[Milsurplus] 618t help

[Lee Ritta]

Howdy Folks
I noticed a Collins manual recently sold on that place, it mentioned
618T3 ,4 ,5 ,6  I know the 618T3 series but what were the 618T-4 and 618T-5
And 618T-6 including the B models is there anyone on the list with a circuit
for the 714E6 control head? Is there anyone who has worked on these radios?
Has anyone a 488A2 inverter they are willing to sell, or know where I can
buy one? Or even a 714E-6 control head?

73 Lee VK5ZNA