[Milsurplus] Submini tubes.

[Kenneth G. Gordon]

Hue Miller

> What features of submini tubes account for their ( apparently,
> according to testimonials here ) long life? 
> Tnx-  Huey Miller

According to Sylvania, they were purposely designed and built to be as 
rugged and long-lived as possible, 40,000 hours being a median life-
span for some selected types.

Although I have not studied their construction very closely, I DO know 
that their small mass makes it more difficult for them to be damaged by 
vibration.

A friend of mine, Walter Wallace, who lived near Billings, Montana 
recounted when he worked for some gummint agency selecting tubes to 
be used in proximity fuses, which were in development at that time. He 
tested the tubes given to him for ruggedness by shooting at them with a 
.22 rifle. Those that survived that, were tested further. Some were 
eventually selected for the circuit. ALL were submins.

At the time he told me this story, about 1970 or so, I thought his 
methods were a bit extreme. Now I'm not so sure.

Ken W7EKB