Gas discharge tubes were used for quite a few years as position indicators on machine tools from the mid 1960's to the late 1970's. This unit would have been very useful to a person troubleshooting problems with those displays. Although I agree, it would have been very tedious to use on a daily basis.
I would guess at a pinch a modern electronically debounced circuit could be used to replace the wetted switch? Incidentally, one place you MIGHT find one are very early IC controlled touchtone telephones from some countries. (They used mercury wetted contacts for precisely the reason given in your video). The [ * ] marking on the key actually makes me wonder if that's where they got it, from a telecomms part manufacturer?
Downloaded and watched your video, I saw one on ebay and bought it. I have a SB 104a and a HW 101, so I have a little need on the 104 to be able to attempt to test some of the IC's that I can not find cross's on. By chance do you have anything that even looks like a manual? 73's AI6BF George
I need one of these to test flip chips from a pdp-8/L computer
What a cool piece of test equipment.
Gas discharge tubes were used for quite a few years as position indicators on machine tools from the mid 1960's to the late 1970's. This unit would have been very useful to a person troubleshooting problems with those displays. Although I agree, it would have been very tedious to use on a daily basis.
Nice tutorial
I wish I had this kit
I would guess at a pinch a modern electronically debounced circuit could be used to replace the wetted switch?
Incidentally, one place you MIGHT find one are very early IC controlled touchtone telephones from some countries. (They used mercury wetted contacts for precisely the reason given in your video). The [ * ] marking on the key actually makes me wonder if that's where they got it, from a telecomms part manufacturer?
Downloaded and watched your video, I saw one on ebay and bought it. I have a SB 104a and a HW 101, so I have a little need on the 104 to be able to attempt to test some of the IC's that I can not find cross's on. By chance do you have anything that even looks like a manual? 73's AI6BF George