1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
All trademarks, copyrights, patents, and other rights of ownership to images and text used on the RF Cafe website are hereby acknowledged.
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These images have been chosen for their uniqueness. Subject matter ranges from historic events, to really cool phenomena in science and engineering, to relevant place, to ingenious contraptions, to interesting products (which now has its own dedicated Featured Product category).
Cool Pic Archive Pages
you ever wondered what is inside the familiar 9V battery? I used a small screwdriver and a pair of pliers to remove
the outer metal case. If you did not already know, you might be surprised to find that there are six AAAA cells
are connected in series.
might just be the world's first atomic wrist watch. It does not need the 60 kHz signal from
Boulder, Colorado, to maintain its accuracy. Some
work is still needed for mass production. I did not see a lady's version advertised on their website.
(thanks to Kevin A. for the link)
is testing a new breed of radiation-resistant transistors for space apps. Those shown here are attached to the International
Space Station for evaluation. High-energy protons, neutrons, and ions streaming through space pose an extreme threat
to critical electronics for both Earth-orbiting and interplanetary missions. The usual silicon dioxide insulating
dielectric is replaced by an organic compound, which assembles itself from three chemical solutions into a 15‑nanometer-thick
layer. The organic dielectric is more radiation-proof than silicon dioxide because it conducts holes well.
a briefcase-borne GPS unit in a specially consigned DHL aircraft, this artist plotted its flight path to create
a self-image the size of the
The idea was conceived as a graduation project for Erik N.'s Advertising & Graphic Design major. It quickly
became an Internet hit. Some irate people questioned the wisdom of wasting so much fuel on such an endeavor. Mr.
N. no doubt has a corner office in a Madison Avenue high-rise by now... or at least a good job with DHL.
of people are passionate enough about their life pursuits that they are willing to indelibly emblazon their flesh
with monuments to those obsessions. This guy evidently loves tuned antenna circuits. Others love mathematics, causing
them to have the Golden number documented to 80 significant places. It gets much weirder. BTW, I saw this bumper
sticker from a tattoo shop, "Yes, It Hurts!"
when substrate real estate was not deemed as valuable as it is today, project managers tolerated IC layout engineers'
proclivity for play. These examples of what has come to be known as "chip art" are the semi equivalent of software
"Easter eggs." They are usually discovered as a result of decapping an IC for reverse engineering exercises. Pretty
Castile-La Mancha region of the Cuenca province in Spain will soon be capable of generating 18 MW. That is enough
electricity to supply 9,200 households. Kyocera is supplying the photovoltaic modules. It will be one of the largest
solar power generating facilities in the world. 89,320 PV modules, and 3,300 tonnes of structural steel were needed.
The total site will have a surface area of 80 hectares and cover a space larger than 100 football fields. Quick
Calc: At $4.75/W, the cost of the PV modules
is about $85M (not including structures, control, distribution, etc.).
1.5 MV home brew Tesla coil is the handiwork of John Miles and his team, initially built for use in a Halloween
spook house. The primary is 6 turns of #6 AWG solid copper; the secondary is 700 turns of #22 polythermalized magnet
wire wound on a 20" diameter cardboard form at a spacing of 10 turns per inch. A 14.4 kV, 5 kW power-pole transformer
fed power to its 10-pole, 3,000 rpm rotary spark gap. Click here to buy a
Tesla coil of your own, if you do not have time and/or
resources to roll your own.
electric propulsion evolution revolution is not the sole domain of ground-based vehicles. The ElectraFlyer C has
pushed the e-frontier a little farther with its custom-designed super high efficiency, light-weight, 18 HP motor.
It will not be performing unlimited vertical aerobatics anytime soon, but with 90 minutes per charge and zero emissions
(and near silence with its low rpm prop), it will be a good motivator for follow-on efforts.
gray noise is actually a scaled photo of 426,000 discarded cellphones. That is the number of phones trashed every
day in the U.S. alone, at least according to the artist that composed the montage. The original print is 150 cm
x 275 cm.
the most intelligent beings in the universe prefer to use Firefox when surfing the Internet. The story released
for public consumption says that some Oregon State U. students made it by stomping down oats, but we all know it's
another Area 51-type cover-up. Watch the video to see the method behind the madness - quite impressive.
the Ancients weren't using them for digging hearts out of unwilling human sacrifice victims, they used these sophisticated
temples for scientific astronomical study. Layout and orientation was very precise. Precession of the equinoxes
causes them to be inaccurately configured for the current epoch. Here are views of the temples/observatories from
the vantage point of GeoEye's Ikonos satellite, 423 miles above Earth at an average speed of 17,000 miles per hour.
copy of "Pike's Arithmetic," believed to be the first mathematics textbook in America, is due to be auctioned along
with his personal journal with "notes, drawings and calculations on various subjects including mathematics, navigation,
and astronomy, dated 1764," according to the auction brochure. Pike's Arithmetic was the dominant math text in the
U.S. for 50 years. The collection should be worth about $20,000 to $50,000.
that necessity is the mother of invention has caused amateur radio antenna designer ZL1CLG to use some very unusual
on-hand components for his implementations. The one shown here is made of metal waste baskets for the 80m band.
There is also one made from those grease splatter screens used for cooking and another from stove pipes.
looks like an oil drilling platform, cruises like an oil drilling platform, and is semi-submersible like an oil
drilling platform, but it's not an oil drilling platform. Boeing's Sea-Based X-Band Radar is a converted commercial
oil drilling platform that is part of the Ground-Based Midcourse Defense system. Systems include X-Band Radar, In-Flight
Interceptor Communications System Data Terminal, and the Ground-Based Midcourse Defense Communications Network.
With a 6-kt cruise speed, you won't be skiing behind it.
colleges are famous for their curricula, some are famous for being party schools, while others, like these featured
schools, are famous for the pranks pulled off by their engineering students. Of course, some are famous for all
three - and more.