A nearly 100-year-old inference problem was caused by radios using “positive feedback” which is found in oscillator circuits that are at the heart of today’s amateur radio equipment. This picture is of a radio direction-finding truck used by the British Post Office in 1927 to find illegal radio transmissions. At the time, the post office regulated radio communications in Britian. The truck was used to track down radio transmitters operated by unlicensed radio amateurs. It was also used in London to track down “bloopers” – regenerative radio receivers that produced interference.
Continue reading “The Shrieks and Howls of “Bloopers””