Hilmer Irvin Swanson (July 25, 1932

Davenport, Iowa Davenport ( ) is a city in Scott County, Iowa, United States, and its county seat. It is situated along the Mississippi River on the eastern border of the state. Davenport had a population of 101,724 as of the 2020 United States census, 2020 cen ...

– July 21, 2005

Quincy, Illinois Quincy ( ) is a city in Adams County, Illinois, United States, and its county seat. Located on the Mississippi River, the population was 39,463 as of the 2020 United States census, 2020 census, down from 40,633 in 2010. The Quincy, Illinois, mic ...

)Hilmer Irvin Swanson 1932 - 2005
, Barry Mishkind – the Eclectic Engineer, theBDR.netHilmer Swanson Dies
RadioWorld, July 22, 2005, accessed April 18, 2012
radiolists.net, July 23, 2005, accessed April 18, 2012 was an American radio engineer who developed several leading, patented techniques for

broadcast radio Radio broadcasting is the broadcasting of audio (sound), sometimes with related metadata, by radio waves to radio receivers belonging to a public audience. In terrestrial radio broadcasting the radio waves are broadcast by a land-based ra ...

Amplitude modulation Amplitude modulation (AM) is a signal modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the instantaneous amplitude of the wave is varied in proportion t ...

(AM) while working for

Harris Corporation Harris Corporation was an American technology company, defense contractor, and information technology service (economics), services provider that produced wireless equipment, tactical radios, electronic systems, night vision device, night visi ...

Early years and education

Swanson was educated in his home town of Davenport, Iowa, from a rural one room school house to high school. He was then drafted into the

U.S. Army The United States Army (USA) is the primary land service branch of the United States Department of Defense. It is designated as the Army of the United States in the United States Constitution.Article II, section 2, clause 1 of the United Stat ...

during the

Korean War The Korean War (25 June 1950 – 27 July 1953) was an armed conflict on the Korean Peninsula fought between North Korea (Democratic People's Republic of Korea; DPRK) and South Korea (Republic of Korea; ROK) and their allies. North Korea was s ...

and served with the 10th Army Mountain Division at

Fort Riley, Kansas Fort Riley is a United States Army installation located in North Central Kansas, on the Kansas River, also known as the Kaw, between Junction City and Manhattan. The Fort Riley Military Reservation covers 101,733 acres (41,170 ha) in Ge ...

. The Army

Signal Corps A signal corps is a military branch, responsible for military communications (''signals''). Many countries maintain a signal corps, which is typically subordinate to a country's army. Military communication usually consists of radio, telephone, ...

sent him to its school at Fort Gordon, where he graduated with honors. Hilmer was assigned to Fort Huachuca where he was involved with AM transmitters with the US Army Electronic Proving Ground (EPG), and began his career in

radio Radio is the technology of communicating using radio waves. Radio waves are electromagnetic waves of frequency between 3 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transmitter connec ...

. Upon demobilization with an honorable discharge on June 25, 1953, he went to Indiana and worked briefly with Bendix, then attended Valparaiso's

Technical Institute An institute of technology (also referred to as technological university, technical university, university of technology, polytechnic university) is an institution of tertiary education that specializes in engineering, technology, applied science ...

(closed 1991), and was awarded the degree of

Bachelor of Science in Electrical Engineering A Bachelor of Engineering (BEng) or a Bachelor of Science in Engineering (BSE) is an undergraduate academic degree awarded to a college graduate majoring in an engineering discipline at a higher education institution. In the United Kingdom, a Bac ...

. He then was awarded the degree of Master of Science In Electrical Engineering from

Iowa State University Iowa State University of Science and Technology (Iowa State University, Iowa State, or ISU) is a Public university, public land-grant university, land-grant research university in Ames, Iowa, United States. Founded in 1858 as the Iowa Agricult ...

on February 4, 1959.

Working life

Swanson worked for

Collins Radio Rockwell Collins, Inc. was a multinational corporation headquartered in Cedar Rapids, Iowa, providing avionics and information technology systems and services to government agencies and aircraft manufacturers. It was formed when the Collins Radio ...

Cedar Rapids, Iowa Cedar Rapids is a city in Linn County, Iowa, United States, and its county seat. The population was 137,710 at the 2020 United States census, 2020 census, making it the List of cities in Iowa, second-most populous city in Iowa. The city lies o ...

and

Dallas, Texas Dallas () is a city in the U.S. state of Texas and the most populous city in the Dallas–Fort Worth metroplex, the List of Texas metropolitan areas, most populous metropolitan area in Texas and the Metropolitan statistical area, fourth-most ...

before joining Gates Radio in Quincy Illinois, which was later bought by

. Swanson worked for Harris for 35 years until retirement in 1999, primarily on the design of high efficiency

amplitude modulation Amplitude modulation (AM) is a signal modulation technique used in electronic communication, most commonly for transmitting messages with a radio wave. In amplitude modulation, the instantaneous amplitude of the wave is varied in proportion t ...

(AM)

transmitter In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna (radio), antenna with the purpose of sig ...

s. His work led to a series of

patent A patent is a type of intellectual property that gives its owner the legal right to exclude others from making, using, or selling an invention for a limited period of time in exchange for publishing an sufficiency of disclosure, enabling discl ...

s on various types of high efficiency modulation, and led to the first commercial implementation of pulse duration modulation (PDM) system,Digital AM Transmitter Page
Jim Hawkins' Radio 77 WABC, date unknown and later progressive series modulation (PSM), polyphase PDM, and digital amplitude modulation. Swanson's patents led to almost all AM broadcast transmitters being designed using digital modulation techniques, and made AM

vacuum tube A vacuum tube, electron tube, thermionic valve (British usage), or tube (North America) is a device that controls electric current flow in a high vacuum between electrodes to which an electric voltage, potential difference has been applied. It ...

transmitters obsolete. Swanson designed and developed a 2 Million Watt transmitter for the Voice of America. It still stands as the world's most powerful AM Broadcast transmitter ever made. One of his last works was a paper, "Performance of Modern AM Modulation Methods for Linear Digital Broadcast Applications," co-authored with John DeLay.

Honors

Swanson was a made a Harris Fellow, the highest honor given to an employee of that company. After retirement, Harris created a scholarship in Swanson's name at the John Wood Community College in Quincy, Illinois for the study of radio broadcast technology. Phillip W. Farmer, former Harris Chairman, President and CEO, said, "Mr. Swanson, a Senior Scientist at the Broadcast Communications Division has become a radio engineering legend in his own time. It is believed that no one has contributed more to the advancement of AM broadcast radio transmitters than Hilmer Swanson. Most famous are his PDM and PSM modulation techniques, and his "Crown Jewel"—the digital AM generation technology for Harris' DX series AM broadcast product Line." In 1990, Swanson received the

National Association of Broadcasters The National Association of Broadcasters (NAB) is a Industry trade group, trade association and lobbying, lobby group representing the interests of commercial and non-commercial over-the-air radio and television broadcasting, broadcasters in th ...

Engineering Achievement Award. He was an honorary member of

Society of Broadcast Engineers The Society of Broadcast Engineers (SBE) is a professional organization for engineers in broadcast radio and television. The SBE also offers certification in various radio frequency and video and audio technology areas for its members. Backgrou ...

(SBE), and a life member of

Institute of Electrical and Electronics Engineers The Institute of Electrical and Electronics Engineers (IEEE) is an American 501(c)(3) public charity professional organization for electrical engineering, electronics engineering, and other related disciplines. The IEEE has a corporate office ...

(IEEE) and the

Sigma Xi Sigma Xi, The Scientific Research Honor Society () is an international non-profit honor society for scientists and engineers. Sigma Xi was founded at Cornell University by a faculty member and graduate students in 1886 and is one of the oldest ...

Science Honor Fraternity. Swanson was awarded at least 28 patents in at least six countriesSwanson Hilmer I - Inventor
patentmaps.com, accessed 18 April 2012

Later life

In his retirement, Swanson and his wife, Carolyn, performed

missionary A missionary is a member of a Religious denomination, religious group who is sent into an area in order to promote its faith or provide services to people, such as education, literacy, social justice, health care, and economic development.Thoma ...

work in

Palau Palau, officially the Republic of Palau, is an island country in the Micronesia subregion of Oceania in the western Pacific Ocean. The Republic of Palau consists of approximately 340 islands and is the western part of the Caroline Islands ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

and

Estonia Estonia, officially the Republic of Estonia, is a country in Northern Europe. It is bordered to the north by the Gulf of Finland across from Finland, to the west by the Baltic Sea across from Sweden, to the south by Latvia, and to the east by Ru ...

working to establish

Christian A Christian () is a person who follows or adheres to Christianity, a Monotheism, monotheistic Abrahamic religion based on the life and teachings of Jesus in Christianity, Jesus Christ. Christians form the largest religious community in the wo ...

AM broadcast radio stations. He was survived by three sons, a daughter, and their families.

References

{{DEFAULTSORT:Swanson, Hilmer 1932 births 2005 deaths United States Army personnel of the Korean War Iowa State University alumni American electronics engineers American Protestant missionaries Protestant missionaries in Palau Protestant missionaries in Chile American expatriates in Palau American expatriates in Chile American expatriates in Estonia Protestant missionaries in Estonia 20th-century American engineers 20th-century American inventors John Wood Community College people Bendix Corporation people