[MRCA] Neat Vacuum Tube Story in Jameco Newsletter

[Radio Station KW1I]

      Thrift Store Parts on a US Navy Ship
      How We Satisfied the Company Representative      
     
By Jack Ward 

I was a Naval Fire Control Technician aboard the naval destroyer USS Turner nearly 60 years ago. That doesn't mean that I fought fires. My team and I were responsible for operating and maintaining the equipment that aimed the ship's guns. My story is about the GFCS (Gun Fire Control System) and its 600 vacuum tubes. One of the cathode ray tubes (CRT) for the GFCS displayed a sweep that had a step in it. 

The step was supposed to be in the center of the screen, but ours was located to the far right. It was completely cosmetic. The equipment worked just fine no matter where the step was located, but whenever a representative from the manufacturer came to inspect it, we were criticized. 





We finally traced the problem to a 6H6 vacuum tube. There were no transistors back then, the closest thing we had were some solid state diodes. As with many tubes, there were various versions—for instance, a 6H6 might be glass or metal and could be short or tall. Under most circumstances these tubes were interchangeable, except as we discovered, one specific type placed the step in the ideal center position and another type moved the step far right. 

Once we figured this out, it was just a matter of getting the right tube, but unfortunately it was no longer available from the ship's store. Since government purchasing decided that there was no need for this specific tube type, it would seem that we had reached a dead-end. We saw it as our mission to avoid criticism though, and we were eager to correct the only discrepancy the factory representative could find. 

Then it hit me one day while I was moseying down Thames Street in the ship's home port of Newport, Rhode Island. I discovered a little thrift shop owned by a really nice old fellow. He collected old TVs and radios and tried to either repair them or salvage their parts. He had accumulated tube boxes and after re-labeling, he filled them with used tubes that read "good" on his tube tester. I aimed my sights on one box and began my hunt for the exact 6H6 tube we needed to get the proper display. 

Eureka! I found not one, but two tubes that fit the bill, and I was even able to buy them with my meager pay. They worked perfectly and for the rest of my tour of duty we received excellent reports from the factory representative. 

That's right, there's a million dollar Gun Fire Control System ready to fight a war that's operating with a used vacuum tube removed from a Newport resident's discarded TV! The moral of the story—I guess we never really know where our old parts end up. 



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Jack Ward was the Director of Instructional Media Services and retired from Bowling Green (Ohio) State University as Associate Professor Emeritus. His hobbies include Ham Radio (K9ZQJ), computer graphics, creating brochures and stitching together multiple photos to print 44 inch long panoramic photos. 
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