[AMRadio] Screwiest Elmac problem ever

[CL in NC]

Maybe a couple of you follow the Elmac emails, but Gary, K3OS has had is AF67 do something weird.  He is a regular check in on the Old Friends group that meets on 75 meter 3 times a week here in the Upstate SC area.  It was working just fine, then the mod fell off to a very low level.  It does have a new modulator interstage transformer from Hammond, which was installed long prior to this problem, the rest original.  He is getting 40 watts out in CW and AM, the modulator has been checked end to end, including terminating the output transformer with a 5K load where he read 300 volts P to P across the secondary.  When you hook it all back up, you get 10-20% mod max.  Voltages, components, all check good, she just won't modulate.  Any ideas?

Charlie, W4MEC in NC