From: pfjw@aol.com   
      
   On Tuesday, October 24, 2017 at 1:29:53 AM UTC-4, kstl...@gmail.com wrote:   
   > The type 83 can operate horizontally just fine, but in one plane, which the   
   TV7 socket position does for you. Think filament sag as they heat up. In one   
   direction, they will have more space so as not to touch the anodes.   
   >    
   > Also, the link given  for an 83 solid-state replacement will not work   
   properly. You need to re-create the 15v drop the 83 has. Search for 83   
   replacements using zener diodes. These will work much more like an 83.   
      
   Three years late - but here you are. Welcome!   
      
   The link works fine from here.    
      
   You *do not* need to recreate anything special - the circuit as-given works   
   just fine. As to Zeners, along the lines of William of Occam, eschew needless   
   complexity.    
      
   When I replaced the 83 in my 539B, I used my calibration tubes (6L6 & 12AX7 &   
   80), I had taken readings with a good 83. With the drop-in replacement, the   
   readings were within a couple of needle-widths. This did prove the concept.    
      
   Hickok put the two rectifier tubes on their sides for the space. That it works   
   does not make it a good idea. The solid-state drop in neatly solves the   
   problem and removes any doubt as to the efficacy of the 83. You pays you   
   money, you takes you chances.    
   These are not precision instruments at any level at all. They are useful to   
   compare one tube to another, cull for obvious defects and failures and   
   reasonably close matching if necessary. But, as always, the best test of any   
   tube is the equipment it    
   serves.    
      
   Peter Wieck   
   Melrose Park, PA   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)