Rudy Severns: Lifetime Achievement Award Winner

Sep 1, 2008 12:00 PM
By David Morrison, Editor in Chief

First Steps in Electronics

Like many who eventually took up electrical engineering, Severns had an early interest in electronics that was sparked by an interest in radio, particularly short-wave radio Around the age of 12 or 13, Severns began experimenting, building crystal sets and one-tube receivers. These early activities even gave him his first experience with power electronics.

At one point, Severns had obtained a war-surplus aircraft receiver for $5, but it required aircraft power to operate. So, he built his first power supply, consisting of a line-frequency transformer and tube rectifiers, which would provide the filament and plate power required by his receiver. Reflecting on that unregulated power supply, which he built in the ‘50s, Severns notes, “It was very much the technology of the day.”

From short-wave radio listening and experimenting, Severns made the natural transition to amateur radio after one of his high-school teachers introduced him to a local ham. That radio amateur helped him learn Morse code (continuous wave or CW, in ham parlance) and study for a ham license. After passing the tests, Severns got his first ham license at the age of 16 and became active as an amateur radio operator.

At 17, that experience opened the door for him to become a radio operator in the naval reserves, which he was encouraged to join by a neighbor who was an officer in the reserves. His status as a ham gave Severns advanced standing in the naval reserves because the technology used by amateur radio operators was close to the technology of the day in terms of how the Navy communicated.

After graduation, Severns spent a summer living with his grandfather in Berkeley, Calif., and attending a University of California, Berkeley summer session. Although he did well academically, Severns decided he was not emotionally ready for college and, knowing that he would have an obligation for military service, decided to enlist.

Although his initial intent was to join the Navy, he soon discovered that the Navy, which was ramping down in the wake of the Korean War, did not need radio operators. However, the Army did, particularly in the Special Forces units. So, Severns soon found himself shipping off to Fort Bragg, N.C., where he would train with the 77th Special Forces Group. After about 15 months there, he was reassigned to the 10th Special Forces Group in Bad Tolz, Germany.

Though his radio skills were his ticket into the Special Forces, where he was surrounded mostly by much more seasoned soldiers, radio communications were not his only responsibility. The main objective of the group was to master the skills of guerilla warfare, so in times of war, they could go behind enemy lines and organize local partisan groups to fight.

Consequently, as a member of a Special Forces unit, Severns trained in the use of all types of weapons and learned demolitions. That training wouldn’t translate into anything he could use later as an engineer. Nevertheless, the danger of the work would require special care, a theme that would be echoed in his later work in high-voltage electronics.

A Quick Start in Engineering

After his three year stint in the Army was over, Severns was ready to start college. However, he would quickly find himself with other responsibilities, as well. In the fall of 1960, Severns began working, enrolled in college, got married and started a family. As if that wasn’t enough, the requirements for becoming an engineer had changed, having gotten stricter in the four years since he graduated high school.

To get into an engineering program, Severns had to prove himself by getting high grades in required courses. He did so during his first year of college at San Francisco State, during which time he was also working as a technician at UC Berkeley’s cyclotron particle accelerator. While working at Berkeley, he learned about the engineering program at UCLA and how it was closely tied in with the aerospace industry in Southern California.

So, wanting a practical, industry-oriented education, Severns enrolled in UCLA’s engineering program. Although UCLA allowed students to specialize in a particular area, it offered a general engineering program rather than an electrical engineering (EE) program. As a result, Severns found himself studying a diverse range of non-EE subjects such as soil mechanics and how to build dams.

However, Severns didn’t simply follow a prescribed curriculum, he “worked the system” to tailor his studies to his interests. “Because I was much older than the majority of students in my grade level and had a lot of practical experience, the dean allowed me to skip many of the required lab courses and in their place take many extra electrical engineering classes and math classes. I graduated with 156 semester hours.”

Much of that additional coursework was in electromagnetic, including a class in magnetic amplifiers (mag amps). “By that time, I was really interested in RF and power,” says Severns. The engineering studies came naturally to Severns. “For me, the real trouble was having to work and raise a family. The engineering was just fun. To this day, I do it for fun.”

Throughout his time in college, Severns worked to pay his way and support his family. That included taking a year off in 1962 to work for Philco Ford, which sent him to Indonesia to install and operate a tropospheric forward scatter system — a precursor to satellite-based systems. This system would provide high-bandwidth radio communications for the Indonesian army across the country’s chain of 1000 islands.

After that experience, Severns returned to school and to his jobs as a technician (and later, junior engineer) at various particle accelerator labs such as UCLA’s cyclotron and CalTech’s synchrotron. In these jobs, he designed and built RF amplifiers, pulse modulators and power supplies. These were mostly tube-based designs because of the voltages and power levels involved. For example, a power supply operating off-line might be needed to generate 50 kV at 10 A using a transformer and multiphase tube rectifier.

The work was dangerous and much of the design challenge related to maintaining safety. “When you’re working at high power levels and you make a mistake, things blow up. Lots of smoke and flames to inform you of your mistakes,” says Severns.

But around this time, the early ‘60s, there was the shift in technology to solid-state that affected even the high-voltage area. For example, in the particle accelerator applications on which Severns worked, devices like mercury-vapor rectifier tubes were being replaced by silicon “door-knob” rectifiers from the likes of Unitrode. These rectifiers were stacked to achieve the necessary voltage ratings.

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