[davemc]

I was watching some YouTube videos involving restoration of Philco shadow meters. One mentioned being able to see the vane through the BACK of the meter - where the lamp shines through a hole.  I had never thought of doing that, and the lamp and its metal cover blocked vision from that side.  I was trying to check the vane operation from the OTHER end.  Well, I removed the lamp and sure enough the vane was visible. I connected up a variable DC power supply and varied the voltage from zero to 15 volts (the highest voltage drop I had observed in my radio). The vane moved smoothly as the voltage was increased, and returned to the center (and vibrated) when the voltage was cut.  So it looked like my coil and magnet were working properly. Except that half of the vane is missing! That of course explains everything that I observed: that only one side of the shadow moved.  Since there is no obvious fix for this, I then just reinstalled the meter in the radio and performed the adjustments.  So at least the meter is functional and works as the radio is tuned.  But only one side of the shadow moves. 

One thing I don't understand is how this could possibly happen! There is no evidence that the meter has ever been opened up.