[Milsurplus] ARR-41 Info...now 618S

[Mike Morrow]

Scott wrote of the 618S-series:

>It's not an advancement, the -1 and -4 came out at the same time! 

Scott,

I have a USAF-contract Collins 618S-1, and the USN's Collins RT-311/ARC-38 and RCA/Collins RT-594/ARC-38A units, and I am familiar with the gross differences that exist between these three non-equivalent units.

However, I do *not* know the difference between the civilian models 618S-1 and 618S-4, nor do I know the significance of the "/MC" that appears at the end of some 618S model numbers.

If I understand correctly, you are saying that the 618S-4 is the exact civilian equivalent to the RT-311/ARC-38, complete with SMO.  If so, did it use a control box that had direct frequency entry somewhat like the later 618T, or did it use complex frequency-versus-code thumbwheels similar to the C-1398/ARC-38?

If you could clear up the differences between the various civilian 618S models, that information would be valuable.

Mike / KK5F