Your browser is out-of-date!

Update your browser to view this website correctly. Update my browser now


A Sequel to the Philadelphia Story

We Learn More About a Historically Fascinating Transmitter From Philadelphia

Was it deliberate disinformation during the hectic, sometimes shady days of World War II? Was it a change of plans on the part of decision-making personnel? Or was it just a case of bad memory regarding events of long ago?

You may remember that we presented the story of Philadelphia shortwave station W3XAU-WCAI-WCAB in Radio World’s Aug. 15, 2007 issue, part of RW’s “American Shortwave” series of occasional articles in cooperation with the National Association of Shortwave Broadcasters.

To review: the CBS shortwave station was launched as a 1 kW home-brew unit in the back room of a radio shop in downtown Philadelphia in 1932.

During the following year this low-powered shortwave transmitter, W3XAU, was moved out to suburban Byberry and a year later again the unit was moved to Newtown Square, where it was co-sited with the huge 50 kW medium-wave transmitter, WCAU.

In 1936, the shortwave transmitter was re-built into a 10 kW unit with two V type antennas (early versions of the popular rhombic, we would guess) beamed on Europe and Latin America.

‘The Spirit of WCAU,’ a pamphlet from the 1930s, courtesy of Charles A. Higgins. Programming for shortwave W3XAU was taken from the CBS nationwide network and from local Philadelphia productions at medium-wave WCAU. In those pre-war days, a 10 kW shortwave signal could be heard widely; contemporary monitoring reports and QSL cards indicate that this international relay station was often heard throughout the Americas and over in Europe, as well as “down under” in Australia and New Zealand.

In August 1939, at the time when the FCC required all shortwave stations in the United States to adopt regularized and approved call signs, CBS redesignated this shortwave transmitter as WCAI. However, two weeks later again, CBS implemented the usage of another call sign, WCAB.

Even though CBS requested the FCC to grant approval for an increase in power to the mandated 50 kW level, this request repeatedly was denied, and shortwave WCAB finally went silent at the end of December 1941. Thus a CBS international voice in Philadelphia was unceremoniously closed, though the international CBS programming was taken over by a new and larger shortwave station located at Brentwood on Long Island.

We concluded our 2007 article in good faith with the following:

“However, that is not the end of the story. The large new international shortwave station at Brentwood was taken into service with OWI-VOA (Office of War Information & Voice of America) programming less than two months later, on Feb. 24, 1942 and the 10 kW unit in Philadelphia was packed up and sent over to England for use by the BBC in London. How interesting it would be to find out what happened to this famous American transmitter while it was in service over there.”

Northern route

We pause now for a moment or two and we introduce the question: What really happened to this historic shortwave transmitter?

Was there some sort of a clue hidden in the information from the memory of station staff in that long-ago era? Had the transmitter actually been transported over to England for use by the BBC? Or was this an item of disinformation intended to cover up real plans for its intended usage?

The Web site for the Broadcast Pioneers of Philadelphia states clearly that the shortwave transmitter was dismantled and sent overseas to aid the BBC war effort.

E-mail communications with colleagues at the BBC in England indicate that they have no record of the usage of this transmitter in England. At that stage, they say, the BBC was using transmitters with a rated power at 100 kW, not 10 kW. They also state that the black propaganda stations in England during World War II were using transmitters rated at 7.5 kW, not 10 kW.

The noted radio historian Jerome Berg states that he has no information regarding the subsequent usage of the 10 kW shortwave transmitter from Philadelphia. Berg has recently released the second and third volumes in an authoritative three-part series on the history of shortwave broadcasting and reception from the beginning right up to our era.

However, as these enquiries were buzzing across the Internet, the Philadelphia radio historian who used to work with the medium-wave and shortwave transmitters at the WCAU complex, Charles Higgins, came across a recent article in QST magazine that provided a solution to the enigma.

The answer? Transmitter W3XAU was in reality sent to a secret location near Toronto in Canada, where it was installed at Camp X for daily communication with Bletchley Park in England.

Camp X

This was a secret spy training facility during World War II, so secret that even the current experienced radio personnel in the area do not know all the answers to this day.

The article in QST magazine, dated January 2006, states that a radio transmitter, code-named Hydra, was installed at Camp X in Canada for secret communication with Bletchley Park in England on 15 MHz; thus it was indeed a shortwave transmitter.

In this article, Gil McElroy states that the original transmitter at Camp X was a 2.5 kW unit and that a 10 kW unit was provided courtesy of WCAU in Philadelphia and subsequently installed.

The only 10 kW transmitter on the air with WCAU during that era was certainly the shortwave relay unit. As a confirmation, the photograph of the 10 kW shortwave transmitter Hydra bears a striking similarity to the 10 kW shortwave transmitter that was previously on the air from suburban Philadelphia as shown on one of their pre-war QSL cards.

Thus, the available evidence indicates that the Philadelphia shortwave transmitter that was “dismantled and sent to England for secret work with the BBC” had instead been installed at secret Camp X near Toronto.

According to William Stephenson in his book “The Secret History of British Intelligence in the Americas, 1940–1945”, the Philadelphia 10 kW transmitter was “overhauled” before its installation as Hydra at Camp X in Canada.

Was it then bad memory on the part of staff that served at the Philadelphia station during World War II that led to the incorrect story? No, not at all; in fact we suggest that they relayed accurately the information that was given to them. Was it a change of plans on the part of senior wartime personnel to have the installation of the transmitter diverted from England to Canada? No, we suggest, not at all.

Was it then a cover up to state that the transmitter would go to England for work with the BBC war effort when it was known that the real intended usage was for Camp X in Canada? In view of the fact that Camp X was such a secret wartime location, we would suggest that this was indeed the real answer.

We might add as far as Hydra is concerned that Camp X was established at Oshawa, 25 miles east of Toronto, and it was opened on Dec. 6, 1941, one day before the infamous attack on Pearl Harbor.


The initial transmitter that was installed at Camp X in mid-1942 for spy communication was a 1 kW unit, apparently medium-wave, that was acquired from Toronto and rebuilt into a 2.5 kW shortwave facility.

The reason for choosing shortwave for communication with England instead of the established undersea cable link was for security purposes; it was feared that German submarines might be able to tap into cable communications. The wireless traffic from North America to England during the Hydra era was usually encrypted with Typex, and subsequently Rockex, cipher machines.

After the 10 kW shortwave unit from Philadelphia was refurbished, it was installed at Camp X in the one large building on the property, a building that had windows placed at 7 feet above ground level, for security reasons. The installation of the larger transmitter apparently was late in the same year, 1942.

Three large rhombic antennas were in use for transmitting to England (and at times to Latin America), and for the reception of incoming shortwave signals. As part of the local coverup, it was stated that the large rhombic antennas were part of a facility for broadcasting the programming of CBC, the Canadian Broadcasting Corp.

The usage of the Hydra shortwave transmitter extended well beyond its original World War II service.

When the war ended, Hydra was taken over by the Royal Canadian Signals as the Oshawa Wireless Station for use during the Cold War. The station was finally closed in 1969, worn out and no longer serviceable.

What ultimately happened to Hydra, the fascinating historical transmitter from Philadelphia, after its World War II and Cold War service in Canada?

In view of the fact that none of the original buildings are left standing at Camp X near Toronto, we guess that the mighty 10 kW shortwave transmitter that had been on the air under the successive call signs W3XAU, WCAI, WCAB and Hydra was simply and unceremoniously scrapped.

For photos of Camp X, see

Dr. Adrian M. Peterson (ex-KA9YPQ) N9GWY is a board member of the National Association of Shortwave Broadcasters. Since 1944 he has written several thousand articles on radio history, published in 25 languages.