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 #160
Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938
Does anyone have any links to some horizontal bipolar coils that people have made? The one I was trying to find but doesn't seem to exist anymore is Dave Huffman's plans. I wondered if the exact placement of the primary coil is vital, for instance using a flat wound coil would be more difficult to adjust than a helical.
Registered Member #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
You actually mean half-wave coil. The primary doesn't have to be exactly centered, however solenoid wound coils are usually the norm for these types of coils.
Also, you will need to put an RF ground on the middle of the secondary if you want a little play in the position of the primary. This will ensure maximum voltage nodes at each end of the secondary (half-wave). However, if you can ensure the primary is exactly centered on the secondary, you can do away with the RF ground.
I've done it both ways, using a solid state primary driver, as opposed to classical spark gap front end.
Registered Member #160
Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938
Yes, a 1/2 wave coil. Does this mean that the tank frequency will have to be twice that of a 1/4 wave coil of the same size? I want to know if it is possible to make a small 1/2 wave SGTC, with a, say 12-16" long secondary. I have not seen any examples of a 1/2 wave coil this small.
Using plastic ties, the coils can be centered very well. I had to use a bigger primary form though, to eliminate the breakdown between pri and sec coils.
Registered Member #160
Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938
Thanks Vasil, that was just the example I was looking for. I had only seen large ones like this arcane looking specimen. I like your site, you have a lot of nice MOT designs.
Registered Member #123
Joined: Fri Feb 10 2006, 12:58PM
Location:
Posts: 162
Hi, Heres a pic of my spark gap bipolar coil. driven by 2 parallel 4kv 8ma transformers. brass spheres are door knobs and the box it's in is an asda bread bin! where else can you get a beach wood box for £9 cheers colin
Registered Member #160
Joined: Mon Feb 13 2006, 02:07AM
Location: Melbourne, Australia
Posts: 938
Very nice Colin. Can you give me some specs on it? What size xformer, caps used, size of secondary, etc. I love the portability of it. Are they ballasts under the spark gap?
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.
Bipolar TC
