David,
As for your earlier comment on the exterior 12 VDC on the left side of the box , here is my real life experience concerning that :
When a contemporary ( meaning 1980's - today ) Signals truck is used in the field in a command post position for example , you have a tent or group of tents forming a work station for the Brigade Staff to hang around and do what staff do. I don't want to go into specifics because that is not the subject.
The Signals personnel would workinside the tent , dismount what is dismountaeble in order to be with the Staff in the tent and be close to pass on orders over the net.
A 2K1 box is may be not a Brigade level equipment but at Battalion or even company level i would see the ''penthouse '' house a few officers including a CO or his 2ic with signals personnel. Signal trucks are too small to accomodate so the tent would add space away from the elements.
So it would be logical to have a No 19 set or smaller unit on the table outside the box in the tent.The 12 VDC outlet would supply current from the batteries inside.
The Signals Van of today work pretty much in the same manner.I am not a Signals officer but an end user . I work at Brigade Staff level in those situations.
I hope my hypothesis will help advance the discussion on the subject and that a signals officer or NCO can chime in and correct me if i am wrong.
