From: phil_a@tpg.com.au   
      
   "patrick-turner"   
      
   Phil mentioned the drive mech for the variable tuning cap in the wien bridge   
   oscilator he has....   
      
   > The shaft is driven by a backlash free, 60:1 worm reduction drive and a   
   > 200 point scale.   
   >   
   > Verrry silky.   
      
   ** Ambiguity fix.   
      
   The 200 point scale is engraved on a 4.4 inch dia steel disk that rotates   
   with the worm drive, making 6000 setting points per range. 30 turns x 200 =   
   6000.   
      
   Well Phil, your dial certainly seems nice by what you say, but how accurate   
   are the 6,000 points on the dial? It would seem that the dial length around   
   the 4.4 inches is roughly 13.8 inches long, 351mm, so distance between each   
   "point" is 351 / 6,000 = 0.058mm and too small to be useful.   
      
   **  ROTFLMAO  !!!!!!!!!!!!!!   
      
    351 / 200  =  1.755mm   
      
   There a 30 turns of the dial for 180 degrees on the gang.   
      
      
      
   ...   Phil   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)