Vacuum tube tester.
https://s3-us-west-1.amazonaws.com/h...ube_tester.jpg
Previously:
https://www.homemadetools.net/forum/...811#post133354
https://www.homemadetools.net/forum/...903#post140545
https://www.homemadetools.net/forum/...720#post159600
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remember the free standing ones in the electronics stores where you could test your tubes to see if you needed new ones? Also test the new ones you just bought.
I remember them. Couldn’t tell you where. Too early for Radio Shack. Lafayette Electronics, maybe?
Tube testers were in the supermarkets up til the mid 60's. I remember my dad taking all the tubes out of the tv, checking them on the tester at the grocery store and buying replacements for the ones that were gone or about to go.
That was know as Hollow State technology (the remnants of a bygone civilization of which there is no longer anyone alive that understands them). :cool:
...plenty of Marshall valve amps available new...Oh and my local small appliance repair shop in Nowra, NSW, still has a similar tester in the workshop! I asked them and they told me you'd be surprised how many valve/tube devices are still out there...cheers
About those free standing units. Many of them were found to be rigged to flag a tube as bad when in fact it was good. And as a kid I thought something was wrong when my tube was "bad" and all of the new ones in the box were also "bad". I can't find the whole story but some of you might remember that...
I remember seeing them at the Radio Shack stores and of course more professional electric suppliers
The local drug store had one, with a full complement of replacement tubes underneath. My electronics teacher in HS used to rent us kids out to the other teachers to come over to their houses with a tester a lot like the one in that picture to fix their TV's. This was the early/mid 70's...probaby '74 or '75...
I've designed ONE device that used a "glass enclosed vacuum filled heat operated FET". It was a laser driver I designed for _____ laser company. One single triode with the grid driven by an APEX high speed high voltage op-amp. TO-3 can, cost $$$ all by itself.
A 100MHz D to A converter drove the op-amp.
The output from the tube followed whatever waveform was loaded into the DAC memory. 0-6000 volts.
Getting the tubes and data sheets on them was a temporary issue. Given the end application of these devices (national research labs in the US desert and one in an island nation near China), the tubes magically appeared on my doorstep. Asking for data sheets raised all sorts of alarms of the "who are you and why do you want to know...and how do you even have one of these tubes" type. On finding out the application they gave me a heavily redacted sheet with just the info I needed visible.
I decided to not ask what these tubes were normally used for.
Went through the same sort of thing back in the early days of DSPs, when a box of several hundred TI DSPs was delivered to my home office the guys with sunglasses had a lot of questions.
I believe you meant “a rogue province.” Wouldn’t want the People’s Republic to turn Sauron’s eye on homemadetools.net. Movie studios and sports leagues have caved under their Great Might. (Hail Mao!)Quote:
...in an island nation near China....
I once hauled a military load from White Sands to the Skunkworks. I was given an exact itinerary to follow while driving there and a black Suburban with black windows followed me a half mile back the entire way. I didn't ask any questions.