[TenTec] 422 Centurion Keying Loop

[Speer, Douglas]

I have lost an e-mail I got from Paul Clinton from a couple years ago.  Using the keying loop of the 422 Centurion with an Omni VII I am unable to key the amplifier.  PTT connections work fine and the keying loop worked fine with an Orion II.  Paul told me to short one of the diodes on the QSK board to enable the keying loop to work correctly with the Omni VII.  I cannot remember which diode.  I'm thinking it might be D4.  At the time I did not really have a need to drive the amp with the Omni so I never made the mod but now I do so.  Can any of you more technical than me forum members confirm it is likely the D4 diode on the QSK board or re-direct me?

Very 73,
Doug, W9PN/5
Amarillo, TX