VTTC Tubes
Dr. Drone, Tue Mar 21 2006, 10:02PM
Re: VTTC Tubes
GimpyJoe, Tue Mar 21 2006, 11:35PM
You could make an amazing art piece. Dozens of secondaries with different size sparks on them, dozens of tubes glowing, all on one of your nice acrylic bases
GimpyJoe, Tue Mar 21 2006, 11:35PM
You could make an amazing art piece. Dozens of secondaries with different size sparks on them, dozens of tubes glowing, all on one of your nice acrylic bases
Re: VTTC Tubes
Hazmatt_(The Underdog), Tue Mar 21 2006, 11:38PM
mmmm....those tubes get way too hot for Acrylic
Hazmatt_(The Underdog), Tue Mar 21 2006, 11:38PM
mmmm....those tubes get way too hot for Acrylic
Re: VTTC Tubes
Dr. Drone, Wed Mar 22 2006, 12:33AM
Dr. Drone, Wed Mar 22 2006, 12:33AM
Re: VTTC Tubes
Hazmatt_(The Underdog), Wed Mar 22 2006, 06:24AM
That's because all the lead in and support rods inside that tube are Tungsten.
The other prominent factor that stands out is the rose color of the glass to metal seal which also indicates the metal is Tungsten.
Now for some glass pics XD
How's that for glass huh!
Hazmatt_(The Underdog), Wed Mar 22 2006, 06:24AM
That's because all the lead in and support rods inside that tube are Tungsten.
The other prominent factor that stands out is the rose color of the glass to metal seal which also indicates the metal is Tungsten.
Now for some glass pics XD
How's that for glass huh!
Re: VTTC Tubes
Dr. Drone, Wed Mar 22 2006, 07:58AM
Dr. Drone, Wed Mar 22 2006, 07:58AM
Re: VTTC Tubes
dan, Wed Mar 22 2006, 08:40AM
Damn I really wish I could have been around back then. I have really started to appreciate the technology of yester years. I mean semis are great and all but vacuum tubes are more on a human scale. Plus you can actually see what’s inside of them! Too bad finding tubes these days is damn near impossible. Especially ones like yours.
I have a very small tube collection. Most of them have either a burned filament or lost their vacuum.
When I was younger I had a whole box of vacuum tubes but I foolishly thrown them out thinking they were useless. I really kick myself every time I think of that.
My very small tube collection:
Four 'Electron' brand 811A's triodes- 1 died when an arc inside the base over heated the support and the glass cracked letting air in.
One Raytheon rkr-72 diode - DEAD.. I melted the plate when I was using it as the level shifter diode in my VTTC.
One Tung-Sol JAN-CTL-3B24WA diode - Still alive! It is a nice diode with a really big graphite plate. It can process 500ma at 20kv!
one RCA 8008 mercury vapor rectifier - not really a 'vacuum tube' but it is still a tube.
dan, Wed Mar 22 2006, 08:40AM
Damn I really wish I could have been around back then. I have really started to appreciate the technology of yester years. I mean semis are great and all but vacuum tubes are more on a human scale. Plus you can actually see what’s inside of them! Too bad finding tubes these days is damn near impossible. Especially ones like yours.
I have a very small tube collection. Most of them have either a burned filament or lost their vacuum.
When I was younger I had a whole box of vacuum tubes but I foolishly thrown them out thinking they were useless. I really kick myself every time I think of that.My very small tube collection:
Four 'Electron' brand 811A's triodes- 1 died when an arc inside the base over heated the support and the glass cracked letting air in.
One Raytheon rkr-72 diode - DEAD.. I melted the plate when I was using it as the level shifter diode in my VTTC.
One Tung-Sol JAN-CTL-3B24WA diode - Still alive! It is a nice diode with a really big graphite plate. It can process 500ma at 20kv!
one RCA 8008 mercury vapor rectifier - not really a 'vacuum tube' but it is still a tube.
Re: VTTC Tubes
Reaching, Wed Mar 22 2006, 11:46AM
wow, nice tubes indeed.
i have a nice collection of tubes too, not as old as your goodies but still quite impressive. many old pentodes ,siemens,valvo etc, many german tubes from the early 70´s.
mhh, interesting and a bit scary, do you mean the Eimac tubes are radioactive because of the tungsten supports inside?
Reaching, Wed Mar 22 2006, 11:46AM
wow, nice tubes indeed.
i have a nice collection of tubes too, not as old as your goodies but still quite impressive. many old pentodes ,siemens,valvo etc, many german tubes from the early 70´s.
mhh, interesting and a bit scary, do you mean the Eimac tubes are radioactive because of the tungsten supports inside?
Re: VTTC Tubes
Steve Conner, Wed Mar 22 2006, 01:24PM
Wow! awesome tube collection! I like collecting tubes too but I only have audio ones. The biggest power tubes I have are some GEC KT88s. I had them in my guitar amp for a while but they would overload the power supply when the volume was turned up full
As to where to get them, I pulled mine from old equipment that was getting scrapped at the university EE department or bought them at flea markets. I also bought a couple of Russian 5881 tubes to see what modern tubes are like. The Russians still make a variety of tubes including the Svetlana 572B, a souped up 811-like tube that would make a good VTTC driver (it's expensive though) The Chinese make tubes too, but the Russian ones seem to be better.
Whose ham shack is that? It looks pretty serious!
Steve Conner, Wed Mar 22 2006, 01:24PM
Wow! awesome tube collection! I like collecting tubes too but I only have audio ones. The biggest power tubes I have are some GEC KT88s. I had them in my guitar amp for a while but they would overload the power supply when the volume was turned up full
As to where to get them, I pulled mine from old equipment that was getting scrapped at the university EE department or bought them at flea markets. I also bought a couple of Russian 5881 tubes to see what modern tubes are like. The Russians still make a variety of tubes including the Svetlana 572B, a souped up 811-like tube that would make a good VTTC driver (it's expensive though) The Chinese make tubes too, but the Russian ones seem to be better.
Whose ham shack is that? It looks pretty serious!
Re: VTTC Tubes
Dr. Drone, Wed Mar 22 2006, 02:19PM
Dr. Drone, Wed Mar 22 2006, 02:19PM
Re: VTTC Tubes
Electroholic, Wed Mar 22 2006, 07:04PM
I got a Eimac 4CX1500b, ceramic/metal type, want to build a VTTC around it sometime.
Electroholic, Wed Mar 22 2006, 07:04PM
I got a Eimac 4CX1500b, ceramic/metal type, want to build a VTTC around it sometime.
Re: VTTC Tubes
Dr. Drone, Wed Mar 22 2006, 07:36PM
Dr. Drone, Wed Mar 22 2006, 07:36PM
Re: VTTC Tubes
vasil, Wed Mar 22 2006, 07:47PM
Ross Overstreet used a 3CX2500 ceramic-metal tube, with 27-28 inches streamers.
http://hot-streamer.com/ross/projects/tube_coil/VTTC_summary.htm
So, this kind of tubes seems to perform very well...
vasil, Wed Mar 22 2006, 07:47PM
Ross Overstreet used a 3CX2500 ceramic-metal tube, with 27-28 inches streamers.
http://hot-streamer.com/ross/projects/tube_coil/VTTC_summary.htm
So, this kind of tubes seems to perform very well...
Re: VTTC Tubes
Dr. Drone, Wed Mar 22 2006, 08:01PM
Dr. Drone, Wed Mar 22 2006, 08:01PM
Re: VTTC Tubes
Hazmatt_(The Underdog), Wed Mar 22 2006, 09:46PM
Reaching:
Because of construction techniques, temprature and currents involved inside the envelope, Tungsten was a necessity so the designers had to find some way of matching the thermal expansion coefficients between the Tungsten and the glass. One way to do this is to make the whole envelope a glass that matches the temp-co. of the Tungsten, but this is very expensive and wasteful. Insted the manufacturer uses a graded seal, which means its a transition from one glass to another. Here the temp-co. of Tungsten closely matches that of Uranium Oxide glass.
The UO glass is still very expensive today, that 5 inch piece is $1 per inch! Now if you're good, you could melt down some vaseline glass and gaff some rods out of it, but I'm not that good. (making rods is called gaffing, and the person who does it is called a gaffer)
Anyways, I have some Tungsten that I will practice making seals sometime, and hopefully a Crooke's tube out of Pyrex. That is if I can get a good constant flame out of my avitar.
Other materials that match Pyrex well are Titanium, Kovar, and Platinum. With the intense heat involved, Titanium would make a good electrode in Pyrex, with the exception that it might catch fire. I dunno yet because I haven't had any responses from a Ti supplier yet.
Hazmatt_(The Underdog), Wed Mar 22 2006, 09:46PM
Reaching:
Because of construction techniques, temprature and currents involved inside the envelope, Tungsten was a necessity so the designers had to find some way of matching the thermal expansion coefficients between the Tungsten and the glass. One way to do this is to make the whole envelope a glass that matches the temp-co. of the Tungsten, but this is very expensive and wasteful. Insted the manufacturer uses a graded seal, which means its a transition from one glass to another. Here the temp-co. of Tungsten closely matches that of Uranium Oxide glass.
The UO glass is still very expensive today, that 5 inch piece is $1 per inch! Now if you're good, you could melt down some vaseline glass and gaff some rods out of it, but I'm not that good. (making rods is called gaffing, and the person who does it is called a gaffer)
Anyways, I have some Tungsten that I will practice making seals sometime, and hopefully a Crooke's tube out of Pyrex. That is if I can get a good constant flame out of my avitar.
Other materials that match Pyrex well are Titanium, Kovar, and Platinum. With the intense heat involved, Titanium would make a good electrode in Pyrex, with the exception that it might catch fire. I dunno yet because I haven't had any responses from a Ti supplier yet.
Re: VTTC Tubes
Vaxian, Wed Apr 11 2007, 07:58AM
I am a serious glowbug myself. I had a MUCH larger tube collection than I do now but plan on adding to it again.
Needing to find a tube that can handle MOT X 2 voltage with a small footprint for my newest project.
I am also a Ham (KG4WTL) and get a warm fuzzy feeling when I click the switch on one of my old boat anchors. I work all CW.
seeing all of your great old gear makes me miss my shack from a few years back, had to get rid of allot of it when my wife joined the ARMY. Building it back up slow but sure!
Keep em glowing!
Dan
Vaxian, Wed Apr 11 2007, 07:58AM
I am a serious glowbug myself. I had a MUCH larger tube collection than I do now but plan on adding to it again.
Needing to find a tube that can handle MOT X 2 voltage with a small footprint for my newest project.
I am also a Ham (KG4WTL) and get a warm fuzzy feeling when I click the switch on one of my old boat anchors. I work all CW.
seeing all of your great old gear makes me miss my shack from a few years back, had to get rid of allot of it when my wife joined the ARMY. Building it back up slow but sure!
Keep em glowing!
Dan
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