[Heathkit] Heathkit IM-18

[Garey Barrell]

OK, I give up.........

I have an IM-18 that has been working for years.  Turned it on, and the meter pegs 'downscale' on 
'AC'.   On 'DC-' it pegs downscale, on 'DC+' it pegs upscale.  ZERO control has no visible effect. 
No combination of the CAL controls makes any visible effect.  Interestingly, results are identical 
with the 12AU7 removed.  DC voltages on the power  supply capacitor are nominal.  Whoever built it 
did a VERY nice job, beautiful solder on board and switch.  Close visual examination shows not 
obvious shorts, bridges, etc.

Open to ideas or suggestions..

73, Garey - K4OAH
Glen Allen, VA

Drake 2-B, 2-C/2-NT, 4-A, 4-B, C-Line
and TR-4/C Service Supplement CDs
<www.k4oah.com>