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 #95
Joined: Thu Feb 09 2006, 04:57PM
Location: Norway
Posts: 1308
Leslie kindly donated some radium watch hands so I could test my counter. The count rate at different distances corresponds to what Leslie got with his SBM-21 counter, so my homemade version definitely works!
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
Uzzors wrote ...
Leslie kindly donated some radium watch hands so I could test my counter. The count rate at different distances corresponds to what Leslie got with his SBM-21 counter, so my homemade version definitely works!
There are plenty of thorium and uranium minerals to look for in Norway!
Registered Member #1134
Joined: Tue Nov 20 2007, 04:39PM
Location: Bonnie Scotland
Posts: 351
Good Idea! I went up to Tyndrum mine in Scotland yeaterday, to prospect for Uranium, with my CD-V700. I didnt get lucky, I`m afraid, but the background count up there is impessively high! I`m thinking Cornwall next, since the Uraninite deposits at Tyndrum are very minor, but it will be a thousand mile round trip!
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
plazmatron wrote ...
Good Idea! I went up to Tyndrum mine in Scotland yeaterday, to prospect for Uranium, with my CD-V700. I didnt get lucky, I`m afraid, but the background count up there is impessively high! I`m thinking Cornwall next, since the Uraninite deposits at Tyndrum are very minor, but it will be a thousand mile round trip!
I visited the spoil heaps of several ruined Cornish tin mines once noted for their pitchblende, without discovering anything very interesting, but the beach near St Austell produced some remarkable treasures in just a few minutes.
The main part of the beach is covered with sand, but at the back of the beach a natural bank of pebbles has formed. In this I found water-worn pitchblende pebbles so active that I could detect them at two or three metres. The most active of these conspicuously heavy, chocolate-brown pebbles measured 150uSv/hr @ 10cm, and the least active, which was a much lighter brown, about 20uSv/hr.
I talked to local folk [who knew nothing of the pitchblende] and it seems that at times of winter storms and tides, the sand may be swept from the beach altogether, exposing the country rock beneath. Here I would expect to find a wealth of pitchblende, as such dense but smooth pebbles would naturally find their way to the bottom layer immediately above the bed rock, and be last to be swept away. [ i.e. gravimetric separation]
These rich ores perhaps come from the same load worked on by the long defunct British and General Radium Corporation Ltd mine at South Terras, which lay between St. Stephen and the Grampound Road somewhat inland from St Austell.
You can see on the Google Maps Satellite image the uranium mill chimney sticking up out of the trees of a small wood which has now overgrown the whole site.
I also found this which may interest Leslie:
"In Scotland the most important uranium mineralization occurs in three locations:-
1. in low-grade, phosphatic and carbonaceous horizons in the Middle Devonian lacustrine basin of the Orkneys and Caithness;
2. in Devonian arkosic breccias marginal to the Caledonian Helmsdale granite at Ousdale on the east coast of Caithness;
3. in veins marginal to the Caledonian Criffel granodiorite at Dalbeattie.
The Ousdale area was drilled in the early 1970s on a 130 m square grid with 41 percussion holes to depths of 80 m. The maximum value found was 850 ppm U within a 15 m intersection.
Uranium-lead mineralization occurs in a fault breccia in Devonian sediments at Mill of Cairston, near Stromness on Orkney. The fault was drilled by the BGS and a mining company consortium in 1971–1972 when maximum values of 1000 ppm U were found, together with 5.5% lead."
[Source: British Geological Survey, Mineral Profile, Uranium, March 2007]
Registered Member #1134
Joined: Tue Nov 20 2007, 04:39PM
Location: Bonnie Scotland
Posts: 351
Thanks! I just got the pdf! Dalbeattie looks parkticularly promising, and is only 200 miles away or so. There is a reference to Pitchblende veins being found in the cliffs there.
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4061
Conundrum wrote ...
Hmm. MacGyver would be impressed :)
I still want to know why someone hasn't devised a servo-like arrangement that simply moves a variable thickness lead/copper alloy on a pivot across the sensor. As the radiation flux increases it rotates to keep the sensor from saturating then applies a scaling factor.
/me scuttles off to try this.
EDIT:- I have three SBM 20's. One removed from my counter erroneously, the other two are in my counter. Does anyone have a use for these?
i also have some 180V zeners here that might be useful for regulating the supply.
Registered Member #543
Joined: Tue Feb 20 2007, 04:26PM
Location: UK
Posts: 4992
There is a detailed account of the rich uranium mineralization in the cliff top near Needle's Eye, Colvend, Dalbeattie, in MINERALOGICAL MAGAZINE, JUNE 1990, VOL. 54, PP. 129--131.
Registered Member #1134
Joined: Tue Nov 20 2007, 04:39PM
Location: Bonnie Scotland
Posts: 351
Wow! that site is looking more and more delicious! Thanks Harry! I`m thinking of taking a wee field trip! According to auto route, I can make it there in about 3 hours, so If I set off early enough it can be a day out! I have been dying to have a crack at extracting Uranium for some time!
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.
Making a Geiger-Müller Counter
