See Page 1 |
2 |
3 |
4 | of the March 2023 homepage archives.
Tuesday the 14th
The origin of the "10 codes"
used in Citizens Band (CB) radio communications is not entirely clear, and there
are several theories about their development. One theory suggests that the codes
were developed by the Illinois State Police in the 1930s to enable faster and clearer
communication over radio channels. Another theory suggests that the codes were developed
by the United States Army Signal Corps during World War II. Regardless of their
origin, the codes became widely used by CB radio operators in the 1960s and 1970s.
They were popularized in part by the 1975 movie "Smokey and the Bandit," which featured
the use of CB radio and the 10-4 code ("message received"). C.W. McCall helped
popularized CB radio with his "Convoy" song in 1975. This list of "10-Codes" came
from my copy of a Radio Shack book titled, "All About CB Two-Way Radio..."
As semiconductor device gate regions have
shrunk in size, vulnerability to electrostatic discharge (ESD) has increased. The
issue came to the forefront of the telecommunications industry's concerns during
the early days of the cellphone era (late 1990's / early 2000's). While working
at RFMD, I did quite a bit of ESD experimenting as part of their efforts to
develop GaAs PA's with a high level of ESD tolerance. Both
human
body model (HBM) and machinehand metal model (HMM) test were done. Huge advances
in ESD protection has been made throughout the electronics industry. This short
article from In Compliance magazine introduces the concept of ESD testing
requirements, procedures, and test equipment...
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.
Gold wire bonding is a popular technique
in the integrated circuit (IC) industry due to its reliability, durability, and
low resistance. The technique is commonly used to create interconnects between components
such as transistors, capacitors, and resistors, as well as to connect ICs to their
packaging. See table of bonding wire properties below. Thermosonic Wire Bonding
is a process used in the manufacturing of integrated circuits (ICs) to create interconnections
between the different components of the IC. This technique involves the use of heat
and ultrasonic vibrations to bond a thin wire made of gold or aluminum to the components
of the IC. The process of thermosonic wire bonding typically involves several steps.
First, a thin wire is fed through a machine that guides it to the correct location
on the IC. The wire is then heated using a combination of high-frequency ultrasonic
vibrations and thermal energy, which softens the wire and causes it to bond to the
components of the IC. One of the advantages of thermosonic wire bonding is that
it can create very strong and reliable bonds between the wire and the components
of the IC. This is because the ultrasonic vibrations used in the bonding process
help to break down any oxides or contaminants on the surface of the components...
"Researchers led by Dr Yi Wang from Birmingham's
School of Engineering created the new type of
high-performance phase shifter using a liquid Gallium alloy, which is said to
vary the phase angle of microwave and millimetre-wave radio signals. The phase shifter
is a key enabling technology for advanced phased array antennas (PAA) used in mobile
base stations, satellites and radar systems. PAA systems use multiple phase shifters
to provide the controlled phase increments that steer the radiation beam. However
current phase shifters typically use semiconductors and suffer from high loss of
signal and relatively poor power handling capability. In a statement, Dr. Wang said:
'An ideal phase shifter would provide a stable, and wide phase angle range with
a minimal loss of signal over the operation bandwidth. However conventional phase
shifters suffer from signal losses which increase as the phase angle increases,
and the phase varies with frequency. Taken together, these issues can cause signal
degradation and impair performance..."
Have you ever wondered what is inside the
familiar 9-volt battery (often referred to as a "transistor
radio battery" in the last century)? I have read about there being AAAA cells
(that's right, quadruple-A, A-A-A-A), but wanted to see for myself. So, I used a
small screwdriver and a pair of pliers to remove the outer metal case. This first
picture shows the six AAAA cells bundled together and contained with heat-shrink
tubing. In the bottom photo, you can see that all six AAAA cells are connected in
series. Each individual cell is 1.5 volts, so 6 x 1.5 = 9.0 volts.
For a size comparison, a standard triple-A (AAA) cell is shown next to one of the
AAAA cells. Here are the specifications for the Duracell Ultra 9V battery: Battery
Capacity: 550 mAh Battery Technology: Alkaline (Single Use) Current: 2.1000 A Depth:
17.0 mm Height: 48.5 mm Width: 26.2mm Voltage: 9.00 V Weight: 44.0 g Since the cells
are connected in series, than means the overall current rating for the battery assembly
is the same for each AAAA cell. So, each AAAA cell is rated at 2.1 amps with an
energy capacity of 550 mAh (milliamp-hours)...
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...
Triad RF Systems designs and manufactures
RF power amplifiers
and systems. Triad RF Systems comprises three partners (hence "Triad") with
over 40 years of accumulated knowledge of what is required to design, manufacture,
market, sell and service RF/Microwave amplifiers and amplifier systems. PA, LNA,
bi-directional, and frequency translating amplifiers are available, in formats including
tower mount, benchtop, rack mount, and chassis mount. "We view Triad more as a technology
partner than a vendor for our line-of-sight communications product line." Please
check to see how they can help your project.
Monday the 13th
Three out of five of these
electronics-themed comics are fire related. Maybe that was a common issue back
in 1960 when they appeared in Radio-Electronics magazine, but it was probably
just a coincidence. The page 39 comic has a topic common in the earlier days of
television as can be seen in some of the others in the huge list of electronics-
and technology-themed comics at the bottom the the page. Being a lifelong teetotaler,
I can't really relate to the page 153 comic, but I'm guessing a lot of RF Cafe visitors
can appreciate it...
Antenova Ltd, the UK-based manufacturer
of antennas and RF antenna modules for M2M and the IoT, is to reveal its latest
compact high precision GNSS module at Embedded World. The new product,
GNSSNova M20072, is a GNSS receiver with integrated GNSS antenna and greatly
reduced power consumption. M20072 uses a MediaTek 12 nm low energy chip with
1.8V power supply which uses 70% less power than older chipsets. The power consumption
of the module can therefore be as low as 21 mW for a GPS fitness tracker, and
GNSS-enabled products built with the M20072 will have a longer battery life. Antenova
created this ready-made receiver solution for easy integration into a design. The
module contains an integrated omni-directional GNSS antenna, on-board LNA and a
SAW filter which work together to boost the signal to the GNSS processor if line-of-sight
to the horizon is difficult...
Here is a great treatise on
waveguide theory put in layman's language, compliments of Samuel Freedman and
DeMornay Budd. Although published in a 1948 issue of Radio & Television
News magazine at a time when microwave frequencies were just coming into common
use, the language and descriptive drawings are similar to what you will find in
modern textbooks. Waveguide is not practical for use at lower frequencies because
the physical dimensions are prohibitively large. For instance, for the FM radio
band (88-108 MHz), waveguide width for a TE10 cutoff frequency at 88 MHz
is around 67.5 inches. According to Wikipedia, the first waveguide was proposed
by J.J. Thomson in 1893 and experimentally verified by Oliver Lodge in 1894...
Keysight Technologies has introduced a new
Iterative Learning Control (ILC) test method that significantly shortens
Digital Pre-Distortion (DPD) test times for power amplifiers. Power amplifiers
(PA) are a core component of wireless communication devices. Characterization of
these components is a critical but time-consuming task that can take hours or even
days during the R&D phase. By shortening the time it takes to complete the design
and validation process, power amplifier manufacturers are able to accelerate their
time-to-market. Keysight meets this need by introducing the innovative ILC DPD test
method that shortens DPD test time to minutes and accelerates R&D time from
test validation to product design and optimization. As a part of Keysight's comprehensive
High-Frequency Measurement Solution portfolio, the ILC test method runs...
Mankind has been fascinated with - and scared
of -
lightning since the dawn of civilization. It's incredible power has been the
cause of much property destruction and loss of life. Benjamin Franklin famously
proved that lightning is in fact a form of electrostatic discharge (he didn't "invent"
electricity). Mr. Franklin exploited that knowledge to invent grounded lightning
rods for tall buildings, thereby nearly totally halting the lightning-caused fire
epidemic in Philadelphia's and other cities' tallest wooden-framed buildings. Much
investigation and implementation of lightning discharge mitigation schemes has occurred
to safeguard against those catastrophic events. Ultimately, though, says author
David Heiserman in this 1973 Popular Electronics magazine article, "Lightning
has no sympathy for the feeble electrical schemes of civilized man..."
New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite
of engineers, technicians, hobbyists, and students all over the world. With more
than 17,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be.
Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Sunday the 12th
To be or not to be - that is the question:
Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous bi-annual
clock shifts, or to take up arms against a sea of contradicting justifications for
and against the existence of "Daylight
Saving(s) Time," and by opposing, end it. (apologies to Will Shakespeare and
Prince Hamlet) Twice each year, a majority of the western world is subject to a
manmade disruption in circadian and habitual cycles with an inane one-hour clock
change on and off of DST. Some historians claim that Benjamin Franklin joked about
DST in the 18th century, but it was New Zealander George Hudson who proposed the
modern day clock shift scheme in 1895. Germany, on April 30, 1916, was the first
country to officially adopt DST. Since then, many other countries have gone onto
and off of Daylight Saving Time. The motivation varies from saving coal during wartime
to giving farmers more daylight for tending to crops to keeping school kids from
being run over by cars on dark mornings. As you might expect, "expert" evidence
is presented in abundance both for and against each issue. Every spring and fall
(actually now winter and fall) the debate begins anew regarding whether DST is still
needed. Some people want to retain the twice-yearly clock shift, some want year-round
Daylight Saving Time, and most of the rest (including me) want year-round Standard
Time (ST)...
This custom RF Cafe
electronics-themed crossword puzzle for March 12th contains only words and clues
which pertain strictly to the subjects of electronics, mechanics, power distribution,
engineering, science, physics, astronomy, chemistry, etc. If you do happen see names
of people or places, they are directly related to the aforementioned areas of study.
As always, you will find no references to numbnut movie stars or fashion designers.
Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds
of them dating back to the year 2000. Enjoy.
Providing full solution service is our motto,
not just selling goods. RF & Connector Technology has persistently pursued a management
policy stressing quality assurance system and technological advancement. From your
very first contact, you will be supported by competent RF specialists; all of them
have several years of field experience in this industry allowing them to suggest
a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable
assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically,
we put priority on process inspection at each step of workflow as well as during
final inspection in order to actualize "Zero Defects."
Friday the 10th
It is no stretch of the truth to say a sub-$100
remote-controlled drone or airplane from the toy aisle in Walmart today has more
sophisticated guidance and stability control than the most advanced missile available
in 1960, when this "Missile
Control and Guidance" article appeared in Radio-Electronics magazine.
Multi-axis accelerometers, processors, motor controllers, and even wireless off-vehicle
communications are integrated into a couple (or a few, depending on the capabilities
of the platform) integrated circuits. A full-color camera, possibly on a controllable
gimbal, might be part of the system. True, scaling vehicle control mechanisms up
to handle the rugged environment of a real-world missile with critical propulsion,
flight, targeting and detonation mission requirements requires much more engineering
than a toy aircraft. My point is that the heart of the system in 1960 was more crude
and less capable than today's recreational vehicles. It is akin to how your smartphone
has more computing and data storage capability than a 1960's era mainframe computer
- and significantly more than the Apollo 11 flight control computer that delivered
three men to and from the moon...
This "Brightest
Light Quiz" created by Robert Balin appeared in the April 1964 issue of
Popular Electronics magazine. I might have titled it "The Brightest Bulb in
the String Quiz" in reference to the saying about how "bright" someone is or is
not. Figuring out the answer is a relatively simple matter of determining which
branch of the circuit has the most current flowing through it. Some, like circuit A,
are pretty easy by noting that all the current flows through just one of the bulbs,
so that has to be the brightest. Re-drawing, either mentally or on paper, helps
with circuits C, G and J and a few others. Un-cross lines and/or combine nodes with
no bulb between them that are at the same potential. Circuit J is probably
the most challenging, so re-drawing it is worthwhile...
Designing IoT products just got a whole
lot easier. Synzen Precision Technology, a leading provider of IoT solutions, has
announced the launch of a new development platform that uses the advanced capabilities
of the
Nordic
nRF9160 module. This new platform is designed to simplify the creation and deployment
of IoT projects while ensuring seamless connectivity and secure data transmission.
The Nordic nRF9160 module is a highly advanced chip that supports LTE connectivity,
Bluetooth Low Energy (BLE), and Global Navigation Satellite System (GNSS). Using
innovative antenna design techniques, engineers at Synzen have developed a new LTE
solution whereby no band switching networks are required, which greatly reduces
costs, complexity, and required PCB real estate. The whole package comes in a small
form factor, measuring a compact 50x50 mm...
"There is no new thing under the sun." -
Ecclesiastes 1:9. "Everything old is new again." - Peter Allen in All That Jazz.
Many such idioms exist regarding how often things tend to run in cycles; it's just
that often times people who think they are witnessing a new phenomenon are not aware
of the previous occurrences. An article titled "OMG! We've Been
Here B4," by Clive Thompson, appeared in the March 2016 issue of Smithsonian
magazine, wherein he points out how many people believe the advent of texting is
leading to the demise of courteous social spoken intercourse. Unlike holding a face-to-face
or telephone conversation where both parties are intimately engaged in a conversation
where each can discern whether the other hears what is being said and can expect
a response, texting provides an easy excuse for ignoring any portion of the communications
and blaming it, if challenged, on not having received or not having noticed the
text message. He alludes to the following poem by Carl Sandburg (c1916) entitled
"Under a Telephone Pole..."
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
Wireless Telecom Group,
comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer
of advanced RF and microwave components, modules, systems, and instruments. Serving
the wireless, telecommunication, satellite, military, aerospace, semiconductor and
medical industries, Wireless Telecom Group products enable innovation across a wide
range of traditional and emerging wireless technologies. A unique set of high-performance
products including peak power meters, signal generators, phase noise analyzers,
signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable
noise generators.
Thursday the 9th
This
vacuum tube shaped crossword puzzle appeared in the April 1964 issue of
Popular Electronics magazine. It won't take you more than a couple minutes
to complete - just a short trip, with a pencil, to the John ;-) Like with
all my custom-made RF Cafe Crossword Puzzles, every clue and word in this crossword
by Stephen Nelson has an application to electronics technology. Unlike with my crosswords,
the across/down grid is very simple with few groups of adjacent empty squares. That
makes creation an easier task, especially when your word selection list is constrained
to a particular topic. Still, it's a good puzzle. Have fun.
This is a true story. When I was in 9th
grade, the class was being shown a film (yes, the celluloid type on a reel, on a
projector, circa 1972-73) where the narrator mentioned how someone had committed
a "boner." A girl in the class busted out laughing so hard that she actually wet
herself. That made the rest of the class laugh. I guess she had never heard the
word used in that context before - remember, we're talking teenagers in the 1970's.
Sorry for the rude reference, but for some reason the incident came to mind when
reading the section labeled "Radio
Boners" in this article from a 1935 edition of Radio-Craft magazine.
Funny what triggers a particular memory. All that has nothing to do with C.W. Palmer's
fine story that addresses some of the common misconceptions about the relatively
new technology called "radio," when even a term like "speaker" might cause confusion...
"Researchers at the Dalian Institute of
Chemical Physics have found a way to deposit
micro-supercapacitors
consistently on surfaces such as silicon as a way to add energy storage directly
to ICs. This is not the first time that supercapacitors have been deposited on such
substrates, but the team claims to have combined unprecedented cell density, electrochemical
performance and cell-to-cell consistency – the latter important if series-connected
cells are to have a long charge-discharge cycle life. Dalian institute micro super
capacitors. The basic structure is planar, with capacitance developed between interdigitated
electrodes on the same flat surface..."
You wouldn't know it from the schematic,
but this
Coronet Model C2 tabletop radio has a very unique feature: The tuning scale/pointer,
and volume and tuning knobs are on the top of the case, that is, the face of the
radio points upward when properly displayed. When searching for photos of the Coronet
C2, I found a few examples where the radio was sitting on a surface with the face
situated vertically like a standard model, but the feet are clearly on the side
opposite the face. The schematic and parts list for the Coronet C2 radio appeared
in the February 1947 issue of Radio News magazine. There are still many people who
restore and service these vintage radios, and often it can be difficult or impossible
to find schematics and/or tuning information. I keep a running list of all data
sheets to facilitate a search...
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...
LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
Wednesday the 8th
Nomographs for calculating and converting
values for resistance, capacitance, inductance, transformer coupling, frequency
and wavelength, path loss, resonant frequency, AC impedance, and other parameters
appeared in many magazines over the decades. In the days before handheld electronic
calculators and, nowadays, smartphones, the use of a nomograph provided rapid solutions
for sometimes complex mathematical equations. This particular nomograph calculates
resistor values in series and parallel, where two resistors are combined to yield
the required resistance. Series resistances are a simple matter of addition, but
parallel resistance requires combinations of addition, multiplication, and division.
Multiplication and division could be carried out with the help of a slide rule,
but addition was still done by hand (slide rules don't do addition or subtraction).
A unique feature of this particular "Parallel
Series Resistance Calculator" from the August 1960 issue of Radio-Electronics
magazine is the inclusion of a straight edge component for cross-referencing the
two scales on the chart. While it might seem clever...
"China's ambitions to build the world's
most powerful
space observation radar - to peer further out and with greater detail than ever
before - moved a step closer on Tuesday, with the start of work on stage two of
the China Compound Eye. Long Teng, president of the Beijing Institute of Technology
(BIT), which is leading the project, said that once completed, Chongqing, where
the project is based, 'will become the world's capital of asteroid research '[The]
launch of the second phase of the China Compound Eye project marks a new stage of
our research. It will promote the development of high-end industries such as big
data, electronic information, and satellite internet in Chongqing,' he said, in
a BIT statement..."
A copyright, as you know, is legal protection
against unauthorized usage or obvious modification of original creative works, something
most people who generate valuable works like because it represents a right to private
property. A copyleft, on
the other hand, is an alternative which permits free distribution of original works
with the only restriction being that it and/or derivative works also be declared
copyleft material. Note how evil Capitalist companies like IBM, Artech House publishers,
and Rohde & Schwarz copyright and patent everything they create in
order to benefit financially from the work of their employees. Doing so allows them
to provide good wages and benefits while creating useful goods and services for
customers. Liberal-dominated companies like Google, Apple, and Facebook, by contrast,
allow everything they create to be freely copied and/or modified by anyone. Their
only concern is the welfare of fellow men. Oh, wait. The fact is those kinds of
companies also copyright and patent everything they create...
Civil aviation requires accurate and reliable
navigation systems for optimizing air traffic control (ATC) and ensuring the essential
public safety while mitigating aircraft risks, delays and costs. Terrestrial air
navigation systems, such as landing systems or en-route navigation systems require
unique test and measurement capabilities. The
R&S EVSD1000 VHF/UHF nav/drone analyzer is a signal level and modulation
analyzer for medium-sized drones. It is the only instrument that combines measurements
of instrument landing systems (ILS), ground-based augmentation systems (GBAS) and
VHF omnirange (VOR) ground stations in a single box. The mechanical and electrical
design is optimized for drone based, real-time measurements of terrestrial navigation
systems with up to 100 measurement data sets per second. The analyzer provides high-precision
signal analysis in the frequency range from 70 MHz to 410 MHz, a critical
requirement for drone based terrestrial navigation signal measurement systems...
The
National
Company of Cambridge, Massachusetts, was one of the first large distributors
of electronics components and appliances. It began life as the National Toy Company.
Under the leadership of Mr. James Millen, W1HRX, National quickly became a market
leader in designing and marketing high quality radio products for both amateur radio
operators and casual listeners of shortwave radios. National Company very often
ran full-page advertisements in the American Radio Relay League's QST magazine,
that were more in the form of an infomercial than pure product promotion. This one,
number 98 in a very long-running series, extolls the virtues of their famous NSM
Modulator. The majority of these ads were written my Mr. Millen, but in this
case it was done by Calvin Hadlock. A bit of trivia: National Company was the first
paid advertiser in The Radio Amateur's Handbook...
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...
KR Electronics has been designing and manufacturing
custom filters for military and commercial radio, radar, medical, and communications
since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass,
bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for
special applications - both commercial and military. State of the art computer synthesis,
analysis and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Please visit
their website today to see how they might be of assistance. Products are designed
and manufactured in the USA.
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.
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