"Wavescan" is a weekly program for long distance radio hobbyists produced by Dr. Adrian M. Peterson, Coordinator of International Relations for Adventist World Radio. AWR carries the program over many of its stations (including shortwave). Adrian Peterson is a highly regarded DXer and radio historian, and often includes features on radio history in his program. We are reproducing those features below, with Dr. Peterson's permission and assistance.
Wavescan, June 14, 2009
"Wonderful Isle of Dreams"
Florida! Vacation state for admiring tourists, winter haven for shivering northerners, holiday playground for traveling families, and jumping off destination for tour boat devotees. However, in addition to these idyllic descriptions that lure the wandering visitors and invite them to flow into Florida, we can also remember that the state of Florida has featured prominently in the international scene of shortwave radio broadcasting. Currently on the air today is the large facility of Family Radio with its fourteen shortwave transmitters located a little north of Lake Okeechobee, and the commercial station WRMI with its two shortwave transmitters located a little north of Miami itself, in Hialeah. In earlier years, there was station W4XB-WBKM-WDJM, the shortwave counterpart of the AM station, WIOD. It all began this way.
Back in the Spring of 1925, Carl Fisher commenced the construction of an AM mediumwave radio broadcasting station on Collins Island, Miami Beach in Florida. He had already built several luxury hotels in this new vacation area which served as a winter haven for visiting tourists from the colder northern regions. The concept in establishing this radio station back in the pioneer days when radio was still a novelty was to publicize his tourist facilities located on this sandspit, which was sandwiched in between the Atlantic Ocean and Biscayne Bay.
A Western Electric WE106A transmitter, rated at 1 kW and tuned to 1210 kHz, was installed in a two story building on Collins Island that also housed the studios and offices for this new radio venture. The antenna towers were erected behind the main building; they stood 250 ft. high, and they were spaced 385 ft. apart. The counterpoise ground system consisted of nearly 14 miles of wire buried in the salt water marshy areas.
Test broadcasts from the new WIOD were authorized by the Department of Commerce on January 5, 1926, and the official license was dated four days later. A regular radio broadcasting service was commenced from the new WIOD on January 19, 1926, as the second radio station in the Miami area. The callsign WIOD, as is so well known in Miami, stands for "Wonderful Isle of Dreams," an idyllic reference to Fisher's tourist area at Miami Beach.
Over the years, station WIOD has moved several times, with studios in the Fleetwood Hotel, and the Miami Herald Building, and the Miami News Building, as well as on Cameo Island, and in North Bay Village, and also Miramar. The WIOD transmitter and antennas have also been moved on several occasions, from Collins Island, which was known later as Clauton Island, to a tower on top of the Miami News Building, and then to Little Cameo Island.
It was a common practice in those days to erect the antenna masts on top of a tall building in an endeavor to gain a greater height and therefore an extended coverage area. However, this widespread practice was discarded a few years later after it was discovered that the poor grounding system of a tall building did not enhance the coverage area of a mediumwave transmitter. Thus, the WIOD transmitter was soon afterwards moved from the tall Miami building to Little Cameo Island.
Among the other changes and developments experienced by WIOD were changes in callsign from WIOD, to WCKR, and back again to WIOD. The transmitter power, originally 1 kW, was increased to 5 kW in 1941 and to 10 kW in 1981. Likewise, there have been several changes in frequency, seven in all, though the current channel, 610 kHz, has been in use continuously since 1937. Today, there are a total of seven AM and FM stations clustered together in the large studio complex at Miramar.
However, as far as the international broadcasting facility is concerned, their era of shortwave broadcasting is of real interest and importance. The purposes for the parallel relay of programming on shortwave was to increase the coverage area of the AM mediumwave station, to encourage winter tourism from the colder northern areas of North America, and to publicize the vacation advantages that can be discovered in Florida.
In 1932, just six years after the mediumwave station was launched, station WIOD announced that a shortwave transmitter was under construction. This unit, assembled by their engineering staff, was inaugurated in July of the same year, 1932, with programming in parallel with the mediumwave unit which was on 1300 kHz at the time. Under the callsign W4XB, this new station was noted internationally soon afterwards with test broadcasts in the 49 metre band. The WIOD shortwave station has always operated on only the one channel, 6040 kHz. The printed schedule for this new broadcast operation showed a few hours in the afternoons and evenings, with extended programming on Sundays.
Interestingly, in February 1933, station W4XB was noted in Australia with test broadcasts in conjunction with Radio Manila in the Philippines. In those days, distant stations would observe a pre-arranged schedule for the purpose of exchanging live programming, and thus listeners in Florida and throughout North America had the opportunity on this occasion of hearing radio programs from a distant country, the Philippines.
Throughout its entire lifetime, shortwave W4XB-WBKM-WDJM was on the air from the same two transmitters, a pair of homebrew units at 5 kW, and always on the same channel in the 49 metre band, 6040 kHz. On occasions, the station was off the air for extended periods of time due to what would be described these days as transmitter maintenance. Available information suggests that there was only ever the one location for the shortwave transmitter, and that was at the original WIOD location on Collins, or Clauton Island. This island is long since gone; it was taken over by a highway and a hospital, and nearby marshy areas were filled in for housing estates.
The original callsign for the shortwave transmitter was W4XB. However, even though this call makes the station look like an amateur operation, this was not the case. Back in that era, callsigns with this type of configuration were looked upon as being experimental, and they could be either amateur or professional. The X after the number indicated experimental.
With armed conflict looming over the international scene in continental Europe, the federal licensing authorities required all shortwave broadcasting stations in the United States to discard their experimental callsigns and to register a regularized callsign, effective September 1, 1939. During the hasty events of this crisis period, WIOD shortwave was noted for a short period of time in Australia and New Zealand with the callsign WKBM. However, shortly afterwards, the shortwave unit operated by the "Wonderful Isle of Dreams" station W4XB, became WDJM.
In another directive a few months later, the licensing authorities required that all shortwave broadcasting stations in the United States should be operating at a power of 50 kW, or have submitted a CP, a Construction Permit, for 50 kW, effective April 1, 1940. At this stage, WIOD decided to drop out of the international shortwave scene and to concentrate on local coverage, AM and later FM.
The final broadcast from shortwave WDJM, the usual relay from mediumwave WIOD, took place some time during the month of September 1940 when the transmitter was quietly switched off for the last time. What was left of the two homebrew units, now combined into one 10 kW unit, was loaded onto a truck and taken up to Scituate Massachusetts, a few miles south of Boston. At station WRUL, the legendary Walter Lemmon re-activated the equipment a few weeks later and returned it to the air at its new location with 10 kW under a new callsign, WRUX.
During its somewhat spasmodic on-air operation over a period of eight years, station W4XB-WDJM in Miami, Florida was heard widely throughout North America, and also in Europe and the South Pacific. This pioneer shortwave station is long since gone, and only the very oldest amongst us can actually remember the events as they occurred. These days, just about all that is known about this station can be seen in a few old and yellowed QSL cards, and in old and crinkled radio magazines.
These days, it is possible sometimes to come across old QSL cards issued on behalf of shortwave W4XB-WDJM, and it would appear that just two different cards were issued; one for the experimental callsign W4XB, and another for the subsequent regularized callsign, WDJM. Interestingly, QSL cards were also issued in Boston for the same transmitter at its new location at Scituate in Massachusetts, under its new callsign WRUX.