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 #1143
Joined: Sun Nov 25 2007, 04:55PM
Location: Vilnius, Lithuania
Posts: 721
here is my new project, large DRSSTC, for it i have 600V 400A ultrafast igbt (4 times greater than CM300 ) so here is my new power supply for IGBT driving (+15 0 -15V )*3
Registered Member #135
Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735
I'm trying to get my test set going so I can do more transmission line analysis, but the thing is the rack mounting stuff is so expensive I have to go cheap for now. I got the handles for the synth and the adapters for the analyzer ( $270 and that was with a savings mind you! @.@ ) But I'll need another $80/unit for the rack rails, and probably another $400 for the rack box, man why does this stuff have to be so expensive! I would probably modify the cart I have here if it could handle the extra weight, but I doubt it could, the analyzer wieghs 120lbs by itself.
I'm trying to get it to talk to the GPIB interface here, which I dunno if its being totally successful. I have some doubts as to the worthiness of the card in the analyzer, but I'll play more with the plotting tool and hopefully get somewhere.
Registered Member #29
Joined: Fri Feb 03 2006, 09:00AM
Location: Hasselt, Belgium
Posts: 500
Wow Hazmatt. I am impressed.. You are getting seriously into the RF world.. Bravo!!!! Be careful not to burn out the front end of that spec. an. (invest in a collection of attenuators and always keep one connected to the input.)
With your wide-band op amps: be careful to terminate them so that they see a good resistive load on thier inputs and outputs and be very careful to keep all connections _short_!
Also...good luck with the GPIB. It can be a headache, altho' it can be done using a parallel port and some clever software... It's pretty much been superceded in modern instruments with built in network and USB capability.
Registered Member #135
Joined: Sat Feb 11 2006, 12:06AM
Location: Anywhere is fine
Posts: 1735
Yea that is a good point, I'll have to get some attenuators soon! I could really use some dust boots too but I don't think I should snag those from work, I'll have to ask.
The real GPIB problem I'm having right now is communication errors. I have to play with it more because I don't know if the instrument's GPIB card is really operating properly. Also the older SA's don't support a lot of the GPIB commands so its going to be more difficult to talk to it. I need to sit down with the manual and read some things over. I hope to get some comm. confirmation soon, right now I get some funky noise floor plots, so I may have to dump the window into memory somehow first then send the plot request, dunno yet, I have to figure that out.
Steve, you could get a 494 for about $3K, stuff really isn't all that expensive now. The SA cost $1800 and the synth cost $600, so its really not that bad now. Of course ... concerning the credit card I'm kinda done for a long time which is a problem because I could really use a new DSO.. heh. (2430A is kinda flaky right now).
But yes I'm really serious about RF, really really serious. See:
What I really want right now is to build some lab amps for myself and the forum so they have test bench equipment.
When I started out with electronics I was always thinking "how can I build that myself for a fraction of the cost", and the end goal was always to have a piece of test equipment for the bench that I could use again. Stuff like small ammeters, or a little RF volt meter, or freq. counter. A lot of times I just didn't have the time to really build the project so I bought the majority of my stuff. Some was even donated if it could help me get closer to answering my questions.
After some of my goals are met right now, one of my future goals is a counter/meter (a frequency counter and RF volt meter in one little package). I would like the meter to be autoranging, but we'll have to see.
Anyway, when its all said and done, I am very serious about questions and answers, I invest heavily in finding out what something really is, but you know it kinda pays off because I learn something from it, and then I try to post as much as possible here so others can learn too (if they can understand what im talking about.. not always the case.. but I try to make it understandable).
RF Amps! hell yea.. I'm all for that, I just need to get that sine wave current booster finished and post all that for the time being.
Registered Member #30
Joined: Fri Feb 03 2006, 10:52AM
Location: Glasgow, Scotland
Posts: 6706
Wow, yup you're definitely "committed" to RF :D
I never bought a spectrum analyzer, since I figure I always have access to one through my work.
For an RF "power amp" I just bought an old HF ham transceiver off Ebay and modified it for general coverage transmit. It gives 100W anywhere from 1.8 to 30MHz, and using a ham antenna tuner, that RF power can be forced into all sorts of places that it was never intended to go
You might want to study the broadband PAs used in these transceivers, they typically use two BJTs like the 66 dollar one you have there.
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.