From: cd6699@notformail.com   
      
   On 3 Sep 2025 13:56:25 GMT, Roger Hayter  wrote:   
      
   >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?   
      
   I'm using purely battery-powered DVMs for this project. I don't even   
   have a bench DVM. Perhaps I'll try a scope instead and see how it   
   reacts to that.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)