Institute for Telecommunication Sciences / October 1925

October 1925: First Radio Test Car Placed into Service

In October of 1925 the Department of Commerce’s first radio test car was put into operation by the National Bureau of Standards Radio Division. The test car was equipped with wavemeters, omnigraphs, sensitive receivers, a radio direction finder, a field intensity measurement system, and other equipment. It was also fitted out to act as an office, with a typewriter, desk, and a 50 watt transmitter for emergency communications. The test car quickly became an invaluable tool for testing radios on ships, administering tests for radio operators, and verifying the frequency and power of commercial stations. Before the radio test car members of the Radio Division were forced to pack the sensitive equipment into boxes stowed in vehicles, and unpack on-site to perform their work. This was the first of many incarnations of radio cars used by researchers in the National Bureau of Standards Radio Division its successor laboratories. In the 1960s, the Central Radio Propagation Laboratory operated a Mobile Noise Lab from a trailer that could be driven around the country. In 1973 the first Radio Spectrum Measurement System (RSMS) vehicle was built on an RV chassis by Hewlett Packard for the Institute for Telecommunications Science and deployed to test spectrum use by government and commercial broadcasters. The current generation vehicle is the RSMS 4 truck, commissioned in 2003, and RSMS now also includes convenient and versatile “suitcase” systems that are designed to be easily portable. Today's RSMS suite is far more versatile and collects hundreds of times more information than the original 1925 radio test car.