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 #72
Joined: Thu Feb 09 2006, 08:29AM
Location: UK St. Albans
Posts: 1659
I can't help you with the resistor colours (I think either gold or silver could mean something like x0.1 or x0.01 the other bands, but I've not seen both together), but can suggest a better method of measurement.
If you have a known current source, or a stable one you can measure, then pass a current through the resistor, and measure the voltage *at the resistor wires with seperate terminals*. This is known as a 4-wire measurement, it avoids adding in the contact and lead resistance of a normal 2-wire measurement. It also allows you to use higher currents and lower voltage ranges than your meter might use by default on its minimum ohm range.
Registered Member #27
Joined: Fri Feb 03 2006, 02:20AM
Location: Hyperborea
Posts: 2058
Black is 0 and it make no sense starting with 0 so what if we ignore the black bands and get 9 * 0.01 = 0.09 Ohm and 5% accuracy. Or 0.08 Ohm if it is a grey and not white band. Seems best to just measure it.
The 4-wire measurement is great for such uses but be careful with large inductors, even if you keep the voltage low you can hurt yourself if you disconnect the current abruptly.
Registered Member #2099
Joined: Wed Apr 29 2009, 12:22AM
Location: Los Altos, California
Posts: 1716
Aside from the uncommon color sequence, the package shape is interesting. I've never seen one that looked so much like a conformal coating over about three turns of thick wire. We could estimate its inductance and corner frequency from the geometry.
When you're done with the four-wire resistance measurement, may I borrow the specimen to make an x-ray of it? Or if your dentist has gone digital, ask him/her to please x-ray the resistor on your next visit. Simpler yet (but less fun): since you said you have many such resistors, perhaps you can dissect one. Thanks!
Registered Member #2431
Joined: Tue Oct 13 2009, 09:47PM
Location: Chico, CA. USA
Posts: 5639
klugesmith wrote ...
Aside from the uncommon color sequence, the package shape is interesting. I've never seen one that looked so much like a conformal coating over about three turns of thick wire. We could estimate its inductance and corner frequency from the geometry.
When you're done with the four-wire resistance measurement, may I borrow the specimen to make an x-ray of it? Or if your dentist has gone digital, ask him/her to please x-ray the resistor on your next visit. Thanks!
i need my own xray lab for this reason, ive PM'ed you... its actually two resistance wires wrapped in CW and then CCW...
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.
Need help, resistor colors....
