Hiram Percy Maxim was an American radio pioneer and inventor, and co-founder of the American Radio Relay League

American Radio Relay League

The American Radio Relay League is the largest membership association of amateur radio enthusiasts in the USA. ARRL is a non-profit organization, and was founded in May 1914 by Hiram Percy Maxim of Hartford, Connecticut...

 (ARRL). He originally had the amateur call signs

Call Signs

Call Signs is the third studio album by Melbourne electronica band Black Cab, released in 2009.The album evokes the atmosphere of the former totalitarian state of East Germany, set to a soundtrack of post-punk and atmospheric electronics. In an interview, the band explained the album's sound was...

 SNY, 1WH, 1ZM, (after World War I) 1AW, and later W1AW

W1AW

W1AW is both the amateur radio call sign and the primary operating station of the American Radio Relay League . This station, which is commonly called the Hiram Percy Maxim Memorial Station, is located on the grounds of ARRL Headquarters in Newington, Connecticut. It was inspired by Maxim's 1AW...

, which is now the ARRL Headquarters club station call sign. His rotary spark-gap transmitter

Spark-gap transmitter

A spark-gap transmitter is a device for generating radio frequency electromagnetic waves using a spark gap.These devices served as the transmitters for most wireless telegraphy systems for the first three decades of radio and the first demonstrations of practical radio were carried out using them...

 "Old Betsy" has a place of honor at the ARRL Headquarters.
He was the son of Sir Hiram Stevens Maxim

Hiram Stevens Maxim

Sir Hiram Stevens Maxim was an American-born inventor who emigrated to England at the age of forty-one, although he remained an American citizen until he became a naturalized British subject in 1900. He was the inventor of the Maxim Gun – the first portable, fully automatic machine gun – and the...

, inventor of the Maxim Machine gun

Maxim gun

The Maxim gun was the first self-powered machine gun, invented by the American-born British inventor Sir Hiram Maxim in 1884. It has been called "the weapon most associated with [British] imperial conquest".-Functionality:...

. In addition, he was the nephew of Hudson Maxim

Hudson Maxim

Hudson Maxim , was a U.S. inventor and chemist who invented a variety of explosives, including smokeless gunpowder. He was the brother of Hiram Stevens Maxim, inventor of the Maxim gun and uncle of Hiram Percy Maxim, inventor of the Maxim Silencer.Maxim was a man of many talents...

, an inventor of explosives and ballistic propellants.