First-Hand:Milton Kant 2007 War Story for the 50th Anniversary Celebration of the EMC Society


Submitted by Milton Kant

I'll go back pretty much to the beginning of my career in EMC which was at Sperry Gyroscope Company.  In those years Sperry was an equipment manufacturer; they made all types of equipment from airborne systems; airborne systems including control systems for drones.  They made navigation systems for aircraft; they made ground equipment; They made high-powered radar for ground systems or ship-boards and they also made submarine equipment.  They were the subcontractor for the Polaris submarine navigation system so our RFI lab started out as a measurement facility.  Once you start making RFI measurements, you end up also helping to fix any problems that you might come up with for the equipment that is out of spec.    You end up learning how to filter unwanted signals, suppress interference, and shield equipment.  This led in turn to trying to educate the design engineers that they should design the EMI suppression and shielding requirements into their equipment as part of the equipment design.  

We used to hold classes for design engineers to try to teach them the basics of EMI design.  Not only was it important to do the design correctly but it was also economical. To try to fix a piece of equipment after it's been designed and pre-production equipment built and gone through tests; to try to change the design after that effort is much more expensive than the effort that is taken during the design to make sure that you analyze the equipment and put the fixes in during design.  Most of the design and circuit engineers at Sperry would only be interested in getting the equipment to work in terms of performance characteristics.  The requirements for interference, reliability, and all the other environmental requirements were usually just an afterthought. That attitude was prevalent throughout the industry.  One of the reasons for forming the EMC Society (for Radio Frequency Interference – RFI) was to try to educate design personnel. By education, we didn't mean educating ourselves, which was part of it, but educating the people who designed the equipment, the equipment designers.  At the time we started, one of the missions of the EMC Society would be to hold sessions during other society symposiums to try to put this concept forth.  A good part of my work at Sperry was trying to educate the equipment designers.

One of the examples I can recall, among the many, deals with submarines.  The Aegis system had a computer, which at that time, was still a tube computer; it used electrical tubes.  They were using a clock bus in the megahertz range, two to four megahertz, around there.  That bus was running around all the equipment.  Naturally, when they tried to meet the spec, the signal was radiating all over the place.  A good effort was made to try to contain clock frequencies within computers and not let them radiate.  Once again, the designers weren't interested in that.  They just knew they needed the clock frequencies to be sent all around their system and how to use them in operation of the computer.

Another facet of this, another example that people didn't understand and still have problems with today, is when equipment is being interfered with from the intentional and desired radiation from a transmitter such as a radar. We were building high powered radars which were being sited across the country as part of the early warning system.  There was a site out at Mantioch, Long Island; they were getting complaints that people were picking up the radar on the radio and hi-fi systems out there.  Another site in Michigan was interfering with a control tower in a nearby airport.  We would go outto the sites. We would check the radiated characteristics of the radar signal to make sure that it meets the requirements and that the harmonic levels were sufficiently low.  We made field measurements and we found out that the radar signals were within the allowable specifications.  Then, you have to convince people that it's not the problem of the transmitter, the design of the audio equipment was the problem. The audio equipment was susceptible to these high-powered radars which supposedly indicated that no audio equipment was tested for susceptibility characteristics, especially commercial equipment.  Which is being remedied these days; I think there is much more awareness of the fact that all of the new electronic equipment is susceptible to high-powered radiations.

My work at Sperry was a good education for me.  When I left Sperry, I went to RCA to work on the Aegis system.  My experience at Sperry, of course, contributed to my work I was doing there. This led to RCA finally being given the Ship Integration responsibility for the Aegis systems, which included the top side design of the whole system: the whole ship.   With EMC being an important part of that, EMC Engineers were given a lot of that responsibility to locate antennas and for the design of the ship.  The Aegis Destroyer not only had the EMC requirements, it had for the basic systems a very high-powered radar. It made it a challenge to make sure all of the other systems on the ship could operate when the radar was operating.  The ship also had all kinds of survivability requirements and low radar cross-section requirements.  So our RF experience as an EMC engineer helped in doing Othello locations, in the ship design characteristics because even at the beginning, even when I think back to Sperry, EMC engineers were considered magicians.  It was an art, black art to a lot of people.  They just didn't know about it.   Part of our development included being able to get more of an engineering approach to the subject.  This led to the development of all the miracle codes and everything they used for antenna location and ship hull design.  I ended up in a position where, due to my EMC background, I could really contribute to the whole top-side design of the Aegis ships.  The culmination of that work was attending the commissioning of the first DD51 Cruiser in 1991, which was just before I retired.  I worked on Aegis for about 22 years.  I applied much of the knowledge that I learned before that at Sperry.  That is a good summary of my career. I don't know if you would call that a war time story or not, but that is it.