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Author Topic: Making of a triode valve (vacuum tube). Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 01-07-2008 11:21 AM                     Some xenon bulb manufacturers will recycle usable components from D.O.A. bulbs....their is a lot of hand made work to those xenon "tubes".  |  IP: Logged Alan Plester Expert Film Handler Posts: 209 From: great yarmouth england Registered: Apr 2001 posted 01-07-2008 11:40 AM                     Watched & watched again, that is one of the most amazing vids i`ve seen in years, wonder how long that takes in real time?.  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 01-07-2008 12:23 PM                     Probably not that long once he's got the tools set up. You see all three electrodes being made in pretty much real time; most of the metalwork is spot welded, which is a quick process. You see quite a bit of the glasswork though obviously it takes a bit longer for things to heat up and cool down than you see. I'm not sure how long the electrodes have to spend in the various baths, and the pumping and bombarding would take a while, though again I'm not sure how long. Sealing metal electrodes into glass is tricky, as most metals expand considerably more than glass does, and therefore can crack the glass as they heat up.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 01-07-2008 01:21 PM                        6L6 and their clones: 6CA7, KT-88, SC-1000m have passed into the public domain years ago. Most tube types were "bartered" between manufacturers. Example GE 6CA7s were actually Amperex (Holland) The rest were probably Mullard G.B. FYI: the original 6L6 was a coproduction of RCA and Motiograph, just prior to WW2; they had a contractual 5 year non-compete and after the war, everyone had them. BTW: We made oscilloscope tubes in high school physics class in the bottom of a flask with a double stopper. Crude, but it worked. Louis  |  IP: Logged Stephen Furley Film God Posts: 3059 From: Coulsdon, Croydon, England Registered: May 2002 posted 01-07-2008 01:58 PM                     Probably not that long once he's got the tools set up. You see all three electrodes being made in pretty much real time; most of the metalwork is spot welded, which is a quick process. You see quite a bit of the glasswork though obviously it takes a bit longer for things to heat up and cool down than you see. I'm not sure how long the electrodes have to spend in the various baths, and the pumping and bombarding would take a while, though again I'm not sure how long. Sealing metal electrodes into glass is tricky, as most metals expand considerably more than glass does, and therefore can crack the glass as they heat up.  |  IP: Logged Aaron Sisemore Flaming Ribs beat Reeses Peanut Butter Cups any day! Posts: 3061 From: Rockwall TX USA Registered: Sep 1999 posted 01-07-2008 02:18 PM                     quote: Louis Bornwasser GE 6CA7s were actually Amperex (Holland) The rest were probably Mullard G.B. While it is true that the American manufacturers stuck their brand name on the Mullard and Amperex 6CA7/EL34s, GE actually made their own 6CA7 (the Fat Boy style) in Owensboro, and Sylvania also made one domestically. The GE ceased production in early 1993, and the Sylvania (later PhilipsECG) ceased ca. 1987. -Aaron  |  IP: Logged Mark Gulbrandsen Resident Trollmaster Posts: 16657 From: Music City Registered: Jun 99 posted 01-07-2008 02:39 PM                     quote: Jack Ondracek High power broadcast transmitting tubes still are. There are two or three companies in the US that do this. The cost is about half what a new tube would run, and carries the same warranty as new. You're right. We used to send the Klystrons back to Varian in Salt Lake City for rebuilding. Every time the tower was struck by lightning(John Hancock building) it would erode away some grapite pieces in the tube which had a similar function to a grid in a regular tube... eventually it would fail. Rebuild cost about 150K every time... Te Aural klystron was only run at 1/3 power and it always lasted the longest of the three. Mark  |  IP: Logged Will Kutler Phenomenal Film Handler Posts: 1506 From: Tucson, AZ, USA Registered: Feb 2001 posted 01-07-2008 09:57 PM                     My Baby...my 1938 RCA 816K uses 2 6L6's in push-pull with a 12 inch electrodynamic speaker Restoration is comming along ok. New custom-wound power transformer (thanks to 3rd party who damaged the original) from Heyboer Transformers using the original end caps. Need to have chassis and other sheet-metal parts replated so I can begin reassembly.  |  IP: Logged Bob Koch Expert Film Handler Posts: 183 From: williams ca Registered: Nov 2001 posted 01-08-2008 01:33 PM                     Louis; I built an amplifier when I was in hi school that had a 6F5 driving a single 6L6. This was quite awhile before the war1937-8]. I certainly never heard anything about Motiograph being involved with any development of any kind. They took over some WE Mirrophonic designs as WE was being escorted out of the film sound reproduction business.  |  IP: Logged

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