Production
The US military told National, "Start building HROs. We'll tell you when to stop.". Before, during, and after World War II, the HRO concept of using plug-in coils with micrometer tuning was copied in several countries, including Germany and Japan. The best known copies are probably two German models widely employed as monitoring receivers by the German services, the KST made by Korting Radio and the R4 made by Siemens.
Following World War II came the HRO-7 (1947–1949, 12 tubes, including 2 miniature tubes), HRO-50 (1949–1950, built-in tuning dials and power supply, push-pull audio amplifier, improved styling and performance), HRO-50-1 (1951, increased IF selectivity), and HRO-60 (1952–1964, dual conversion for coils B (7-14.4 MHz) and A (14-30 MHz), heater current regulation for the HF oscillator and mixer tubes). These were followed by two solid-state receivers that did not use plug-in coils: the HRO-500 (October 1964-1972, 5 kHz - 30 MHz, and HRO-600 (1970-1972?, 16 kHz - 30 MHz). Breaking with tradition, the HRO-600 used a frequency counter instead of a micrometer tuning dial. Ironically, the HRO-600 used tubes for its digital frequency display and thus was, technically, no longer "all solid-state" as its predecessor, the HRO-500, had been.
HRO receivers were said to be outstanding and continued to be popular although even better and more expensive general coverage receivers from such companies as Collins Radio became available in the 1950s and later. One can still find HRO receivers dating back to the original model that have been restored by vintage amateur radio enthusiasts and other hobbyists.
Read more about this topic: National HRO
Famous quotes containing the word production:
“Perestroika basically is creating material incentives for the individual. Some of the comrades deny that, but I can’t see it any other way. In that sense human nature kinda goes backwards. It’s a step backwards. You have to realize the people weren’t quite ready for a socialist production system.”
—Gus Hall (b. 1910)
“Constant revolutionizing of production ... distinguish the bourgeois epoch from all earlier ones. All fixed, fast-frozen relations, with their train of ancient and venerable prejudices are swept away, all new-formed ones become antiquated before they can ossify. All that is solid melts into air, all that is holy is profaned, and man is at last compelled to face with sober senses, his real conditions of life, and his relations with his kind.”
—Karl Marx (1818–1883)
“The development of civilization and industry in general has always shown itself so active in the destruction of forests that everything that has been done for their conservation and production is completely insignificant in comparison.”
—Karl Marx (1818–1883)