Homebrewing With Vacuum Tubes
"Glowbug" is a term used by US amateurs to describe a simple home-made tube-type radio set, reminiscent of the shortwave radio-building craze of the 1920s and 30s. Classic glowbug designs from that era include the famous twin triode Doerle regenerative receiver and single-tube Hartley, TNT and TPTG transmitters. "Glow" refers to the glow of the vacuum tubes and "bug" to the gear's relatively diminutive size. Generally, any small, home-built tube-type transmitter or receiver may be referred to as a glowbug. The majority of glowbug transmitters are designed to be used in the CW radiotelegraphy mode. A number of radio amateurs also build their own tube receivers and AM voice transmitters.
As late as the 1960s, glowbugs were part of many beginner ham stations, and the ARRL Radio Amateur Handbook for those years exhibited a number of such simple, tube-based designs. Today, glowbugs are enjoying a resurgence of interest among QRP enthusiasts and others with a penchant for constructing their own equipment. A growing number of hams are "getting back to their roots" by assembling glowbugs on steel chassis, tin cakepans, and wooden boards, and putting them on the air. Amateur radio glowbug enthusiasts can often be heard communicating on the shortwave bands via CW using Morse code. A popular frequency to hear glowbug contacts is 3.57950 MHz. Simple oscillators for this frequency can be built with common NTSC color burst oscillator crystals, which operate at 3.579545 MHz.
Read more about this topic: Amateur Radio Homebrew
Famous quotes containing the word vacuum:
“Teenagers who are never required to vacuum are living in one.”
—Fred G. Gosman (20th century)