Tuesday, February 16, 2010

In the Air and On the Air - NBC SW Transmitter

In the Air and On the Air with Many Callsigns & Many Locations - SW Transmitter - Part 1

In this feature, we go back to the balloon era some eighty years ago, and we trace the history of a small shortwave transmitter that was on the air, and in the air, under three different callsigns. This is what happened.
Back during the early 1930s, there was a space race on between the United States and Russia to see who could get the highest first. In 1933, plans were implemented to launch a massive high flying balloon somewhere in the United States. This would be a joint project between the National Geographic magazine and the United States army.
The location chosen for launching was near Rapid City in South Dakota, and teams of personnel, civilian and army, made all things in readiness. The balloon when inflated stood at a mind boggling height. There was a strong gondola strung beneath the balloon, and it contained many scientific measuring instruments, as well as an 8 watt shortwave transmitter under the callsign W10XCX.
On July 28, 1934, the launch of the Explorer balloon began with a rapid ascent near Rapid City South Dakota. Progressive observations were radioed on shortwave from W10XCX to a 200 watt station on the ground, W10XCW, for onward relay to shortwave W3XL & W3XAL in New Jersey. There are no known QSL cards verifying these relay broadcasts.
Just before the Explorer reached a new record height, a tear was noted in the fabric of the balloon, and the entire craft began to plummet towards the ground. In good time, the three man crew parachuted to safety, and the gondola crashed to the ground.
Soon afterwards, plans were laid for another balloon flight from the same location with similar equipment and this took place on November 11 in the following year 1935. It would appear that the previously used low powered shortwave transmitter was rescued, repaired and re-installed in the gondola for the next flight. It was still rated at 8 watts and still operating on the same channel 13050 kHz, though a new callsign was given, W10XFH.
The balloon, re-designated as Explorer 2, was upgraded and fitted with a newly designed and sealed gondola and the strange craft now stood at a staggering height of 315 ft. This second flight proved to be more successful than the earlier flight and they set a new height record at 74,000 feet, a little over fourteen miles high.
During this flight the Explorer 2 personnel talked with ground station W10XFN, and also to the new China Clipper airplane, callsign KHABZ, that was on a test flight in California. Relay broadcasts from the gondola were again carried by the NBC network via their shortwave stations W3XL & W3XAL in New Jersey. NBC in New York issued specific QSL cards for the transmissions from both W10XFH in the air and the 200 watt W10XFN on the ground.
During this same era, Pan American Airways, known better as PanAm, were implementing plans to launch an air service across the Pacific. They procured three Martin seaplanes which they named as China Clipper, Hawaii Clipper, and Manila Clipper, though the first one, China Clipper, became the most famous.
As part of a publicity plan, a shortwave broadcast transmitter was installed on the plane for its inaugural flight across the Pacific. This transmitter was the previously used light weight unit, known as W10XCX & W10XFH for the balloon flights during the past two years, though it was repaired and modified, with a power increase from 8 watts up to 100 watts. A new callsign was allocated, this time WOEH.
The farewell ceremony in Los Angeles for the commencement of the inaugural flight was a gala event. The Captain, with the family name Musick, read a congratulatory letter from President Franklin Delano Roosevelt, there was band music, and the usual speeches from participating dignitaries.
The China Clipper flew out of Los Angeles California on Friday afternoon November 22, 1935 with a cargo of postal mail numbering 110,000 items, as well as two personnel from the NBC radio network, an engineer and an announcer. The first leg of the flight was to Honolulu, a journey of two thousand four hundred miles, a flight of eighteen hours, at an air speed of 125 miles per hour.
The first official flight of the China Clipper, from Los Angeles in California to Manila in the Philippines, took almost sixty hours of total flying time, for a distance of more than seven thousand miles. Overnight stops took place at Honolulu, Midway Island, Wake Island, and Guam, with the final destination for this historic pioneering flight at Manila.
En route, the transmitter WOEH was in use for progressive radio broadcasts to nearby radio stations. On several occasions, these broadcasts were picked up and relayed back to the United States for network mediumwave coverage. One such broadcast was taken on relay by the RCA communication station located at Kahuku on the northern tip of the island of Oahu.
Other noted broadcasts were made from Midway Island and also Wake Island. As the China Clipper was nearing Manila on this first occasion, the NBC personnel aboard the plane made a broadcast specifically to the well known mediumwave station KZRM in Manila.
During the following year, 1936, the NBC portable shortwave transmitter WOEH was transferred into a Douglas DC plane for a flight to Alaska piloted by the well known aviation entrepreneur, Howard Hughes. Program relays were arranged with the RCA stations at Bolinas in California, KEE on 7715 kHz and KEI on 9490 kHz.
Later in the same year, Howard Hughes made another memorable flight in a low winged monoplane from New York to Paris. With him on this occasion also was the same 100 watt transmitter, WOEH. Relay broadcasts in the United States were arranged through the RCA receiving station located at Riverside on Long Island.
Even though the relay broadcasts from the transmitter WOEH were heard by international radio monitors throughout the United States and in the South Pacific, there are no known QSLs verifying these transmissions.
No, that was not the end of transmitter WOEH. During the next year, 1937, it was incorporated into the electronic equipment of another radio broadcasting station that was on the air in the Pacific and later in Europe. More about that next week.
(AWE Wavescan/NWS51 via Adrian Peterson)