These archive pages are provided in order to make it easier for you to find items that you remember
seeing on the RF Cafe homepage. Of course probably the easiest way to find anything on the website is
to use the "Search RF Cafe" box at the top of every page.
are still a lot of people who wind their own coils, whether it be
for an amateur radio rig or for work in the lab. I know I've wound
many a coil around a drill bit or wooden dowel. This simple
coil winding machine that appeared in a 1931 edition of QST
magazine would be a handy addition to anyone's bag of tricks, especially
if find yourself winding single-layer coils that have a fixed space
between the windings. The home stores like Lowes and Home Depot
sell small pieces of oak that would be perfect for this kind of
project. A little stain and a coat of varnish would give it a real
vintage look. Use your soldering iron to burn your name onto the
Model No. PIA-10G-CD-1 is a
10 GHz Integrated, Dielectric Resonator Oscillator (DRO)
Module with 3 outputs, each having a 0-360 degree analog controlled,
variable phase shifter and 0-10 dB analog controlled, variable
output control capability on each output. Provides low harmonic
output of -50 dBc typical and output power of +19 dBm
typical. ±15 VDC, 6.25” x 2.5” x 1.0” package.
Other frequency ranges available.
few autopsies are being done now that many medical students get
out of school never having seen one." - Gregory Davis, U. Kentucky
College of Medicine, November 2012
Scientific American. That's as ridiculous as an EE student graduating
without ever having to learn to troubleshoot circuits. Oh, wait...
MECA Electronics Intros Line of Unequal
Electronics' new line of
unequal power splitters
consists of six models offering a 2, 3, 4, 6, 8, or 10:1 signal-split
ratio respectively, over 698-2700 MHz (Cellular, PCS, AWS,
and BRS/EBS frequencies) and feature low PIM ratings – (better than
-150 dBc.), with ultra-low VSWR and minimal coupling variation
over the entire frequency band. They easily handle high power levels
of 300 W (CW) and have an operational temperature range of
-55°C to +85°C. As with all MECA products, they are MADE
IN THE USA and are offered with a standard 36 month warranty.
NuWaves Engineering Adds to Its Int'l Reseller
Engineering, a Radio Frequency (RF) and Embedded Systems solutions
provider, announced today that the company has increased its international
presence by adding authorized resellers in Europe, Southeast Asia,
and the Middle East. These new partners will represent the company’s
high-performance module-level RF products and engineering design
Entry Level RF Applications Engineer Wanted
LLC has new opportunity for a junior or entry level engineer that
is looking to aid in the applications engineering of discrete and
MMIC RF and Microwave power products on Nitronex’s unique GaN-on-Silicon
process. You’ll be driving the post production applications development
of MMICs and discrete devices that span from UHF to X-Band. Nitronex
is a quickly growing company that requires driven, talented individuals
to bring new technologies to market that will enable devices to
operate to X-band and as high as 65V. Candidates must hold a BSEE
and a demonstrated interest in RF electronics, including hobbyist/enthusiast
experience, senior design work, elective coursework etc. and a desire
to work in a fast paced, startup environment. Alternatively, candidates
can possess an MSEE with relevant coursework/thesis in RF and Wireless
Webinar: Precise Cable and Antenna Measurements
for Precise Cable and Antenna Measurements in the Field Date,
by Agilent and TESSCO, Wednesday, October 24, 1:00 PM ET. This webcast
introduces measurement and calibration techniques for cable and
antenna testing (CAT) using the new Agilent FieldFox handheld microwave
analyzers. We will discuss a variety of measurements such as cable
insertion loss, return loss, VSWR and Distance-to-Fault (DTF) testing.
Antenna measurements are also discussed and several examples of
return loss and antenna-to-antenna isolation will be provided.
Les Fantômes de la Seconde Guerre Mondiale
photos are the result of superimposing images of scenes during
World War II on top of modern images of the same locations in
France today. It was a time when
were not asked for passports when entering the country by sea
and air. Historical expert Jo Teeuwisse, from Amsterdam, began the
project after finding 300 old negatives at a flea market in her
home city depicting familiar places in a very different context.
of us have joked about wishing we had a job like the weatherman's
since it didn't seem to mater how often or egregiously he was wrong,
he got to keep his job. No
hurricane forecaster ever went to jail for failing to foretell
the ultimate effects of a storm system, nor an avalanche expert
for not predicting exactly where and when a snow pack would leave
its mountain mooring. It would be unreasonable to expect that level
of prognostication from practitioners of the scientific method,
right? Not anymore. A new precedent has just been set by an Italian
court that found
six earthquake experts guilty of manslaughter for not properly
warning of the 2009 earthquake in the city of L'Aquila that killed
308 people. They can kiss freedom goodbye for 6 years
(maybe less with good behavior).
So, bureaucrats who routinely fail to predict untold numbers of
financial and civil catastrophes that have directly or indirectly
caused loss of life will continue to get promotions and pay raises
while scientists who fail to predict a *&%$@ natural phenomenon
now go to jail. Congratulations, Italy, you have set an example
that will soon be coming to a country near the rest of us.
Copper Mountain Technologies Featured in
Mountain Technologies' website declares, "Virtual Instruments.
Real Performance. Real Value." What that means is their line of
"virtual" instruments are as "real" as an all-in-one test box. CMT's
network analyzers have a USB interface to your computer, where supplied
software provides the user interface and number crunching power.
Portability and price is a huge benefit. Their 300 kHz - 1.2 GHz
model starts at just $2.5k. Going to 8 GHz costs you $17k.
Microwaves & RF magazine did a nice feature article on them.
The origin of the company name, detailed in the column, is kinda
Amateur Broadcasting - A Menace
Bach (not Johann S.) was amazingly
prescient in 1944 with the specific types of RF-based devices that
would come to be common place in our modern world. Dig this: "Radar
can even be applied to the home, as a burglar-alarm, for example,
or to detect obstructions on the cellar steps. Electronic devices
will find many other uses as high-frequency paint-dryers, veneer-gluers,
and even cordless permanent-waving machines for the ladies. Garage-door
openers and other remote-control devices are not only possible but
practical. Then there are certain to be other applications such
as personal pedestrian telephones, two-way wrist-radios and nursery
baby-cry announcing systems." Nostradamus' divination record might
not even be that good. His tongue-in-cheek thesis of ubiquitous
RF interference due to the presence of Ham radio operators is not
far off either, although the accused "menace" would have to be extended
to include all the many varied emissive devices being used by tech-ladened
RFMD Intros Control Components for Cable
today unveiled two new CATV control components, in conjunction with
the SCTE Cable-TEC Expo, in Orlando, FL. The new components include
RFSA2654, a 75-ohm broadband digital step attenuator, and the
RFSW1012, a high power handling single-pole, double-throw switch
Microwave Office Designs "Right the First
Technology, Ltd., (ATL) a provider of leading-edge RF power
amplifiers (PAs) for defense, commercial, industrial, scientific,
and medical applications, used a unique combination of AWR’s Microwave
Office RF/microwave design suite and AMPSA’s MultiMatch Amplifier
Design Wizard to design a complex multi-octave bandwidth, high power,
high efficiency PA.
Please Thank Hittite Microwave for Their
modules, subsystems &
instrumentation for technically demanding digital, RF, microwave
and millimeter wave applications covering DC to 110 GHz. The
Company's standard and custom products apply analog, digital &
mixed-signal semiconductor technologies, which are used in a wide
variety of wireless / wired communication and sensor applications
for automotive, broadband, cellular infrastructure, fiber optics,
microwave & millimeter wave communications.
Analog Engineering Theme Crossword for 10/21/2012
the sake of avid cruciverbalists, each week I create a new
crossword puzzle that has a theme related to engineering, mathematics,
chemistry, physics, and other technical words. You will never be
asked the name of a movie star unless he/she was involved in a technical
endeavor (e.g., Hedy Lamar).
Calculus of Negligence aka "Hand Rule"
reading an article on legal liability, I ran across a reference
Hand Rule, formulated by Judge Billings Learned Hand
(yes, that was his given name).
Hand, who studied both philosophy and law, was a judge credited
with a keen sense of honor and fair play as applied, in conjunction
with Constitutional principles, to such as patents, torts, admiralty
law, and antitrust law. The Hand Rule
was born out of a trial where an improperly secured barge escaped
its moorings and caused damage to other boats. Per the Hand
Rule: "[T]he owner's duty, as in other similar situations,
to provide against resulting injuries is a function of three variables:
(1) The probability that she will break away; (2) the gravity of
the resulting injury, if she does; (3) the burden of adequate precautions.
In mathematical terms: B < PL, where B is the cost
(burden) of taking precautions,
and P is the probability of loss, and L is the gravity of loss.
Simply stated, negligence is ruled if the effort required to prevent
an event is less than the likelihood that the event will occur,
multiplied by the severity of the loss. This, of course, is all
subjective, which is why he who hires the lawyer best able to define
values for B, P, and L wins the case. I propose an alternate name
for it: Fuzzy Law.
RFMD Unveils GaN-Based Amps for CATV Applications
Micro Devices unveiled multiple leading-edge GaN-based CATV amplifiers,
in conjunction with the SCTE Cable-TEC Expo in Orlando, FL. The
new CATV amplifiers include the
RFPD2940 – a best-in-class, high-power GaN-based CATV power-doubler
amplifier, as well as a new family of GaN-based push-pull CATV amplifiers,
led by the
Many Thanks to SigaTek for Their Support
microwave specializes in high quality, high frequency microwave
communication components up to 60 GHz. As a pioneer supplier
of microwave RF components,
the main products include directional couplers, bias tees networks,
power dividers / combiners, 3 dB hybrids 90° and 180°, microwave
mixers, frequency doublers, load terminations, and coaxial connectors
Undersampling Changes Bandwidths, by Jon
Titus is a lot like Bob Pease - only without the scraggly beard
- when it comes to
circuits. Along with having a PhD and being the former editor
of EDN and Test & Measurement magazines, Jon
has an innate knowledge of circuit theory and is very good at presenting
complex information to lesser beings like myownself[sic]. Most of
us want to be like them when we grow up. One big difference between
Jon and Bob, though, is that Jon does not eschew the use of computers.
I think Mr. Pease might have been OK with the ENIAC, but once IBM
introduced the XT, it surely dumbed down every future engineer from
that point forward according to his oft-repeated denouncements of
anything with a silicon-based processor. Fortunately for Bob - and
for those of us to whom he addressed - he didn't need a computer
for most tasks. This short column from Jon Titus titled "Undersampling
Changes Bandwidths" is a great primer on how undersampling works.
In a Pease-esque way, Jon uses hand-drawn sketches to illustrate
the sampling phenomenon.
Equipment Connection handles sales, rentals and leasing of refurbished
electronic test and measurement equipment to the R&D, manufacturing
and quality assurance industries. All major lines including Agilent,
Tektronix, Anritsu, Rohde & Schwarz, Advantest and Fluke.
A Surprising Message from Scott Adams
creator of Dilbert, Dogbert, Catbert, Wally, Alice, Asok, and the
pointy-haired boss has just endorsed a presidential candidate based
medical marijuana prosecution. Keep in mind that
suffered a rather severe nervous system malady in the middle of
the last decade. Although I cannot find anything for certain about
whether he uses it himself, there is a good chance that he does.
you might recall, lost his ability to speak and to draw for a couple
years, then miraculously gained back most of his functionality.
The Dilbert cartoon rarely ventures overtly into political themes,
so it will be interesting to see if a strip on the subject appears
between now and election day.
An Old Spark Soliloquizes
it has been a while since you read a story with terms and phrases
like "splinters of galena," "the day of the tuning coil that stretched
from the front bedroom to the back library; or from the attic to
the cellar," and "Ether God," then this article from the December
1931 edition of QST is for you.
Galena, by the way, is a semiconductor with a bandgap of about
0.4 eV that was used as the crystal in crystal radio sets.
It was used as a point-contact diode along with a safety pin or
similar sharp wire, commonly known as a "cat's whisker".
Please Welcome DCH Systems as a New Supporter
Systems is engaged in the design and manufacture of
RF power amplifiers
and systems. Their mission is to provide advanced, highly linear,
and efficient RF amplification solutions for customers in the aerospace
/ defense, telecommunications, and science communities. DCH Systems'
core competency is the ability to design and manufacture RFPAs utilizing
pre-distortion techniques, and possesses the expertise to implement
the high-complexity analog and digital circuitry to produce user-friendly,
reliable RFPA products that are suited for both low and high volume
How to Talk to Non-Hams
is a pretty funny story that, although it is fictional, it could
easily have really happened. I'm not much of a party-goer, but base
on what little experience I've had at social functions and the stereotypical
behavior often portrayed in movies, the author's scenario likely
actually did occur. Maybe he exaggerates just a bit, though. The
follow-up situation would be a great gag to play on someone if you
ever get the chance. It probably would not be hard to get people
to fall for it.
RFMD® Intros 915 MHz ISM Tx/Rx Module
RFFM6901 is a single-chip front end module (FEM) for applications
in the 868/915 MHz ISM Band. The RFFM6901 addresses the need
for aggressive size reduction for typical portable equipment RF
front end design and greatly reduces the number of components outside
of the core chipset, thus minimizing the footprint and assembly
cost of the overall solution.
Office/AXIEM software, GreenPeak was able to successfully perform
RF board analysis, validation, and optimization for best RF performance,
certification margin, and production yield, while at the same time
cutting design iterations down to one or two when integrating its
custom design into the ZigBee remote control device.
are dressing for the office far more seriously, in an effort to
maintain a level of job security" -- Steven Faerm, Parsons the New
School for Design, in OFA
Please Welcome Mayfield Plastics as a New
Plastics provides in-house thermoforming and twin sheet forming
processes that can achieve the look and feel of injection molding
without the expensive tooling charge. Pressure forming
is able to form details normally found only in injection molding.
Thermoforming has many advantages over the use of sheet metal, such
as lower unit cost, lighter weight, and enhanced appearance.
Radomes, device enclosures, and control panels are among possible
Please Visit IPP to Thank Them for Their
is a manufacturer of RF passive components - 90° Couplers, directional
couplers, RF resistors and terminations. Connectorized, surface
mount. Custom designs are available.
Thanks to Antenna Factor for Long-Time Support
Factor, a division of Linx Technologies, manufactures standard
and custom antennas - monopole, dipole, embeddable, specialty, dualband,
GPS, fixed point, Yagi, evaluation systems, custom designs. Hole-mount
and magnetic bases available.
Anaconda Copper Mining Company Advertisement
not often that you will see a full-page ad promoting a particular
element in the periodic table, but in 1950 that wasn't the case.
This advertisement for
Anaconda Copper Mining Company promoted the virtues of element
number 29 - copper (Cu , from the Latin "cuprum"). Aluminum and
iron were other popular topics of advertising. If you do a search
on the history of Anaconda, which is today owned by the Atlantic
Richfield Company (ARCO), what dominates is the harm done to workers
and to the environment. The short video below is one of the less
vicious reports on the company's operations in Butte, Montana and
As with many forms of mining back in the day, miners were subject
to very hazardous conditions, lived in company towns in company
houses, sent their kids to company schools, and bought their groceries
at company stores. It was a rough life, and we who enjoy the abundant
freedoms and conveniences availed to us today owe...
GE "Black-Daylight" TV Ad in 1950 Saturday
might think I tend to dwell too much on the past because of all
the articles posted and references to vintage electronics companies
and their employees. Maybe I do. My motivation is two-fold. First,
I enjoy waxing nostalgic over the simpler, less crowded days of
yore that were the 1920s through 1940s, and even into the 1950s.
Things were not ideal by any means, but America was a thriving bastion
of national innovation and manufacturing. A "wow" factor surrounded
new discoveries and deserving heroes were created. Our friends as
well as our enemies were well-defined and our schools put more effort
into teaching literature, mathematics, and science than into what
"rights" could be demanded without earning them. Second, which really
follows from the first, is that I hope by reminding people of, or
in some cases - especially younger website visitors - introducing
for the first time, the fact that being a country that is fundamentally
independent while at...
Amateur Radio Stations VE2CP
the caption for a photograph in a 1931 article refers to an
"antiquated" motor, you can be sure you're looking at a really
old motor. Indeed it does look very old. Whenever I see vintage
photos or films of electrical / electronic apparati[sic] and operators,
I always look for safety issues like no eye protection while soldering
or when using powered tools to fabricate enclosures, lack of protective
shields around electrical connections and mechanical drive mechanisms,
wearing of inappropriate clothing near rotating machinery, etc.
In this case you can see a very long, totally exposed drive belt
running between that aforementioned antiquated motor and DC generator
that it drives (to power the transmitter). The author mentions how
the floor shook while it was running. I wonder if the filaments
were shaken enough to introduce the vibration frequency into the
audio (mircophonics)? Ah, the not quite so good old days.
AWR Announces Slate of Activities during
AWR Announces Slate of Activities during European Microwave
Week 2012. Highlights Include Software Demos in Booth #416 of AWR
2011 Product Portfolio and Analyst™; AWR and Partners MicroApps;
AWR/National Instruments Workshop; and Customer Appreciation Event.
SNL Skit on iPhone 5 Issues
is a hilarious spoof that
Saturday Night Live came up with for addressing the well-known
issues with the new iPhone 5. Christina Applegate plays the
host to a panel of tech industry gurus and a "trap" panel of Chinese
iPhone 5 factory workers. "Tech Talk" faux representatives
from real-life entities CNET, Wired Magazine, and Gizmodo gripe
about the funky maps, "purple haze" from the camera, and how easily
scratched the case is (these are the top 3 complaints by users).
After smarmily registering their complaints, the hostess then presents
employees from the iPhone 5 factory (Foxconn is never mentioned
by name) who proceed to sarcastically address each topic with responses
demonstrating how petty the whining is compared to their life's
woes in China under Communist rule. I won't give any more away;
you'll have to watch it to get the full effect of its humor.
Many Thanks for Backing by Linx Technologies
controls, evaluation kits and master development systems feature
straightforward hardware configuration and clear documentation.
Linx products make it simple for engineers and hobbyists to integrate
wireless features without the hassle and expense of engineering
RF functionality from scratch.
Sherlock Ohms: These Fuses Melt in Water
Ohms is a regular feature of Design News that presents submissions
from readers about troubleshooting challenges and how they were
solved. This one is titled "These
Fuses Melt in Water."
Free IEEE-USA eBook
for Success—An Engineer’s Guide, Volume 1: Designing for Success.
In the first book of this four-book series, award-winning author
Tom Moran presents writing from an engineer’s perspective: looking
at comparisons between the steps that lead to good engineering practice,
and those that result in writing excellence. Free download for members
through October 31, 2012.
Felix Baumgartner Sets Jump Height &
Sunday, October 14, 2012, Austrian parachutist
stepped out of his balloon-borne pressurized capsule at a record-setting
height of 128,000 feet and became the first man to break the sound
barrier during free fall (1.24 Mach).
The previous record had been set way back in 1960 by Joe Kittinger,
who handled communications with Felix during his stunt. Felix missed
breaking Joe's free fall duration record by a mere 6 seconds.
Red Bull sponsored the Stratos project.
Please Thank Apex Wireless for Its Continued
1985, Apex Wireless has offered consulting, engineering, and design
services focusing on high-performance, cost-optimized products that
employ wireless RF transmitters, receivers, and transceivers. To
complement our RF design expertise, we work with local experts in
DSP, ultra low power design, packaging, certification, and manufacturing.
Thanks to Alliance Test Equipment for Support!
rentals and leasing of refurbished electronic test and measurement
equipment to the R&D, manufacturing and quality assurance industries.
Alliance Test Equipment carries all major manufacturers' equipment.
Parallel Water Filters Increase Flow Like
municipal water supply here in Millcreek, Pennsylvania
(next to Erie), leaves a bad taste
in my mouth - literally. It's hard to make a good cup of coffee
with bad water, so I decided to install a high quality water filter.
The water pressure for the supply line is pretty good, so I figured
that pressure reduction due to the filter's presence would not be
too bad. I was wrong. This was no surprise since I have installed
the same type of filters in other houses. After about two years
of having about half the water flow from the cold water faucet as
from the hot, I decided to do something about it. Changing the filter
helped a bit, but not much. So, I figured it was time to test the
equivalency between water pressure and electromotive force pressure
(voltage) when applied through
parallel resistances. In this case the resistance is provided by
the water filters and the pressure is provided by the town's water
120,000-foot Parachute Jump in Process Live
Watch Felix Baumgartner make his ascent in the
Stratos capsule to 23 miles above Earth, then do a free fall
that could make him the first skydiver to break the sound barrier.
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
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