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4 of the September 2022 homepage archives.
Friday the 30th
This "Introduction
to Radar" material is from the U.S. Air Force's "Air University" collection
of tutorials. I found it in a bin at Goodwill, bound along with a few other sections
by the Extension Course Institute including Electronics Fundamentals and Television
Principles. This treatise on radar is the first of those sections which will be
posted here on RF Cafe. No date is included in the document, but my guess based
on the content and drawings is sometime in the late 1950's. No mention is made of
Doppler (a 1940's development), although it was used to some degree toward the end
of World War II. The existence of over-the-horizon radar (a 1960's development)
is alluded to, but not expounded upon. The "A" in the "A-scan" radar display stands
for "amplitude;" it is an oscilloscope time-based sweep. An "A-scan" display is
what the mountaintop UHF radar operators in Hawaii were monitoring when Japanese
aircraft attacked Pearl Harbor on December 7, 1941...
"The Department of Defense (DOD) seeks innovative
and creative solutions to complex, classified challenges, but the DOD is currently
only able to access a limited pool of companies cleared to work on them. Companies
must have a facility clearance and their employees must hold security clearances
to do classified work. But for a company to have a facility clearance, it must have
a contract requiring classified work to justify the clearance. This current model
results in a cyclical pattern that precludes the injection of new companies and
ideas into the classified DOD research and development ecosystem. DARPA announced
the Bringing Classified Innovation
to Defense and Government Systems (BRIDGES) program, which aims to tap into
innovation from companies that traditionally do not work with the DOD on classified
research and development efforts. BRIDGES will connect innovators directly to the
challenging problems that exist in the classified realm so they can help develop
solutions. 'There's a large U.S. innovation talent base at small companies across
our country that we currently aren't able to tap into for solutions to classified
technology challenges..."
Here's a little more
electronics humor from the November 1961 issue of Popular Electronics
magazine. This time the topic is stereo equipment, which was a big deal in the era.
Most equipment was still of the vacuum tube variety, and the country was still enjoying
the post-Korean war and low inflation economy, so there was disposable income to
be spent on creature comforts. Hobby and home improvement magazines od the day were
filled with reviews and recommendations on receivers, speakers, phonographs, tape
players, tone arms, stylus types, cables, antennas, and all the support equipment.
Articles on room design for optimized acoustic properties included sound absorbing
ceilings, walls, and floors, speaker placement, furniture location for the best
stereo (and quadrophonic) experience, etc...
Signal Hound's
SM435C 43.5 GHz, high-performance spectrum analyzer and monitoring receiver
is now available to order. The SM435C includes a 10 Gigabit Ethernet SFP+ port,
enabling the SM435C to communicate with a PC over long distances using a fiber optic
cable. Designed for remotely-located accurate RF data analysis at the lowest cost
possible, the SM435C also includes a signed calibration certificate and a printed
packet of calibration data. The Option-80 variant of the device provides downconverter
functionality, allowing engineers working with 5G to utilize 800 MHz of continuous
real-time data for in-depth analysis. The SM435C Option-80 is also a perfect fit
for applications requiring extremely clean phase noise. The affordability of the
SM435C opens the door to industry professionals who were previously unable to attain
this power in a compact and economic package. It is available now, with a U.S. retail
price of $25,380...
"QRT" is the Q-code used in amateur radio
to tell someone to stop transmitting. Hams very much anticipated the day when Germany
and Japan would be defeated, the war would end, and they could go home to resume
their beloved radio hobby. You might know - or not - that during
World War II ham radio transmissions were prohibited in the U.S. for a
mix of reasons. Foremost was to inhibit the broadcasting of information, intentionally
or unintentionally, that might give away strategic military strategy. Innocent chatter
about whose son left for boot camp, where he was going afterwards, what his ambitions
and fortes were, which factory Mom and Aunt Rosie worked for and what they did (Auntie
was riveter, maybe), who died in service to his country, blackout hours, scrap material
recycling collections, all was potential fodder for enemy tacticians. Another reason
for the prohibition was to free up production materials and labor for the making
of military equipment. The fate of the free world depended on it - literally...
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!
Axiom Test Equipment allows you to
rent or
buy test equipment,
repair
test equipment, or sell or trade test equipment. They are committed to providing
superior customer service and high quality electronic test equipment. Axiom offers
customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
electronic test equipment. For anyone seeking a way to offload surplus or obsolete
equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today!
Thursday the 29th
A few interesting historical statistics were
presented in this "Electronics
and Car Thievery" episode of "Mac's Service Shop," which appeared in a 1972
issue of Popular Electronics magazine. One is that steering column locks first came
out on 1970 auto and truck models. My 1969 Chevy Camaro did not have a steering
column lock, come to think of it. Also, a year earlier (1971), one in a hundred
cars in the U.S. were stolen. The aforementioned steering column lock dramatically
reduced the number of stolen vehicles. Car jacking was a thing in the early 1970's,
so that's not a relatively new crime - it's just that now we have video surveillance
everywhere so we get to see it. This story was particularly pertinent to a couple
recent experiences (not the same day) where visitors to our daughter's house locked
keys in their cars...
"For more than a decade, [Museum
of Consumer Electronics] in Solothurn, Switzerland, has been a place where history
buffs can explore and learn about the development and growth of computer and consumer
electronics in Switzerland and the rest of the world. On display are computers,
calculators, floppy disks, phonographs, radios, video game consoles, and related
objects. Thanks to a new four-year partnership between the museum and the IEEE Switzerland
Section, IEEE members may visit the facility for free. They also can donate their
time to help create exhibits; translate pamphlets, display cards, and other written
media; and present science, technology, engineering, and math workshops..."
As a life-long aircraft enthusiast, my attention
is always drawn to photos, drawings, and titles in articles dealing with any aspect
- but particularly a historical aspect - of aviation. This 1937 edition of Radio-Craft
magazine reported on the fledgling field of aircraft radio maintenance, and in particular
the opportunities presented to radio repairmen.
Aircraft electronics (aka avionics) have of course changed significantly over
the last 80 years. Accordingly, maintenance has become such a highly specialized
skill that other than swapping out entire pieces of equipment, relatively few facilities
exist that are qualified for the task. According to the article, at the time there
were a mere 5k privately owned airplanes. As of 2019, the AOPA estimated a total
of around 220k private aircraft (down from 224k in 2011), with 720k currently licensed
pilots (all categories) per the FAA...
ConductRF supports customers with all standard
RG cables, however, a very common standard is
M17/60-RG142.
This cable has a solid PTFE Dielectric core over a Solid Silver Covered Copper Clad
Steel Conductor. It is double braided and has an outer jacket of Tan colored FEP.
ConductRF offers a wide selection of standard connectors including out Type-N males
which offer a coupling nut that allows both finger tightening and torque wrench
tightening. ConductRF 100% validates RF performance of these assemblies through
factory network analyzer testing prior to shipping...
In the 1930s, electricity and electronics
were mysteries to most of the population. The concepts were relatively new and few
had a firm grasp on the technology. That reality was exploited by Hugo Gernsback
during the 1934 Electrical Exposition to challenge attendees to discover how "the
Mystery Set" radio receiver sitting on the top of an empty, clear glass case
was being powered. It was a clever ruse that reportedly stumped most people. The
secret is revealed here in this 1934 issue of his Radio-Craft magazine.
BTW, my guess is that an even smaller proportion of our current citizens would be
able to figure it out, or for that matter even realize that maybe there should be
a power source of some sort...
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...
Centric RF is a company offering from stock
various RF and
Microwave coaxial components, including attenuators, adapters, cable assemblies,
terminations, power dividers, and more. We believe in offering high performance
parts from stock at a reasonable cost. Frequency ranges of 0-110 GHz at power
levels from 0.5-500 watts are available off the shelf. Order today, ship today!
Centric RF is currently looking for vendors to partner with them. Please visit Centric
RF today.
Wednesday the 28th
The term "metallized
dielectric" at first might seem like an oxymoron. After all, if you add a conductive
substance to the dielectric of a capacitor, then you have compromised the integrity
of the dielectric as a non-conducting substance. Here's the deal: The dielectric
material between the conductive plates does not receive the metallization; a non-conductive
(dielectric) material like paper is impregnated with metal and that is used for
the plate material. The advantage of this scheme is that the plate material can
be thinner, thereby reducing the size of the capacitor package for a given capacitance
value. It comes with a price, of course, and that is a lower operational and maximum
applied voltage rating. With proper design in circuits like power supplies, metallized-dielectric
capacitors can facilitate great space savings. A major benefit of metallized-dielectric
capacitors is an ability to self-heal when the plate material develops a short circuit
through the dielectric...
3D printing of antenna and waveguide components
has been advancing rapidly in the past few years. Early research used plastic that
was then coated with a conductive substance. Once 3D printing using a metallic filament
was developed to the point that the structure could withstand heat cycling, vibration,
and shock associated with aerospace environments, the creation of complex, compound
shapes never deemed possible with traditional machining became reality. Using proprietary
additive manufacturing techniques developed in-house, virtually any form of waveguide
and/or antenna can now be fabricated by companies like
Swissto12,
based in Switzerland. As can be seen in the included images from the
Swissto12 website, the surfaces are not perfectly
smooth...
Designing, building, and tuning
low frequency filters is much easier for the person without a professional grade
suite of software, fabrication, and test equipment than is RF / microwave frequency
filters. Most of my design and integration work has been with system level transmit
and receive racks for radar and satellite earth station installations, and typically
for prototyping and/or very low quantity production. Accordingly, I often used connectorized
components cascaded together where each functional block was predefined and tested.
I would be handed a system input/output document that specified parameters for gain,
phase noise, intercept points, noise figure, group delay, bandwidth(s), power levels,
switching and settling times, current consumption, volume, weight, cost constraints,
etc. That explains why my software offerings like RF & Electronics Symbols for
Visio and RF Cascade Workbook all deal with system level design...
Altum RF, a supplier of high-performance
RF to millimeter-wave semiconductor solutions for next generation markets and applications,
announces a new grant and collaboration with Industrial Technology Research Institute
(ITRI), the largest applied technology research institution in Taiwan, and TMY Technology
Inc. (TMYTEK), a leading mmWave solution provider targeting the 5G/B5G and SATCOM
markets. Altum RF, ITRI and TMYTEK will collaborate on an
Antenna and Semiconductor Integrated Modules (AIMS) project for satellite communications
systems. The grant comes from the Eureka Globalstars Taiwan framework. The project
began in August 2022 and is slated to continue for two years. The purpose of the
AIMS project is to develop a millimeter-wave antenna-in-package (AiP) module for
phased array Ka-band satellite communication systems. Developing this module will
make satellite communication systems...
If you are from a family of electronics hobbyists
and/or professionals, then there is a good chance your grandfather and possibly
even your father kept a handy-dandy list of common
circuit design formulas handy. The list here Part 2 includes all the formulas
on this page, which dealt primarily with vacuum tubes, the schematics for which
were presented in Part 1 of the series. There was not an "app for that" back in
those days. Prior to a smartphone in every pocket, notes were pinned to a lab wall
or kept in a hand-written notebook...
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...
Copper Mountain Technologies develops innovative
and robust RF test and measurement solutions for engineers all over the world. Copper
Mountain's extensive line of unique form factor
Vector
Network Analyzers include an RF measurement module and a software application
which runs on any Windows PC, laptop or tablet, connecting to the measurement hardware
via USB interface. The result is a lower cost, faster, more effective test process
that fits into the modern workspace in lab, production, field and secure testing
environments.
Tuesday the 27th
This is one of the few times I disagree
with Hugo Gernsback. It's not that his conclusion about economics being the reason
for the
delay in producing promised newfangled radios after the end of World War II
is wrong. My problem is that he excuses the manufacturers who blamed delays on the
large amount of time and effort required to incorporate all the new technology developed
during the war. As Radio-Craft magazine reader C.G. Little wrote in this August
1946 issue, companies were running advertisements a year before V-E Day (May 8,
1945) promising to have all-new radios with wonderful new technology developed from
advances made in radio and radar during the defeat of Axis forces. Japan surrendered
on V-J Day (September 2, 1945). The fact is those companies had a year to prepare,
and the U.S. government was gradually relinquishing control over production facilities
as the War Powers Act impositions faded. Nobody was taken by surprise. This was
either a case of government-backed propaganda, or false advertising by the manufacturers...
An Electronics Weekly article entitled
"Modelling
Grid Effects of Electric Vehicle Charging in the Next Decade" references
Nature magazine study "Charging Infrastructure
Access and Operation to Reduce the Grid Impacts of Deep Electric Vehicle Adoption,"
which indicated high density areas with currently (no pun intended) stresses electric
supply grids will be problematic. It is a Captain Obvious announcement to anyone
following the existing issues like a couple weeks ago California telling EV owners
not to charge their cars because of the power shortage. It begins: "Researchers
at Stanford University have modelled over-night home charging of electric vehicles
and predict that it is not the correct strategy, for the Western US, at least. Stanford
EV charging model Simulation is based on a model, revealed in March, for charging
demand that can be applied to different human populations under different conditions.
In a demonstration..."
For several years I have been scanning and
posting Radio Service Data Sheets like this one featuring the
RCA Victor Model R-78 B1-Acoustic 12-Tube Superheterodyne floor console radio
in graphical format, and run OCR on them to separate the textual content and make
it searchable. 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 will keep a running list of all data sheets to facilitate a search.
The RCA Victor Model R-78 B1-Acoustic 12-Tube photo was found on the RadioMuseum.org
website...
Brendon McHugh has an interesting article
on the Microwaves & RF website entitled, "Strengthen
SATCOM with SDR-Enhanced Phased-Array Antennas." It begins: "Many SATCOM apps
require constant communication between the satellite and ground station, which can
be difficult with conventional antennas. Phased-array technologies, coupled with
SDRs, provide the robust comm link necessary for proper operation. Satellite communication
(SATCOM) is one of the pillars of the modern world, with applications including
Global Positioning System (GPS) and Global Navigation Satellite System (GNSS) navigation,
space research, telecommunications, internet access, weather monitoring, and law-enforcement
surveillance. Together with the satellite itself, ground stations are crucial to
the SATCOM industry. They transmit and receive data to and from the satellite, process
the information, and apply it to different purposes, depending on the application.
Therefore, it’s fundamental to ensure an efficient, reliable, and robust..."
Included in this first of a series of the
"Simple
Mathematics for the Serviceman" articles that ran in Radio-Craft magazine is
another "cheat sheet" full of oft-used formulas. It begins with basic Ohm's law,
resistance, inductance, and capacitance, then builds from there. What was valid
in 1930 is still valid in 2022. See the October 1930 issue for the next installment
that includes yet another handy-dandy cheat sheet of formulas. A couple examples
are given...
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 12,000 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. I also re-broadcast homepage
items on LinkedIn. If you need your company news to be seen, RF Cafe is the
place to be.
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 26th
I learned a new word in this issue of
Electronics World magazine's special report on
ceramic capacitors: "discoidal." It looked like a made-up word to describe something
that looks like a disc. Anyway, the July 1965 issue contained a collection of articles
on the various sorts of capacitors in use at the time. Other types of dielectrics
covered were tantalum, glass, plastic-film, mica, paper, and metallized-dielectric.
Ceramic and electrolytic capacitors were by far the most widely used capacitors
during the vacuum tube era since they were relatively inexpensive to manufacture
and could handle high voltages. Hobbyists who service and/or refurbish vintage electronic
equipment still need this information if for no other reason than to verify component
values based on color codes. It also helps to know how the electrical properties
vary over temperature, frequency, applied voltage, etc., when deciding which type
of modern capacitor will best serve as a suitable substitute...
Sam Benzacar of Anatech Electronics, an RF
and microwave filter company, has published his August 2022 newsletter that features
his short op-ed entitled "It's
Official: DSRC is Dead," where he discusses how the 1999 era (Y2K era remember?)
"Dedicated Short-Range Communications (DSRC)," which was allocated 75 MHz of spectrum
at 5.9 GHz for "intelligent transportation systems," is no more. "Cellular to Everything
(C-V2X)" is its replacement. Also reported is the introduction of C-Band-proof radar
altimeters, a THz development grant to NYU's Tandon School of Engineering, and HawkEye
360 developing RF-sensing capabilities for U.S. Army. As always, Sam demonstrates
a keen awareness of the industry for which his company, Anatech Electronics, services...
There are still many old-timers and beginning
nostalgic collectors out there who nurse heirloom and otherwise procured vacuum
tube radios - like this
Admiral Model 7C63, Chassis 7C1 - back to health (operating condition) and/or
keep them in good health. The thumbnail to the left is an example from the RadioMuseum.org
website. While it is possible to purchase schematics, parts lists, and service instructions
from many different models, there are still some that have escaped the scanners
of those publishers. For those kindred spirits in search of such reference materials,
I happily scan, clean up as necessary, and post this collection (see complete list
at bottom of page). I have dozens more that will eventually be added over time,
so check back later or send me an e-mail if I have an issue (check the lists first,
please) of Radio News, Radio-Craft, etc., known to contain the
information you need...
Any day now we'll see a headline about a
Stasi (aka
FBI) raid on Scott Adams' home at 6:00 in the morning to confiscate his cellphone.
Evidently it's not OK to poke fun at the "woke" agenda according to (as of now)
77 newspapers which cancelled the "Dilbert"
comic strip. Many newspapers have gone out of business or are on the verge of doing
so due to disappearing subscribers. People are sick of having one view forced at
them with no counterpoints. I'm sure Adams makes plenty of $$$ from other Dilbert-related
ventures, so he probably will not miss the revenue. A lot of people still subscribe
to newspapers mainly for comics and puzzles. This will just add to the "go woke
- go broke" phenomenon we're witnessing happening to politically correct businesses.
Go to Dilbert.com for all your Dilbert needs.
Since its inception in 1934, the Federal
Communications Commission's (FCC) Enforcement Bureau has taken seriously its charter
to monitor and protect designated frequency bands against both intentional and unintentional
interference. Except for malicious attacks on legitimate operations, most instances
of interference are the result of utter ignorance or accidental broadcasting due
to inattention to detail (wrong frequency dialed in) or equipment malfunction. Standard
practice is to issue an immediate cease and desist order to the offending party,
and then go forward with prosecution if compliance does not follow. News stories
appear fairly often about
pirate broadcasters and idiots exacting revenge on someone else who allegedly
offended said idiot. The $500 fine levied on Mr. Winston in 1931 is the equivalent
of a $9,938.62 fine in 2022 (see BLS Inflation Calculator). That is a lot of money,
but it pales in comparison to the typical $25k and higher fines charged recently
to habitually errant Hams. Evidently, his case fell under the intentional interference
category...
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 ...
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 25th
This custom made
Electrical Engineering theme crossword puzzle for September 25th is provided
compliments of RF Cafe. It's a big one with more than 240 words - good for
a long flight. All RF Cafe crossword puzzles are custom made by me, Kirt Blattenberger,
and have only words and clues related to RF, microwave, and mm-wave engineering,
optics, mathematics, chemistry, physics, and other technical subjects. As always,
this crossword puzzle 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...
The
Wireless Telecom Group,
comprised of Boonton, CommAgility, 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.
Friday the 23rd
TGIF. Even with being self-employed, I still
am always glad when Friday gets here. Aside from some morning work posting content
for my AirplanesAndRockets.com hobby website, Saturday is my only day completely
off from RFCafe.com business. Anyway, a good way to wind down the week is with some
good old-fashioned humor. These couple
electronics-themed comics from a 1959 issue of Radio-Electronics magazine
are literally old-fashioned. The comic on page 52 is actually a tongue-in -cheek
criticism aimed at the housewife who must have make a remark about how easy television
servicing probably is. However, the technician's response is really not such a bad
high-level check of the health of the vacuum tubes. Heater elements burning out
was a fairly common cause of a tube being bad. Of course nobody would want to go
through and feel all the tubes' temperatures because those suckers can get hot enough
to burn...
Note
that while Zenith Electronics (now owned by LG) has only been around 40 years,
Zenith has
been manufacturing TVs in the U.S. since 1939. Per the IEEE Spectrum article
- "Why the last major U.S. television set maker, Zenith, finally gave up. Driven
finally into unprofitability in its traditional market by ever stiffer competition
from abroad, harmed rather than helped by a decade of economizing cutbacks in research
and development, Zenith Electronics
Corp. - the sole surviving U.S. manufacturer of television receivers - reportedly
plans to call it quits in the business it helped to create and nourish through some
40 years of innovation. Indeed, nothing so neatly reflects the company's present
situation as its latest and arguably its second greatest innovation: a flat shadow
mask for a flat-faced cathode ray tube hailed everywhere as a major breakthrough.
Announced in 1986, the Flat Tension Mask, as it is called, increases the brightness
of the cathode ray tube by up to 80%, its contrast ratio by up to 70%, and its resolution
by up to 15% over current tube designs, which use a curved face plate and curved
shadow mask..."
Copper Mountain technologies' new R140B
1-Port 14 GHz Analyzer is an enhanced version of its predecessor - the
R140 reflectometer - featuring faster measurement speeds, wider IFBW, and an improved
dynamic range. The R140B incorporates a new housing design similar to CMT's R60,
taking advantage of enhanced heat exchange characteristics and a sturdy USB shroud.
It will feature a new connector assembly, which includes four different port connector
options (N male, female; 3.5 mm male, female). The new connector assembly enables
flexible configuration while maintaining a small form factor suited for laboratory,
field, or production environment applications. "With built-in differential measurement
capabilities, this product will enhance the design and production of next-generation
HDMI and USB cables for consumer goods and high bandwidth data...
I have often said that some of the most
capable and enthusiastic engineers and technicians - and even managers - I have
worked with in my 30-something year electronics career have been amateur radio operators.
They are the rare few who are able to combine a hobby passion with a profession
that pays for the hobby... kind of like the airline pilot who flies model airplanes
or the druggie who works at a pharmacy. Oh, wait, scratch that last example. Here
we see a video from Chevrolet where two engineers, one of them a Ham, took up the
challenge to replace the AM/FM whip antenna originally planned for the 2011 Camaro
convertible with a
blended,
inconspicuous antenna. Leaked photos of the prototype car showed the whip, which
caused Camaro aficionados to descend upon Chevy requesting its removal. The flexible,
folding rear window prevented an embedded solution as is the norm for many cars.
The ultimate solution? Embed the antenna in the spoiler. Given the retro nature
of the Camaro, the hew and cry against the whip antenna is a bit surprising. I had
a '69 Camaro SS and a '74 Camaro SS, and of course both had whip antennas. Kirt
Blattenberger (circa 1977) 1969 Camaro SS w/350 cu.in. LT-1 engine (Wikipedia says
production began in 1970, but actually late 1969) Bracket Racing Trophy from Capitol
Raceway According to the video, the two engineers spent 10 months rushing to get
the antenna into the spoiler prior to rollout. So, how much did the change likely
cost...
Quantic PMI, a leading supplier of custom,
high-reliability MIC/MMIC components and subsystems for applications in space,
military, communications, commercial and consumer electronics systems for more than
three decades, introduced six new products this month in their extensive line of
RF and microwave components. Included are a bi-directional switched bit attenuator
operating from 400 to 1400 MHz, an RF Limiter that operates over 1.0 to 2.0 GHz,
a low noise amplifier with a frequency range of 8 to 12 GHz, a reflective, SP2T
switch that operates over 2 to 18 GHz, a SP2T Reflective Pin Diode Switch with a
frequency range of DC to 18.0 GHz. Contact Quantic PMI today for more information...
Hogarth is a comic character invented by
the
Echophone Radio Company. Their bespectacled Army grunt was one of the first
technology nerd types who always managed to appear with pretty girls. His caricature
evolved quickly over the two or three year run of the advertisements. Most Echophone
Radio ads I have seen either feature Hogarth and his woman/women or Hogarth and
a demanding sergeant. This full-page advertisement appeared in the August 1945 edition
of Radio-Craft magazine. A search on the name "Hogarth" does not give any clue as
to the reason for choosing it. For what it's worth, here is the Ancestry.com data
on Hogarth. Echophone radios can still be found on eBay for fairly low prices -
often less than the shipping cost...
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...
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.
Thursday the 22nd
Call me a skeptic, but somehow I doubt the
accuracy of the "Radiation
Curve Representing All VHF Channels" presented in this Rear-Guard antenna ad.
It appeared in the December 1954 issue of Radio & Television News magazine.
Truth in advertising laws were probably not as strictly enforced as they are today.
The main lobe utterly dominates the response, with barely any power in the side
and back lobes. Even a well-designed, narrow-band parabolic dish is fortunate to
have such a near-perfect directional pattern. Aside from that, I wonder how many
people today "get" the picture of the kid with a pillow strapped to his behind and
understand the relationship to "Rear-Guard?" Back in the day, kids sometimes experienced
marshal punishment in the form of a hand or a wooden paddle to the body area normally
sat upon. It was known as a spanking. I know from personal experience that the threat
of receiving such punishment often served as sufficient deterrence from committing
certain naughty acts...
ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test
Cables for labs. ConductRF makes production and test coax cable assemblies for
amplitude and phased matched VNA applications as well as standard & precision
RF connectors. Over 1,000 solutions for low PIM in-building to choose from in the
iBwave component library. They also provide custom coax solutions for applications
where some standard just won't do. A partnership with Newark assures fast, reliable
access. Please visit ConductRF today to see how they can help your project!
Almost certainly the earliest observed evidence
of the existence of an ionosphere as part of the Earth's atmosphere is aurora activity.
Alley Oop, B.C., and friends had no idea that the wavering colors were the
result of high energy, charged particles from our sun interacting at altitude with
the Earth's magnetic field. This article from a 1935 issue of Short Wave Craft
magazine gives a nice introduction to what was known of the ionosphere at the time,
which wasn't a whole lot since no in situ measurements had yet been made via sounding
balloon or rocket. All that was known was inferred from the behavior of radio waves
as they were affected by the charged space. It wasn't until 1926 that Scottish physicist
Robert Watson-Watt coined the term "ionosphere."
Although not mentioned here, it was amateur radio operators who first discovered
the ability of the ionosphere to reflect and bend short wave radio waves to enable
round-the-world communications. Ironically - or perhaps expectedly - the U.S. Congress
in 1912 passed the Radio Act of 1912 that restricted amateur radio operation to
frequencies above 1.5 MHz (a wavelength of 200 meters or less). Shortly thereafter,
the FCC reclaimed much of the spectrum for itself...
"Few fields invite as much unbridled hype
as quantum computing. Most people's understanding of quantum physics extends to
the fact that it is unpredictable, powerful, and almost existentially strange. A
few years ago, I provided an update on the state of quantum computing and looked
at both the positive and negative claims across the industry. And just like back
in 2019, I remain enthusiastically optimistic today. Even though the hype is real
and has outpaced the actual results, much has been accomplished over the past few
years. First, let's address the hype. Over the past five years, there has been undeniable
hype around quantum computing
- hype around approaches, timelines, applications, and more. As far back as 2017,
vendors were claiming the commercialization of the technology was just a couple
of years away - like the announcement of a 5,000 qubit system by 2020 (which didn't
happen). There was even what I'd call anti-hype, with some questioning if quantum
computers would materialize at all..."
This Radio Service Data Sheet is for the
Crosley Model 425 (Travo) 4-Tube Portable AC/DC Superheterodyne radio which
appeared in the March 1936 edition of Radio-Craft magazine. No example
of this 1935-era Crosley Model 425 could be found in searches, but interestingly,
the term "Travo" returns a Model 166 by that name and the same year of manufacture.
I post this schematic and functional description of the manufacturers' publications
for the benefit of hobbyists and archivists who might be searching for such information,
either in a effort to restore a radio to working condition, or to collect archival
information...
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...
KR Electronics designs and manufactures
high quality filters for both the commercial and military markets. KR Electronics'
line of filters
includes lowpass, highpass, bandpass, bandstop 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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