See Page 1 |
2 |
3 |
4 | of the April 2023 homepage archives. Friday the 7th
 Being that this
Circuit Quiz appeared in a 1966 issue of Radio-Electronics magazine,
the amplifier components shown are transistors, rather than vacuum tubes. I have
to admit to not doing very well on it. One of the challenges is first determining
what the intended function of the circuit is supposed to be, then you figure out
what is wrong with it. Spoiler alert: I'm going to use circuit A as an example.
It is declared to be a voltage regulator circuit, and the deficiency is the lack
of a stable voltage reference. The architecture is typical of a voltage regulator
with the common base setup used to increase the current supply. However, there is
no reason to necessarily assume the DC IN is not itself already regulated, and the
function if merely to increase the current supply capacity. If that is the case,
then the circuit seems sufficient as shown. Maybe the fact that there is no problem
otherwise should tell you make an assumption about the designer's intention and
look for something that would be suspect under that condition. Anyway, that's my
excuse and I'm sticking with it ;-)
 "Researchers at the Department of Instrumentation
and Applied Physics (IAP)have designed a novel
ultramicro supercapacitor, a tiny device capable of storing an enormous amount
of electric charge. It is also much smaller and more compact than existing supercapacitors
and can potentially be used in many devices ranging from streetlights to consumer
electronics, electric cars and medical devices. Most of these devices are currently
powered by batteries. However, over time, these batteries lose their ability to
store charge and therefore have a limited shelf-life. Capacitors, on the other hand,
can store electric charge for much longer, by virtue of their design. For example,
a capacitor operating at 5 volts will continue to operate at the same voltage even
after a decade. But unlike batteries, they cannot discharge energy constantly -
to power a mobile phone, for example. Supercapacitors, on the other hand, combine
the best of both batteries and capacitors - they can store as well as release large
amounts of energy, and are therefore highly sought-after for next-generation electronic
devices..."
 Prior to the advent of thyristors and semiconductor
lamp and motor control circuits, a relatively simple and safe - although heavy and
bulky - method for controlling AC voltage was with the use of saturable core transformer
arrangements. By using a DC winding to control the
saturation level of the transformer core material, the inductance, and therefore
inductive reactance, of secondary windings can be controlled. Doing so has the same
effect as using a Variac that uses mechanical control of the coupling and transformer
voltage input/out ratio. The method shown here has a potentiometer for adjusting
the DC current level, but, as the author mentions, electronic control circuits were/are
also widely used...
 Modelithics will be at WAMICON on April
17th and 18th. Modelithics is pleased to announce the release of version 23.0 of
the Modelithics COMPLETE+3D Library for use with Ansys HFSS. This version includes
Modelithics' collection of over 500 3D electromagnetic (EM) geometry models for
inductors, capacitors, filters, packages, and connectors. Also included are nearly
400 highly scalable Microwave Global Models™ for components from many popular vendors.
With both circuit and 3D EM models, the Modelithics COMPLETE+3D Library together
represent over 26,000 individual components. Version 23.5.1 of the Modelithics Qorvo
GaN Library is now available for use with Keysight Technologies' PathWave Advanced
Design System (ADS) and Cadence AWR Design Environment®. This latest version offers
new models for Qorvo's QPD1025, QPD1028, QPD1425, and QPD1425L discrete GaN-on-SiC
HEMTs. Version 23.5.1 also offers 2 new embedding models for the T2G6000528-Q3 and
T2G6003028-FL devices...
 Before
silicon and germanium semiconductors came online for use as diode rectifiers, selenium
was the material du jour. Selenium devices were widely adopted for use as bridge
rectifiers in power supplies and as detectors in AM radios, where applicable, in
place of vacuum tubes. At the time, they were not particularly cheaper to implement,
but there was an advantage in greater ruggedness, longer lifetime, and lower power
consumption (no heater element or high bias voltage required). Electronics magazines
of the era published many articles about selenium rectifiers, including After Class:
Working with Selenium Rectifiers, The Semiconductor Diode, New Selenium Rectifiers
for Home Receivers, Selenium Rectifiers, Applications of Small High-Voltage Selenium
Rectifiers, and Using Selenium Rectifiers.
 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.
 TotalTemp Technologies has more than 40
years of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
recirculating & circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
Thursday the 6th
 Bell
Telephone Company played an important role in the development of the aviation industry
by providing communications systems for airlines. As intimated in this promotion
in Boys' Life magazine, in 1961, Bell introduced the
"air-ground-air" radio system, which allowed pilots to communicate directly
with air traffic controllers on the ground, improving safety and efficiency in air
travel. This system was a major technological advancement, as it replaced the earlier
system of communicating via Morse code, which was slow and prone to errors. The
air-ground-air system allowed pilots to communicate in real-time with controllers,
enabling faster and more accurate instructions for takeoff, landing, and navigating
airspace. Bell Telephone Company continued to innovate in the aviation industry,
introducing new technologies such as satellite-based navigation systems and weather
radar systems, which have greatly improved air travel safety and efficiency...
 "New technologies often are introduced through
spectacle: Think of the historic demonstrations carried out by Faraday, Edison,
Morse, and Bell, or, more recently, by Steve Jobs onstage in his black turtleneck
at Macworld 2007, holding the first iPhone. Indeed, hyped-up product announcements
at industry events like the Consumer Electronics Show (now CES) and the Game Developers
Conference have become regular features of the digital world. There's also a parallel
tradition - less flashy but no less important - of industry events that focus attention
on digital infrastructure. Several of these events, such as the first public demo
of the ARPANET in 1972, or the mid-1980s conferences now known as Interop, alerted
experts to new technologies, and, in some cases, altered the balance between competing
approaches. Here we describe a few of these
do-or-die moments..."
 If you think paying $80-$100 per night for
a relatively low end chain hotel/motel is outrageous, then this advertisement in
a 1930 issue of Radio-Craft magazine will help justify your indignation.
While in California for the
IMS 2016 show, a convention-goer likely paid $200 or more per night for a room
within walking distance of the Moscone Center in downtown San Francisco. Compare
that rate to, say, the Eastgate Hotel or St. Clair Hotel in Chicago in 1930. Room
prices started at $2.50 - including free garage parking. The Madison Hotel in Atlantic
City had rooms starting at $4 per night that even included "Showers and Baths Throughout."
According to the CPI Inflation Calculator published by the U.S. Bureau of Labor
Statistics, $2.50 in 1930 is the equivalent of $45.58 in 2023 currency, and $4.00
equals $72.93. Those were prices for downtown medium grade hotels in downtown areas
of major cities. Yeah, you're being shaken down, alright...
 Axiom Test Equipment, Inc., an electronic
test equipment rental and sales company has published a new blog post entitled "Measure
the Efficiency of Renewable Energy Grids," that that covers how the latest
power analyzers and grid simulators can keep the power flowing efficiently and without
fail on energy grids. Developing and maintaining these power grids requires regular
voltage and current measurements on AC and DC power lines and junctions. Fortunately,
the latest power analyzers and grid simulators combine the test speed and accuracy
needed to ensure the highest-quality power from renewable energy sources and the
power grids they support. Basic measurements of AC and DC electric power in power
grids include voltage, current, efficiency, power, and total harmonic distortion
(THD), with accuracy within a fraction of one percent...
 Unashamedly I offer up these vintage yet
timeless
electronics-themed comics for your enjoyment. I freely admit to reaching for
the comics page(s) of the newspaper to read the latest antics of Beetle Bailey,
Dilbert, Hagar the Horrible, Garfield, Dennis the Menace, Peanuts, Blondie, and
many others. As if that was not bad enough in some people's opinion, what would
really keep me from getting invited to any more high class dinner parties if the
word got out is the fact that I actually try to spot the 6 differences in Bob Weber,
Jr.'s drawings. Melanie and I also like to work the crossword puzzles together;
supposedly that helps keep ageing gray matter from undergoing atrophy...
/jobs.htm"> 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 /jobs.htm">job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 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...
 Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
Wednesday the 5th
 The first time I ever saw a silicon boule
was in my semiconductor physics course at the University of Vermont, circa 1989.
For some reason that class gave me trouble. I got a B+ grade, but that was after
spending an inordinate amount of time with it. Energy level diagrams, doping, and
the equations behind them never quite found a good home in my gray matter. Fortunately,
the world has not missed my participation in semiconductor development. When this
"Evolution
of an Integrated Circuit" article appeared in Radio-Electronics magazine
in 1966, germanium was still a fairly large player in the semiconductor world. Silicon
began to overtake germanium as the primary semiconductor material in the late 1950s
and early 1960s. Germanium was the first material used to create transistors in
the 1940s, but it had some limitations, such as its high sensitivity to temperature
and its low ability to amplify signals. Silicon, on the other hand, had better electrical
properties and was more stable, making it a more practical material for creating
electronic devices...
 Discovering new oil reserves usually takes
more than the good fortune of being out shoot'n at some food, when up from the ground
come a bubbl'n crude - oil that is, black gold, Texas tea. Over the decades, chance
has been replaced by high tech prospecting methods including
ground-penetrating radar, radio and acoustic wave sounding, ultrasonic transponders,
and even satellite sensors that discern telltale variations in gravitational pull,
and magnetic fields. This article from a 1948 issue of Radio News describes
the use of radio for coordinating activities between the point of explosions and
where recording equipment is located, all of which required the transmission of
precise timing signals...
 "Transistor
advances have gone through several stages over the years, each driven by the need
to meet new demands in terms of size, performance, and power consumption. Explore
the
historical journey of the transistor and the race to meet new apps. When John
Bardeen, Walter Brattain, and William Shockley built the first successful working
model of a transistor in 1947, little did they know that it would go on to become
the most important invention for modern-day electronics. What started off as an
ambition to solve longstanding issues of power and size caused by vacuum tubes,
laid the foundation for the impact that electronic devices would have on people's
lives today. No doubt, 76 years is a long period of time for one to reflect on,
long enough that most of us can't imagine a world without transistors. Over the
years, engineers have devoted their careers to understanding the transistor’s use
and applications while reinventing the humble transistor several times..."
 These
engineering and science tech-centric jokes, song parodies,
anecdotes and assorted humor have been collected from friends and websites across
the Internet. I check back occasionally for new fodder, but it seems all the old
content is reappearing all over (like this is). The humor is light-hearted and clean
and sometimes slightly assaultive to the easily-offended, so you are forewarned.
All three pages are workplace-safe.
 Withwave is a leading designer and developer
of a broad range of RF, microwave, and millimeter−wave test solutions and subsystems
with a focus on electromagnetic field analysis and signal processing. As available
bandwidth gets increasingly crowded, technology must advance to facilitate higher
and higher frequencies of operation. Companies such as Withwave work hard to design
and manufacture components enabling engineers and technicians to create and maintain
cutting edge building blocks and systems. Two new sets of
between−series and in−series connector adapters have been introduced by Withwave.
New 0.8 mm Adapter Series (DC to 145 GHz) Withwave's 0.8 mm to 0.8 mm
Adapter Series are manufactured to precise microwave specification and constructed
with male and female gender on both side. The precision microwave connector interfaces
ensure an excellent microwave performance up to 145 GHz...
 Unless you happened to live close to a television
broadcasting tower, receiving an acceptable signal has always been largely a matter
of luck. Obstructions such as buildings and terrain can greatly attenuate signal
strength and multipath can generate telltale ghost images and confuse the synchronization
portions of signals. It was bad enough with black and white (B&W) broadcasts,
but the advent of color made the situation notably worse because more information
needed to be received properly in order to display a good picture. Color TV adoption
really began to take off in the late 1960s, and that is about the same time when
electronics and technology magazines started publishing articles like this one about
how to select a
roof-mounted TV antenna. A follow-up article appeared in the April 1973 issue
of Popular Electronics. The December 1958 issue had an antenna selection
article as well, obviously for B&W TVs...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic
drawings! Every object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Symbols are provided
for equipment racks and test equipment, system block diagrams, conceptual drawings,
and schematics. Unlike previous versions, these are NOT Stencils, but instead are
all contained on tabbed pages within a single Visio document. That puts everything
in front of you in its full glory. Just copy and paste what you need on your drawing.
The file format is XML so everything plays nicely with Visio 2013 and later...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products
such as RF signal generators, RF synthesizers, RF power detectors, mixers, up /
downconverters. Since the conception of WFT, we have introduced products that have
been purchased by a wide range of customers, from hobbyists to education facilities
to government agencies. Worldwide customers include Europe, Australia, and Asia.
Please contact Windfreak today to learn how they might help you with your current
project.
Tuesday the 4th
 Here is a different kind of crossword puzzle.
Called the "R-E
Puzzler," it has only Across words and clues - no Downs. Its sort of a crossword
puzzle with training wheels, or a crossword puzzle for the vertical word challenged.
Actually, not having cross-linking Down words can make solving it a bit more difficult
since only the one or two provided letters are available to assist in figuring out
the correct word. Other variations of this sort of word grid has the provided letters
spell out a word or phrase, but this one doesn't. Every word is related to electronics
or electrical principles. Bon chance...
 "A rocket carrying
CubeSats launched into Earth orbit
two years ago, on 22 March 2021. Two of those CubeSats represented competing approaches
to bringing the Internet of Things (IoT) to space. One, operated by Lacuna Space,
uses a protocol called LoRaWAN, a long-range, low-power protocol owned by Semtech.
The other, owned by Sateliot, uses the narrowband IoT protocol, following in the
footsteps of OQ Technology, which launched a similar IoT satellite demonstration
in 2019. And separately, in late 2022, the cellular industry standard-setter 3GPP
incorporated satellite-based 5G into standard cellular service with its release
17. In other words, there is now an IoT space race. In addition to Lacuna and Sateliot,
OQ Technology is also nipping at the heels of satellite telecom incumbents such
as Iridium, Orbcomm, and Inmarsat for a share of the growing satellite-IoT subscriber
market. OQ Technology has three satellites in low Earth orbit and plans to launch
seven more this year, says OQ Technology's chief innovation officer, Prasanna Nagarajan..."
 Special Snowflake alert on this article
from a 1939 edition of QST magazine! Do not read the first paragraph if
you are easily offended or easily induced to self-flagellation over misplaced guilt
for statements made by people you had no relation to or control over. If you are
brave and decide to continue, author George Grammer provides a very good guide regarding
how to be safe around high voltage, high power electronics equipment. A lot of the
opportunity for harm has been removed with modern transistorized circuits and improved
chassis design, but there are still plenty of people who work with vintage and/or
homebuilt equipment and are thereby exposed to potentially (pun intended) dangerous
levels. This note on the voltage present at the ends of a λ/2 dipole fed
with a 1,500 W full limit power (Ham radio) has 4,397 Vrms or ±6,200 Vpeak
- that'll leave an RF burn mark on 'ya...
 Since January, I have used ChatGPT to generate
many mini essays on various technical topics such as company histories, biographies
on notable engineers and scientists, physics principles, and industry standards.
My goal is to reduce the amount of references to off-site information like Wikipedia.
A careful reading of ChatGPTs replies is always performed because inaccuracies appear
fairly often. Overall, I find it very useful, but caution is needed. In example,
today I queried ChatGPT for an equation of the
voltage distribution along a half-wave dipole antenna. It took three rounds
of correcting its response to finally get an accurate answer...
 When this story was published in 1938 in
Radio−Craft magazine, India was a country of roughly 2 million square miles,
while the 48 U.S. had about 3.1 million square miles. Radio station growth in the
U.S. already had a 3-decade head start in establishing a nationwide network of broadcast
and receiving stations. Manufacturing of the required equipment was well established
within our borders. India, by contrast, relied heavily on outside sources for equipment
and the training of operators and servicemen. The U.S. never has had and still does
not have an official "state radio" as was
All-India Radio. A nice feature of the system was inclusion of a time-keeping
signal that would allow anyone within the reception of a clear signal to synchronize
clocks. The included map shows where the first four 10 kW main shortwave transmitters
were installed in key population areas. The terms "direct-ray" and "indirect-ray"
were used at the time to describe non-skip and atmospheric skip, respectively, propagation...
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.
 Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas. "We've Got You
Covered."
Monday the 3rd
 The electrical circuit entitled "Resistors
Galore," which was part of the collection of posers in the June 1966 issue of Radio-Electronics
magazine's "What's Your EQ" (EQ = Electronics Quotient, a la IQ = Intelligence Quotient)
feature, resulted in an interesting response from a reader. Mr. Milton Badt
submitted the bit shown to the left ("Ladder Lingo") in the following January edition
of the magazine. Interestingly, while he pointed out the significance to the relation
to phi (φ), defined as (1+√5)/2, he did not also note that the fraction is commonly
referred to as the
Golden Ratio, and its result, 1.618034... is called the Golden Number. A rectangle
with side lengths who's proportions are according to a/b = φ is called
a Golden Rectangle. There is also a resistor | capacitor voltage divider, and a
mystery power source challenge...
 Q: Why, if we call a memory resistor a "memristor"
(not memresistor), don't we call this memory inductor a "memductor" and the memory
capacitor a "mempacitor?" "Dr. H. Rusty Harris, associate professor in the Department
of Electrical and Computer Engineering at Texas A&M University, has identified
a new circuit element known as a
meminductor.
A circuit element is an electrical component used to help direct and control the
flow of electricity through an electrical circuit. The classical three are known
as the resistor, capacitor and inductor. Two additional circuit elements, the memristor
and the memcapacitor, were only discovered in the past 15 years. These newer circuit
elements are known as the mem- versions of their classical counterparts, and their
current and voltage properties are dependent on previous values of current or voltage
in time, like a memory. 'Those two discoveries set the world a little bit on its
head as far as electrical engineering,' Harris said. 'All of the sudden, we thought
we had three, but now we found these two others. And so that led us to think, 'OK,
there's got to be more then, but how do we understand what they are? How do we map
all of these things relative to each other?' And it turns out, there is a relationship
between each of the resistors and its family and each of the capacitors and its
family..."
 Electronic ignition, computer-controlled
fuel injection and air intake, alarm systems, radar, rear back-up cameras, GPS,
stereo sound systems, Bluetooth tire pressure monitors, hands-free telephones, automatic
headlight directors, drowsy driver detectors, collision avoidance, anti-lock brakes,
fuel efficiency management, air bag deployment, self-parking and even self-driving
features are now or soon will be standard features in automobiles. Mac McGregor
and Barney hit upon a lot of these items - some explicitly, some implicitly - in
this 1973 installment of "Mac's Service Shop" found in Popular Electronics
magazine. Amazingly impressive devices and systems are fermenting in the minds of
engineers and scientists today that will begin appearing in new car models a decade
or decades from now. While I am duly impressed, I would gladly trade my 2011 Jeep
Patriot for a nicely restored 1960s or 1970s pick'em-up truck. I'll add the desired
newfangled gizmos myself...
 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 cavity bandpass filter with a bandwidth of
5 MHz and a minimum return loss of 20 dB, a 1920-1980 / 2110-2170 MHz
cavity duplexer with 90 dB of isolation, and a 240-320 MHz LC bandpass
filter with a 1.5 dB insertion loss. 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...
 "DXing," or long distance communications,
has been a goal of amateur radio operators since the inception of radio. The sport
is as popular today as it was in 1959 when this article appeared in Popular
Electronics magazine. As you might expect, achieving success at making contacts
with like-minded hobbyists half-way around the world has been made quite a
bit easier both by vastly improved transmitters, receivers, and antennas and by
a much greater knowledge of propagation paths and accommodating atmospheric conditions.
In 1959, you relied on monthly publication of reported conditions that was itself
a few months old. Nowadays a DXer simply visits one of many websites with real-time
status on meteorological status and current operator reports on contact conditions,
equipment being used, frequency and power levels, etc. Still, though, it takes a
special kind of dedication to earn the coveted "Worked
All Continents" certificate...
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...
 SF Circuits' specialty is in the complex,
advanced technology of PCB fabrication and assembly, producing high quality multi-layered
PCBs from elaborate layouts. With them, you receive unparalleled technical expertise
at competitive prices as well as the most progressive solutions available. Their
customers request PCB production that is outside the capabilities of normal circuit
board providers. Please take a moment to visit San Francisco Circuits today. "Printed
Circuit Fabrication & Assembly with No Limit on Technology or Quantity."
Sunday the 2nd
 This custom RF Cafe
electronics-themed crossword puzzle for April 2nd contains words and clues which
pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. If you do see names
of people or places, they are intimately 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...
 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...
 Alliance Test Equipment sells
used / refurbished
test equipment and offers short- and long-term rentals. They also offer repair,
maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP,
Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization
with ability to source hard to find equipment through our network of suppliers.
Alliance Test will purchase your excess test equipment in large or small lots. Blog
posts offer advice on application and use of a wide range of test equipment. Please
visit Allied Test Equipment today to see how they can help your project.
 You wouldn't know it from the schematic,
but this
Coronet Model C−2 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...
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.
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