7eae257b   
   From: spam@flippers.com   
      
   Corvette Bob wrote:   
   > Hi Guys,   
   >    I'm working on a Seeburg AY100U and want to test the 0A2 voltage   
   > regulating tubes in a Hickok 6000A tester. Unfortunately, there is no   
   > 0A2 settings on the chart.  Just a 0A4 which I don't think is a   
   > substitute.  Thanks for any help you can provide.   
   > Bob   
      
   Hi Bob,   
      
   You can test the OA2s in circuit - if you show are 150VDC across each   
   tube then they are good. They also glow purple when working correctly.   
      
   These tubes rarely fail, but if they were to fail they would either   
   short - I've never seen that - or they get gassy, again rare, (or they   
   loose vacuum completely) and then they would arc and spark and be rather   
   obvious that they are sickly.   
      
   If you want to check them out of circuit then you need a power supply   
   that can provide at least 175VDC (to turn on the OA2) - be sure to have   
   a few hundred ohm resistor in series with the supply to act as a current   
   limiter.   
      
   If you have a tube book you can check if the OA4 and OA2 are similar and   
     what differences exist - then see if you can adjust your tube tester   
   accordingly.   
      
   John :-#)#   
      
   --   
       (Please post followups or tech inquiries to the newsgroup)   
     John's Jukes Ltd. 2343 Main St., Vancouver, BC, Canada V5T 3C9   
     Call (604)872-5757 or Fax 872-2010 (Pinballs, Jukes, Video Games)   
                        www.flippers.com   
          "Old pinballers never die, they just flip out."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)