Who Was K6BJ?

by Wayne Thalls KB6KN SK

There are special reasons why the Santa Cruz County Amateur Radio Club station uses those particular call letters. The call memorializes one of the early giants of ham radio in the U.S., John L. Reinartz (JL, 1XT, 1XAM, 1QP, K6BJ)

John L. Reinartz was born in Germany in 1894, the oldest of seven children. In 1904 the family migrated to America, where they settled on a Connecticut farm. 

When he was 14 years old, John became interested in the new science of wireless. He erected a 600-foot wire between treetops and went on the air with a spark-gap station.  In these days, before government licensing, it was common for experimenters to use their initials as call letters. John chose to use JL as his call.

Ten years later, during World War 1, Reinartz taught wireless to military radio operators. He was one of the large numbers of amateurs who joined in the military effort. The ARRL was even forced to suspend publication of QST during the war when the editor was called to service in the Army Signal Corps.  

New Designs

Around 1921 John Reinartz developed a new receiver circuit, called the Reinartz Tuner. The unit had an unheard of tuning range from 200 meters down to 28 meters. Construction information was published in QST and numerous other magazines. Thousands of experimenters built the receiver. It was the predecessor of modern day multi-band receivers.


This schematic shows an improved version of the receiver as described in QST for March 1922.

In 1921 Reinartz began publishing a free magazine, How to Build Receivers and Transmitters at Low Cost. Throughout the twenties he was a prolific contributor to QST, Radio News and other magazines. Many of his articles dealt with improvements to his Reinartz Tuner.

With the coming of federal licensing of radio stations, John was assigned the calls 1XAM and 1QP. On November 27, 1923 the first successful two-way trans-Atlantic amateur communication took place. 1XAM was one of three stations participating in this feat. 1XAM and 1MO were in the U.S. and 8AB was located in France. All three stations utilized Reinartz designed transmitters and receivers.

This photo accompanied a story of the event, which appeared in Radio News for February 1924. 


The October 1924 issue of QST reported that 1XAM was copied solid in Australasia (Australia/New Zealand) on May 29 of that year. Reinartz was operating CW at 108 meters, running 1 KW input.

Understanding Why

Propagation of radio waves was not well understood. Reinartz was driven to achieve ever-increasing communication range. To achieve this he conducted numerous studies of antennas and of propagation during the early and mid nineteen twenties. He devoted much of his effort to solving the problem of skip in short wave communications. His article Reflection Theory of Short Waves was published in the April 1925 issue of QST. He presented an engineering explanation of the phenomena of wave propagation. 

In 1925 Reinartz set a new record for DX by communicating with 6TB in Santa Monica, California on 20 meters at high noon. 

Reinartz’ work attracted the attention of the U.S. Navy. He was recruited as radio operator for an expedition to the North Pole in June of 1925. Commander MacMillan, USNR, headed this project. 

Reinartz designed the short wave radio gear used aboard the expedition ship Bowdoin. The second in command of the expedition was Commander E. F. MacDonald, Jr., president of Zenith Radio Corporation, who was stationed aboard the Neptune. Neptune was equipped with marine radio gear produced at Zenith Laboratories. Reinartz collaborated in the design of the Zenith equipment. 

He joined RCA in the early thirties. There he conducted further research on radio propagation and short waves. He was called to active duty by the Navy in 1938 and given the task of assembling a corps of experienced radio personnel. He drew heavily upon the ham community.

One stateside city was in daily contact with Reinartz and the Arctic explorers. In Cedar Rapids, Iowa a young high school student, named Arthur Collins, maintained daily schedules from his amateur station 9CXX. Collins later established the radio company that bore his name. It was a long-time producer of high quality amateur and commercial radio communication equipment.   

The Bowdoin was the flagship of the expedition.

 Two radio-equipped airplanes played a key role in the exploration. Air operations were under the command of Lt. Commander Richard E. Byrd, USN. In the 1930’s Admiral Byrd became renowned for his own Arctic and Antarctic exploration.

Following the Arctic expedition, Reinartz did further radio research and experimentation for the Navy. In 1929 he was rewarded for his work with a commission as a Lieutenant in the Naval Reserve.

He joined RCA in the early thirties. There he conducted further work on radio propagation and short waves. 

Reinartz served in numerous positions during his Navy service. Among other assignments, he conducted radio and radar research. Captain Reinartz was discharged at the end of the war. He returned to RCA in 1946. 

Reinartz held 28 patents. His work encompassed many areas. He developed a super-regenerator receiver, which offered improved VHF reception; his loop antenna design was used in microwave radar; his design for high efficiency tuned circuits was used in transmitters. He also developed equipment for aerological and meteorological studies. In 1958 he was named a Fellow in the Institute of Radio Engineers—now the IEEE. 

In 1949 John retired from RCA. He moved west to join Eimac, as manager of their Amateur Service Department. Upon his retirement in 1960 John and his XYL, Gertrude K6MJH, moved to Aptos. They became members of this club. 

Captain John L. Reinartz, K6BJ, became a silent key on October 5, 1964 at the age of 70. He is buried at Golden Gate National Cemetery. Not only was John an important figure in the development of radio communications, he also represents the American story—youthful immigrant who pulls himself up by his bootstraps and then makes significant contributions to his adopted country.

The Santa Cruz County Amateur Radio Club applied to the FCC for the call K6BJ following the death of this illustrious member. Local 440 and 2 M repeaters operate under the call as memorial stations dedicated to the memory of Reinartz, and his fellow ham experimenters who paved the way for long distance short wave communications.  

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