[Collins] Kwm-2a no SSB audio drive

[walnutcreek at appstate.net]

Hi all,
I recently moved and have been working on one rig after another as I unpack.  I hooked this 2a up and it tested fiine for output and receive.  It works fine in CW, but when I switched to USB and LSB I have no audio driving the RF amplifier.  I'm going to have to get out my manual and dig through it, but if anyone can shoot me an e-mail telling me which tube is the likely culprit I'd love to hear from you.
Thanks,
Cam
WA4JKW