[Milsurplus] SC-901X question

[Mike Morrow]

Jim wrote:

> Don't know what it was like designing with early silicon
> transistors.  Perhaps tubes were more rugged then transistors
> or perhaps more linear?

On my ship, the USS Daniel Boone SSBN-629 ballistic missile submarine 45 years ago we used R-1051*/URR, AN/BRR-3, and AN/WRR-3* receivers.  (The AN/BRR-3 14 to 30 kHz sets were the most important by far.)  These were all vacuum tube or had vacuum tube front ends.  The generally-accepted reason was superior vacuum tube resistance to EMP damage. but I don't know of any official statement of that.  The R-1051/URR to R-1051H/URR system was in service for about 30 years and later models could have been design-modified to be all solid state if there had not been some specific reason for retaining the vacuum tube design, especially when the H model was costing more than $50,000 each.

Mike / KK5F