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Friday the 27th
Thursday the 26th
Wednesday the 25th
Tuesday the 24th
Monday the 23rd
Friday the 20th
 This might be a perfect application for
QuentComm. "Researchers led at the University
of Science and Technology of China (USTC), have achieved a major milestone in quantum
communication. For the first time, they demonstrated a key component required for
scalable quantum repeaters, which later allowed them to carry out device-independent
quantum key distribution (DI-QKD) across 100 kilometers. The results, published
in Nature and in Science, represent important progress toward building a functional
quantum internet. The work also reinforces China's position at the forefront of
quantum research and technology..."
 This Radio Service Data Sheet for the Clarion
"Replacement" Chassis, Model AC-160 A.V.C. Superhet is an example of the dozens
of similar schematic and alignment instruction sheets that have been posted on RF
Cafe over the years. Obtaining technical information on most things, even readily
available items, prior to the Internet era was often very difficult - if not impossible.
Service centers had what was need provided by manufacturers and distributors, but
if you wanted to find a part number or service data on a refrigerator, radio, lawn
mower, garage door opener...
 Remember the test patterns that used to
be broadcast by over-the-air broadcast stations that were used to align the electron
beam defection circuitry in CRT-based televisions? That pattern of squares, circles,
parallel and radial lines was generated by a special tube called a "Monoscope" on the transmitter end. Focus, 4:3 picture aspect ratio,
linearity, frequency response, and contrast and brightness were all tweaked to optimize
the pattern on the TV receiver circuitry. Of course not all sets were capable of
obtaining a perfect alignment due to inferior design and/or a scheme by the manufacturer
to provide a lower cost model with the tradeoff being a poorer picture - that it
the type of TV we always had in our household as...
 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."
Thursday the 19th
 Dave Harbaugh created a great many electronics-themed
comics back in the 1960s for magazines like Popular Electronics, QST,
"73", and others. His "Hobnobbing
with Harbaugh" series usually depicted hobbyists and technicians in a state
of surprise and/or dismay over some event while in the act of pursuing his passion
(electronics, that is, not a woman). Although I have never run across any evidence
of it, I wonder how many of the scenarios are derived from personal experience.
Many do not have captions. I have to admit to being stumped at what he is trying
to convey in the comic where the guy is staring into the back of the TV while his
wife...
 Competition amongst countries and businesses
existed long before the advent of radio receivers. Here is an interesting story
which demonstrates how international politics and corporate policies has been part
of the electronics industry since its inception. In order to circumvent what were
considered to be outlandish patent licensing fees, Danish engineer Carl Arne Scheimann
Jensen developed a new "gridless" type of vacuum tube (aka valve) which was called
the "Renode." Rather than using a screen grid in the path between the
cathode and plate, the Renode employed two sets of beam concentrator and deflector
plates on either side of the electron beam's path to modulate the conduction. According
to measurements it provided a slight improvement in both linearity and selectivity...
 "Sixth-generation wireless networks, or
6G, are expected to achieve terabit-per-second speeds using terahertz frequencies.
However, to harness the terahertz spectrum, complicated device designs are typically
needed to establish multiple high-speed connections. Now research suggests that
advanced topological materials may ultimately help to achieve such links. The experimental
device the researchers have made, in fact, achieved 72 gigabits-per-second data
rates, and reached more than 75% of the three-dimensional space around it. Current
solutions typically achieve only one or two of these features at a time and often
rely on complex
antenna arrays or mechanical steering..."
 This week's
RF & Microwave Companies crossword puzzle includes the names
of all my current advertisers and a few others that will be familiar to many of
you. These kinds of puzzles take a particularly long time to create because of needing
to force words into certain positions. That leaves the software with fewer options
for fitting the other words. All the words in RF Cafe crossword puzzles are relevant
to engineering, science, mathematics, etc., stored in a hand-built (over more than
two decades) lexicon of thousands of terms and clues. Enjoy...
 Mystery stories were broadcast on radio
stations in the days before television - and for quite a while after TV was available
for that matter. Families gathered around the living room radio set in excited anticipation
of the next adventure of shows like "The Shadow," "Amos 'n' Andy," "Tales of the
Texas Rangers," "Dragnet," and "The Green Hornet." During that era, it was common
also for electronics magazines, which focused largely on radio communications, to
experiment with printed dramas that had a radio-centric theme. Here is the first
of a series tried by Radio-Craft magazine in the late 1930s. A couple decades
later the Carl & Jerry adventures were run in Popular Electronics,
but other than that I don't recall seeing a lot of these things...
Wednesday the 18th
"Sixth-generation wireless networks, or
6G, are expected to achieve terabit-per-second speeds using terahertz frequencies.
However, to harness the terahertz spectrum, complicated device designs are typically
needed to establish multiple high-speed connections. Now research suggests that
advanced topological materials may ultimately help to achieve such links. The experimental
device the researchers have made, in fact, achieved 72 gigabits-per-second data
rates, and reached more than 75% of the three-dimensional space around it. Current
solutions typically achieve only one or two of these features at a time and often
rely on complex
antenna arrays or mechanical steering..."
 Diode characteristics and their applications
have not changed fundamentally since this article was published in 1952. Sure, the
die are smaller, power handling and frequency range has increased, package styles
are greatly expanded, and the cost per unit is way down, but if you are looking
for some basic diode information, you will find it here in this 4th installment
of a multi-part series in Radio & Television News magazine. Don't let
the vacuum tubes in schematics scare you off and think that it makes the story irrelevant
for today's circuits. For purposes of illustration substitute a transistor's collector
(or drain) for the tube's plate, a transistor's base (or gate) for the tube's screen
grid, and a transistor's emitter (or source) for the tube's...
 The term "drone"
these days for most invokes the image of a little plastic spider-looking thing with
propellers mounted at the ends of the arms - usually with a toothless bumpkin at
the controls. Those same people often think drones are relatively new devices. People
with a just a little more information automatically classify all radio control (R/C)
models, be they traditional fixed-wing aircraft or helicopters, as drones. Pilots
of the aforementioned models are even likely, per observers, to have all their teeth
and bathe regularly. I happen to be one of the latter type R/C modelers and while
I no longer possess all 32 teeth I had at birth, I do bathe regularly. Drones have
been around since World War I where they were used for target practice by ground-based
mark...
 "If you have dark eyes and blonde hair.
and are under 30, you're due for some easy squeezing. Milligan's Appliance Center,
84 Main Street, is giving every girl between 16 and 30 who has these striking features
a newly patented orange squeezer, to introduce the new item ... Note: Any traces
of recent peroxide rinse will disqualify applicants." That is advertising copy offered
as an example effective promotional material in a 1947 edition of
Radio News. My first reaction was to think how something
like that would never fly today, but then I wasn't so sure. It seems there must
be anti-discrimination laws in this "offend nobody" climate today...
 Imagine having a serviceman of any sort
arrive at your house, fix your problem, and present you with a bill of $6 - parts
included. He would walk away satisfied that he had done a good job and was well
compensated for the work considering the effort invested in training and qualification.
$6 in 1932, per the Bureau of Labor Statistics'
Inflation Calculator is worth $135.97 in 2015 money - that's a
cheap service call even in today's economy. Further, the $14 stated as a day's earnings
is $317.26 in 2025, which equates to 50 (work weeks/year) x 5 (days/week) x $243.86
(/day) = $79,315 (/year) - not too shabby. Just between you and me, that's more
than I'm currently making per year running RF Cafe...
 Aegis Power Systems is a leading supplier
of AC-DC and DC-DC power supplies
for custom and special applications. Aegis has been designing and building highly
reliable custom power supplies since 1995. They offer a complete line of switch
mode power supplies and power converters for a variety of markets including defense,
industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom,
and embedded computing applications. Design and manufacture of custom power supply
solutions to meet each customer's exacting specifications. Please visit Aegis Power
Systems today. Manufactured in the USA.
Tuesday the 17th
 Oscillators were never my forte. My biggest
exposure to oscillators was unintentional oscillations in amplifier circuits ;-(
. This
Oscillator Quiz, published in the November 1962 issue of Popular Electronics
magazine, would embarrass me if I attempted to complete it. Therefore, I will simply
state that I highly regard your oscillator prowess if you do better than 50% on
it. I guessed correctly at a couple of the more familiar circuits, but cannot even
make an educated guess at most of them. Don't let the presence of vacuum tubes scare
you off; mentally replace them with a FET and move on...
 These letters represent an unfriendly exchange
between The Electrical Experimenter editor Hugo Gernsback and Dr. K.G.
Frank, of the Telefunken System of Wireless Technology, of Germany. Gernsback correctly
accused Dr. Frank of engaging in espionage for Germany and against the United
States of America, during World War I at a time we were not officially at war
with the Axis powers. He was arrested and interred for the duration of the war for
sending out "unneutral
messages" from the broadcast station at Sayville, Long Island, New York. See
"Radiobotage" in this month's (September 1941) editorial...
 "There's an interesting development in amateur
ballooning: using so-called
superpressure
balloons, which float high in the atmosphere indefinitely rather than simply
going up and up and then popping like a normal weather balloon. Superpressure balloons
can last for months and travel long distances, potentially circumnavigating the
globe, all the while reporting their position. You might imagine that an undertaking
like this would be immensely difficult and cost thousands of dollars. In fact, you
can build and launch such a balloon for about the cost of a fancy dinner out. You
just have to think small! That's why amateur balloonists call them pico balloons.
The payload of a pico balloon is so light..."
 Many of the words in this week's
crossword puzzle pertain to radar engineering. All the rest of
the words are related to technology, engineering, science, mathematics, aeronautics,
ham radio, chemistry, etc. There are no names of Hollywierd actors, shoe designers,
or romance novel titles. I will be glad to create a special edition crossword for
your newspaper, newsletter, etc. Enjoy...
 It's time to gather 'round for another story
about fictional radio service shop owner
Mac McGregor and his trusted sidekick technician, Barney. In this
episode, an errantly wired bypass capacitor on a chassis from one of the old AC/DC
radio sets caused Mac to get a 300-volt wakeup call when his hand brushed against
it. After explaining the situation to Barney and apprising him of the danger it
poses to an owner who unwittingly sticks his/her hand into the back of the cabinet,
Mac lists a few other common dangers to watch for. Radios that ran on either AC
or DC power were very common back in the early days because there were homes and
businesses that had both type systems wired in to the premises - in part due to
the famous battle between Thomas Edison's preferred DC electrical distribution system
and Nikola Tesla's preferred AC electrical distribution system. Another reason for
DC compatibility was that prior to the
Rural Electrification Act of 1936, many...
Monday the 16th
 An incredibly glaring example of the famous
admonishment* that those who ignore history are condemned to repeat it, Radio-Craft
editor Hugo Gernsback wrote in May of 1941, a full half year before the United States
of America officially entered World War II, about how current conditions regarding
domestic commercial radio broadcast stations were likely being used by German agents
to send
coded messages to offshore vessels (ships, submarines, and aircraft).
In example, he cited, amazingly, an article he himself published in 1915 in
The Electrical Experimenter accusing Dr. K. G. Frank, of the German Telefunken
company, of conducting spy operations from the Sayville, NY, station on Long Island...
 Considering that not much more than a year
before this article was written that the transistor had been invented, it is impressive
that already Raytheon was producing a commercially available
CK703 "crystal triode." That nomenclature was a natural extension
of the preceding crystal diode already being widely adapted in circuit design. If
you have wondered how the transistor schematic symbol came to be as it is, you will
learn why here where the emitter and collector symbols actually both have arrows
on the ends that contact the base, indicating the "point contact" physical arrangement
of the semiconductor junctions. Shortly thereafter the arrow on the collector port
was eliminated, primarily, I suppose to avoid confusion when the E, B, and C labels
are not present...
 "CDimension recently unveiled a technology
that enables conventional semiconductor fabs to use ultra-thin semiconductor materials
to manufacture vertically integrated arrays of extremely small, fast, and efficient
"2D" transistors. It has the potential to change what's possible for both digital
and power devices. According to the company, it's already helping several chipmakers
explore how to apply their technology to produce digital and analog ICs that offer
dramatically higher logic densities, operating speeds, and energy efficiency..."
 Here are three more Radio Service Data Sheets
added to the online archive. As mentioned many times in the past, I post these for
the benefit of hobbyists looking for information to assist in repairing or restoring
vintage communication equipment. These particular radio models -
Emerson Model 20A and 25A,
Pilot Model B-2,
General Electric Model K-40-A - were featured in a 1933 edition
of
Radio-Craft magazine...
 Nationwide commercial
television broadcasting companies wasted no time stringing coaxial
cable and microwave towers from sea to shining sea once the NTSC format standard
was adopted and manufacturers had spooled up production after World War II.
Adoption of cable services was slow because a fee was involved, but once purely
cable channels started being added the perceived value increase convinced consumers
to open their wallets. Eventually cable eclipsed over-the-air broadcasts for all
but extremely rural areas that were not serviced by cable. Along came satellite
TV to take care of filling that void. Once a small, inexpensive, unobtrusive Ka-band
antenna replaced the huge S-band backyard parabolic dishes and subscription prices
dropped significantly, suburbanites and city dwellers picked it up. Soon, cable
companies were feeling the pinch as their customer bases shrunk. Not ones to sit...
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 Here are a couple more electronics-themed
comics from Electronics World magazine, good for winding down the week.
They appeared in the January 1963 issue. The page 86 comic reminds me of the professor
I had for solid state circuit design. He was supposedly the first person to successfully
use gallium arsenide (GaAs) as a semiconductor, although he also did pioneering
work with silicon. Anyway, Prof. Anderson would say he takes at least one "business"
trip each year to Portugal in order to search for higher quality raw semiconductor
material in sand on the beaches. He spoke Portuguese, BTW. The page 89 comic is
reminiscent of the pre-GPS days of navigation. Raise you hand if you ever drove
around utterly lost while looking for an off-the-beaten-path location...
 It seems most of the articles we see on
the subject of attenuator pads are based on signal reduction in terms of decibels
for units of power. Although it is a simple matter to convert power decibels to
voltage decibels, it would be more convenient if you are working with voltage to
have formulas and tables of values based on voltage ratios. This article does just
that. As a reminder, the decibel representation of a ratio is always 10 * log10 (x).
If you have a voltage ratio of V1/V2 = 0.5, then
10 * log10 (0.5) = -3.01 dB. If you have
a power ratio of P1/P2 = 0.5, then 10 * log10 (0.5) = -3.01 dB.
Does that mean that -3.01 dB of voltage attenuation is the same as 3.01 dB
of power attenuation...
 At Parvoo University, amid relentless November
rain, H-3 dormmates Carl and Jerry pursue H-2's prank: a stolen bronze trophy plaque
hurled into a half-mile muddy stretch of river. Cold, turbid waters bar preclude
dives for a search; non-magnetic bronze defies current-day metal detectors. Jerry
repurposes his cousin's boat depth-finder as an
enhanced sonar, exploiting echo signatures. A motor rotates a neon tube across
a depth-calibrated dial; at zero, contacts trigger a 200-kc ultrasonic pulse from
the transducer in transmit (speaker) mode, flashing initial glow. Bottom echo reflects
to transducer in receive (microphone) mode, amplifying...
 Details of ancient Parthian
electrochemical batteries unearthed near Baghdad by archaeologist Wilhelm Konig,
dating over 2,000 years, was reported in this 1964 Popular Electronics
magazine article. Housed in earthenware jars sealed with asphaltum (bitumen), they
featured a copper cylinder soldered with 60/40 tin-lead alloy - identical to modern
electronics, prior to PB-free mandates - encasing a corroded iron rod for electrodes,
enabling electroplating of gold, silver, and antimony via electrolytes like copper
sulphate, ferrocyanides, or lye. GE engineer Willard F.M. Gray replicated them successfully
for Pittsfield's Berkshire Museum, using iron rods for series connections. More
cells surfaced in a Seleucia magician's hut and Berlin Museum...
 Here is a great primer on the operation
of
traveling wave tubes (TWT). A controversy exists over who first invented the
TWT - Bell Telephone Labs' Dr. Rudolf Kompfner, or Andrei Haeff while at the Kellogg
Radiation Laboratory at Caltech. Regardless of its provenance, the device was a
major advancement in the development of high power microwaves. A TWT amplifies broadband
microwaves continuously: an electron gun emits a high-speed beam through a vacuum
tube, interacting with the weak input signal propagating along a helical slow-wave
structure. The helix slows the signal's phase velocity to sync...
 A lot of the guys I knew from my time in
the U.S. Air Force as an Air Traffic Control Radar Repairman (AFCS 303x1) went to
work for the government or defense contractors after separation. Many were retirees,
so they were (are) collecting military retirement pay on top of really good pay
doing field service work. At this point, probably most of those guys are now doubly-retired,
and collecting Social Security. They're living pretty well these days, probably
with nice homes paid off long ago. 1957, the year this solicitation for
field engineers appeared in Popular Electronics magazine, was right
at the end of the Korean War, and only a decade after World War II. A lot of
new equipment was designed and delivered...
2015 September - 1
 "Firefly Aerospace's Blue Ghost Mission
2 with the LuSEE-Night radio
telescope aboard will attempt to become the third successful mission to land
there. The moon's far side is the perfect place for such a telescope. The same RF
waves that carried images of Neil Armstrong setting foot on the lunar surface, Roger
Waters's voice, and hundreds of Ned Potter's space and science segments for the
U.S. broadcast networks CBS and ABC interfere with terrestrial radio telescopes.
If your goal is to detect the extremely faint and heavily redshifted signals of
neutral hydrogen from the cosmic Dark Ages, you just can't do it from Earth..."
 "Advanced threats lead to open architecture
approaches and new
analysis of electronic countermeasures. Over the past decade, preeminent countries
involved in major military conflicts mainly focused on asymmetrical warfare - surprise
attacks by small groups armed with modern, high-tech weaponry. During that same
period, however, near-peer adversaries began attaining impressive electronic warfare
(EW) capabilities. As a result, a plethora of new, dynamic threats flooded the EW
spectrum, pushing threat detection and analysis to keep pace. Large military forces
must now engage in ongoing..."
 "Google's parent Alphabet has reached a
definitive agreement to
acquire renewable energy developer Intersect Power for $4.75B, a transaction
that signals a structural transformation in how Silicon Valley intends to power
the AI era. By owning a power utility, Google can secure energy for its data centers
directly. This acquisition marks a departure from the industry's decade-long standard
of signing Power Purchase Agreements, where companies contract for energy from third-party
developers. Instead, Google is taking ownership of a 3.6-GW pipeline of late-stage
solar and wind projects, along with 3.1 GWh of battery storage..."
 "Scientists at the University of New Hampshire
are using artificial intelligence to dramatically speed up the search for
new magnetic materials. Their approach has produced a searchable database containing
67,573 magnetic materials, including 25 previously unknown compounds that retain
their magnetism at high temperatures, a key requirement for many real-world applications.
'By accelerating the discovery of sustainable magnetic materials, we can reduce
dependence on rare earth elements, lower the cost of electric vehicles and renewable
energy systems, and strengthen the U.S. manufacturing base,' said Suman Itani, lead
author of the study..."
 "Broadband achromatic wavefront control
plays a central role in next-generation photonic technologies, including full-color
imaging and multi-spectral sensing. A research team led by Professor Yijun Feng
and Professor Ke Chen at Nanjing University has now reported a significant advance
in this field in PhotoniX. The researchers introduced a hybrid-phase cooperative
dispersion-engineering approach that combines Aharonov-Anandan (AA) and Pancharatnam–Berry
(PB) geometric phases within a single-layer metasurface. This strategy enables
independent achromatic control of wavefronts for two different light spin states..."
 Have you noticed how many wooden utility
poles are
bending under the load of communications cable weight they were never designed
to withstand? Some are ridiculously burdened - and it is not "engineered deflection"
for line tension changes. Power companies want to charge the communications companies
for pole and/or cross bar replacement and/or upgrading, but the FCC just ruled that
pole owners cannot charge the full cost of replacement. That financial deficit,
of course, gets passed on to electric power customers. You wonder why your monthly
bill has skyrocketed in the last few years? That is part of it - along with
us peoples subsidizing wind and solar generation, and paying for free Internet and
cellphones to half the population (including Illlegals). Do you fell violated? I
do.
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