[NJARC] Atwater Kent 82 Volume Control Problem

[George B. Shields, Jr.]

Hi All,
I am working on an AK82 and am encountering an interesting problem with volume control stability.  On this model set, the volume is regulated by controlling the cathode on a "control" tube which is a 224 type.  This tube also serve as the AVC regulator tube.  When the radio is first turned on volume comes up and then rapidly fades after a few seconds.  Of course, turning up the volume control will bring the volume back.   However after a while the volume will begin to fluctuate wildly, and sometimes will completely cut out.  Adjusting up the volume control will bring the volume back however the volume may suddenly surge back up and then flip flop back and forth between loud and complete cutoff.  Then it may settle down again for an extended period of time however the volume can either cut off or flair up without warning.  The volume is thus unstable.
Appears to me that the values of the resistors associated with the grids are correct.  I have not yet begun to take extended voltage measurements at the individual pinouts of the control tube.
Anyone ever run into this problem with an AK82????????
Thanks,-George-