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 #3324
Joined: Sun Oct 17 2010, 06:57PM
Location:
Posts: 1276
Hi, 4hv
the local hamfest is coming up soon in a few days (UK - poole) what things should i look out for to get? can you think of any things i should look out for that could be of use?
Things To Look out for ang get: Oscilliscope MultiMeter Capacitor Reader Inductor Reader Function Generator Vacuum Tubes Variacs Heatsinks Component Storage Bins Large Capacitors High Voltage Capacitors Large Transformers Components Wire High Voltage Equipment Ferrite Copper Busbar
Things to bring with me: Multimeter (Checking Variacs) Screwdriver (Checking Variacs)
Registered Member #1822
Joined: Fri Nov 21 2008, 08:04PM
Location:
Posts: 300
If you want to build a Tube TC then you should find several different model #s of tubes to look for. If you want to buy a variac make sure you bring a multimeter to test for continuity.
Registered Member #816
Joined: Sun Jun 03 2007, 07:29PM
Location:
Posts: 156
Be wary when buying test equipment, or any seller using the words “untested†All too easy to pay money for something you expect to work only to find out it doesn’t.
I seem to be amassing a small pile of oscilloscopes that are probably beyond economical repair / can’t obtain the parts ect.
You will also see some equipment that is so outdated that it’s debatable if it can be of any practical use other than a collectors item.
Components are always worth having, as you cant beat having a good selection around when you want to make something, transistors and IC’s can be tricky unless you are familiar with what the part numbers are.
Oh and if you live with anybody be prepared for the “why on earth did you buy that for?†line when you struggle in with your best bargin of the day.
Registered Member #2919
Joined: Fri Jun 11 2010, 06:30PM
Location: Cambridge, MA
Posts: 652
Things I look for: Class IV lasers Ferrite toroids _nice_ test equipment (Fluke multimeters and such) Weird big things (large pulse caps, etc) that are no fun to ship from Ebay *sigh* I can never seem to find any Little consumables that are nice to pick up locally RPN calculators People who practically give stuff away Large 'lytics if they are less than $10 and over 4000 uF, or are especially cute (never found one :()
Registered Member #3414
Joined: Sun Nov 14 2010, 05:05PM
Location: UK
Posts: 4245
Tom Williamson wrote ...
good point!, reccommended price about?
Personally, I'd avoid turbo-molecular pumps, unless they are 'guaranteed' and have the controller and connecting lead.
Rotary vane pumps are 'tricky'. I reccomend the older belt drive ones. Edwards are best our side of the pond as you can still get the service kits (Welch are better on the 'other side' of the pond).
Diffusion pumps are good because they are simple, although expect to have to clean it out with acetone or similar and replace the oil. Heater elements 'may' also need replacing. Don't get one that is too big. around two to three inch is sufficient for most 'amateur' stuff.
For either rotary vane or diffusion (you need both for a 'high vacuum' system, I'd say £20 is good if it works, I wouldn't go higher than £50 unless I really needed one and it was guaranteed.
(I did pay £150 for a 'new, unused, still in the box', 2 1/2" water cooled Edwards diff pump last year, though. I've still not used it.)
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.
hamfest
