See Page 1 |
2 |
3 |
4 of the December 2022 homepage
archives. Wednesday the 14th
 Concern over electrical shock is a good attitude
to adopt for just about any item that plugs into an outlet. Much has been done to
mitigate the opportunity for personal injury since this Mac's Service Shop article
entitled "Electric
Shock" appeared in a 1965 issue of Electronics World magazine. At the
time, there were still older radios and televisions that had an internal metal chassis
which could be at the line voltage (usually 110-120 V) depending on which way
the power cord was plugged into the wall. Polarizing wall receptacle slots (neutral
on left is taller, hot on right is smaller) helped to assure that a lamp socket,
for instance would have the outside area of the screw-in socket was at neutral and
not hot, thus minimizing the chance of receiving a shock. Adding a safety ground
to power cords that bonded to user accessible metal parts was a good first step,
but at least in the early days many receptacles did not have the third hole to accept
the ground prong. The only option for people determined to use the device was to
cut off the ground prong or use an adapter. The better option was to assure no metal
components were external to the product, and even adopting a "double insulated"
practice where at least two layers of insulation stood between the user and the
potentially...
 The ambition of amateur hobbyists has always
amazed me. In practically every area of technology, amateurs have contributed significantly
to the effort of pushing back the frontiers of ignorance by developing new applications,
improving existing products, and demonstrating to commercial companies a need for
new features or products. Many of those innovative hobbyists make a living in the
field they choose for off-hours recreation. As a heavy reader of technology and
hobby magazines of all sorts, I know this to be true for musicians, boaters, pilots,
radio operators, gardeners, science experimenters, woodworkers, and many others.
Levels of quality of finished products are awesome in the master class competitions.
The amount of money spent by some for their "hobbies" is shocking. This
laser communications article from the May 1970 Popular Electronics
magazine is a prime example of that. The author uses off-the-shelf components to
construct both the transmitter and receiving components. A quick tally of the most
expensive parts...
 During
this time of year 44 solar orbits ago (yikes!), I was "enjoying" my fifth week of
USAF Basic Training. It marked the transition from a trade in residential and
commercial electrical wiring to a career in electronics. November 9, 1978 was a
date which will live in infamy - for me, anyway. That was the day I left my comfortable,
oblivious 20-year-old existence as an electrician in Mayo, MD, and boarded a Delta
Airlines flight to San Antonio, Texas. About six months earlier I had signed up
under the Delayed Enlistment program. I was on my way to becoming a fully trained
and qualified Weather Equipment Specialist, a career field chosen based on my keen
interest in weather phenomena, aviation, and aerospace. The plan was to survive
six weeks of Basic Training (BT) at Lackland Air Force Base, TX, and then go on
to technical school at Chanute AFB, IL. My first official act was to carry along
with me a sealed envelope containing the data of all enlistees boarding the flight
from BWI airport, to be surrendered to the sergeant who would ask for it upon arrival
in San Antonio. I was psyched. Following deboarding at SAT, a uniformed person directed
our troupe to a staging area while awaiting a bus for the ride to Lackland AFB.
We were to stand quietly, looking forward. It was a small sampling of what was to
come. After what seemed like a long bus ride, we drove past the guard house at the
gate, rode to some building and were led into a dining hall for grub...
 Anatech Electronics (AEI) manufactures and
supplies RF and microwave filters for military and commercial communication
systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters,
and RF products. Standard RF filter and cable assembly products are published in
our website database for ease of procurement. Custom RF filters designs are used
when a standard cannot be found, or the requirements dictate a custom approach for
your military and commercial communications needs. Sam Benzacar's monthly newsletters
address contemporary wireless subjects. Please visit Anatech today to see how they
can help your project succeed.
 To be honest, I didn't know a controversy
existed over "Who Really Invented
the Thumb Drive?" It certainly doesn't seem to be on the level of whether A. Bell
or E. Gray invented the telephone, or whether it was the Wrights or Whitehead
who first succeeded in powered flight. Evidently, though, some technophiles debate
the thumb drive issue with passion, or else the IEEE's Spectrum magazine
would not likely have devoted an article to the subject. It begins: "Thumb drive,
USB drive, memory stick: Whatever you call it, it's the brainchild of an unsung
Singapore inventor. In 2000, at a trade fair in Germany, an obscure Singapore company
called Trek 2000 unveiled a solid-state memory chip encased in plastic and attached
to a Universal Serial Bus (USB) connector. The gadget, roughly the size of a pack
of chewing gum, held 8 megabytes of data and required no external power source,
drawing power directly from a computer when connected. It was called the ThumbDrive.
That device, now known by a variety of names - including memory stick, USB stick,
flash drive, as well as thumb drive - changed the way computer files are stored
and transferred. Today it is familiar worldwide..."
 A decade ago, I featured a quilt made by
Sara Schechner that depicted the 26" Alvan Clark telescope. She later contacted
me about having learned of its appearance on RF Cafe. Sara is the curator of the
Collection of Historical Scientific Instruments at Harvard University, and holds
a PhD from Harvard. She wrote a book in 1997 entitled, "Comets, Popular Culture,
and the Birth of Modern Cosmology." It includes an extensive collection of ancient
drawings and etchings of astronomical events such as comets, meteors, super novae,
and solar system conjunctions, as well as implications of such phenomena in significant
world events. While reading it, I ran across this etching depicting "Archimedes
beholding both [planets and comet] in his Jacobs Staff." The first thing that struck
me in the image is that the
Jacob's Staff looks
an awful lot like a log periodic antenna. Could Archimedes actually be pointing
a directional radio frequency antenna at the comet in an attempt to communicate
with alien beings in a starship, rather than using it to determine the celestial
coordinates of the object? Maybe aliens provided it to him...
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
Tuesday the 13th
 If you were around during the Y2K era, which
was from about the middle of the 1990's through the last day of the 20th century,
you had to have heard about the looming disaster being caused by outdated computer
software, hardware, and firmware that would not be capable of properly handling
the rollover of dating years from 19xx to 20xx. The programming languages mentioned
in this 1968 "Computer
Lingo - Today's New Machine Languages" Radio-Electronics magazine articles were
all still present to some degree at the end of the 1900's. One of the biggest problems
was that limited size data fields (often 8-bit words) led many - actually most -
early mainframe systems to assume the "19" part of a year, so after midnight of
December 31st, 1999, the next day would be interpreted as January 1st, 1900 rather
than 2000. Any date-dependent function would fail utterly, and possibly cause a
catastrophic result. Electric grids, waterworks, industrial processing plants, accounting
departments, and other such entities would be in chaos. The problem was not limited
to large mainframe computers. Many embedded processors in systems and individual
products were destined to fail as well. Even personal computers would suffer date-related
failures...
 "This article presents the amazing development
of the
Tesla coil, its issues with electromagnetic interference, and how the coil is
still being used today. Steve Taranovich writes in Electronics Design:
"When I lived in Long Island, N.Y., I had a most interesting experience when visiting
Nikola Tesla's Wardenclyffe Tower location. The tower stood tall from 1901 to 1917,
on a 200-acre plot, in this remote location on the North Shore of Long Island. It
wasn't far from my home for most of my life. Now just imagine a relatively small
Tesla coil able to generate an electromagnetic field that could induce electrical
currents in nearby conductors. Imagine how much havoc this could wreak on present-day
computers, communications, building wiring, and other electronics. Tesla's Tower
would be far more powerful than a small, experimental coil tested in a lab..."
 Increasing
women's roles and interest in STEM (science, technology, engineering, mathematics)
careers has been a major effort by schools in the last couple decades in an attempt
to "remove barriers," both real and perceived, inhibiting entrance into the fields.
There are still many realms of STEM that women have avoided, but computer programming
and mathematics are examples their representation having seen steady increases.
Dr. Frances Bauer can be seen in this 1955 Popular Electronics magazine story on
Project Cyclone, which reports on her role programming what was at the time one
of the largest computers in the world. Her work ran the gamut between civil engineering
on bridge projects to predicting missile flight paths for the military. You might
recall the U.S. Navy's Grace Hopper, who is credited with coining the term "bug"
for computers...
R&S Liquid Cooled Air Traffic
Control over Greenland
 In the summer of 2023, Rohde & Schwarz
will be delivering low-maintenance and compact
R&S SK4105 shortwave transmitters to Naviair, the Danish air navigation
service provider that handles air traffic in the lower airspace from the Flight
Information Center (FIC) in Greenland. Greenland’s airspace is huge and transmitter
stations are placed in remote locations. Naviair operates several HF and VHF radio
systems at strategic points along the Greenlandic coast. The Flight Information
Center (FIC) in Nuuk, Greenland, is responsible for primary communications. Its
legacy HF transmitters will soon be replaced with the new, high power R&S SK4105
shortwave transmitters...
 "Merry Christmas!" Here is a 2-page advertisement
run by the
E.F. Johnson company in the December 1953 issue of the ARRL's QST
magazine. E.F. Johnson was a major player in amateur radio, and then later
Citizens Band (CB) radio. They also manufactured a large array of point-to-point
commercial radio products (Land Mobile Radio Service, LMRS, and Commercial Mobile
Radio Service, CMRS), as well a large line of RF connectors and adapters. The wireless
automatic meter reading (AMR) industry was pretty much born out of a very capable
group of engineers, technicians, assembly workers, and managers at E.F. Johnson's
facility in Waseca, Minnesota. They occupied a portion of the very large building
where E.F. Johnson manufactured its many products (back when Americans actually
built electronics equipment). The break-off company was originally named Enscan,
and was later bought by Itron. Sensus is another major AMR product maker...
RF Cascade Workbook is the next phase in the evolution of
RF Cafe's long-running series, RF Cascade Workbook. Chances are you have
never used a spreadsheet quite like this (click here for screen capture). It is a full-featured RF system
cascade parameter and frequency planner that includes filters and mixers for a mere
$45. Built in MS Excel, using RF Cascade Workbook 2018 is a cinch
and the format is entirely customizable. It is significantly easier and faster than
using a multi-thousand dollar simulator when a high level system analysis is all
that is needed. An intro video takes you through the main features...
Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
Monday the 12th
 The November 1965 issue of Electronics World
magazine featured a set of articles reporting on the fledgling semiconductor industry.
The title of this one, "Integrated
Circuits: What's Available?" would require volumes to print today, but at the
time the selection could be summed up with a relatively small amount of paper and
ink. Author Donald Lancaster exuberantly and correctly predicted some of the many
products and uses that miniaturization and capability the burgeoning technology
would enable. Among them he cites desk[top] computers priced lower than mechanical
adding machines, picture-on-the-wall TV, truly portable communications, vehicular
anti-collision devices, precision counters, clocks, and controls. That's impressive
foresight. That's pretty impressive. He further mentions extended (compared to vacuum
tubes) temperature and frequency ranges, along with greater mechanical robustness.
Of course prices would rapidly drop not only for the semiconductor devices themselves,
but for the accompanying parts and products they are designed into...
 "Maverick's next wingman might be a drone.
Make that four or five collaborative combat aircraft, or CCA, working together to
execute a set of 'plays' with minimal direction from a human pilot, who 'quarterbacks'
the mission from a formation positioned near those drones. That's the vision of
the U.S. Air Force for its sixth-generation fighter, and one of the service's seven
operational imperatives for the future force, specifically 'Defining the Next Generation
Air Dominance (NGAD) System-of-Systems.' In March 2022, during the Air Force Association's
Warfare Symposium, Secretary of the Air Force Frank Kendall said during his keynote
address that 'NGAD must be more..."
 As with the article in this month's issue
of Radio-Craft magazine (December 1937), the reference to a 200th anniversary
is understated by 78 years for 2015.
Luigi Galvani was sort of the Benjamin Franklin of biology in that just as Franklin
demonstrated that lightning was a form of electricity, Galvani showed that signals
sent from the brains to the appendages of animals were electrical in nature. In
my high school days in the 1970s, we duplicated his experiment by making deceased
frogs' legs twitch when motivated by a D cell. Today, such an exercise would likely
be met with demonstrations by animal rights people (whose lives, BTW, have probably
in some way been improved as a result of previous such experiments). But, I digress.
Mr. Galvani's name is now paid attribution through the many words based on
it, such as galvanization, galvanometer (mechanical meter movement), galvanic corrosion
(eroding of dissimilar metals)...
 RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees and/or managers of hiring companies are welcome
to submit opportunities for posting at no charge (of course a gratuity will be graciously
accepted). 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors ...
 Withwave manufactures an extensive line
of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated
4-port vector network analyzer (VNA) calibrator, between- and in-series connector
adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes &
probe positioner. Special test fixtures for calibration and multicoax cable assemblies.
Frequency ranges from DC through 110 GHz. Please contact Withwave today to
see how they can help your project succeed.
Sunday the 11th
 This is your custom made
Electronics Themed crossword puzzle for December 11th, 2022. All RF Cafe crossword
puzzles are custom made by me, Kirt Blattenberger, and have only words and clues
related to electronics, electricity, radio, radar, RF, microwave, and mm-wave engineering,
optics, mathematics, chemistry, physics, and other technical subjects. As always,
this crossword contains no names of politicians, mountain ranges, exotic foods or
plants, movie stars, or anything of the sort unless it/he/she is related to this
puzzle's technology theme (e.g., Reginald Denny or the Tunguska event in Siberia).
The technically inclined cruciverbalists amongst us will appreciate the effort.
Enjoy!
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
Anatech Electronics (AEI) manufactures and
supplies RF and microwave filters for military and commercial communication
systems, providing standard LP, HP, BP, BS, notch, diplexer, and custom RF filters,
and RF products. Standard RF filter and cable assembly products are published in
our website database for ease of procurement. Custom RF filters designs are used
when a standard cannot be found, or the requirements dictate a custom approach for
your military and commercial communications needs. Sam Benzacar's monthly newsletters
address contemporary wireless subjects. Please visit Anatech today to see how they
can help your project succeed.
Friday the 9th
 This set of
electronics-themed comics from a 1956 issue of Radio-Electronics magazine hits
on a variety of topics that were big in the day. Computers were coming into the
public realm rather than just being a sci-fi wonder. Home personal computers were
still a couple decades away, but mainframes were being imposed on the public through
accounting and merchandising venues, rather than just curiosities of research laboratories.
The "large screen" 27" television cabinet was necessarily deep enough to park a
car in because cathode ray tubes (CRT's) were used, not flat screen plasma, LCD,
or LED displays. Look closely at the captionless hospital scene to see what's going
on there. Finally, as usual, the trials and travails of the typical TV repairman
is included...
 "In May 2022, the
TeraByte InfraRed Delivery (TBIRD) payload onboard a small CubeSat satellite
was launched into orbit 300 miles above Earth's surface. Since then, TBIRD has delivered
terabytes of data at record-breaking rates of up to 100 gigabits per second - 100
times faster than the fastest internet speeds in most cities - via an optical communication
link to a ground-based receiver in California. This data rate is more than 1,000
times higher than that of the radio-frequency links traditionally used for satellite
communication and the highest ever achieved by a laser link from space to ground.
And these record-setting speeds were all made possible by a communications payload
roughly the size of a tissue box. MIT Lincoln Laboratory conceptualized the TBIRD
mission in 2014 as a means of providing unprecedented capability to science missions
at low cost. Science instruments in space today routinely generate more data than
can be returned to Earth over typical space-to-ground communications links..."
 An avid philatelist in my teens and twenties,
I collected, along with other stamp varieties, many First Day Covers, which are
specially designed envelopes bearing a new stamp design and are postmarked in the
city, on the day which they are formally released. Last night I finally got around
to digging out my
First Day Cover commemorating The International Geophysical Year (IGY), released
on May 31, 1957, in Chicago, Illinois. The IGY (actually IGYaaH - IG year-and-a-half)
began on July 1, 1957 and ran through December 31, 1958. It was the dawn of space
/ high altitude flight and there was a great need to learn as much as possible about
the physics of the upper atmosphere and the void of space. The USSR successfully
flew their first three Sputnik satellites and the U.S. was scrambling to get Echo
into orbit (finally on August 12, 1960, after the end of IGY). "During
this time, more than 5,000 scientists and engineers of more than 60 nations are
conducting intensive investigation and study of the earth, the atmosphere and the
sun. Into these 18 months are crammed 30 or 40 ordinary years of research as science
attempts...
 Just as optimizing the transmission path
between an RF transmitter and receiver helps guarantee the best possible fidelity
in receiving an exact copy of the transmitted signal, so, too, does
optimizing the signal path for an audio signal help guarantee a faithful replicate
of the original sound. This article from the March 1959 edition of Popular Electronics
magazine is a primer on the topic of understanding how the human ear perceives sound,
and how to best facilitate a good match between the speaker and the ear drum. In
the era, home-base hi-fi equipment was a big deal, as was building out listening
areas for optimal performance. Room floor, wall and ceiling materials and finishes,
dimensions, and placement of furniture, window coverings, wall decorations, etc.,
were all taken into account for serious audiophiles...
 Here is a sample of what passed as big news
in the electronics world in 1965 as reported in none other than Electronics
World magazine. Linear integrated circuits were beginning to be designed into
commercial products and a lot of effort and money was invested in promoting the
newfangled technology to the public. Prices were rapidly falling as acceptance increased.
The truth is the vast majority of the general public had no idea what the
difference was between vacuum tube and semiconductor equipped radios, televisions,
phonographs, tape recorders, etc., from a performance standpoint. What they did
notice was the smaller size, lack of warm-up time, and lower power consumption (i.e.,
less heat). Prices were about the same at the beginning of the technology transition.
Some anti-semiconductor naysayers tried to argue that at least with tube equipment
you had a chance of fixing a malfunctioning unit simply by replacing a $1 tube,
but failed to note that the equivalent semiconductor product almost never experienced
a failure. Of course there were some crappy transistorized products, but that was
the exception rather than the rule...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 The leading website for the PCB industry.
PCB Directory is the largest directory of
Printed Circuit Board (PCB)
Manufacturers, Assembly houses, and Design Services on the Internet. We have listed
the leading printed circuit board manufacturers around the world and made them searchable
by their capabilities - Number of laminates used, Board thicknesses supported, Number
of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical
location (U.S., China), kinds of services (manufacturing, fabrication, assembly,
prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
Thursday the 8th
 "The equivalent to a
wormhole in space-time has been created on a quantum processor. Researchers
in the U.S. used an advanced quantum teleportation protocol to open the wormhole
and send quantum signals through it. By studying the dynamics of the transmitted
quantum information, the team gained insights into gravitational dynamics. The experiment
could be further developed to explore quantum gravity or string theory. A wormhole
is a bridge in space-time that connects two different locations. While wormholes
are consistent with Albert Einstein’s general theory of relativity, they have not
been observed by physicists. Unlike wormholes in science fiction, they are not traversable
– meaning things cannot pass through them. Although general relativity forbids travelling
through a wormhole, it is theorized that exotic matter..."
 The Radio Service Data Sheets that were
published in Radio-Craft magazine usually seem to have more information
included than those published in other magazines, at least in the same era (1940-ish).
It might have to do with how much material is provided by the manufacturer rather
than a decision by the magazine editors. Either way, here are the schematics, chassis
layout, and service info for the
Lafayette Model B-100 through B-103. As with most radios built in the era, the
woodwork and artistic design of the cabinet are exquisite. There are still people
searching for such data, but fortunately the Internet is making it much easier to
locate. None of the three models show up on eBay as of this writing...
 Anatech Electronics offers the industry's
largest portfolio of high-performance standard and customized
RF and microwave filters and filter-related products for military, commercial,
aerospace and defense, and industrial applications up to 40 GHz. Three new
filter models have been introduced - a 650 MHz LC lowpass filter with
a maximum passband 1 dB insertion loss (SMA connectors), a 30 MHz LC lowpass
filter with a minimum passband return loss of 15 dB (N connectors), and a 3800 MHz
lowpass filter with a maximum insertion loss of 1 dB (SMA connectors). Custom
RF power filter and directional couplers designs can be designed and produced with
required connector types when a standard cannot be found, or the requirements are
such that a custom approach is necessary...
 Here you are -
portable satellite communications in the mid 1960s per this photo from Electronics
World magazine. It has a unique "cloverleaf" ganged parabolic antenna array
with phasing control. Today, we have "manpack" type systems which use compact antennas
that can be quickly assembled and disassembled in any environment, along with receivers
that have sensitivities much greater than the type shown here. As the name implies,
they are transportable in backpack form. Software-defined radio (SDR) technology
facilitates programmable modulation and frequency band operation. The Mark V AN/TSC-54
Satellite Communications Link Terminal featured here operated at 8/7.5 GHz
up/down. An information page for the Mark V AN/TSC-54 can be found on the GlobalSecurity.org
website, which includes in part, "It is completely transportable in two C-130 cargo
aircraft." I guess the definition of "portable" has changed a bit since then...
 Empower RF Systems is the technological
leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat
Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers
incorporate the latest semiconductor and power combining technologies and with a
patented architecture we build the most sophisticated and flexible COTS system amplifiers
in the world. Solutions range from tens of watts to hundreds of kilowatts and includes
basic PA modules to scalable rack systems.
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees and/or managers of hiring companies are welcome
to submit opportunities for posting at no charge (of course a gratuity will be graciously
accepted). 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors ...
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.
About RF Cafe.
Homepage Archive Pages
2025:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2024:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2023:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2022:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2021:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2020:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2019:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2018:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2017:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2016:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2015:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2014:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2013:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2012:
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 (no archives before 2012)
- Christmas-themed
items
|
