This is the place to get LTspice.
This is genuine freeware, it is like Pspice, has not been
crippled, runs on windows with a very functional and intuitive
GUI. Best bit is that is also runs well under WINE for my fellow
penguinistas. I used to use the classical SPICE running on linux,
but it is reasoneably hard to use. It is still the best and
fastest, but its clunky interface makes the "let see what happens if we
do this" change and test scenario quite hard. Linear
Technology Corporation gives away this very functional spice
implementation because they want you to evaluate their fine chip level
products with their SPICE models with this cooooool program
http://www.linear.com/designtools/software/switchercad.jsp
SUPER MORSE
MORSE CODE training program
I was teaching myself morse code so
as to get the full ham radio certification. Then the morse requirement
was dropped but not before I got to 5 wpm with the help of this
beautiful little MSDOS program. It is very thorough, does random
groups, training levels from newbie to advanced and completely
configurable. This also runs well in Linux using either
WINECONSOLE or DOSBOX
http://www.murrah.com/sm/
This jolly site generates random
Computer Science academic papers
http://pdos.csail.mit.edu/scigen/
you too can now become a respected computer science academic with only 7 mouse clicks
Military Wireless Radio Manual site.
The best site, no ifs and no buts!
A
dammn fine technology blog
http://marxy.org/
very readable and beautifully presented
The Apollo Moon Mission
Those old enough to remember sitting in front of the old black and
white boggle eyed television set in the the sixties looking at grainy
blured images of astronauts hopping across the moonscape may appreciate
this site. It has archival technical information and reports from the
the latter Apollo series. There are gems such as the the Saturn V
Rocket Flight Manual, 255 pages of the technical detail that was never
included on the back of cornflakes packets. Ever wondered what all
those hoses and foofer valves were for ? I used to wonder at the
marvel that Saturn 5 could actually clear the launch tower, let alone
make it to the moon. After reading the flight manual it was clear to
see that absolutely nothing was left to chance. I can image
people slapping Verner Von Braun on the back exclaiming "it worked...it
worked" and von Braun coldly replying " Off Course".
http://history.nasa.gov/alsj/frame.html
this site
rocks big time!
ATLC
an arbitary transmission line and coupler calculator
This tool when given an arbitary transmission line or coupler as a BMP
file will calculate by finite element methods assorted transmission
line parameters, most usefully the characteristic impedance
atlc.sourceforge.net
IC and other electronic component data sheets
the best source of data and specification sheets in the entire internet
http://www.datasheet4u.com
NXP corporation, a spinoff of Phillips
many applications notes and product data
http://www.nxp.com/all_appnotes
a very nice ham radio linking site pointing to lots of very coooool technical and hobbyist sites
www.101science.com/amateurradio.htm#SATELLITE
MMANAa very nice human front end to MININEC
free as in beer!MMANA
is a GUI interface to mininec, the classical and definitive antenna
modelling code. Mininec input is very difficult and arcane to program,
but this is a human gui front end that permits relatively easy input of
antenna geometry specification. It comes with numerous example files.
The GUI was written for Windoze but I have found that it runs
perfectly using wine on linux. Mininec dates from mainframe codes
written in the sixties, indeed, the native input format is the card
deck. Thats why commercial gui versions were quite successfull.
There are various sites around the planet that host this binary executeable
mine came from here
http://ave.dee.isep.ipp.pt/~ssantos/RAPP/MMAnaApres.htm
US Navy Historical Documents Site
This
site has recently declassified US NAVY manuals for not only some
electronic equipments but complete manuals for submarines, WW2 era
battleships, PT boats. There are entire Navy
Electronics/Electrical courses. There are the maintenance manuals
for the amazing analog computers that were inside the RANGEKEEPER
mechanisms that dynamically solved ballistics equations to aim the huge
Naval Guns as mounted on WW2 era battleships. These must be read
to be believed. Compulsory reading for all Armchair Admirals
www.hnsa.org/doc
There is enough scanned material here to keep you engrossed for literally years