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 Here is another article about a
"prodigal" Ham who returned to amateur radio after about a 30-something year
respite, per this 1955 Popular Electronics magazine. Author Charles Meistroff's
previous experience had been with surplus World War I - yes that's WWI! He must
have been in Heaven to be able to now get his hands on all the new-fangled equipment
now (then) available on the World War II surplus equipment market! I don't know
if the military is still making surplus equipment available like they did even up
through Korea and Vietnam. There must be some great stuff from the Middle East wars
if it is circulating within the surplus market. Then again, other than ruggedness
factors, most commercial equipment is as good or better than MIL-SPEC stuff...
 "If the car is parked in a dark remote spot
it is better to do the job where the car is. This is because auto burglary is a
lesser crime than stealing the whole damn car." That remark was made by a 'former'
thief who ostensibly gave up a life of crime after spending nearly two decades in
the slammer for various infractions of the law. One of his specialties was breaking
into cars to
steal radios - AM, FM, CB, Ham, or whatever was available. Mr. X
volunteered his insight for the benefit of QST readers who might want to take proactive
steps to help minimize the chance of being a victim. The year was 1967, but you
can bet the same mindset pervades the thinking of modern day break and grab thieves
today. Even though most modern portable electronics equipment is protected from
access by passwords, that wouldn't stop a thief from stealing...
 Prior to the emergence of
silicon-based semiconductors, selenium and copper(cuprous)-oxide
rectifiers were the alternatives to vacuum tubes. Copper-oxide (Cu2O)
was popular as a small signal detector since its forward voltage drop was similar
to a Schottky type diode - typically around 0.2 V. Copper-oxide diodes were
used in radios and test equipment meters. Selenium (Se) has a forward voltage drop
of around 1 V, but its high reverse voltage withstanding of 20 V or more
made it popular for voltage rectification, with as many layers as necessary being
stacked serially as required. Selenium rectifier stacks...
 Centric RF is a company offering from stock
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distributors, so please contact us if interested. Visit Centric RF today.
 Welcome to the
RF Cafe Coaxial Cable
Quiz, a technical assessment designed to sharpen your proficiency in the fundamental
transmission media that underpin all radio frequency communications. Whether you
are scaling a tower for antenna installation, troubleshooting impedance mismatches
in a feedline system, or calculating loss budgets for a long-run cable deployment,
a firm command of coaxial theory is vital for maintaining signal integrity and power
efficiency. This quiz challenges your understanding of critical transmission line
metrics, including characteristic impedance calculations, the impact of dielectric
constants on velocity factor, the physics of the skin effect, and the thermal limitations
of power handling. By testing your knowledge...
 If you were hanging around here in 2014,
you might recall a paper I published titled, "Drone-Based Field Measurement System™ (dB-FMS)™." Since that time,
I have seen news items about a few companies using drones to measure antenna radiation
patterns and many more others are coming online all the time. Some amazing working
systems have been implemented that seem to perform very well. I'm not saying
they got the idea from my article because more than one person can have the same
brilliant idea ;-). It's just good to know that my concept had some merit in
the real world...
 My
Vise-Grip pliers have performed a lot of hard duty over the decades.
Many rusted nuts and bolts would still be unremoved if it weren't for their
sharp, corrugated locking jaws. I have 10", 7", and 4" w/cutter, and 6" long nose
models. These are all manufactured under the Petersen Manufacturing Company name,
before they bought Irwin, who now manufactures Vise-Grips. Even high quality tools
eventually show signs of wear after decades of use and abuse. A few of mine had
jaws worn down to the point where they no longer would "bite" into the bolt head
or nut being clamped. I was about to buy a couple new pairs of Vise-Grips, but then
wondered if I could recondition the jaws to put the pointed shape back on the jaws
with a triangle file. Being hardened steel, a lot of times a standard file will
barely scratch the surface, but in this case I managed to dress the jaws of four
pairs of Vise-Grips before the file (double taper triangle) got dull...
 "Stratovision" sounds about as serious as "Wonkavision," but unlike
the candy maker's fictional machine that transported chocolate bars across the
room, Stratovision was in fact a serious proposal. It was an early form of satellite
television. Since orbiting communications satellites would not be practical for
another decade, Westinghouse devised a system in 1945 using aircraft flying at high
altitude to relay television signals. Engineers calculated that 14 airplanes circling
at 25,000 feet could provide coverage to 78% of the country. By 1950 they had a
working system, but needless to say (because nobody has ever heard of it... except
you, now), the concept ultimately did not pan out. It was not because the system
failed to work as designed, but because there was not enough demand...
 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.
 According to this full-page advertisement
in the June 1955 issue of Radio & Television News magazine, Bell Telephone
Laboratories was responsible for designing and fielding "waveguide pipe," aka flexible circular waveguides. According to
other historical sources, both George Southworth of Bell Telephone Laboratories
and Wilmer Barrow of the Massachusetts Institute of Technology (M.I.T.) independently
and simultaneously developed circular waveguide, but the early devices were rigid
pipe rather than being fabricated from tightly wrapped, insulated wire that permitted
it to be bent rather than requiring separate corner and offset pieces. Insertion
loss and VSWR is typically not as good as with rigid waveguide, but the ease of
installation in many situations justifies the poorer electrical performance. Bell
Telephone Laboratories was responsible...
 Having recently struggled a little with
re-stringing the dial cord on a vintage Realistic (Radio Shack) Patrolman-50 Radio,
it really became apparent why the
Sams Photofact Folders were of such value to electronics servicemen.
Unlike the tangled mess of dial cord shown in the ad, I had the advantage of being
able to carefully open the chassis and photograph the routing and wrapping of the
broken dial cord around pulleys and shafts. Even so, a lack of experience required
some trial and error to get the tensioning correct. No doubt many unqualified radio
owners attempted to fix their own broken dial cords prior to breaking down and committing
to spending a few bucks to have a pro do it correctly. The tight quarters in my
portable radio had me using tweezers to do some of the routing...
 My mother loved
Norman Rockwell paintings for their ability to get to the heart of Americana.
She was an avid collector of books on Rockwell and decorated plates for display
- as avid as one can be on my newspaper classified ad manager father's feeble
salary, anyway. I, too, have a great appreciation for Rockwell's great talent
to choose his subject matter and models and to, when fitting, include a nearly photographic
level of detail within. The Saturday Evening Post magazine featured many of his
works spanning from 1916 until 1971 - from the middle of World War I and on
through World War II, Korea, and Vietnam. Summer, spring, fall, and winter;
Christmas, Easter, Veteran's Day, President's Day, Mother's Day, New
Year's, and other annual events; experiences of love, happiness, joy, surprise,
sadness, and a host of other emotions...
 Time to put on the thinking cap again for
three more "What's
Your EQ?" circuit challenges, compliments of Radio-Electronics magazine
in May 1962. The first is a classic "black box" type problem which, from reading
its description, involves some sort of resonant circuit. that's all I'll say on
that. The next, called "An Easy One?" should, by the way it is drawn, be a clue
that it might be easier to solve if you re-draw it to make a familiar-looking circuit.
Hint: Summons the spirit of Sir Charles Wheatstone. Just the name of the last one,
"Iterative Network," is enough to induce a cold sweat. As with most of these "What's
Your EQ?" problems, successful completion of a first year college circuits course
is plenty to get through them. A few are better attempted by people with hands-on
experience troubleshooting circuits, but don't let that scare you off...
 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. Update: KR Electronics
has been acquired by NIC, where KR Electronics'
legacy of quality and innovation will continue to thrive, offering the same trusted
products and services under NIC's leadership. For over three decades, NIC has delivered
high-quality component performance and reliability, ensuring the successful deployment
and operation of our clients' mission-critical solutions. Designed and manufactured
in the USA. Please visit NIC today to see how
we might be of assistance.
 Roger McCraw sent me these photos from his
assignement in U-Tapao, Thailand, cicra 1973. I submitted a couple of the images
to AI for colorization - amazing! Says Roger, "The pictures were taken at U-Tapao,
Thailand and are dated April 1973. I was there from Jan 73 till Jan 74
and was a 30351 in the 1985th Comm Squadron. Since I was the newbie I was selected
to change the light bulbs so I decided to give a Nixon peace sign for the photographer.
The MPN was on a turntable so it could service both approaches to the runway. The
ATC displays were in a trailer that was attached to a building, it was just to right
of truck in picture. I only remember the name of one person because his name is
listed on TWS website. He bought a four function calculator...
 This installment of the After Class series
in the December 1957 edition of Popular Electronics deals with inductors.
It is a beginner-level introduction to how
reactive components behave in circuits. For some reason the concept
of magnetism's influence on electrical current (present with inductors but not
capacitors) seems to be more difficult to comprehend than that of electrons, even
though James Clerk Maxwell shows in the mid 1800s that the two phenomena are interrelated.
I am tempted to say that back in the 1950s when this article appeared, people were
less familiar with the relatively new concept of electronics, but in thinking about
it, your typical 2019 reader is probably even less likely to know anything at all
about electronics or the way basic components work. I would bet that maybe 1% could
even tell you the difference between AC and DC current...
 Not very long ago I mentioned
Jean Shepherd (original assignee of W9QWN and later K2ORS call
signs) as being one of my favorite old-time radio broadcasters (1960s-1970s). Jean
was famous for recounting stories of his own life and for reporting news of the
time in a way that could hold you in rapt attention from beginning to end. His humor,
wit, and command of the English language was acknowledged by his contemporaries.
If you listen to enough of his broadcasts you will notice the frequent mention of
electronics and his experiences as a licensed amateur radio operator beginning at
a tender young age. Just recently I listened to him recount his first day in high
school when a SNAFU in the computer-generated (must have been a UNIVAC) class schedule
mistakenly had him reporting to the girls' swimming pool...
 I was born in the era of screw-in glass
fuses in household electric service panels. There was always a supply of replacements
in the cabinet above the stove. Sometime around 1978, prior to enlisting in the
USAF, I replaced the fuse panel with a Square D circuit breaker panel - a skill
learned through four years of electrical work. In the Air Force, I worked on a 1950s
era air traffic control radar system which consisted of many chassis assemblies
having fuse holders on their front panels. The racks themselves had a circuit breaker
panel, but it was a retrofit from sometime in the early 1970s. That was my introduction
into the wide variety of cylindrical glass fuses - high and low voltage, normal-,
slow- and fast-blow, time delay, etc. I learned of the reason why circuit designers
employed each type, and always used exact replacements when possible. Later, as
a circuit and systems design engineer myself, I always was careful to specify the
most
appropriate fuse type. This 1960 article in Radio-Electronics magazine
is a good primer on fuse handling...
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 Mostly just old farts like me remember anything
about
LORAN (LOng RAnge Navigation). My familiarity with it came not from boat navigation,
but from airplane navigation. Before LORAN became totally obsolete due to GPS (phased
out in U.S. and Canada in 2010), the transmitter stations were commonly tuned in
in order to obtain positional fixes via triangulation. Whilst taking flying lessons
at Lee Airport, in Edgewater, Maryland, the ground instructor included it in the
lessons, and even the FAA Private Pilot exams had a question or two on LORAN. The
el cheapo Piper Colts that I flew were lucky to have a VOR (VHF omnidirectional
range ) receiver in it, so I never actually used LORAN. They did have direction
finders (DF), which could tune in, among other things, VHF television station channels...
 Just as you will never get everyone to agree
on who was the first person to successfully fly a powered aircraft (Wright, Whitehead,
Curtiss, etc.), there will never be a consensus on
who invented the radio. Most people would probably agree that it was Guglielmo Marconi,
but this author makes a case for none other than Thomas Edison. I don't recall ever
hear anyone making that claim before, but before you dismiss the opinion, read on...
 The December 13, 1965 issue of Electronics
magazine was largely dedicated to assessing
Japan's status in the electronics industry. Japan, with the help of the United
States, made a remarkable recovery from defeat during World War II to have
become an emerging power in electronics. "Made in Japan" labels on products had
transformed from being the butt of jokes because of pre-war low quality products
to representing assurance of low cost, high functionality and high value products.
It still does to this day. The Japanese people have worked hard to acquire the world's
respect as smart innovators and hard workers, and have been sure to maintain manufacturing
bases within their borders. When you read this article, be prepared for a few dated
terms like a "Kita" diode...
 Citizen Band (CB) radios were all the rage
during my high school years (1973-76). Previously the domain of over-the-road haulers,
by then everybody who was anybody had a 23-channel CB in his/her car or pickup truck.
My 1969 Camaro SS, of course, sported one - probably the cheapest model available.
Those were the days of C.W. McCall's "Convoy" and Cledus Maggard's "The White Knight"
lyrics. Everybody knew the words to it. Smokey and the Bandit fed the craze.
After all, there were no cellphones. Rather than learning text messaging shortcuts
like OMG, *$ (the company didn't even exist then), B4N, and IMHO, we learned to
use clever words and phrases like "10-4," "bear in the air," and "what's your 20?"
It's been a long time...
 The
American Telephone and Telegraph Company (AT&T) was founded as part of the
Bell Telephone System to build a nationwide wired, long distance communications
service. When this advertisement was printed in a 1917 issue of The Saturday Evening
Post magazine, many American households still did not have a telephone installed,
and most of those that did subscribed to "party line" hookups. Party lines were
a service sharing agreement whereby multiple users were connected to the same telephone
number and agreed to share the line. The upside was a discounted phone bill, but
the downside was the any other member of the "party" could listen in on your conversation.
I remember back in the 1960s when our house had a party line. My sister and I (both
preteens) would sometimes carefully pick up the phone receiver and listen in hopes
of...
 Montgomery Ward (aka "Wards" or even "Monkey
Wards") had their own line of radios, electric guitars, and other products that
went by the name of "Airline." Sears, Roebuck and Company, by the way, had the "Silvertone"
series of radios, electric guitars and, other electronics products. This 2-page
radio service data sheet for the
Montgomery Ward Airline Model 04BR-1105A console type radio appeared in a 1941
issue of Radio-Craft magazine. Some of the electronics magazines of the
era ran these features to help out people who wanted to attempt troubleshooting
and aligning their own equipment. Many electronics manufacturers would sell service
data documentation only to authorized dealers and repair shops. Unlike today where...
 These custom-made
engineering and science-themed crossword puzzles are done weekly for the brain-exercising
benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. The jury
is out on whether or not this type of mental challenge helps keep your gray matter
from atrophying in old age, but it certainly helps maintain your vocabulary and
cognitive skills at all ages. A database of thousands of words has been built up
over the years and contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing
your knowledge of a numbnut soap opera star or the name of some obscure village
in the Andes mountains. You might, however, encounter the name of a movie star like
Hedy Lamarr or a geographical...
 Maybe it comes from having crossed the half-century
Rubicon, but with increasing frequency I find myself seeking out vintage magazines
to learn how the world used to be. I am a realist who has no misconceptions about
how idyllic things used to be and that today is utter debauchery, but it is apparent
from a lot of the publications that we surely have changed significantly in the
last 50+ years - better in some ways, worse in others. For many years I have been
purchasing of
WWII era
QST magazines off eBay. As I have been doing for a while on my Airplanes and
Rockets website, I am going to begin scanning and posting vintage electronics magazine
advertisements and articles. A lot of the information is timeless in its application,
especially since vacuum tubes are still in widespread use in the Amateur Radio realm.
Of course electronics...
 All types of
sales and repair services get accused of ineptness of skill which requires more
time than necessary, overcharging for parts and/or labor, underhandedness in faking
problems and selling unnecessary replacement parts, improper customer interfacing,
sloppiness in appearance and/or work environment, failure to arrive on time for
appointments, etc. Some of the most often cited these days are auto mechanics, cellphone
repairers, home improvement contractors, lawn care, and builders. Up until about
a decade ago when cellphone repair began to dominate over computer repair, the latter
was a big source of complaints. In the 1950s and 60s, it was TV and radio repairmen
who took a lot of abuse not just from their customers...
 IC designers have been striving to make the
"ideal" opamp ever since the device type was first conceived. An ideal opamp has
a certain set of well-defined properties that permit it be used in circuits defined
by neat mathematical equations without the need for compensating or limiting terms.
An example of compensation might be having an input impedance of something other
than infinite ohms that causes a voltage division effect on the input voltage, and
a limitation would be a gain-bandwidth product that prevents it from being used
in high frequency applications. Opamps appeared in electronics before semiconductors
came onto the scene, and a couple companies attempted to market prepackaged vacuum
tube opamps that plugged into a standard octal kind of socket . EE120 at the University
of Vermont introduced me to operational amplifier theory...
 The first thing I learned (or re-learned)
in reading this article is that in 1967, "Hertz" had only recently been assigned
as the official unit of frequency. According to Wikipedia, International Electrotechnical
Commission (IEC) adopted it in in 1930, but it wasn't until 1960 that it was adopted
by the General Conference on Weights and Measures (CGPM) (Conférence Générale des
Poids et Mesures). Hertz replace cycles per second (cps). The next thing that happened
was that I was reminded of how images such as the op-art tracing of antenna oscillation
that are routinely generated today...
 Unlike even the vacuum tube type AM radio
in the dashboard of my parents' car in the early 1960s that were self-contained
units, even earlier radios designed for cars and trucks had their bulky electronics
mounted under the sea or in the trunk, with a remote volume and tuning control mounted
in the dashboard. That greatly complicated the installation as well as the design
of the radio. This circa 1940
Belmont Model 678 Auto-Radio is a prime example. Note the unique cylindrical
shape of the radio chassis, and that the remote control is a pushbutton assembly
with rotating knobs for tuning and volume. Operating from a 6 volt DC car battery
(12 volts came later), these radios required a "vibrator" circuit to convert DC
to AC (and back to a higher level DC) in order to transform to a couple hundred
volts for the plate voltage of the tubes...
 Designing a
log periodic antenna is a piece of cake. Just punch in your computer program
or smartphone app a few parameters for frequency range, power handling, directivity,
impedance, etc., and out pops boom and element lengths, diameters, and spacings
- and probably radiation gain profiles for elevation and azimuth. That is the way
it's done today. However, when Dwight Isbell and Raymond DuHamel of the University
of Illinois came up with the log periodic concept in 1958, they did not have the
convenience of a computer or even a hand-held calculator. Slide rules and logarithm
tables were the order of the day. After trudging through the equations for building
the antenna...
 It was only the first day at engineering
college and already their first familiar techno-caper was underway. Indiana's Parvoo
University was about to get an initiation into the world of
Carl Anderson and Jerry Bishop, who during their high school years together
solved many a mystery and pulled many a prank in their hometown somewhere in northern
Indiana. As with all of John Frye's tales this one mixes serious electronics topics
with a bit of fun and a life lesson. There were no 'bad guys' here as in many other
episodes, but the boys did get an unexpected introduction to Parvoo U.'s president!
Despite the story's title, the day ended well...
 I know I keep saying this, but it keeps being
true so I say it again: The
basics of electricity and electronics have not changed in the last 75 or more
years, so these articles from vintage issues of electronics magazines are as applicable
today as they were back then. If you are just getting into the field of electronics,
valuable information can be found here to supplement your learning process. In fact,
I have seen examples in some of these articles where I re-learned something long-ago
forgotten, and some of the stuff is rarely, if ever, seen in contemporary writings.
Regardless, making yourself aware of the work done by pioneers in the industry is
always valuable because it gives you a sense of approaches taken that have led to
success, and sometimes... |
