not yet known, but an endeavor is being made to obtain the use of the calls GMD and 2 GYA for the base station and advance station respectively. Other expeditions which have been equipped with RADIO BROADCAST apparatus are those of Francis Gow Smith and of Commander MacVtillan. Gow Smith sailed many months ago 'or the wilds of Brazil, seeking more information for the museum of the American Indian. He appealed to 2 GY (the experimental station of RADIO BROADCAST) for a receiver so that he would be able to receive the short-wave trans Radio with the The Laboratory of Radio Broadcast Has Sup' plied Short-Wave Equipment to Three Famous Expeditions, that of Commander Dyott to the "River of Doubt" Being the Most Recent missions of WGY and KDKA while he was in the jungles. We have since heard from this famous explorer that he has been singularly successful in his efforts to listen to the short-wave broadcasts from the outer world and, thanks to the cooperation of the General Electric Company in sending out special time signals, he has regularly been able to ascertain his geographical positions very accurately. On June 29th, Commander MacMillan sailed for Greenland with two vessels, his own Bowdoin and a new schooner, the Sachem, built by Rowe Metcalf. On the latter vessel, as radio operator, is Austin C. Cooley who described in RADIO BROADCAST some time ago his experiments) in picture transmission by radio. Up to the present time 2 CY has maintained nightly communication with KGBB, the Sachem, although she is, as we write these words, in the region of continuous daylight off Greenland. The receiver used by Mr. Cooley was built by the operators at 2 GY. It is similar to the Silver-Marshall set used at the base station of the Dyott Expedition. TRANSMITTERS Which will play an important part during the expedition up the River of Doubt. The small transmitter shown above was built by Mr. Perkins, and will accompany him up the river so that he will be in touch with the base station. To the right is shown the 25O-watt transmitter built by Cardwell which will be used to communicate with the outside world from the base station, and with Mr. Perkins up the river DYOTT BRAZIL • EXPEDITION i