That mean if the tube in some critical application according to specs "SU 3.301.001 TU" fails before 50 hours somebody must go to prison...
"SU" there means "Special Conditions".
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"Time of stable operation - min. 50 hours".
I find this hard to believe. I have a quad of them in my Aikido 6SN7/6SN7 line stage with hundreds of hours on them and no problems.
I also purchased some of the cheap plastic base tubes as well as the better grade with the metal base. Thes don't cut it sonically. The 1578 is the leader in my opinion. Even my wife can immediately tell a difference in the sound between the cheap tube and the 1578. She could even hear a difference between the 1578 and the 5692's in the Aikido. She also picked the 1578's.
"Time of stable operation - min. 50 hours".
I find this hard to believe. I have a quad of them in my Aikido 6SN7/6SN7 line stage with hundreds of hours on them and no problems.
I also purchased some of the cheap plastic base tubes as well as the better grade with the metal base. Thes don't cut it sonically. The 1578 is the leader in my opinion. Even my wife can immediately tell a difference in the sound between the cheap tube and the 1578. She could even hear a difference between the 1578 and the 5692's in the Aikido. She also picked the 1578's.
Don't dramatize, Wavebourn
Do you know anyone who went behind the bars for failing to produce the tube according to TU? I don't.
In the U.S. military, the 50 hour minimum guarantee meant that the tubes were run for fifty hours before being shipped. Since the great majority of tube failures occur in the first fifty hours, the tubes that passed were very likely to give full service. This is probably true for Soviet tubes since they took from the Americans what ever they could.
John
John
John, that's pure speculation.
Actually, correct translation of that line in the data sheet should be as follows:
"Time of stable operation - not less than 50 hours".
After those 50 hours, per specs, the tube is allowed to go south, mission accomplished.
From the next page in the book:
"Criterium for stable operation - change of plate current not more than +/-15%"
For such low hours count one application comes to mind (without warrenty returns) and that is in a missile
One thing is for certain the 1578's are far superior to the american 5692's. I seriously doubt that the Russians borrowed anything from our ill performing noisy run of the mill 6SN7's. Even the cheap $4.00 6N8S's are quieter than the high priced 6SN7's that we seem to covet.
Don't dramatize, Wavebourn
I myself almost got there because one inspector wanted to. However, the real problem was about one woman he wanted, but he tried to find violations of TU to do so. I worked in railway support and development then, it was far from military applications, but anyway could go behind the bars. That's why manufacturers of parts and equipment for "Special Applications" tried to negotiate safe margins in specs.
All that octal tubes were fair copies of early RCA tubes, when RCA was in zenith. It happened during WW-II, when our fathers were allies and fought together against technologically superior Germany. Red Army used as well borrowed from U.S Army electronics and supplied parts for it. Tubes even had the same names, until during Cold War Khrushchev commanded to ban "Names of potential enemy" and rename all tubes in Cyrillic. Like, 6N7 to 6H7C, 6SN7 to 6H8C, 6SL7 to 6H9C. But at that time new tubes become available for military, like Gu-50, 4P1L and other Loctal types based on German prototypes. Also, miniature tubes were developed for missiles and other similar applications, like 6N16B, 6N17B, 6J5B, and so on. 6N16B were replacing 6SN7 in miniature equipment, 6N17B were replacing 6SL7.
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Now there's an old canard that needs to be put to rest. American and British electronics were far in advance of Germany's. What Rosenberg gave to the Soviets was so critical because Germany had nothing like the gunnery control radar/artillery proximity fuse technology that made it possible to shoot down Gary Powers. In addition, there was a famous remark by a German admiral that the allies' use of centimetric radar to find submarines was "not fair".
John
The M-9 gunnery control system was mainly used against the V-1. Something like 2000 were shot down, essentially one artillery shell per kill. Where Germany had somewhat better stuff was their defensive weaponry, because that's where they were forced to concentrate their efforts - not a desireable position to be in at war. Overall, the German air fleet was inadequate compared to America's.
I'm not convinced Germany had better vacuum tubes. Which ones did you have in mind?
John
I'm not convinced Germany had better vacuum tubes. Which ones did you have in mind?
John
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You can compare pre-war and during-war tubes from RCA and Telefunken. Take for example LS-50 and 807 used in aircraft transmitters of similar power and compare their quality.
Yes, Germans forced Allies to develop much better defense systems, and to learn how to fight... So, after the end of WW-II they could not stop fighting, started Cold War against each other in militarization rush spending valuable resources for nothing...
Guys, I've pulled the last several posts for getting too political. You're free to repost any of the technical content.
having worked in the Russian Federation for six years as QC Engineer, i know for a fact that technicians doing work as a licensee of the government really do take their jobs seriously....they stick to procedures no matter what....and the reason they always give me is that they can go to jail if something goes wrong, these guys sign "acts" or protocols for testing....so the "jail thing" that Anatoly mentions is very real...
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