Das glaube ich allerdings auch. Die 6C33 war ja im Radarsystem der MIG 25 verbaut. Also denke ich mal, dass die nicht nur vom Aufbau her stabil ist, den MIL Grade gibts gleich inklusive.
hab hier mal was zu der Röhre gefunden:
Also, the 6C33-B is an extremely solid, stable, and durable tube, its operating qualities can only be compared with the American make of Bandix in the 1950s, 1960s, which makes tubes for military use. The glass of these tubes are extremely hard, because it has to be able to withstand the extreme gravity load of 7G in high altitudes of tens of thousands of feet, and being able to operate normally. In the military forces, military expert verifies that these tubes have a working life of 10,000 hours, but in real life situations, it is much more than that.
It was said that, a Russian pilot flew a top secret fighter aircraft, the MIG 25 ( NATO refers it as Fox-bat), into Japanese territories, and landed at Hokkaido airport without being detected by Japanese forces. This incident brought serious concern to the Japanese and American forces.
The American forces dissected the fighter plane and putting it back together before handing it back to the Russians. Later, western experts described the MIG 25 as coarsely made but with exceptional fighting qualities, extremely efficient regarding the outdated equipments used. It was only then that the 6C33-B vacuum valve tube first came into light, because it was used on the M.I.G. 25.
Gruss Flo