2022-06-25 00:11:39 <KipIngram   > Wow - I'm delving through one of the books from that website of old engineering texts I posted a day or two ago - it's on vacuum tube applications.  There's some solid gold stuff in there, man.  A lot of it would be applicable to transistor circuits as well; having more to do with the circuits themselves than the tube proper.
2022-06-25 00:11:58 <KipIngram   > Equations would probably have to be worked out for the different situation, but the ideas would apply.
2022-06-25 00:12:11 <KipIngram   > Stuff like compensating amplifiers to extend the frequency range and so on.
2022-06-25 00:13:17 <KipIngram   > imode: yeah, routing is a big pain.
2022-06-25 01:06:36 <imode       > KipIngram: wild, do you have the link to that site?
2022-06-25 03:24:33 <imode       > it kinda looks like reads are blocking but writes aren't on the GA144.
2022-06-25 03:24:49 <imode       > i.e signals exist for the absence of a value, but the writer doesn't block on writing.
2022-06-25 10:02:37 <KipIngram   > imode: http://www.tubebooks.org/
2022-06-25 10:07:50 <KipIngram   > Guy went to a whole lot of trouble to get that all in place, and doesn't seem to be "exploiting" it in any way whatsoever.  Just someone that doesn't want to see the knowledge lost.
2022-06-25 10:08:21 <KipIngram   > Scanned them all himself.
2022-06-25 10:53:24 <klys        > https://www.ebay.com/itm/223870481183
2022-06-25 10:53:47 <klys        > nixie tube clock, 179.00
2022-06-25 11:22:56 <klys        > note it's cheaper to buy your own nixie tubes, https://www.ebay.com/itm/363864063197  https://www.ebay.com/itm/254023927919
2022-06-25 11:45:42 <veltas      > We call vacuum tubes 'valves' in the UK which I find kind of interesting
2022-06-25 11:46:19 <veltas      > Because they're kind of like valves but with electricity
2022-06-25 12:46:24 <KipIngram   > Yeah - the moniker makes TOTAL sense.
2022-06-25 12:46:36 <KipIngram   > I think that used to be a somewhat common appelation over here too.
2022-06-25 12:47:38 <KipIngram   > appellation
2022-06-25 12:48:18 <KipIngram   > You could use it in the same way for transistors, but I guess it was "taken" by the time transistors came along.
2022-06-25 12:48:29 <KipIngram   > FET transistors in particular function pretty strongly like tubes.
2022-06-25 12:49:07 <KipIngram   > Bipolar transistors are essentially current-controlled devices, but FETs (especially MOSFETs) are voltage controlled, much like tubes.
2022-06-25 12:49:19 <veltas      > Isn't a vacuum tube essentially a slow transistor?
2022-06-25 12:49:45 <KipIngram   > In some cases there's a strong parallel.  Completely different low level physics, though.
2022-06-25 12:49:53 <veltas      > Or I guess it's the inverse of a transistor because it inhibits while it's unpowered
2022-06-25 12:50:06 <KipIngram   > I find the tube physics somewhat easier to understand.
2022-06-25 12:50:28 <veltas      > But it probably switches on/off very slowly
2022-06-25 12:50:34 <KipIngram   > In the sense that basic high school physics gets you somewhat prepped to grok them, whereas semiconductor physics is kind of a new layer.
2022-06-25 12:50:57 <KipIngram   > Well, yeah - just like larger transistors tend to be slower than smaller ones.  Size definitely has an influence.
2022-06-25 12:51:34 <KipIngram   > Size governs the capacitances that are associated with the thing, and larger capacitance means more charge has to be moved to accomplish the various changes.
2022-06-25 12:52:26 <KipIngram   > And the cathode and plate of a tube are generally much further apart than the differently doped layers of a transistor; just takes longer for charge carriers to move across the larger distance.
2022-06-25 14:26:40 <KipIngram   > When electrons first come loose from the cathode (because it's hot), they generally aren't moving very fast.  But the plate voltage accelerates them, and they can be boot scooting by the time they get to it.  Nonetheless, t hough, once an electron is on the way (once it's past the grid) you can't stop it, so even when you cut the flow off by changing the grid voltage, you're still stuck with current flow for
2022-06-25 14:26:42 <KipIngram   > the time period it takes for the last electrons to make the trip.
2022-06-25 14:26:53 <KipIngram   > So that's a "built in switching delay."
2022-06-25 14:27:09 <KipIngram   > Same when you turn the grid back on.
2022-06-25 14:29:19 <KipIngram   > In a transistor everything is a lot closer together, but on the other hand there's a crystal lattice sitting in the way that puts obstacles in the path of the charge carriers.  Also transistors are typically operated at much lower voltages, so the force on the carriers may  not be as large.
2022-06-25 14:29:32 <KipIngram   > But work it all out and numbers pop out.
2022-06-25 14:30:35 <KipIngram   > But God, we make transistors so amazingly small that it's ridiculous, so it's not surprising they're super super fast.