Boatanchor Legends · Tribute No. 41

Warren B. Bruene, W5OLY

The Quiet Engineer Who Made Single Sideband Practical

If you have ever spoken into a Collins KWS-1, listened on a 75A-4, run a 30L-1 or 30S-1 amplifier, watched a Bruene-coupler wattmeter swing on the way to centring the SWR null, or simply enjoyed an evening of single-sideband ragchew on the HF bands, you owe a quiet debt to Warren Bruene. He spent forty-four years at Collins Radio, held twenty-two patents, designed the transmitters that gave the Strategic Air Command and the Voice of America their reach, and was the engineer Art Collins personally selected to author the report that put SSB on its industrial footing. He did all of it, by every account, without ever raising his voice.

Cedar Rapids, 1939

Warren Bruene walked into Collins Radio in 1939, at the tail end of the Depression, with an Iowa State engineering education and the call WØTTK. He married Mildred Meyer in Cedar Rapids in July 1941. By December the country was at war and Warren was buried in Navy ground-transmitter design — the equipment that, in his colleagues’ understated phrasing, helped win the Second World War. He would remain at Collins through the post-war commercial expansion, the move of the SSB business to Texas, the merger with Rockwell, and his own retirement, before adding another six years at Electrospace Systems. Forty-four years at one company, eight broadcast bands of engineering history.

The Team of Nine

In the early 1950s, Collins had two pieces in hand that nobody else had assembled together: stable mechanical filters and the kind of low-noise, drift-free oscillator work that would later become the company’s signature. Art Collins decided to find out what could be done with them. He pulled together nine engineers and pointed them at the problem of making single-sideband voice communication practical for general military, commercial and amateur use. Warren Bruene was one of those nine.

The 1952–53 investigation produced the circuit topologies, the IMD measurement methods, the linear-amplifier feedback techniques, and the operating procedures that the SSB industry would run on for the next two decades. Art Collins selected Warren personally to write the report, which was published in May 1954. From that report flowed an extraordinary catalogue of equipment, much of it with Warren’s name on the schematic.

Each one of those projects was, in its own right, a significant piece of engineering. Taken together, they describe a man whose work touched the bench of nearly every serious HF operator alive.

The 3-400Z Story

There is a small anecdote that captures Warren’s working method better than any list of patents. Warren’s team had an engineering prototype of the 30L-1 desktop linear on the bench, running a pair of old type 811A triodes. Bill Eitel of Eimac happened to be in town for an IRE convention and dropped by. Eitel could not stand to see those old triodes in a modern Collins amplifier. Warren, in his usual quiet way, told Eitel that he and his team would happily use a nice new Eimac tube — provided Eimac could build a zero-bias triode equivalent to a pair of 811s, short enough to fit in the 30L-1 chassis, at no more than twice the price of a pair of 811As.

Eimac built samples. The distortion was initially poor, but the design was refined, the geometry settled, and the result was the Eimac 3-400Z — a tube that, in its own form or as the 3-500Z derivative, still glows under the chassis of more ham linear amplifiers than any other power triode in history. It exists because Warren Bruene wrote a one-paragraph specification on the back of an afternoon conversation. He did the same favour for the industry later, writing the spec that produced the Eimac 4CX5000A ceramic tetrode after his team had pushed a parallel-trio of 4-1000As to the limits in a 5 kW SSB transmitter.

The Bruene Coupler — and the Conjugate-Match Argument

In April 1959, QST carried Warren’s article on a new directional-coupler topology. The circuit used a current-sampling toroidal transformer and a voltage-sampling capacitive divider to produce clean forward and reflected indications across a wide frequency range. Collins put it into the 302C wattmeter the following year. Within a decade the Bruene coupler was the de facto reference design for SWR meters across the amateur, commercial and military markets. If you have ever tuned an antenna, you have used Warren’s circuit.

Less universally celebrated but no less important was Warren’s long quarrel with the “conjugate match” school of transmission-line theory. From inside a career that spanned 250 mW exciters to 250 kW transmitters, Warren maintained that no professional RF engineer he had ever met actually designed a transmitter by consciously applying the conjugate-match concept — that the real design problem was matching a 50-ohm load to the plate, collector or drain load-line resistance needed for a specified output power at a specified IMD, and that the conjugate-match formulation was a teaching simplification mistaken for a design tool. The debate ran for years in the pages of QST and on the air. Warren never raised his voice in it either.

The CCA Years

Warren and Mildred moved to Richardson, Texas in 1964, when Collins consolidated much of its commercial transmitter work there. He became a fixture at the Richardson Wireless Klub and, after his retirement, at the Collins Collectors Association. In April 1992 the CCA secured him as guest speaker for its second annual Dayton Hamvention forum. His afternoon presentation, “Art Collins, Power Amplifiers and RF Output Network,” appeared in the May 1992 issue of the Collins Collectors Magazine. That evening, at the Radisson banquet, he gave a second talk — “Anecdotes about Art Collins and the Collins Radio Company” — drawn from personal friendship with Art and four decades inside the company. CCA founders Bill Wheeler KØDEW, Floyd Soo KF8AT and Jay Roman KBØATQ later described the 1992 forum as the pivotal event that formalised the Collins Collectors Association. Warren’s presence gave it its credibility.

Recognition

Iowa State University awarded Warren its Professional Achievement Citation in Engineering. He served on standards committees for the FCC, the Department of Defense, and other industry bodies, and he wrote and lectured throughout his career. He was a longtime member of the IEEE, the Richardson Wireless Klub, the Collins Collectors Association, and Toastmasters. In 2014, the year after his Silent Key, CQ Magazine inducted him into its Hall of Fame, and the Richardson Wireless Klub renamed its highest honour the Warren Bruene Award, given annually at the President’s Dinner to the member judged to have rendered the most outstanding service to the klub.

Silent Key

Warren B. Bruene became a Silent Key on 28 September 2013, in Richardson, Texas, at the age of ninety-six. A memorial service was held on 3 October at the First United Methodist Church in Richardson.

The body of work that he left behind is, in the most precise sense, foundational. Any reasonable history of single-sideband communication must place the 1952–53 Collins investigation at its centre, and Warren’s May 1954 report at the centre of that. Any reasonable history of HF linear-amplifier design has to account for the 30K, the 30L-1, the 30S-1, and the 204/205 series. Any list of indispensable shack accessories has to include the Bruene coupler. Any account of the 3-400Z and 3-500Z tubes that have powered amateur amplifiers for six decades has to end with a quiet conversation in a Collins lab in the late 1950s.

Warren never claimed the title of “father of SSB,” and was content to let others use it or not. The work itself was sufficient. It still is.