I have a very old Western Electric it is made of a Beryllium Oxide white ceramic, and has silver-plated rings around it and it was plugged into a socket in the middle of the wave guild, the exposed part outside the socket was a circular heatsink-shaped like a cylinder with fins about 1-1/2 wide and tall, the tube side with beryllium oxide microwave window that looks like a hollow white ceramic cylinder from outside the contact rings that decrease in sizes like a cone and is about 2 inches long. The whole tube with the heatsink was about 3-1/2 inches long. After removing a couple of screws the whole TWT came out of the socket by twisting the heat sink and pulling on it. That cotton wiring connected to both sides. The socket had wiring on both sides of the chassis that went down machined-out channels to the final stage transistor boards. This thing had radio shielding seals, thick aluminum plates, and hundreds of screws all over it. It looks more like it came out of a machine shop, not a 1950s electronics manufacturing plant, the whole radio housing was first sand cast with several cavities for circuit boards on but divided both sides front and back then it was machined out for metal mesh radio seals. The back of the radio chassis had a couple of boards but mostly had that cotton wiring. The waveguide bolted to it was 1950s cool. It had a machined flexible part with a scale for adjusting standing waves with large Bakelite knobs for locking the adjustment down. It kinda adjusted the way elbows in your arm would but everything else was stationary. I'm a PMC tech and work on digital and I'm more familiar with micro-controllers than anything else but I've collected transistors all my life and know just enough about radio to describe what I was looking at. I had to study microwave theory to get my degree in Robotics.
I looked like it could be replaced in seconds but the gold-plated Western Electric transistors nearby were in a machined-out cavity inside a cast aluminum case like everything else and very difficult to get to and that was what I was after. The TWT had easy access to the outside, it had some screws but you could get to it easily. It seemed like if the solid-state side failed the whole transmitter was shot because there were so many screws and things in the way. Most of the repair would be mechanical assembly and I was breaking things being careful. It was made not to be taken apart. It was still working they had to replace it to go digital. Of course, I keep the TWT. Everything is being packed and given to my local electrical museum except for the transistors being divided between museums, they are very rare. It would have been nice to keep the whole thing but I would have had to throw it away I move so much and history would have been lost. Those 1953 Western Electric transistor inside was the rarest component inside that whole switch room building, they were never sold to the public.
Most of the transistors in the switchroom were made by Motorolla but they put a Western Electric part number on it. I got most of the circuit cards in the toll long-distance part. That stuff got wethered because I had no place to put them but I got the transistors saved now. These Western Electric transistors look more homemade from a micro metal fabrication shop compared to transistors made today and the whole case is gold plated and very pretty. In the end, before tearing everything out of the building and going digital they let me walk around inside the building taking stuff.
Back in the old days, I have seen Eimac 304TL's that used U glass. They were politely referred to as "Canary glass" and they were rather uncommon but very attractive looking power tubes. Then there is the Thorium impregnated in the Tungsten emitter. I never got overly concerned, and I'm still ticking.
In the 60s, when I worked at a NASA satellite ground station, we used gas discharge regulator tubes. These were radioactive to ensure consistent striking. The boxes they came in had a warning not to store more than a certain number together!
This was interesting. I also have a TWT which was damaged so I had to checked this out. Mine is not made from uranium glass and shows no sign of radation.
Interesting ! Say, were you going to see if you could open up the other end of that TWT and see what the target end looks like ? Or, maybe it's just a simple flat plate and un-interesting ? Thanks for the excellent teardown.
I was flabbergasted last week when a friend of mine did the same test with a smoking cigarette only to show me that the darned thing was way more radioactive then your piece of tube. The Geiger counter was popping like crazy when the cigarette was brought close to sensor. And I thought cigarettes were bad for you. Now I know they are even worse than bad.
Now try a fluorescent tube starter... Way back in the 1990s someone told me that those things were slightly radioactive. I didn't believe him until about ten years ago Philips presented the first "radioactive free" starters. Even today they boast to manufacture the only starters free from radioactive isotopes.
I have a very old Western Electric it is made of a Beryllium Oxide white ceramic, and has silver-plated rings around it and it was plugged into a socket in the middle of the wave guild, the exposed part outside the socket was a circular heatsink-shaped like a cylinder with fins about 1-1/2 wide and tall, the tube side with beryllium oxide microwave window that looks like a hollow white ceramic cylinder from outside the contact rings that decrease in sizes like a cone and is about 2 inches long. The whole tube with the heatsink was about 3-1/2 inches long. After removing a couple of screws the whole TWT came out of the socket by twisting the heat sink and pulling on it.
That cotton wiring connected to both sides. The socket had wiring on both sides of the chassis that went down machined-out channels to the final stage transistor boards. This thing had radio shielding seals, thick aluminum plates, and hundreds of screws all over it. It looks more like it came out of a machine shop, not a 1950s electronics manufacturing plant, the whole radio housing was first sand cast with several cavities for circuit boards on but divided both sides front and back then it was machined out for metal mesh radio seals. The back of the radio chassis had a couple of boards but mostly had that cotton wiring. The waveguide bolted to it was 1950s cool. It had a machined flexible part with a scale for adjusting standing waves with large Bakelite knobs for locking the adjustment down. It kinda adjusted the way elbows in your arm would but everything else was stationary. I'm a PMC tech and work on digital and I'm more familiar with micro-controllers than anything else but I've collected transistors all my life and know just enough about radio to describe what I was looking at. I had to study microwave theory to get my degree in Robotics.
I looked like it could be replaced in seconds but the gold-plated Western Electric transistors nearby were in a machined-out cavity inside a cast aluminum case like everything else and very difficult to get to and that was what I was after. The TWT had easy access to the outside, it had some screws but you could get to it easily.
It seemed like if the solid-state side failed the whole transmitter was shot because there were so many screws and things in the way. Most of the repair would be mechanical assembly and I was breaking things being careful. It was made not to be taken apart.
It was still working they had to replace it to go digital. Of course, I keep the TWT. Everything is being packed and given to my local electrical museum except for the transistors being divided between museums, they are very rare. It would have been nice to keep the whole thing but I would have had to throw it away I move so much and history would have been lost. Those 1953 Western Electric transistor inside was the rarest component inside that whole switch room building, they were never sold to the public.
Most of the transistors in the switchroom were made by Motorolla but they put a Western Electric part number on it. I got most of the circuit cards in the toll long-distance part. That stuff got wethered because I had no place to put them but I got the transistors saved now. These Western Electric transistors look more homemade from a micro metal fabrication shop compared to transistors made today and the whole case is gold plated and very pretty. In the end, before tearing everything out of the building and going digital they let me walk around inside the building taking stuff.
Back in the old days, I have seen Eimac 304TL's that used U glass. They were politely referred to as "Canary glass" and they were rather uncommon but very attractive looking power tubes. Then there is the Thorium impregnated in the Tungsten emitter. I never got overly concerned, and I'm still ticking.
That's a really good explanation of something not that easy to explain. Good to watch the discovery process too.
Thanks man!
In the 60s, when I worked at a NASA satellite ground station, we used gas discharge regulator tubes. These were radioactive to ensure consistent striking. The boxes they came in had a warning not to store more than a certain number together!
Nice tear down. I wonder if there’s thorium in that cathode too? See my comment in other video about the beryllium.
This was interesting. I also have a TWT which was damaged so I had to checked this out. Mine is not made from uranium glass and shows no sign of radation.
Interesting ! Say, were you going to see if you could open up the other end of that TWT and see what the target end looks like ?
Or, maybe it's just a simple flat plate and un-interesting ? Thanks for the excellent teardown.
I will try to see if I can open the other end without totally shatter the tube. I'd assume it's just a piece of metal, but could be wrong.
Wow, almost missed this!
Slick. Another channel I can enjoy! :)
Thanks!
I was flabbergasted last week when a friend of mine did the same test with a smoking cigarette only to show me that the darned thing was way more radioactive then your piece of tube. The Geiger counter was popping like crazy when the cigarette was brought close to sensor. And I thought cigarettes were bad for you. Now I know they are even worse than bad.
Wow, never thought of testing a burning cigarette. Actually quite shocked that they are that radioactive!
While you're at it, you also might try bananas. Anecdotal evidence shows them to be slightly radioactive too.
That's really cool! Thanks.
Thanks! Glad you liked it.
Now try a fluorescent tube starter...
Way back in the 1990s someone told me that those things were slightly radioactive. I didn't believe him until about ten years ago Philips presented the first "radioactive free" starters. Even today they boast to manufacture the only starters free from radioactive isotopes.
I wish I had saved those fluorescent tube starters.
I am a EEVBlog viewer I think this is a RAD tube
Hi Jamie, thanks for visiting my channel!
Interest video 73'er pa3deeghztv
Thanks!