This heterodyne resonance indicator is a must-have for any signal generator enthusiast. Made in the USSR in 1979, this vintage piece of equipment is a great addition to any collection. It is perfect for measuring and inspecting signals, and is sure to come in handy in any business or industrial setting. Whether you're a seasoned professional or a hobbyist, this signal source and conditioning device is a true gem. Don't miss out on the opportunity to own a piece of history.