[TenTec] Does VOX work from the AUX input on the Orion?

[NZ8J]

I'm trying to use the Orion aux input (DIN jack)  on the back to work the
digital modes, does the vox work like it does on the Argo V or do you need
the PTT line activated?  I can't seem to get it to key using vox using the
aux input.. The same setup on my Argo V works fine using vox. I just unplug
it from the Argo V and plug it into the Orion and it won't key.. I have set
the input to "aux" and adjusted the input gain, made sure I tried both
channels, etc.... but no luck... probably doing something wrong .....any
ideas??...
Thanks
Tim
NZ8J