See Page 1 |
2 | 3 | 4 | of the May 2024 homepage archives. Tuesday the 7th
 I was born in the era of screw-in glass
fuses in household electric service panels. There was always a supply of replacements
in the cabinet above the stove. Sometime around 1978, prior to enlisting in the
USAF, I replaced the fuse panel with a Square D circuit breaker panel - a skill
learned through four years of electrical work. In the Air Force, I worked on a 1950s
era air traffic control radar system which consisted of many chassis assemblies
having fuse holders on their front panels. The racks themselves had a circuit breaker
panel, but it was a retrofit from sometime in the early 1970s. That was my introduction
into the wide variety of cylindrical glass fuses - high and low voltage, normal-,
slow- and fast-blow, time delay, etc. I learned of the reason why circuit designers
employed each type, and always used exact replacements when possible. Later, as
a circuit and systems design engineer myself, I always was careful to specify the
most
appropriate fuse type. This 1960 article in Radio-Electronics magazine
is a good primer on fuse handling...
 Robert Balin created scores of electronics-related
quizzes for Popular Electronics magazine (see list at bottom of page).
Having appeared in the December 1965 issue, some of the subjects are a bit dated,
but hey, this is an
Electronics History Quiz so it shouldn't matter. I scored 80% - yeah, sort of
pathetic - but I don't recall ever hearing of Raymond Heising and I couldn't figure
out what item "A" in the drawing is (spoiler: it's a TV iconoscope). That left me
with a guess between "A" and "G" for #9 and #10, which of course I got wrong with
a 50-50 chance. C'est la vie...
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. We are pleased to announce
our Low−Noise Amplifier (LNA) covering 18.0 - 40.0 GHz. The
LNA3007−1 produces +10 dBm power with a 20 dB power gain. The unit
is a small Class A linear design for optimum reliability & ruggedness for all
applications. The unit has nominal dimensions of 14.95 x 18.8 x 8.9 mm with
2.92 mm K-female connectors. Features include Class A linear design, suited
for K-Ka broadband linear applications and for all single channel modulation standards.
Built-in protection circuits with high reliability and ruggedness...
 Cable operators offering digital communication
services on their systems provide customers with Internet access, digital video
and business network solutions to add flexibility and profitability to their systems.
A major system consideration for successful implementation of a modem digital cable
system is system linearity. Inadequate system linearity distorts the channel information
and can lead to low system operability or reliability. Amplifying components placed
within the system for signal amplification or frequency conversation contribute
to system distortion. All amplifiers and frequency conversion components exhibit
non-linear amplification and produce distortion, causing
intermodulation
products. This distortion corrupts the channels and can lead to high bit-error
rates. The problem is more severe in these wideband cable systems because each amplifying
component input sees the entire high-power multichannel cable system spectrum...
 One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 280k
per year (in eight locations on each page, with >17k pages)...
 Werbel Microwave is a manufacturer of RF
directional and bidirectional couplers (6 dB to 50 dB) and RF power dividers
/ combiners (2− to 16−way) with select models operating up to 26.5 GHz and
100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are
designed and manufactured in our Whippany, NJ, location. Custom products and private
label service available. Please take a couple minutes to visit their website and
see how Werbel Microwave can help you today.
Monday the 6th
 Bell Telephone Laboratories (Bell Labs)
is a prime example of how a company builds a reputation as a provider of excellent
products and services. Engineers, technicians, and managers designed and built a
telephony system that was the envy of the world. It did so through extensive testing
of designs and stringent quality control during manufacturing. The nationwide network
build-out was equally robust and reliable. Constant maintenance and improvement
methods developed by Bell Labs assured customers that service would be available
whenever needed. Internal research in both the electronic and the mechanical arenas
played a large part in their success. Being able to withstand the rigors of environmental
factors (heat, cold, vibration, dirt, water, etc.) was the result of a major investment
in science and engineering. Unfortunately, success went to their metaphorical corporate
head and monopolistic practices caused the federal court to order a breakup of the
leviathan company into small parts that needed to compete with other innovators.
I'm still dubious about the decision, since Bell Telephone deserved some protection
against infringement...
 When the electronics product world consisted
of vacuum tube based circuits, the physical sizes of standard fixed-value passive
resistors, inductors, and capacitors were not of much concern in terms of how much
volume they consumed. R's, L's, and C's, had wire leads protruding from their molded
bodies, or in the case of larger power supply filtering capacitors had solderable
tabs. Point-to-point wiring consisted of components and hookup wire suspended in
the air between solder terminal strips and tube base tabs. Even with miniature (peanut)
tubes, all but the largest passives had no significant impact on overall unit size.
Once semiconductors came onto the scene, everything changed. Suddenly, even the
standard 1/4 W carbon resistor and tantalum capacitor became a significant
factor when attempting to
reduce size and weight of electronic assemblies. Component manufacturer research
and development departments shifted into high gear to keep up with what would become
a rapid paced race to see who could make the smallest, lightest R's, L's, and C's.
By the time this article appeared in a 1964 issue of Electronics magazine...
 "A summer storm on Tuesday damaged a
floating solar plant at Madhya Pradesh's Omkareshwar dam. The floating solar
plant, situated in the backwater of the dam, is the biggest of its kind in the world.
A joint venture between Madhya Pradesh Govt and National Hydroelectric Power Corporation
(NHPC), the project was nearly completed and ready for its launch. A part of the
project became operational last week. The project near the village of Kelwa Khurd,
aimed at generating 100 MW of electricity... However, on Tuesday, summer storms
with the speed of 50 kmph [31 miles per hour] hit the project and threw
the solar panels all around the place. No employee was fortunately injured..."
-- I wonder whether any employee was unfortunately injured?
 Believe it or not, there are still radio
operators using
Citizen Band (CB) and Business Radio (BR) equipment. That's right, cellphones
(which are themselves radios) have not totally supplanted traditional radio for
person-to-person communications. Prior to the widespread use of cellphones beginning
in the mid-1990s, CB and BR were the only radios available for use by laymen without
an individual license. When I worked as an electrician between high school and entering
the U.S. Air Force, my service truck was equipped with a radio dispatch transceiver
in the Land Mobile Radio System (LMRS) band. I did not have an FCC license to operate
the radio, but was allowed to communicate under the station license just as I was
able to work as an unlicensed electrician under the purview of the company owner's
Master Electrician license. Although companies could legally use CB channels (27 MHz)
and equipment at a much lower cost, LMRS permitted power levels were higher (both
base and mobile) with an accompanying greater range. Unlike on the CB channels,
competition for voice traffic was virtually nonexistent...
 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.
Friday the 3rd
 A few years back, I bought the issues of
The Saturday Evening Post which contained the very first published comics from
Peanuts creator Charles Schulz. As with just about everything else, they were available
on eBay for a few bucks apiece (although prices have really gone up since the beginning
of the year). Most of the issues also had articles and advertisements - and even
comics - that make appropriate fodder for both RF Cafe and my hobby website, Airplanes
and Rockets. Here are a few of the tech-related comics I found. The first one might
seem to be a bit distasteful to the survivors of the RMS Titanic disaster and/or
their relatives, given that only 36 years had passed. The middle one is about architectural
engineer's expertise on how structures are built, and the Hazel comic (raise your
hand if you remember watching the show) qualifies since it applies to the recreational
habit of many engineers and engineering managers. FYI, I colorized the original
B&W line drawings...
• China
Eases Foreign Ownership Limits for Telecoms Services
• Significant
Impact of Manufacturing on UK Economy
• FCC
Seeks Workarounds for Lapsed Auction Authority
• Market Impact of
Falling Satellite Costs
• U.S.
Nuclear Power Industry Upbeat on Small Reactors
 This full-page advertisement by Bell Telephone
Laboratories in the June 1956 issue of Radio & Television News magazine
seems to imply that their Dr. S. Weisbaum and/or his contemporaries was/were
the original developer/s of the
waveguide isolator. If so, it would be no surprise since Bell Labs was responsible
for many technology innovations during its history - RF, microwaves, telephony,
information theory, switching, transmission lines, test and measurement, and much
more. Other information available on the Internet assigns credit to Bell Labs in
the same timeframe. From the ad: "This isolator is a slab of ferrite which is mounted
inside the waveguide, and is kept magnetized by a permanent magnet strapped to the
outside. The magnetized ferrite pushes aside outgoing waves, while unwanted reflected
waves are drawn into the ferrite and dissipated..."
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.
Thursday the 2nd
 Heliographs (from Greek "sun," "to write")
are used as signaling systems by reflecting flashes of sunlight reflected by a mirror.
That was fine for a sunny day. At night and when otherwise dark enough, lamps and
even bonfires were used to message between distant locations when the time and/or
effort needed to physically transmit a message via ground-based carrier was untenable.
Militaries used light signaling on the battlefield. As electronics technology advanced
to where it could support modulation and demodulation of light signals, designers
began devising systems which could reliably send messages. By its nature optical
communications is a line of sight phenomenon. On Earth, distance over open, flat
ground is limited to 3-4 miles due to surface curvature for a transmitter and receiver
about 5 feet off the ground. From a tower or mountaintop to a point below or on
another mountain, the range can be extended to 50 miles or more. In space, between
two satellites, thousands of miles are attainable...
 Long before any one was overly concerned
with relatively paltry
electrostatic discharge (ESD) current causing damage to semiconductor components,
there was a need to model the human body's resistance to current flow due to electric
shock concerns. Even with a huge number of people being severely shocked and/or
killed due to exposure to potentially lethal voltage levels, it was not until the
late 1960s that OSHA and the National Electric Code began requiring exposed metal
components (chassis, switches, etc.) to have a safety ground connection. Popular
Electronics magazine ran an article titled "Shocking But True" in the August
1959 issue dealing with the subject. Many older radio and TV chassis would be "hot"
if the 2-pronged plug was inserted the wrong way into the wall receptacle, so touching
any metal component (even an exposed tuning knob or volume control shaft) would
light you up. The situation was even worse in the early days of AC electric service
because in many cases there was no earth ground established at the service entrance...
 Teledyne Relays announces the release of
its latest innovation, the CCR-67V series. This advanced range of
DC to 67 GHz SPDT coaxial switches is specifically designed to meet the rigorous
demands of 5G telecommunications, high frequency automated test equipment, and millimeter-wave
communication systems. The CCR-67V series represents a significant advancement in
electromechanical switch technology with both failsafe and latching models available.
Key Features and Innovations -- Longevity and Reliability: Engineered for endurance,
these switches feature an impressive contact life of 2 million cycles, ensuring
reliable performance under the most demanding conditions. High-Performance Connectivity:
The series features 1.85 mm connectors, delivering outstanding performance and is
compatible with the two most common mounting hole patterns, ensuring easy integration
and interchangeability with a variety of existing systems...
 Amateur radio operators - and all electromagnetic
spectrum users for that matter - have always lamented crowded bands and interference
(QRM and QRN). That goes for licensed and unlicensed bands. In 1976 when this editorial
was printed in the ARRL's QST magazine, spectrum occupation within allocated
bands was defined by commonplace analog AM and FM methods. Co-existence was generally
not possible for operation within a common frequency range. Spread spectrum modulation
/ demodulation changed all that beginning in the 1990s, but prior to then such schemes
were largely the exclusive domain of military communications, as were many other
spectrum-saving methods which are commonplace today. A big part of the reason is
the significant advances in digital processing hardware and software, along with
declassification of some of the algorithms that eventually found their way into
cellphone, WiFi, and other commercial applications. Given that many of the professional
engineers* and scientists who played a role in the transition were also Amateur
Radio operators...
 Crane Aerospace & Electronics' products
and services are organized into six integrated solutions: Cabin Systems, Electrical
Power Solutions, Fluid Management Solutions, Landing Systems, Microwave Solutions,
and Sensing Components & Systems. Our Microwave Solution designs and manufactures
high-performance
RF, IF and millimeter-wave components, subsystems and systems for commercial
aviation, defense, and space including linear & log amplifiers, fixed &
variable attenuators, circulators & isolators, power combiners & dividers,
couplers, mixers, switches & matrices, oscillators & synthesizers.
Wednesday the 1st
 At least two relatively new methods of wireless
communications was employed in the "Earth Radio" system for intercontinental ballistic
missile (ICBM) launch control in this 1961 issue of Popular Science magazine.
Surface wave transmission would provide the signal medium from ICBM command and
control centers to the underground silos where the missiles were stored, ready to
launch at a moment's notice if Russia decided to initiate a nuclear attack on the
homeland. Author Pursglove pays tribute to amateur radio's contribution to pioneering
the science of surface waves. The other pioneering technology being used was spread
spectrum encoding/decoding. Both methods provide innate security advantages. Surface
waves are a relatively short range transmission means, so anyone wanting to transmit
or receive bogus signals needs to be nearby. Spread spectrum, whether frequency
hopping (FHSS) or direct sequence (DSSS) requires a key for decoding or encoding
signals, so spoofing is nearly impossible. Another form of communications for through-the-earth
signaling, called Lithocom (lithosphere communications), was also explored. It was
eventually found useful in mining operations...
 "In 2016, the Japanese government announced
a plan for the emergence of a new kind of society. Human civilization, the proposal
explained, had begun with hunter-gatherers, passed through the agrarian and industrial
stages, and was fast approaching the end of the information age. As then Prime Minister
Shinzo Abe put it, 'We are now witnessing the opening of the fifth chapter.' This
chapter, called Society 5.0, would see made-on-demand goods and robot caretakers,
taxis, and tractors. Many of the innovations that will enable it, like artificial
intelligence, might be obvious. But there is one key technology that is easy to
overlook: lasers. The lasers of Society 5.0 will need to meet several criteria.
They must be small enough to fit inside everyday devices. They must be low-cost
so that the average metalworker or car buyer can afford them - which means they
must also be simple to manufacture and use energy efficiently. And because this
dawning era will be about mass customization (rather than mass production), they
must be highly controllable and adaptive. Semiconductor lasers would seem the perfect
candidates, except for one fatal flaw: They are much too dim. Laser brightness -
defined as optical power per unit area per unit of solid angle - is a measure of
how intensely light can be focused as it exits the laser and how narrowly it diverges
as it moves away. The threshold for materials work - cutting, welding, drilling
- is on the order of 1 gigawatt per square centimeter per steradian (GW/cm2/sr)..."
 Whether you are new to the subject of noise
figure or are just looking for a quick review, this "Hot
and Cold Resistors as UHF Noise Sources" article in a 1976 issue of QST magazine
is a good source. Author Benjamin Lowe, K4VOW, does a nice job of explaining the
concept of electrical noise, and then presenting equations governing the calculation
of noise factor and noise figure. Actual numerical examples are provided to demonstrate
how the formulas work. Using this method, you can make a fair measurement of the
noise figure of a receiver without the need for expensive test equipment. An important
caveat is to be sure the equipment you use has an operational bandwidth sufficient
to allow accurate measurement of the noise...
 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+ 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...
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
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)
|
