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 The transformative role of ferrites - crystalline
structures composed of iron oxide and metallic additives - in advancing modern electronics,
is reported in this 1961 Electronics Illustrated magazine article. Ferrites
uniquely combine magnetic properties with electrical insulation, enabling high efficiency
at frequencies where standard iron cores fail due to eddy current losses. This "electronic
wonder material" proved critical for television development, allowing for larger
picture tubes through efficient flyback transformers and deflection yokes. Furthermore,
ferrites revolutionized computing by providing reliable, compact memory cells, replacing
failure-prone vacuum tubes in machines like the Whirlwind I. Beyond these core
applications, the material facilitates innovations such as ultrasonic ...
 "In 1627, a year after the death of the
philosopher and statesman Francis Bacon, a short, evocative tale of his was published.
The New Atlantis describes how a ship blown off course arrives at an unknown island
called Bensalem. At its heart stands Salomon's House, an institution devoted to
'the knowledge
of causes, and secret motions of things' and to 'the effecting of all things
possible.' The novel captured Bacon's vision of a science built on skepticism and
empiricism and his belief that understanding and creating were one and the same
pursuit. No mere scholar's study filled with curiosities, Salomon's House had deep-sunk
caves for refrigeration, towering structures for astronomy, sound-houses for acoustics,
engine-houses..."
 Werbel's new
WM2PD-1.5-20.5-S-ECO, 2-way power divider covers 1.5 to 20.5 GHz and is
designed for engineers who need wideband performance in a compact, cost-efficient
package. Optimized for size, bandwidth, and manufacturability, it is well suited
for high-volume applications, lab use, and general-purpose signal distribution where
extreme port match is not required. Designed, assembled, and tested in the USA.
"No Worries with Werbel!"
 The radar system I worked on in the USAF
used two early memory types described in this 1956 Popular Electronics
magazine article. In fact, the radar was designed during that era, so it is no surprise.
Our IFF secondary radar had a whopping 1 kilobyte of
magnetic core memory in its processor circuitry. It consisted of 1024 tiny toroids
mounted in a square matrix with four hair-width enamel coated wires running through
them as x and y magnetization current lines, sense, and inhibit functions. If my
memory serves me (pun intended) after three decades away from it, the TTL circuitry
(no microprocessor) stored range values to calculate speed and direction from sample
to sample. The other memory type was a mercury acoustic delay line contraption having
a piezoelectric transducer at one end to launch an electrical pulse along its length
and another transducer at the other end to convert back to an electrical pulse...
 These are the schematics and parts list
for vintage vacuum tube radios
Westinghouse Model H-133;
Arvin Models 150TC, 151TC; and
Admiral Model 7C63, Chassis 7C1 as they appeared in the December
1947 issue of Radio News magazine. I scan and post these for the benefit
of hobbyists and historians seeking such information. As time goes by, there is
less and less likelihood that records of these relics from yesteryear's archives
will be made available. As with all historical information, it takes someone with
a personal interest in preserving the memories in order to fulfill the mission...
 KR Electronics has been designing and manufacturing custom filters
for military and commercial radio, radar, medical, and communications since 1973.
KR Electronics' line of filters includes lowpass, highpass, bandpass, bandstop,
equalizer, duplexer, diplexer, and individually synthesized filters for special
applications - both commercial and military. State-of-the-art computer synthesis,
analysis, and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Designed and
manufactured in the USA. Please visit NIC today
to see how we might be of assistance.
 Here is another electronics quiz for you
to try. Intuition from experience goes a long way here, but if all else fails you
can work out the details of the rectifier circuits to determine
which lamp received the most current. Keep in mind that the diode
symbols are not LEDs; it is the "A," "B," and "C" symbols inside circles
that are the lamps whose brightnesses are being considered. LEDs did exist at the
time this quiz was created in 1969, but the circuits would perform differently if
in fact LEDs were used for double duty of rectification and illumination...
 The more things change, the more they stay
the same. That saying applies to many recreational activities. Pick up a copy of
QST magazine that was published in the last year and look at
reader comments and you will find laments about the dwindling
participation of youngsters, an increased degree of incivility and rule breaking
during engagement, the high cost of getting into the hobby, yadda yadda yadda. I
witness it regularly in the model aircraft world, too. That is not to say the issues
are not true or irrelevant, just that they are persistent. Each generation, it has
been said, tends to think...
 I have long-maintained that the vast majority
of electrical problems on consumer products can be attributed to bad connector or
switch contacts. Just yesterday, I restored a 1970's-era TI talking kids' toy to
working order just by cleaning the plug-in program module and mating motherboard
contacts. RF Cafe website visitor / contributor Bob Davis sent this suggestion for
curing intermittent or non-responsive front panel buttons on test equipment and
other electronic gear like radios, remote keypads, games, tools, vehicles, keyboards,
locks, etc. His problem was with a R&S spectrum analyzer. He found a solution
from ButtonWorx, who manufactures replacement
pressure contacts for a large range of products. Some are entire arrays to replace
original parts, and others are individual switches for custom requirements.
 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...
 Have you noticed that every time a shooting
or other attack event occurs - especially pertaining to "R" targets - the quality
of the video looks like something from the 1970s, or of a UFO sighting? Most private
surveillance cameras in homes, cars, and businesses - even traffic cams - have resolution
and full color so good you can distinguish faces and even identify brands of clothing,
weapons, etc. This is a frame from the attempted assassination attempt this weekend
at the White House Correspondents Dinner. The perp, a celebrated "Teacher of the
Month" from California, rushed the security point with multiple weapons. Conceal
carry, do training, and watch your six.
 In the early 1950s, the U.S. Navy built
what was at the time the world's largest and most powerful radio broadcast transmitter
station at the
Jim Creek Naval Station on Wheeler Mountain in Washington state.
Its 1.2 MW, 24.8-to-35 kHz VLF transmitter (call sign NLK) can reach anywhere
in the world, even to submarines. A half wavelength at 24.8 kHz is 19,830 feet.
Photos indicate that the transmitter is located in the middle of a dipole arrangement.
"Catenary cables," if you are unfamiliar with the term, refers to the sagging shape
assumed by both the antenna cables and the tower support cables. "Catenary" stems
from the word "chain" since it is in the form...
 Carbon tetrachloride (CCl4) was
a common cleaning agent used commercially through about the early 1950s when it
began receiving a lot of bad press due to a linkage to severe kidney damage from
exposure even in vapor form. I notice that Mac mentions having read an article about
the potential danger of "carbon-tet" in an edition of Radio & Television
News magazine, not coincidentally the publication where the "Mac's Radio Service Shop" series appears. He also mentions a publication
called International Projectionist, which included instructions for cleaning
movie film with carbon tetrachloride, and had...
 It is amazing to me how many times I read
an article, whether in a vintage magazine like this 1947 issue of Radio News,
or a current edition of QST, how when discussing maximum power transfer
from a source to a load, the author states merely that the load impedance must equal
the source impedance. The fact of the matter is that the source and load impedances
must be the
complex conjugates of each other in order for maximum power transfer
to occur. That is to say that if the source has a complex impedance of R + jX, then
the load must have a complex impedance of R - jX (and vice versa)...
 Unlike today when resources of all types
seem to be endlessly available, during World War II countries needed to collect
and recycle much in the way of metal, rubber, cloth, and other basic materials for
re-purposing into products used in fighting the enemy. Media coverage of bottle,
metal, and tire drives showed children pulling Radio Flyer wagons loaded to overflowing
with such items gathered from trash piles and soliciting neighborhood residents
for anything that could be spared. Raw materials were not the only type of items
needed, however. "Use
it up, Wear it out, Make it do, or Do without" was the slogan. Finished goods
like electronic components - vacuum tubes, transmissions cable, transmitters and
receivers, tuning capacitors, d'Arsonval meter movements, and other parts -
were sorely needed by manufacturers both for building new equipment and for servicing
damaged gear. After the war was won, the War Assets Administration...
 Around the time when this "The
Great QSL Quarrel" appeared in a 1960 issue of Electronics Illustrated
magazine, there was a long-standing friction between amateur radio operators and
shortwave listeners regarding the exchange of QSL confirmation cards. Far from mere
paper, many hams view their custom-designed cards as valuable reflections of their
personal rigs and efforts. Consequently, they often discard subpar listener cards
that are illegible, aesthetically dull, or lacking meaningful data. To ensure their
reports are actually welcomed, shortwave listeners are urged to adopt higher standards:
utilizing professional printing or clear handwriting...
 A momentous development that changed the
field of radio communications warranted merely a half-page announcement in 1935
when
frequency modulation inventor Edwin Armstrong had his article
published in Radio-Craft magazine. It indisputably changed the world while causing
poor Mr. Armstrong much grief while defending his right to the invention. Spread
spectrum modulation / demodulation would be the next big communications advance
that began with the frequency hopping (FHSS) scheme dreamed up by Hollywood actress
Hedy Lamarr and pianist Antheil George during World War II. Direct sequence
spread spectrum (DSSS) followed in the digital age, and since then I do not know
of any fundamentally new communications technology in that time...
 Since 2005, San Francisco Circuits has been
a trusted U.S. provider of advanced PCB manufacturing and assembly solutions for
R&D innovators, prime contractors, and integration experts.
Flying Probe Testing (FPT) has long been a reliable method for validating PCB
designs, particularly for prototypes and low volume production. Unlike traditional
in circuit testing (ICT), which relies on custom built fixtures, flying probe systems
use movable probes to test electrical connections directly, eliminating the need
for dedicated hardware. Flying probe testing uses multiple programmable probes to
contact pads...
 The February 1947 issue of Radio News
only had two
electronics-themed comics. Many months have up to half a dozen
comics. Maybe the winter blues had set in with the magazine's illustrators. The
first comic is a tad bit prescient in that it depicts a robber running past a television
store and seeing a TV in the front display window showing a real-time video of the
cop chasing him. That was way before there was a video surveillance camera on every
street corner. I haven't discovered a vintage magazine yet with someone taking a
"selfie." There is a growing list...
 These are the schematics and parts list
for vintage
Emerson vacuum tube radio models 501, 502, and 504;
Crosley model 56TD-W; and
Arvin model 140P as they appeared in the November 1947 issue of
Radio News magazine. I scan and post these for the benefit of hobbyists
and historians seeking such information. As time goes by, there is less and less
likelihood that records of these relics from yesteryear's archives will be made
available. As with all historical information, it takes someone with a personal
interest in preserving the memories in order to fulfill the mission...
 John Comstock created many crossword puzzles
for Radio & TV News magazine, and a couple others, in the 1950s and
1960s. This one titled "Test
Equipment Teaser," appeared in the March 1959 issue. It is not a densely populated
grid with complex intersections of crossing words (unlike the RF Cafe crossword
puzzles, which do have them), but at least with this kind, all of the words and
clues are directly related to electronics and technology (like RF Cafe crosswords).
Anyway, it shouldn't take you too long to zip through this one. The only clue/word
that might give you trouble is 32 Across. Enjoy...
 Exodus Advanced Communications' representatives,
in discussions during last month's EMV (Elektromagnetische Verträglichkeit) show
in Cologne, had many attendees express interest in receiving an Exodus brochure
covering our RF amplifier solutions for
drone (UAS) applications. Exodus supports defense contractors with a family
of RF amplifier modules optimized for UAV, drone, mobile, and fixed Counter-UAS
platforms. At the center of this portfolio is the
AMP10008, an ultra-lightweight solid-state RF amplifier module
that demonstrates what is possible when SWaP is treated as a primary design driver
rather than a compromise...
 The cover of this month's Radio &
Television News magazine is part of the issue's story on performance testing
of resistors. The author was an engineer for
International Resistance Company (IRC), which is still in business
as part of TT Electronics. The massive ovens were used for load-life testing to
certify resistor products for both military and commercial uses. When required,
humidity enclosures subjected resistors to increased levels to test for insulation
breakdown at high voltage. As the article observes, since a 10-cent resistor can
take down a multi-thousand system, it is important to guarantee every component's
integrity...
 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.
 RF Cafe's spreadsheet-based engineering
and science calculator,
Espresso
Engineering Workbook™, is a collection of electrical engineering and physics
calculators for commonly needed design and problem solving work. The filter calculators
do not just amplitude, but also phase and group delay (hard to get outside of a
big $$$ simulator). It is an excellent tool for engineers, technicians, hobbyists,
and students. Equally excellent is that Espresso Engineering Workbook™ is provided
at no cost, compliments of my generous sponsors. 49 worksheets to date...
 Although the Japanese attack on Pearl Harbor
on December 7, 1941, was a complete surprise and shock to the nation, that fact
that the United States would eventually be drawn officially into World War II
was well known. The amateur radio community had begun talking about the potential
impact on radio communications hobbyists earlier in the year, as evidenced by articles
printed in QST and other magazines. Within a couple weeks of Congress declaring
war, all unauthorized transmissions from Ham stations were terminated in order to
prevent both intentionally and unintentionally conveyance of information that could
proves useful by the enemy. Along with being a patriotic bunch that were eager to
help defeat Axis powers, they also...
|
 • U.S.
Engineering
Ph.D. Programs Losing Students?
• What
Hormuz Exposed About Semi Supply Chain
• Broadband
Equipment Market Set for 2026 Rebound
• Foundry
Revenues to Grow 24.8% YoY
• U.S.
Manufacturing Sector Flexes Its Muscles
 The
RF Cafe Homepage Archive
is a comprehensive collection of every item appearing daily on this website since
2008 - and many from earlier years. Many thousands of pages of unique content have
been added since then.
 Did you know that you are likely a TLV? That's
right, a
Television Looker. The modern equivalent is CP - Couch Potato. In the early
years of television, TLVs were as fascinated with the device itself and the technology
as they were with the information being displayed. As this story tells, Hams were
involved in TV transmission (ATV) early on. I did not know that amateur television
was banned during World War II. During WWII, all amateur radio operations were suspended
with the exception of those authorized to continue under the Radio Amateur Civil
Emergency Service (RACES)...
 Here's a topic -
power
supply filter design - that never goes out of style. It was originally published
in a 1952 issue of QST magazine. Without bothering to worry about source
and load impedances, this brief tutorial on the fundamentals of power supply filter
design using series inductors and parallel capacitor combinations. Author Gabriel
Rumble offers a rule-of-thumb type formula for guessing at a good inductor value
based on peak-to-average expected current. This is by no means a comprehensive primer
on power supply filter design and is directed more toward someone new to the concept
of removing or reducing noise and AC ripple from the output of a DC power supply...
 Windfreak Technologies is proud to announces
the availability of our
FT108, an innovative
programmable bidirectional filter bank spanning a frequency range of 5 MHz
to 8 GHz in 15 bands. Band selection can be controlled through USB, UART or
at high speeds through powerful triggering modes. Each unit is factory tested via
network analyzer with unique data stored in the device to help with its use. Crossover
frequencies are stored so the user can send a frequency command and the FT108 will
utilizes Intelligent Band Selection logic to automatically toggle the optimal
filter path based on minimum insertion loss. Readback of FT108 insertion loss at
any frequency between crossover points allows for easy amplitude leveling...
 Cathodic protection is a major field of
electronics and electrical distribution. It has two primary forms - galvanic and
impressed-current. The goal of each is to negate the electrical current between
dissimilar metals which leads to corrosion. The galvanic method typically uses a
passive sacrificial metal element to dominate the electron migration. An example
is the anode rod inside your hot water heater (HWH). Most people have no idea they
exist and are supposed to be checked regularly and replaced as needed. It's fairly
easy to do, requiring shutting off the water supply and draining the tank below
the level of the top. Once a year, I also open the drain valve at the bottom of
the HWH to rid it of any debris. Impressed-current cathodic protection is more sophisticated
and involves injecting a counter-current in an engineered system to cancel out destructive
currents. This "Cathodic Protection" article from the March 1963 issue of Radio-Electronics
magazine is a good primer for the science behind it...
 Even if you have no use for building a "twin
lamp" standing wave indicator for a twin lead transmission line (solid
or open ladder type), this article makes an interesting read for its theoretical
description of how the device works based on current phases in the circuit. A pair
of flashlight bulbs and couple feet of wire is all that is needed. When operating
properly, the "twin lamp" indicator indicates by virtue of whether one or both bulbs
are illuminated whether there is a significant standing wave present on the line.
Author Charles Wright warns that the VSWR level cannot be reliably determined based
on relative brightnesses of the two bulbs; it is meant for use as a best case indication
for tuning and/or as a gross fault indicator...
 Here is your custom made RF theme crossword
puzzle for March 27th, 2022. R's and F's are prominent in this crossword. 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 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!
 Stanley Leinwoll wrote a couple articles
about shortwave broadcasting for the September 1969 edition of Electronics Illustrated
magazine. "They're Taking the Guesswork out of Scatter Communications" discusses
advances (at the time) in ionospheric scattering of shortwave radio signals, and
also this one entitled "The
Grim Facts on Short-Wave Broadcasting." This is another example of the old adage
of how the more things change, the more they remain the same. Frequency crowding
was then and is now a continual challenge for operators in non-privileged bands
(spectrum purchased for private, military, government, or commercial use, e.g.,
cellphone carriers). Mitigation techniques include narrowing of channel bandwidth
(via improved modulation techniques or improved transmitter / receiver spectral
requirements), decreased transmit power levels, modification of usage regulations,
and allocation of new spectrum...
 Before there were electric generators onboard
airplanes to power communications equipment, aviators relied on storage batteries
to operate their radios. Before that, there were no radios at all aboard airplanes.
Although Wilbur and Orville Wright first piloted their Wright Flyer in 1903, by
the end of the decade airplanes were becoming a common sight across the country
and across the civilized world. By the middle of the second decade experiments were
being done with airborne radio. They were heavy vacuum tube units with heavy
lead-acid batteries. Antennas sometimes hundreds of feet long needed to be
reeled out and in once at altitude. The earliest transmitter (for 2-way
communications) were spark gap types, meaning of course Morse code was the
medium...
 It's hard to imagine a time when
unlicensed radio frequency bands were not the norm, but early in the history of radio,
strict spectrum control was necessary in order to prevent unintentional radiation from
crappy equipment interfering with services. Remember that even in the mid 1940s, many,
if not most, casual users were cobbling together their own transmitters and receivers
from scratch. Transmitter powers were easily high enough to interfere with nearby and
distant receivers, but even improperly shielded receiver oscillator ("exciters") could
cause interference with a neighbor's nightly Lone Ranger broadcast.
Around 1945, the FCC began entertaining the idea of allocating bandwidth for the
use of the newfangled "walkie-talkies" that were developed for field
communications during World War II...
 This is a nice short article covering the
calculation of inductances for coils wound on cores and wire sizes. It appeared
in a 1932 issue of Short Wave Craft, but of course inductance has not changed
since then so it is still relevant. The author recognized that standard formulas,
although concise and accurate, are sometimes difficult to work with when calculations
for a large number of values is needed for a particular circuit design. To address
the situation, he presents a handy nomograph, chart, and a table of typical values.
He also introduces a rarely seen term "Nagaoka's correction factor*" for skin
effect. A smartphone app, a spreadsheet, or a desktop computer program would be
used today to calculate inductance...
 Whether or not this kind of stuff goes on
over the Ham bands these days, I couldn't tell you. It is easy to believe the level
of obnoxiousness of some people back in the 1940's when this "'Phone-Band
Phunnies" article appeared in QST magazine, featuring "Little Stinky."
Of course if you assume the way kids are portrayed in contemporary movies and TV
shows is typical of the real world, even the behavior described herein would seem
mild in comparison. Fortunately, kids today have a plethora of social media venues
for treating others to their brands of personalities, so maybe the Ham bands are
spared the abuse...
 I recently created a new reference page titled
"Resistivity (ρ) & Conductivity
(σ) of Metals, Alloys, Rocks, and Soils." Values for materials are pulled from my
copy of Reference Data for Radio Engineers, Sams Publishing. Resistivity, also
referred to as specific resistance, is dependent on the nature of the material as well
as its volume definition (shape and size). Resistivity is expressed in units that are
the product of resistance and length; e.g., Ω·cm. As an example of calculating a volume's
resistance, consider the drawing to the left. Assume 12 AWG copper wire with a resistivity
of 1.72x10-6 Ω·cm, a cross-sectional area...
 October 1954 arrived with the first-ever
issue of Popular Electronics. Editor Oliver Read wrote this introductory note describing
the magazine's grand plans for providing its audience with a sampling of as many
facets of electronics as possible, with projects for the do-it-yourself type (many
needed to be at the time), related hobbies like amateur radio and radio controlled
airplanes, military and commercial applications, short stories, tutorials, and an
endless supply of advertisements offering just about anything your budget could
afford. It turned out to be a pretty nice magazine, and many of the well-written
articles are still useful in today's world of nano-everything circuits - the fundamentals
haven't changed much: voltage still equals resistance times current...
 Time to put on your thinking caps once again.
No person is credited for these three "What's
Your EQ?" challenges from the March 1963 issues of Radio-Electronics
magazine. In other instances (see below) it is E. D. Clark. BTW, EQ stands for Electronics
Quotient. My solution for the "Four-Bulb Puzzler" was different from the one proposed.
Given that semiconductor diodes were available at the time, I put a 6.2-V zener
diode (a common value at the time) across each bulb, figuring if the bulb burnt
out (open-circuited), the zener would drop the voltage normally dropped by the 6 V
bulb. While the bulb is operating, the voltage across the zener would not turn it
on. Of course there could be a problem with the current through the diode being
too high when turned on, without a limiting resistor. "Simple Circuit?" would take
more time than I am willing to expend right now. With "Ohms, Sweet Ohms" don't let
the wording of the proposition bias (pun intended) your analysis...
 If you happen to be Estonian, you might
think of something entirely different than most RF Cafe visitors do when we hear
the word "getter."
In fact, you probably capitalize the word since it is the name of a pop singer from
your country, Getter Jaani. If you are a child living in Japan, you would probably
think of Getter Robo, an anime from a popular cartoon series. I suspect just about
everyone who visits RF Cafe knows getter as the silvery deposit (typically barium)
that resides inside vacuum tubes for the purpose of helping to maintain the vacuum
and to absorb pesky random molecules that might otherwise cause electrical noise
in the circuit. This article from a 1958 edition of Radio-Electronics magazine
discusses the purpose of getter. BTW, I had never heard of either of the other two
Getters, probably due to OGS (old guy syndrome)...
 Voltage multipliers were found in nearly
every form of battery-powered electronics in the days of vacuum tubes, because of
the 100-volt or more requirement for plate voltages. Primary batteries in 30, 45,
and 67½ volt sizes were produced by Eveready, Burgess, and a few other companies
in order to help simplify biasing circuits. They were bulky and heavy, often comprising
a significant portion of the assembly's volume. Heavy transformers contributed mightily
to the weight and size as well. Exell still manufactures 30, 45, and 67½ V
batteries both for the few products that are still designed to use them, and for
vintage radio owners. Most circuits that need higher DC voltages these days use
DC-DC converters, many of which are ICs...
 Here is a fascinating story from a 1946
issue of the ARRL's QST magazine of the ordeal one Catholic priest experienced
while serving in the Philippines during the Japanese occupation in World War II.
Father Visintainer exploited his personal interest in
radio communications to help keep local residents apprised of the war's progress
and talk to the outside world. Japanese troops confiscated all the existing shortwave
radios and converted them to their own frequencies. Some were re-converted by daring
servicemen and then hidden. Batteries were recharged using covert water wheel powered
generators located in the woods. Drama hit a peak one day when an attempt to formulate
a make-shift battery electrolyte resulted in an explosion that brought Japanese
running to the church lab. For a guy who claims, "But I am not a chemist," he has
an amazing knowledge of chemicals. Read on to learn how Father Visintainer escaped
certain death...
 While reading this vintage
Electro-Voice hi-fi speaker promotion from a 1957 issue of Radio-Electronics
magazine, the thought occurred to me that reconstituting that practice of offering
products for sale in kit form could help solve at least three problems we have these
days: high product costs, lack of knowledge and ability by most people for building
material things and understanding how they work, and a shortage of workers willing
to do factory jobs. With inflation in the 9% and up range, and government handouts
removing the necessity of being a productive citizen by providing handouts, not
only are formerly easily procured products difficult to obtain, but the prices are
rising outrageously fast. Heathkit and other electronics products companies had
a good idea that endured up through the 1980's, until manufacturing made a mass
exodus from the U.S. to offshore venues in order to drive prices down. Americans
lost good jobs that paid a decent wage while citizens of China and other countries
did the work instead for compensation that barely paid for food, clothing, and shelter.
Many were, and many still are, virtual slaves at the mercy of Communist dictatorships...
 Here in the February 1947 issue of Radio-Craft
magazine is part three of a six-part series on
Antenna Principles. The first two parts concentrated on dipole antennas and
feeders, and multi-element long-line and rhombic antennas. Part three is on directional
arrays and radiation fields. In addition to a bit of theory, real-world examples
are given of various directional antenna configurations along with field strength
graphs. Without powerful computers to calculate and plot out predicted radiation
patterns, a large combination of experience and in-situ measurements was required.
A huge amount of time was spent for even relatively simple arrays. Finitely detailed
topographical and structural models are now available which, along with very precise
electromagnetic field calculation algorithms allows efficient and accurate planning... |
