metal tubes
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They are called plate caps or top caps. Sorry I can't help on the UK source
MikoKensington
Well-known member
I don't think that is a good practice. Top Anode Caps are scary enough. Probably the most lethal kind of tube.
Are you looking for a 5 pin with top anode cap? I've been poking around but can't find much. Give me a better idea of what you're looking for. My dad was working on some designs with top anode tubes. He may know where to source such an item.
-miko
Are you looking for a 5 pin with top anode cap? I've been poking around but can't find much. Give me a better idea of what you're looking for. My dad was working on some designs with top anode tubes. He may know where to source such an item.
-miko
BYacey
Well-known member
I would try some antique radio suppliers. This cap can also be a grid on some tubes, especially on tubes from the 20's and 30's.
they aren't anodes on the tops, which supprised (and releaved ) me, just grids. the tubes are 6l7(crazy 5 grid thing) and 6j7(pentode). both octal bases.
just soldered them on for the time being, and once i've got the project working i'll have a hunt around.
cheers for the help guys
toby
just soldered them on for the time being, and once i've got the project working i'll have a hunt around.
cheers for the help guys
toby
BYacey
Well-known member
You should be able to use a 3AG type fuse clip as Mikkel mentioned, the type meant for PC board mounting. Just solder your lead wire to it. These caps are about .25 inches diameter so it should be a good fit.
> sockets for the pin on the top of metal tubes, or even what they're called?
Not just metal tubes. Many glass tubes had top-caps. The generic term used to be "double-ended", meaning the Input and Output were not on the same end of the bottle. That helps reduce stray radio feedback. It was also the only way to get a Tetrode on a 4-pin base, but Octal base was a better plan.
On small tubes, the top cap is almost always a grid cap. This is handy in audio: if you touch the grid cap, you should hear big buzz in the speaker. You can find a dead tube in seconds this way.
On many power tubes the top cap is the plate cap. Touching it may be lethal, especially since they didn't use plate-caps unless the plate voltage was more than an Octal socket can stand.
If you can still buy grid caps, it will be from radio restoration suppliers. They were common in radios around 1930. But they don't go bad, so there may not be much call for replacement grid-caps.
The standard 0.25" PCB mount fuseholder clip is a neat fit. It is nicer to find the old Bakelite streamline covers, and for low-level work on metal tubes there was a 1" tall can that covered the grid-cap for shielding. But these are frills.
Not just metal tubes. Many glass tubes had top-caps. The generic term used to be "double-ended", meaning the Input and Output were not on the same end of the bottle. That helps reduce stray radio feedback. It was also the only way to get a Tetrode on a 4-pin base, but Octal base was a better plan.
On small tubes, the top cap is almost always a grid cap. This is handy in audio: if you touch the grid cap, you should hear big buzz in the speaker. You can find a dead tube in seconds this way.
On many power tubes the top cap is the plate cap. Touching it may be lethal, especially since they didn't use plate-caps unless the plate voltage was more than an Octal socket can stand.
If you can still buy grid caps, it will be from radio restoration suppliers. They were common in radios around 1930. But they don't go bad, so there may not be much call for replacement grid-caps.
The standard 0.25" PCB mount fuseholder clip is a neat fit. It is nicer to find the old Bakelite streamline covers, and for low-level work on metal tubes there was a 1" tall can that covered the grid-cap for shielding. But these are frills.
I would not solder on that grid terminal. You may let air into the tube.
Antique Electronoc Supply sells them. They come in a few different sizes.
They will import to the UK, but that seems like a long way to go just to get a grid/anode clip.
Antique Electronoc Supply sells them. They come in a few different sizes.
They will import to the UK, but that seems like a long way to go just to get a grid/anode clip.
