If you need assistance, please send an email to forum at 4hv dot org. To ensure your email is not marked as spam, please include the phrase "4hv help" in the subject line. You can also find assistance via IRC, at irc.shadowworld.net, room #hvcomm.
Support 4hv.org!
Donate:
4hv.org is hosted on a dedicated server. Unfortunately, this server costs and we rely on the help of site members to keep 4hv.org running. Please consider donating. We will place your name on the thanks list and you'll be helping to keep 4hv.org alive and free for everyone. Members whose names appear in red bold have donated recently. Green bold denotes those who have recently donated to keep the server carbon neutral.
Special Thanks To:
Aaron Holmes
Aaron Wheeler
Adam Horden
Alan Scrimgeour
Andre
Andrew Haynes
Anonymous000
asabase
Austin Weil
barney
Barry
Bert Hickman
Bill Kukowski
Blitzorn
Brandon Paradelas
Bruce Bowling
BubeeMike
Byong Park
Cesiumsponge
Chris F.
Chris Hooper
Corey Worthington
Derek Woodroffe
Dalus
Dan Strother
Daniel Davis
Daniel Uhrenholt
datasheetarchive
Dave Billington
Dave Marshall
David F.
Dennis Rogers
drelectrix
Dr. John Gudenas
Dr. Spark
E.TexasTesla
eastvoltresearch
Eirik Taylor
Erik Dyakov
Erlend^SE
Finn Hammer
Firebug24k
GalliumMan
Gary Peterson
George Slade
GhostNull
Gordon Mcknight
Graham Armitage
Grant
GreySoul
Henry H
IamSmooth
In memory of Leo Powning
Jacob Cash
James Howells
James Pawson
Jeff Greenfield
Jeff Thomas
Jesse Frost
Jim Mitchell
jlr134
Joe Mastroianni
John Forcina
John Oberg
John Willcutt
Jon Newcomb
klugesmith
Leslie Wright
Lutz Hoffman
Mads Barnkob
Martin King
Mats Karlsson
Matt Gibson
Matthew Guidry
mbd
Michael D'Angelo
Mikkel
mileswaldron
mister_rf
Neil Foster
Nick de Smith
Nick Soroka
nicklenorp
Nik
Norman Stanley
Patrick Coleman
Paul Brodie
Paul Jordan
Paul Montgomery
Ped
Peter Krogen
Peter Terren
PhilGood
Richard Feldman
Robert Bush
Royce Bailey
Scott Fusare
Scott Newman
smiffy
Stella
Steven Busic
Steve Conner
Steve Jones
Steve Ward
Sulaiman
Thomas Coyle
Thomas A. Wallace
Thomas W
Timo
Torch
Ulf Jonsson
vasil
Vaxian
vladi mazzilli
wastehl
Weston
William Kim
William N.
William Stehl
Wesley Venis
The aforementioned have contributed financially to the continuing triumph of 4hv.org. They are deserving of my most heartfelt thanks.
Registered Member #3832
Joined: Thu Apr 14 2011, 11:57PM
Location: Downtown Chicago, IL
Posts: 37
Hey all. First, I want to introduce myself- my name is Steve, I'm from Cleveland, OH. I like playing with big tube-powered toys, as well as rail guns, transmittera, tesla coils, really anything that has an awesome amount of power. I work in the film industry, so I don't have any sort of engineering background or anything.
Anyway, I love your forum here and finally decided to join as a member to contribute my fun.
A friend of mine recently dumped off a nearly unused navy surplus Eimac 4-1000a to me. It's the largest glass tube I've ever seen or owned, and I quite frankly can't decide what the he'll to do with it! I had a few ideas:
Excessive VTTC The largest BCB AM transmitter I've ever built Induction heater
Registered Member #3429
Joined: Sun Nov 21 2010, 02:04AM
Location: Minnesota, USA
Posts: 288
Hi STeve, welcome to 4hv!
The 4-1000 is normally used in the final amplifier stage of a radio transmitter. The number 4 indicates that it's a tetrode (cathode, control grid, screen grid, and plate), and the number 1000 indicates that the plate can dissipate up to 1000 watts of power.
As for those projects you mentioned, I'm sure that you understand that you will need a LOT of other high power components to power that big tube! And don't even think about using it as a BCB transmitter unless you want the FCC kinocking at your door! (but of course you CAN transmit on the broadcast band if you are properly licensed).
The 4-1000 is an awesome tube, but expect to spend a lot of cash on the power supply and the perifpheral components unless you have a well-stocked junk box!
If/when you do build a project with it, please share the details with us here on 4hv!
Registered Member #3610
Joined: Thu Jan 13 2011, 03:29AM
Location: Seattle, WA
Posts: 506
Seems like the power supply shouldn't be too big of an issue. A lot can be done with a MOT or two, and they can be had for free.
Ought to make a nice VTTC. A tube that size could handle some serious power without pushing it anywhere near the limit. You could run the coil for good lengths of time and still get a lot of life out of the tube.
Registered Member #3429
Joined: Sun Nov 21 2010, 02:04AM
Location: Minnesota, USA
Posts: 288
steve516 wrote ...
Thanks Mike!
We'll see what I can come up with. Right now Tesla coil is looking like the best choice. I may wind the filament tranny out of an old MOT.
I could just display it, it's a beautiful tube all by itself.
Steve
I recently built a VTTC with a 6146 tube, which is quite a bit smaller than your 4-1000, but I was pleased that it works fairly well for my intended purpose (a plasma speaker). You should be able to built a very large VTTC with that big tube!
In my opinion, putting a working vacuum tube on display, and not using it, is like displaying a beautiful but functional gun. A gun is meant to shoot, even though some of us wacky gun collectors love to admire the fine craftmanship of a quality handgun. Put that tube to good use!!
By the way, do you have the tube socket for that tube? I recall from my amateur radio days that high power transmitter tubes have expensive sockets which often include a glass cooling shroud, and a fitting for forced-air cooling. A 4-400 tube that I once used in a linear amplifier had that type of socket and glass shroud. The socket cost me more than the tube did back then!!
Registered Member #1316
Joined: Thu Feb 14 2008, 03:35AM
Location: Cambridge, MA
Posts: 365
If you build a VTTC out of it, make a base fed audio modulated one (plasma tweeter). The base fed design requires few components to handle the reactive power, and a large plasma tweeter is impressive. I built one using a 4-400 which is a bit smaller then your tube. Worked good except it had some modulation issues.
Registered Member #3832
Joined: Thu Apr 14 2011, 11:57PM
Location: Downtown Chicago, IL
Posts: 37
Weston wrote ...
If you build a VTTC out of it, make a base fed audio modulated one (plasma tweeter). The base fed design requires few components to handle the reactive power, and a large plasma tweeter is impressive. I built one using a 4-400 which is a bit smaller then your tube. Worked good except it had some modulation issues.
That would be awesome... I have no idea how to audio modulate it, but I would love to do that. Maybe you all can help out there! :p
Registered Member #3429
Joined: Sun Nov 21 2010, 02:04AM
Location: Minnesota, USA
Posts: 288
steve516 wrote ...
I have no idea how to audio modulate it, but I would love to do that. Maybe you all can help out there! :p
There are plenty of scematic diagrams and construction plans on 4hv and other places on the web for "plasma tweeters" and "plasma speakers". You can also find some information if you search on "singing arc".
FYI -- I audio modulated my 6146 plasma speaker by capacitor coupling my audio signal into the screen grid of the 6146 tube. You can also modulate the tube with an audio transformer in series with the plate B+ supply, and I've even seen a design that fed the audio signal into the cathode of the tube, across the cathode resistor. So, there are many ways to modulate, but it must be done correctly, otherwise your audio will be weak and/or distorted (as are many projects found on YouTube).
If you have limited electronic experience, especially with vacuum tubes and RF circuits, then a project of this sort may be more than you should tackle until you've gotten more education and experience. My biggest cocern here is with electrical safety. The voltages and currents that typically power a large transmitting tube like the 4-1000 are extremely dangerous, and can be fatal if you make only ONE mistake!
This site is powered by e107, which is released under the GNU GPL License. All work on this site, except where otherwise noted, is licensed under a Creative Commons Attribution-ShareAlike 2.5 License. By submitting any information to this site, you agree that anything submitted will be so licensed. Please read our Disclaimer and Policies page for information on your rights and responsibilities regarding this site.
So I got this Tube...
