|
 Mac's young technician sidekick Barney decides
to one-up the
do-it-yourself television repair books that were flooding magazine
pages those days by writing a series of do-it-yourself surgery books. He figures
if the other guys can get rich by convincing Joe Sixpack that he can easily fix
problems in his TV set - where potentially lethal voltages lurk in every corner
- in as little as five minutes while saving hundreds of dollars from those rascally
shop owners, then surely those same people might buy his books for removing your
own appendix or tonsils. Deny the greedy doctors...
 This week's
Science & Engineering Crossword Puzzle has a special message included that has to do
with why you might be off work on Monday for a holiday. Oh, and it also happens
to be the world's most revered religious time of commemoration, which to the
delight of some and to the sorrow of others, is rapidly fading into the shadows
of time. The colorful "no-letter" squares were inspired by the type of candy I
am eating as I make the puzzle. As always all the other words are from a hand
assembled file of thousands of terms from science, engineering, mathematics,
chemistry, astronomy, etc. 7 Across + 15 Across to all...
 It really was not all that long ago when
wiring images for news stories literally meant
transmitting photographs over a twisted pair of telephone lines
either to a fax machine or to a computer on standby waiting for incoming files.
Videocasts were being regularly performed via satellite of ground relay microwave
stations since the 1960s, but most still shots were sent via phone lines. For the
last decade and a half, both still shots and videos have been transmitted as a routine
matter via camera-equipped cellphones, and as with most technologies we have quickly
become so accustomed to the convenience that memories of the old ways are quickly
(even thankfully) forgotten. This article from a 1936 edition of Radio-Craft
magazine
describes one of the really early systems. Notice that coupling to the telephone
line is...
 On
sale through the end of June! Werbel's new
WM3PD-6-18-S, 3-way Wilkinson divider that operates from 6 to 18 GHz.
It is part of Werbel Microwave's catalog of splitters that offer a wide range of
port count and frequency ranges. Its compact aluminum enclosure measures 1.57 x
1.57 x 0.38 inches. The device is RoHS compliant, however it may be specially
ordered with lead solder. Return loss 14 dB typical input, 15 dB typical
output. Insertion loss above 4.8 dB is 0.3 dB typical. Isolation 23 dB
typical. Phase balance 3.4° typical. Designed and assembled in the USA. "No Worries
with Werbel!"
 Velocity modulation, aka deflection modulation,
of electronic images was evidently considered by some engineers to be potentially
disruptive technology when this article was published in a 1951 issue of Radio &
Television News magazine. You can see from the pictures that the result is
an image that today's digital software would render with an "emboss'" technique.
More vertical relief seems to be generated with the analog velocity modulation technique
compared to what my graphics program does when embossing the original photo. At
the bottom of the page is a velocity modulation video demonstration found on YouTube...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products such as
RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters,
and a 15-band programmable filter (5 MHz-8 GHz). Since the conception
of WFT, we have introduced products that have been purchased by a wide range of
customers, from hobbyists to education facilities to government agencies. Worldwide
customers include Europe, Australia, and Asia. Please contact Windfreak today to
learn how they might help you with your current project.
 Fortunately, there is a constant flow of
people newly interested in electronics who are seeking information on basic principles.
Some will find an article this one on
Ohm's law fundamentals and decide maybe being just a user of electronics
is good enough. Others will, as did you and I, read this kind of material and be
amazed at how ultimately predictable electrical circuit parameters are. If he or
she continues and launches into a career in electronics or electrical engineering,
it won't be long before he or she will, as do you...
 Whilst reading this Carl Kohler technodrama
entitled "Thin Air My Foot!," I happened upon this word new to me: "din,"
as in "It was dinned into me." OK, maybe you already knew that, but surely I should
have been aware of its alternate meaning other than being a loud noise ("the agitated
cat made quite a din."). Fortunately, I am not subject to a household of people
who refuse to put things back in their respective places when through with them,
but this tale of woe tells what might be a familiar scenario to you. To be honest,
this could have been written about me as a boy - before the U.S. Air Force taught
me a thing or two about organization and neatness - since I continually frustrated
my father by leaving his tools (and hardware and lumber and paint) scattered in
forgotten places around the house and yard...
 Antenna radiation (beam) patterns published
by manufacturers are obtained under ideal - or close to ideal - conditions with
a carefully prepared and calibrated open air test site (OATS) or an enclosed anechoic
chamber. Multipath, imperfect earth ground, obstacles both manmade and natural,
misshapen elements, poor VSWR, antenna orientation (in both azimuth and elevation)
are among the many factors which produce real-world operational results that do
not jive with a manufacturer's datasheet. Without employing some far field 3-dimensional
field strength scheme see
Drone-Based Field Measurement System™), there is no way to obtain
a complete picture of how your antenna performs in all directions...
 It has been quite a while since posting
a
Carl & Jerry adventure tale. The teenage-neighbors-cum-Ham-radio-operators-cum-electronics-hobbyists-cum-amateur-detectives-cum-pranksters
are the creation of John T. Frye. He published a monthly episode in Popular
Electronics magazine. Mr. Frye is also the author of the
Mac's Radio Service Shop series of instructional stories
that ran in Radio & Television News magazine. This adventure is quite
a digression from the typical storyline in that the boys actually engage in a bit
of deceit in order to save face based on a bet...
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
 Is
the
BOMARC an airplane or a rocket? If it is an airplane, then it is the pilotless
type (aka "drone"). If it is a rocket, then it is the ultimate in controlled trajectory
hardware - at least in its day. The DoD referred to it as a surface-to-air guided
missile. The name is a combination of "BOeing Airplane Company"
and "Michigan Aeronautical Research
Center." Clever, non? If memory serves me correctly (it's been
30+ years), the AN/TPX-42 IFF (Identification Friend or Foe) secondary radar system
(built by Gilfillan) I maintained as an air traffic control radar technician reserved
a special "X" bit in its data packet to designate the BOMARC - and maybe other guided
missiles. That might have been a military secret at the time...
 "Israel's Iron Beam laser weapon that can
destroy drones for a few dollars 'a pop' are being developed and introduced into
combat service. The Chinese
Hurricane 3000 system is another new weapon developed to tackle the growing
use of drones in combat. However, unlike the laser-based Israeli system, the Hurricane
3000 system uses microwaves to disable drones and drone swarms at ranges exceeding
3 kilometers (1.9 miles). This is a similar weapon to the US Army's Leonidas microwave
weapon, although China claims that the 3000's reported three-kilometer-plus range
is over a kilometer more than the Leonidas system...
 This is interesting. The title for the
General Motors S1B radio says it is a 25-cycle model, as compared
to the S1A, 60-cycle model. According to an IEEE Xplore paper, "At 8:53 PM on 12
October 2006, a 66-kV circuit breaker tripped and locked out at the Harper Substation
in Niagara Falls, New York, due to downed transmission conductors near Buffalo,
New York. That event marked the end of over 111 years of 25-Hz alternating current
(ac) electric power service on the American side of the Niagara Frontier." 25 Hz
was considered a good, low frequency for...
 Here is a good
quiz that tests your knowledge of classifications of science fields.
It appeared in a 1949 edition of The Saturday Evening Post magazine. Even
if you do not particularly know the relationships, you should be able to get most
if not all twelve correct with a combination of surety, recognition of word roots,
and a process of elimination. Good luck...
 ConductRF is continually innovating and
developing advanced solutions for RF cable assembly and various RF through millimeterwave
interconnect requirements. We'll be posting their latest RF cables and technical
articles here at RFcafe.com, but to stay abreast, you're encouraged to visit their
Updates section at https://www.conductrf.com/blog
and sign up for their monthly news releases.
 During the early 1960s, Short-Wave Listening
(SWL) was a remarkably popular era-defining hobby, as enthusiasts worldwide competed
to pull in distant broadcasts from London, Moscow, or Hong Kong. "How
to DX Satellites" challenged these listeners to advance beyond Earth-bound stations
to the ultimate frontier: intercepting signals from orbiting spacecraft. While skeptics
dismissed satellite DXing as impossible due to extreme distances, low power, and
elusive verification, the author maintained it was achievable for those with the
right patience and gear. Successful monitoring required sensitive communications
receivers, crystal calibrators...
 Radio Shack,
like so many of America's original great companies, was born and lived long and
prospered during its glory days, then eventually waned into insignificance and obsolescence
within the last decade or so. It is not always simply an unwillingness to adapt
to new technologies and methods that dooms them. The forces behind those life cycles
are often beyond their control because start-ups vying for market share do not carry
the burden of and have to deal with established investments in people, facilities,
and infrastructure...
 Although obviously (but getting less so)
before my time, the mention of this airborne radar surveillance system having been
built by
General Electric, in Utica, New York, struck a chord since that
is where I had my first engineering job after having graduated from the University
of Vermont with a BSEE degree. It seems to me the work at the time was all done
in the converted textile complex on Broad Street. They were the glory days of GE,
Westinghouse, Collins, Raytheon, and other electronics titans whose engineers, technicians,
assemblers, and program managers...
 The June 1949 issue of Radio & Television
News had four
television-themed comics. Television at that time was a relatively
new home appliance, so there was a huge amount of interest in the technology. It
hadn't really been all that long since the public got used to hearing sound (i.e.,
'talkies') in the movie theater, so the mystique that surrounded television made
it the subject of a lot of puns and jokes. 1949 was a mere four years after the
end of World War II, and the post-war economic boom was primed by a surplus
of left-over electronic components along with lots of available talent both in the
areas of design and assembly...
 Temwell is a manufacturer of 5G wireless communications filters
for aerospace, satellite communication, AIoT, 5G networking, IoV, drone, mining
transmission, IoT, medical, military, laboratory, transportation, energy, broadcasting
(CATV), and etc. An RF helical bandpass specialist since 1994, we have posted >5,000
completed spec sheets online for all kinds of RF filters including helical, cavity,
LC, and SMD. Standard highpass, lowpass, bandpass, and bandstop, as well as duplexer/diplexer,
multiplexer. Also RF combiners, splitters, power dividers, attenuators, circulators,
couplers, PA, LNA, and obsolete coil & inductor solutions.
 Both my father and grandfather were
stamp collectors - philatelists is the technical word - who dabbled
in a recreational way with commemoratives from foreign countries. Nearly all were
canceled (used) stamps that today, as back in their
day, have no real value other than to someone interested in history. Of course none
are the rare types. I now possess many of those stamps in an album that was painstakingly
hand-illustrated and assembled to arrange each stamp according to its country and
issue date. At one time I, too, dabbled in the hobby, having collected many plate
blocks and special issue U.S. stamps in the 1970s and 1980s, along with purchasing
a few designs of special purpose such as those with aerospace and communications
themes...
 Exodus Advanced Communications offers a
scalable portfolio of
high-power solid-state RF amplifiers designed for electronic warfare, GPS/GNSS denial,
and counter-drone applications. These systems are engineered to support high-power
RF denial architectures capable of disrupting control, navigation, and payload links
across multiple frequency bands. Integrated into mobile, fixed, and expeditionary
platforms, Exodus amplifiers enable reliable, long-range electronic attack performance
in complex and evolving threat environments. These solutions are deployed within
high-power RF denial systems across mobile and fixed counter-UAS platforms, as illustrated...
 "Measuring low-frequency electric fields
with high precision remains a significant challenge. Existing sensing technologies
often cannot deliver traceability, compact design, and the ability to detect field
direction all in one system.
Rydberg atoms are gaining attention in electric-field quantum metrology because
they have large electric dipole moments and their behavior can be tied to well-defined
atomic properties. Most current methods for detecting low-frequency or DC electric
fields using Rydberg atoms rely on vapor-cell electromagnetically induced transparency
(EIT) spectroscopy. However, this technique is limited..."
 Here are the
Majestic Chassis Models 380 A.C. T.R.F., and 400 A.C.-D.C. Superheterodyne
and
Delco 32-Volt Radio Receiver Chassis Radio Service Data Sheets
as featured in a 1933 edition of
Radio-Craft magazine. As mentioned many times in the past,
I post these online for the benefit of hobbyists looking for information to assist
in repairing or restoring vintage communication equipment. Even with the availability
of SAMS Photofacts, there are some models that cannot be found anywhere other than
in these vintage magazines...
 For the sake of avid cruciverbalists amongst
us, each week I create a new
crossword puzzle that has a theme related to engineering, mathematics, chemistry,
physics, and other technical words. You will never be asked the name of a movie
star unless he/she was involved in a technical endeavor (e.g., Hedy Lamar). Clues
in this week's puzzle with an asterisk (*) are directly from this week's "High Tech
News" column on the RF Cafe homepage (see the Headline Archives page if necessary)...
 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 354,801 products from more than 2478 companies
across 485 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.
 In 1961, when these
tech-themed comics appeared in Electronics Illustrated magazine, the
"Space Race" was in full swing. That, along with home hi-fi stereo equipment, newfangled
color televisions, and - gasp - transistors, filled the headlines. They were also
the subject of many forms of humor. These four comics touch on many of those aspects,
all centered on the Space Race. Of course, everything is noticeably dated. "Flunking
the code test" means not much to Amateur radio licensees who earned their first
license (like me, in 2010) after the 5 WPM Morse code requirement was removed. Building
something in "kit form" was a good way to save some money and learn something...
 In our present "No user serviceable parts
inside" world of electronic products, it is easy to understand why very few people
have an appreciation for the technical prowess needed to troubleshoot and repair
them. When reading through these episodes of "Mac's Radio Service Shop" that appeared in mid last century editions
of Radio & Television News magazine, I am inspired to envy the skills
that small electronics repair shop owners had for working on the old vacuum tube
based radio and television sets. Digital electronics has its own unique set of quirks
and special knowledge requirements to troubleshoot, but when everything is analog
rather than merely being required to be a "0" or a "1"...
|
 • Amazon
Might Buy Globalstar
• AI Could End
Online Anonymity (or falsely identify)
• How
Test and Measurement Will Evolve in 2026
• AI
and Geopolitics Forge Memory Market Crisis
• European
Electronics Distribution Gains Momentum
 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.
 You are taught early in your electronics
career to be mindful of the tendency for
measurement equipment to affect the circuit it is measuring, and therefore the
indicated results. In the case of high frequency circuits, even minute amounts of
capacitance and/or inductance can render results utterly unusable, but even in circuits
operating down to D.C. the simple internal resistance of a meter can profoundly
affect measurement accuracy. High impedance circuits are particularly vulnerable
to such "loading" effects by test equipment. For example, consider a circuit being
measured (device under test, aka DUT) that has an impedance of 10 kΩ and the
internal resistance of the VOM is 100 kΩ (see diagram to left). If the open
circuit "true" voltage level is 11 V, then voltage division effected by the
100 kΩ meter in series with the DUT's 10 kΩ internal resistance would
produce a VOM reading of 10 V (ten elevenths of 11 volts) - clearly incorrect.
In the days before FET (field effect transistor) input multimeters, when most volt-ohm-milliammeters
(VOMs) consisted...
 When I originally tagged this Electronics
magazine article for posting, it was before Golden State Warriors guard Stephen
Curry tapped into his immense cerebral power to inform us all that NASA has been
faking its accomplishments in space - notably all the moon landings. Now, based
on such unimpeachable authority, I'm not so sure this story should even be posted,
lest it potentially perpetuate a long-running ruse. In the manner of contemporary
news pieces reporting on criminal activity while avoiding legal claims of libel
or character assassination, please mentally preface all of the claims here with
"alleged" or "allegedly." The world's first successful spacecraft rendezvous, accomplished
by
Gemini 6 and Gemini 7, happened on December 15, 1965.
Both astronaut crews participated in many communications experiments that included
radio, visual, and laser media...
 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...
 Continuing with the series on capacitor
types, particularly dielectric material, this July 1965 Electronics World
magazine article reports on glass materials used by Corning Glass Works. Glass dielectrics
are popular for aerospace and space applications because of their tolerance for
high radiation levels found in regions not protected by the Earth's atmosphere.
Glass compound consistency provides for mass producing values with tight tolerances
and exceptional parameter tracking over temperature. High "Q" values and low loss
at extreme temperature and high frequency (at the time) made them the component
of choice by missile and satellite designers. 0.5 pF through about 0.01 μF
is the typical value range for
glass dielectric capacitors. Author Archer Martin mentions radiation exposures
of 1018 NVTth, which appears to be a measure of neutron flux exposure, but I could
not find a good definition of the term ("NVT," without the "th" is used here)...
 Electric shock, depending on severity, can range
in damage from mere discomfort to body organ damage to instant death. If you have experience
an
electric shock, you know that avoiding another incident is top priority when working
around high voltages. My worse electric shock was either the time when I got hit with
a 3-phase 440 VAC supply on an industrial air compressor motor, or the B+ vacuum
tube plate supply on the air traffic control radar systems I worked on in the USAF. Both
were, thankfully, from finger to finger or finger to forearm (no vital organs in the
current path). I've been zapped a few other times, but nothing severe enough to require
being resuscitated. Neither have I ever witnessed anyone else being shocked to the point
of needing resuscitation. There are probably some gruesome...
 This seventh installment in an eleven-part
series on "Theory
and Application of U.H.F." appeared in the October 1944 issue of Radio News
magazine. Author Milton Kiver covered a wide range of topics including basic and
advanced circuits, tube types, modulation, resonant cavities, oscillators, transmission
lines, waveguides, antennas, electromagnetic fields, and Maxwell's equations. Part 7
continued the discussion of how waveguides, both rectangular and circular, support
the conduction of electromagnetic waves. Methods for injecting and extracting signals
is covered as well. Interestingly, the Smith chart never appeared even though Phillip H.
Smith had introduced it around 1936. In fact, the first mention of the Smith Chart
in Radio News, per a WWW search, was in 1950...
 RF Cafe visitor and former Watkins-Johnson
engineer Paul Johnson (no relation to the "J" in WJ), recently sent me this note
regarding the Watkins-Johnson catalog page that contained the famous "Phase
vs. VCTL vs. Frequency vs. Phase of the Moon" graph on the WJ-G1/SMG1
Voltage-Controlled Attenuator Module (5 to 2,000 MHz). We all suspected it was
not an officially approved feature, but now a first-hand account of the prank
confirms it...
 Someone sent me a link to a viral video of a group
of teenagers (aka "Millennials") attempting to use an old school
dial type telephone.
Two things are notable. #1: They do not remove the handset from the cradle prior to dialing.
#2: One of them asks whether it is necessary to let the dial spin all the way back to
rest before dialing the next number. It's really not their fault since except for in
dusty old places like my house, finding a dial phone is difficult. Many historians have
commented that two innovations most responsible for America's greatness in the last century
were the interstate highway system (for moving goods) and the telephone system. Bell
Telephone Labs engineers designed phones and all the equipment that connected them to
be simple, highly functional, robust, and to have...
 Apologies to Chrysler aficionados for not
having similar articles for your classic automobiles, but this article from a 1957
edition of Radio & TV News only covers
Chevrolet radios. Maybe someday I will acquire editions with other models. Transistors
were fairly recent newcomers on the portable radio scene (on any radio scene for
that matter), so you will please excuse the absence of them in most radios of the
era. In fact, as evidenced by a companion article in this same edition titled "Delco's
All-Transistor Auto Radio," such newfangled devices like transistors were reserved
for top-of-the-line models like Cadillac's Eldorado Brougham. A move toward printed
circuit boards, rather than the time-honored point-to-point wiring, was well underway,
and push-button tuning was being sold to the car buying public as an indispensible
safety feature...
 Sure, there are lots of resources on the
Internet for identifying various
screw types, styles, shapes, and sizes, but sometimes there are so many that
it can be time consuming to peruse through them all, particularly if what you are
looking for is an older type. This chart from a 1960 edition of Popular Electronics
magazine might be just the thing you have been looking for when working on a piece
of vintage electronic and/or mechanical gear. Interestingly, at first I thought
there might be a typographical error in labeling one type screw head as "Bristo,"
thinking it is probably supposed to be "Bristol." I could not find many references
to a Bristo screw type in searches, but evidently it did exist back in the day.
They now go by the name Bristol...
 The September 1932 issue of Radio Craft
contained an article titled, "Radio a la Cortlandt Street!," the original "Radio
Row" located at the corner of Cortlandt and Washington Streets in Manhattan. It was
a mecca of new and used electronics components and assemblies. After World War II
there was a huge supply of surplus parts and equipment made available to the public as
a means to clear out inventory and also as a "thank you" to the citizens who voluntarily
donated critically needed panel meters, tuning capacitors, connectors, and other items
to the War Department. That really helped the market boom. Post-war electronics
magazines were chock full of ads by dealers selling surplus electronic and
mechanical supplies...
 You know you've gotten old when you have
an "I remember when..." line for just about every kind of product or process mentioned
in a magazine article, video, or conversation. Here is mine for microwave ovens.
I remember that it was sometime around 1977-79 that my father gave my mother a
microwave oven for Christmas. It was the most expensive gift anyone in our household
had ever received. According to this 1971 Radio-Electronics magazine article,
household microwaves had only been on the scene for about a decade. A look at the
wiring diagram shown for this International Crystal microwave...
 In this "Pi
in the Sky and Big Twist" episode of John Frye's "Carl & Jerry" series,
the boys are by now into their college years at Parvoo University. Having been a
mix of electronics experimenters, Ham radio operators, and high tech sleuths since
high school times, the two friends find themselves once again participating in an
event that depends upon cool heads and quick thinking. As is typical of Mr. Frye's
tales, more than one topic is woven into the story, and usually real-life products,
companies, and scenarios are incorporated in an effort to inform his readers. The
Midwest Program on Airborne Television Instruction (MPATI) mentioned was an out-of-the-box
idea in the pre-satellite era for broadcasting educational programming to areas
that otherwise did not experience good quality over-the-air reception...
 Dr. Lee DeForest might have had something
like National Public Radio (est. 1970) in mind when he penned this article in 1933.
In it, the famous vacuum tube amplifier inventor lamented and criticized the commercialization
of broadcasts because of all the paid product announcements (aka commercials) that
had been steadily increasing over the years. He also was critical of the "hit-or-miss,
higgeldy-piggeldy mélange program basis" of programing; i.e., the same station playing
a mix of jazz, opera, swing, syndicated story-telling, etc. The good doctor did
not elaborate on where funding for such dedicated, uncorrupted broadcasts would
originate if not from paying advertisers, and I do not recall ever reading about
a DeForest Radio Network paid for by his vast fortune. I don't like commercials
any more than the next person, but a company deserves time to pitch its products
and/or services if it helps deliver...
 Breaking news from May 1958: "Hardly a month
passes nowadays without the announcement of some 'sensational' new amplifying device.
The great majority of these startling inventions, after their brief flurry in the
popular and technical press, disappear into oblivion. But we believe that the
Tecnetron, just announced in France, has a brilliant and enduring future." Have
you ever heard of a Tecnetron? I didn't think so; neither had I before reading this
article in Radio-Electronics. I guess that pretty much negates the preceding prediction.
The holy grail of the Tecnetron, whose etymology in and of itself is worth reading
about (it's not what you would guess), is that its transconductance increases with
frequency. Construction is such that although it is fabricated from a shaped rod
of germanium, it has a current controlling component that acts like a cross between
a triode vacuum tube and a depletion mode field effect transistor. My guess is that
the rapid improvement of standard semiconductor junction field effect transistors
rendered...
 Here is an electronics
Lamp Brightness Quiz for you to try, compliments of Popular Electronics
magazine. 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. Good luck...
 According to this story in a 1945 issue of
Radio News magazine, Raytheon certainly had an ambitious plan with its
"Sky-top" network of microwave relay stations from border to border and coast
to coast. No orbiting satellites existed at the time, so purely terrestrial methods
were necessary. The basic idea was to build facilities at the peaks of the highest
mountains in the U.S. to enable high bandwidth, reliable, high quality broadcasting
of all known forms of services - television, facsimile, aircraft and nautical navigation,
telephone, emergency, et al. The funding and logistical investment would be enormous,
particularly with getting access roads, materials and electricity to all the remote
sites. Automation was to mitigate the difficulties involved in manning stations
fulltime, but there would be the need for periodic maintenance and repair. Plans
included tests for frequencies into K-band (26 GHz), which was really stretching
the limits of technology at a time when a few tens of MHz were challenging for most
applications...
 Anyone visiting RF Cafe (other than by accident)
almost certainly knows of
Drs. Bardeen, Brattain and Shockley fame for their transistor invention while
jointly working at the Bell Telephone Laboratories. The trio shared The Nobel Prize
in Physics in 1956. Bell was so proud of their employees' efforts that they ran
full page advertisements to boast of the accomplishment. This one appeared in the
February 1957 edition of Radio & Television News. Alas, Ma Bell's moment
of glory was a bit diminished by needing to add a footnote admitting that Drs. Bardeen
and Shockley no longer work there. Note that while the ad says the transistor was
announced in 1948, the first demonstration to Bell managers was in December of 1947...
 OK, I give up. What is a "pukka
amateur?" According to an online dictionary: pukka, adj (esp in India) 1. properly
or perfectly done, constructed, etc. a pukka road 2. genuine pukka sahib. Then,
we have a Blattnerphone. That sounds an awful lot like Blattenberger, or maybe more
like Blattnerberger. Anyway, a Blattnerphone was an early attempt at recording sound
on a steel tape - never heard of it before now. My native language is English, but
evidently there are still a lot good words to learn which have been forgotten by
society over the years. If you read enough vintage magazines from the first half
of the 20th century, you will run across many words and phrases that are still in
the Merriam-Webster dictionary, but you hardly ever see or hear them used anymore.
These are some great candidate words for Scrabble... |
