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 #535
Joined: Sun Feb 18 2007, 06:03AM
Location:
Posts: 65
this is my el cheapo laser listener. the laser is a 15$ wal-pellet gun laser rated at 5mw. The reciever is one of those cheap 6 in. parabolic ear things I had laying around. I replaced the electret microphone with a phototransistor from radio shack. I housed the transistor in back of a 1 in. pvc tube I painted black to keep down the light noise. I set up a test lab in my garage with a radio behind a sheet of glass. It works pretty good. As for real world applications this is the stuff of movies. An evil genius book I have claims to read the laser on the window and decode that instead of directly receiving the bounced reflection!!! I think this amazing 1 info umlimited guy is full of BS! tell me what you think. any suggestions on optics or such?
Registered Member #15
Joined: Thu Feb 02 2006, 01:11PM
Location:
Posts: 3068
wrote ...
As for real world applications this is the stuff of movies. An evil genius book I have claims to read the laser on the window and decode that instead of directly receiving the bounced reflection!!! I think this amazing 1 info umlimited guy is full of BS! tell me what you think. any suggestions on optics or such?
Actually, not BS at all. I have actually built a laser listening device which worked quite well and at considerable distances. Its actually quite simple.
The only difficult part, which is basically what makes it non-practical is alignment. Thats the difficult part. But as far as getting it to work, thats simple!
Something I'd ask is, where does one find a well-collimated not-visible laser with optics already in it? Otherwise a laser mic gives itself away to the observee
Registered Member #33
Joined: Sat Feb 04 2006, 01:31PM
Location: Norway
Posts: 971
EastVoltResearch wrote ...
wrote ...
As for real world applications this is the stuff of movies. An evil genius book I have claims to read the laser on the window and decode that instead of directly receiving the bounced reflection!!! I think this amazing 1 info umlimited guy is full of BS! tell me what you think. any suggestions on optics or such?
Actually, not BS at all. I have actually built a laser listening device which worked quite well and at considerable distances. Its actually quite simple.
The only difficult part, which is basically what makes it non-practical is alignment. Thats the difficult part. But as far as getting it to work, thats simple!
I think he means that Robert Iannini claims to be able to "hear" what goes inside the room just by looking at the laser dot on the window, which is total BS.
Registered Member #535
Joined: Sun Feb 18 2007, 06:03AM
Location:
Posts: 65
yes anders that is the point I was getting at. After spending some time on the board alot of my pipe dreams in that book became reality. althought the new one 101 spy gadgets for the evil genius is by far the most practical and usable book yet. Alignment does make this pretty impractical. I have not yet started to look for a laser in the infrared spectrum. I think alignment would be a bi%# as it is hard enough with one you can see lol.
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.
3$ laser listener
