home bbs files messages ]

Forums before death by AOL, social media and spammers... "We can't have nice things"

   sci.electronics.repair      Fixing electronic equipment      124,925 messages   

[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]

   Message 124,762 of 124,925   
   Roger Hayter to Cursitor Doom   
   Re: Mystery Problem   
   03 Sep 25 13:56:25   
   
   From: roger@hayter.org   
      
   On 3 Sep 2025 at 14:20:34 BST, "Cursitor Doom"  wrote:   
      
   > Gentlemen,   
   >   
   > I have an early AVO valve tester (twin panel type, Mk1 or Mk2) which   
   > I'm trying to get fully working. Anyway, I have a problem with it   
   > which I've never encountered before. I set the panels up to test a   
   > valve, set the anode and heater voltages etc, the valves are glowing   
   > just like they should, but when I apply the prods of a DVM across the   
   > heater pins to check if they're correct WRT the switch setting, that   
   > tiny extra load completely collapses the supply to the heaters! The   
   > meter reads 0V (or close enough) and the heater glow dims to nothing.   
   > Any idea WTF's going on here?   
   >   
   > Cheers,   
   >   
   > CD   
      
   Suppose you didn't actually use a bench DVM with one input connected to mains   
   earth?   
      
   --   
      
   Roger Hayter   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)   

[   << oldest   |   < older   |   list   |   newer >   |   newest >>   ]


(c) 1994,  bbs@darkrealms.ca