Made in the USSR: microwave
In general, in laboratory conditions, microwaves for heating various substances began to be used back in the 1920s. And at the 1933 Chicago World's Fair, Westinghouse Electric's booth showed food heating between two metal plates connected to a microwave transmitter.
In 1945, physicist Percy Spencer, an employee of Raytheon, investigated in detail the possibilities of microwaves for heating, developed and patented a modern type of microwave oven with an enclosed space for food, using a compact magnetron of its own design as a wave source.
In 1947, Raytheon launched Radarange, the first microwave oven for commercial use. She was 1.8 meters tall, weighed 340 kg and cost $ 5, 000 ($ 52, 988 today). Before the sixties, other companies began to produce microwaves, but the devices remained expensive and heavy - they were used exclusively on an industrial scale, for example, in restaurants. The first attempt to build a home-use oven was the 1955 Tappan model, but the first really widespread microwave ovens were the Raytheon of 1967 (they cost only $ 495 or $ 3, 513 for today's money and were slightly larger than modern ones).
And in the USSR, the first microwave ovens began to be produced at the very end of the 1970s. True, in very small batches (they were always in short supply) and for a lot of money.
How many exact models were produced in the USSR is difficult to establish. On the web you can find traces of 23 models:
1. Electronics SP-01 2. Electronics SP-10 3. Electronics SP-18 4. Electronics SP-23 5. Electronics SP-23 ZiL (produced at the ZiL factory) 6. Electronics SP-25 7. Electronics SP-27 8 Dneprjanka-1 9. Dneprjanka-2 10. Mriya 11. Mriya-MV 12. Temp 13. Pluto 14. Volzhanka 15. Rado-Gourmet 16. Electronics SP-25 17. Fairy 18. Bereginya 19. Yukon 20. Lena 21 Mila 22. Mila-2 23. Yuzhpolymetal