XPost: rec.radio.shortwave   
   From: spam@spam.com   
      
   On Thu, 17 Nov 2011 16:38:50 +0000 (UTC), Peter Irwin    
   wrote:   
      
   >In rec.audio.tubes dave  wrote:   
   >> On Thu, 17 Nov 2011 07:34:03 +0000, Geoffrey S. Mendelson wrote:   
   >>>   
   >>> They showed some promise in the missile and space exploration systems of   
   >>> the time, because transistors could not stand the temperature extremes   
   >>> or cosmic radiation they would be exposed to. That also did not last   
   >>> long, as improved "space grade" transistors came out.   
   >>>   
   >>   
   >> Cold Cathode tubes were voltage regulators, displays, etc. I have never   
   >> seen a cold cathode amplifier.   
   >   
   >I think the tubes being referred to are field emission triodes and   
   >various microwave tubes.  You can certainly make a linear amplifier   
   >with field emission devices.   
   >   
      
   Valves in space have probably finally met their match with Gallium   
   Nitride. It is pretty radiation-hard, and capable of valve-type power   
   outputs.   
      
   d   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)