See Page 1 |
2 |
3 |
4 | of the August 2023 homepage archives. Tuesday the 22nd
 These
"Old-Fashioned Puzzles" - and particularly the riddles - from the 1956 issue
of Old Farmer's Almanac are definitely of a different ilk than what you
would find in a modern copy. Even Batman's notorious question-mark-bedecked foe
would probably have trouble with the "Anagrams" below. In fact, it is the solicited
solutions which are anagrams, and even then they are a stretch. I can't imagine
anyone figuring them out; I certainly couldn't. The "Conundrums" proved a tad bit
easier, but even they are quite a challenge. The "Problems," finally, should be
solvable by anyone practiced in working word problems using simple algebra with
multiple unknowns...
 Empower RF announces delivery of the
SKU 2245, a 2-4 GHz, 4.1 kW solid state power amplifier (SSPA).
Designed to deliver extreme power with unmatched reliability, the model 2245 is
a GaN on SiC amplifier. This liquid cooled amplifier delivers a minimum of 4100 W
CW from 2 to 4 GHz with 5 kW mid band performance. Reliability is a key
feature and the result of its distributed RF architecture. With no single point
of RF failure, the 2245 boasts extreme Effective Mean Time Before Failure (EMTBF).
The modular architecture allows hot or muted swapping of the integrated amplifier
drawers or cold swap of the 3U system controller in less than 15 minutes. Repair
is modular, fast and easy, bringing life time costs down. Specialized technician
training is not required and there are no dangerous high voltage supplies to contend
with...
 The introduction of field-effect transistors
(FETs) into the electronics world was a major benefit to designers needing lower
power consumption and perhaps more importantly, high input impedances for active
circuits. The two most fundamentally distinct type of FETs are the metal-oxide-semiconductor
field-effect transistor (MOSFET) and the
junction field-effect transistor (JFET). Both FET types are voltage-controlled
devices and do not require a bias current (hence the high input impedance) like
a bipolar junction transistor (BJT) does. Neither FET type has a PN junction. A
JFET uses a high resistance semiconductor channel region between the source and
drain with an ohmic contact to the gate, whereas the MOSFET has a insulative oxide
layer between the gate and the channel. Check out the links to each transistor types
for more theoretical detail. I don't have Part 1 yet, but hope to be able to
buy the May 1969 issue soon. One of the most immediate uses of JFETs was in multimeters
to achieve a high input impedance that imposes very little impact on the circuit
being measured due to the voltage division effect. My first JFET multimeter was
a Micronta (Radio Shack) model 22-208 purchased in 1978. Its $59.95 price in 1978
is equivalent to about $275 in today's money (per BBLS Inflation Calculator). Looking
at the 1979 Radio Shack catalog page, compare the input impedance of the el cheapo...
/2023/Antenna-Radome-Design-Engineer-II-RTX-4-16-2023.htm">
 RTX / Raytheon is seeking an
/2023/Antenna-Radome-Design-Engineer-II-RTX-4-16-2023.htm">
Antenna and Radome Design Engineer II at their Tucson, AZ, location. This position
is eligible for a minimum of $10,00 Sign-On Bonus. The candidate will be responsible
for leading and shaping antenna, radome, and antenna measurement system technology
within the Company. The selected candidate will also be expected to lead diverse
teams, provide technical oversight, delegate tasks, and work with the Engineering
organization to establish technology roadmaps, enable modernization, and contribute
to general innovation. In addition, the candidate will work with government personnel
and programs, and define and refine requirements to validate hardware compliance.
The candidate will be responsible for providing guidance, coaching, mentoring, and
training to other employees across the business within the candidate's areas of
expertise...
 The Institute of Electrical and Electronics
Engineers' (IEEE) annual trade show, now called the International Microwave Symposium
(IMS), is conducted by the Microwave Theory and Techniques Society's (MTT-S). Year-specific
references are of the form "IMS 2018" or, alternately by many older attendees, "MTT-S
2018." According to "50 years of the IEEE Microwave Theory and Techniques Society*,"
the first MTT-S show was held in New York in 1957 (see excerpt). This advertisement
for the "IEEE
Show '64" appeared in a January 1964 issue of Electronics magazine. It was held
the week of March 23-26, and was split between the New York Coliseum and the New
York Hilton...
 Banner Ads are rotated in all locations
on the page! RF Cafe typically receives 8,000-15,000 visits each
weekday. RF Cafe
is a favorite of engineers, technicians, hobbyists, and students all over the world.
With more than 17,000 pages in the Google search index, RF Cafe returns in
favorable positions on many types of key searches, both for text and images.
Your 728x90-px and 160x600-px Banner Ads are displayed on average 225,000 times
per year! New content is added on a daily basis, which keeps the major search
engines interested enough to spider it multiple times each day. Items added on the
homepage often can be found in a Google search within a few hours of being posted. If you need your company news to
be seen, RF Cafe is the place to be...
 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. Please visit
their website today to see how they might be of assistance. Products are designed
and manufactured in the USA.
Monday the 21st
 When transistors finally began operating
in the hundreds of MHz in the 1960s, power handling was still relatively low, and
the devices could be damaged or destroyed by a large signal, particularly, as cited
in this "RF
Circuit Protection" article from a 1969 issue of Radio-Electronics
magazine, when the relay switching the antenna between transmit and receive does
not have adequate isolation. Another scenario is operating in a close-quarters group
of radio operators at a Hamfest, emergency communications post, etc. Over time,
more robust transistors were designed, and some had built-in protection diodes.
As gate sizes shrank, vulnerability to electrostatic discharge (ESD) reared its
ugly head in RF integrated circuits like frontend modules and switches. During the
early 2000s, IC makers like RF Micro Devices (now Qorvo), Skyworks (spun off from
Alpha Industries), Renesas, and a few others, were in a race to conform to the de facto
ESD standards for human body model (HBM) and machine model (MM, not used any more)
survivability. The challenge was not so much being able to protect the I/O pins,
but the amount of wafer real estate required to accommodate the protection diodes
and/or transistors...
 Gallium in critical supply due to heavy
use in LEDs. "The US Department of Energy (DOE) has released its
2023 Critical Materials Assessment, which evaluated materials for their criticality
to global clean energy technology supply chains and has hence determined the 2023
DOE Critical Materials List of energy-specific critical and near-critical materials
through 2035. The Assessment focuses on key materials with high risk of supply disruption
that are integral to clean energy technologies. The final list includes aluminum,
cobalt, copper, dysprosium, electrical steel (grain-oriented steel, non-grain-oriented
steel, and amorphous steel), fluorine, gallium, iridium, lithium, magnesium, natural
graphite, neodymium, nickel, platinum, praseodymium, terbium, silicon, and silicon
carbide. Gallium (Ga) continues to be critical due to its use in light-emitting
diodes. In addition, the use of gallium has increased both in magnet manufacturing
and in semiconductors including gallium arsenide (GaAs) or gallium nitride (GaN),
the Assessment notes..."
 TV antennas in the early days of broadcast
television were typically fairly simple designs that worked well for city dwellers
and anyone living within a few tens of miles of the tower, but rural dwellers struggled
for a good signal. Even urban and suburban TV owners had problems with multipath
reception that created ghost images on the display. The farm folks needed the high
gain of a more complex antenna for pulling small signals out of the noise, while
urbanites needed high directivity to be able to reject signals that were bouncing
off buildings and bridges before combining in the receiver to produce multiple versions
of the picture. Unlike today where relatively small, compact antennas with a low
noise preamplifier at the antenna does a pretty nice job of guaranteeing a good
signal, large structures with many large elements were needed. Recall photos of
building rooftops in a large city that were chock full of TV antennas. This article
describes a means of
stacking multiple identical antennas vertically for achieving additional gain
with careful phasing of the transmission lines between them...
 TotalTemp Technologies, a worldwide leading
provider of research laboratory and production temperature chambers and thermal
platform equipment, introduces their model
VmSD49 N Cryogenically Cooled Temperature Vacuum Chamber (TVAC), which performs
thermal tests through the use of forced air convection. TVAC systems increase understanding
of how components and materials respond in a space simulated environments Space
simulation adds another dimension to thermal testing. In vacuum environments, heat
is transferred by radiation or conduction since transfer by air currents (convection)
is of course not possible without air. This is easily accomplished using thermal
platforms in portable TVAC systems. As is the case with temperature chambers, space
simulation systems are often sized considerably larger than required due to a lack
of knowledge of what future requirements will be. This results in several inefficiencies.
Portable space simulation equipment is cheaper to acquire Smaller systems don't
take up as much valuable lab space to use and to store when not in use...
 There is not much chance you will see an
advertisement from
Espey Manufacturing & Electronics now like this one from a 1948 issue of
Radio News magazine. Espey is still in the business of defense electronics,
but their advertising / public relations group would be hauled into court if they
produced copy like that today. In fact, I hope as a result of my bringing up the
subject that some overly sensitive snowflake won't try to sue them for past offenses.
Does this documented instance of former official company policy suffice as legal
proof of a corporate history of sexism and exploitation in our current litigious
atmosphere? You could probably lose your job just by having this page open on your
lab bench computer or cellphone in view of one of the aforementioned extremist types.
Is that the sound of ambulance-chasing lawyers scratching notes on their yellow
legal pads that I hear in the background?
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
 Amplifier Solutions Corporation (ASC) is
a manufacturer of amplifiers for commercial & military markets. ASC designs
and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers
for low, medium and high power applications using Gallium Nitride (GaN), Gallium
Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs
operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film
designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility
in the town of Telford, PA. We offer excellent customer support and take pride in
the ability to quickly react to evolving system design requirements.
Sunday the 20th
 This custom RF Cafe
electronics-themed crossword puzzle for August 20th contains words and clues
which pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. If you do see names
of people or places, they are intimately related to the aforementioned areas of
study. Being that "T" is the 20th letter of the alphabet, it is used as the first
and/or last letter of many words in today's crossword puzzle - as well as in-between.
Those clues are marked with an asterisk (*). As always, you will find no references
to numbnut movie stars or fashion designers. Need more crossword RF Cafe puzzles?
A list at the bottom of the page links to hundreds of them dating back to the year
2000. Enjoy...
 The newest release of RF Cafe's spreadsheet
(Excel) based engineering and science calculator is now available -
Espresso Engineering Workbook™. Among other additions, it now has an extensive
coaxial cable parameter calculator. Since 2002, the original Calculator Workbook
has been available as a free download. Continuing the tradition, RF Cafe
Espresso Engineering Workbook™ is also
provided at no cost, compliments of my generous sponsors.
The original calculators are included, but with a vastly expanded and improved user
interface. Error-trapped user input cells help prevent entry of invalid values.
An extensive use of Visual Basic for Applications (VBA) functions now do most of
the heavy lifting with calculations, and facilitates a wide user-selectable choice
of units for voltage, frequency, speed, temperature, power, wavelength, weight,
etc. In fact, a full page of units conversion calculators is included. A particularly
handy feature is the ability to specify the the number of significant digits to
display. Drop-down menus are provided for convenience. Now that a more expandable
basis has been created, I plan to add new calculators on a regular basis...
 Withwave manufactures an extensive line
of metrology quality coaxial test cable assemblies, connectors (wave-, end-, vertical-launch,
board edge, panel mount), calibration kits (SOLT), a
fully automated
4-port vector network analyzer (VNA) calibrator, between- and in-series connector
adaptors, attenuators, terminations, DC blocks, torque wrenches, test probes &
probe positioner. Special test fixtures for calibration and multicoax cable assemblies.
Frequency ranges from DC through 110 GHz. Please contact Withwave today to
see how they can help your project succeed.
Friday the 18th
 Here is a fun "Question
Bee" to test your scientific knowledge. It appeared in a 1939 issue of Popular
Science magazine, but it does not require you to be aware of contemporaneous
information. Topics include electricity, music, astronomy, automobiles, paint, tools,
conservation, physics, and even chewing gum. There are 20 questions. I scored 95%,
having incorrectly guessed at question #11, having to do with cave dwellers. To
be honest, I also guessed at question #2, but managed to get it right. Go ahead
and give it your best shot. It's really a pretty good mix of questions...
 "Chinese military scientists have announced
a major
breakthrough in laser weapon technology, claiming they have developed a new
cooling system that allows high-energy lasers to operate 'nfinitely' without any
build-up of waste heat. According to scientists at the National University of Defense
Technology, in Changsha, Hunan province, the new cooling system completely eliminates
the harmful heat that is generated during the operation of high-energy lasers. The
issue has been a major technical challenge for laser weapon development. With the
new technology, weapons can now generate laser beams for as long as they want, without
any interruption or degradation in performance..."
 "Are you ready for this year's
NASA TechRise Student Challenge?
From researching Earth's environment to designing experiments for lunar and planetary
exploration, schools are invited to join NASA in its mission to inspire the world
through discovery. If you are in sixth to 12th grade at a U.S. public, private,
or charter school - including those in U.S. territories - your challenge is to team
up with your schoolmates and develop a science or technology experiment idea for
one of the following NASA TechRise flight vehicles: High-Altitude Balloon with approximately
four hours of flight time at 70,000 feet and exposure to Earth's atmosphere, high-altitude
radiation, and perspective views of our planet Rocket-Powered Lander that will fly
for approximately two minutes at an altitude of 80 ft (~25 m) over a test
field designed to look like the Moon's surface..."
 The medical x-ray machine shown here reminds
me of the "Illudium
Q-36 Explosive Space Modulator" contraption Marvin the Martian wanted to use
in "Hare-Way to the Stars" to disintegrate the Earth (because it blocks his view
of Venus). Of course our hero Bugs Bunny thwarts his plan, whereupon Marvin asks,
"Where's the kaboom?" Can you imagine being fraught with cancer and getting strapped
into a chair with that huge hypodermic-needle-looking thingy pointed at you, as
shown in this 1959 issue of Popular Electronics magazine? The Caduceus
sword in the pic doesn't help matters, either. The trauma of such an experience
might have been worse than the treatment for some people. As usual the pioneers
took the arrows so that we can benefit from the treatments enjoyed today, and the
equipment does not look nearly as intimidating. See also "After Class: X-Rays" for
more info...
 Werbel Microwave's family of wideband power
splitters / combiners offers exceptional performance across a wide frequency range.
Model D-8066 spans from 500 MHz to 6 GHz. This 8-way, 0˚ splitter /
combiner can handle 30 W of power as a splitter. It offers low insertion loss
across the entire frequency range of 500 to 6000 MHz, making it suitable for
a wide range of wireless communication bands, including SatCom IF and more. By combining
high power and low loss, this model effectively minimizes power dissipation resulting
from inherent losses, ensuring excellent signal fidelity from input to output. It
also provides high isolation between ports and exhibits low amplitude and phase
imbalances. Enclosed in a rugged aluminum alloy case measuring 8.25 x 5.00 x 0.63"
and featuring SMA connectors, it offers durability and reliable performance...
 This "drive-by" schematic and parts list
for the
Westinghouse Model H-165 vacuum tube radio appeared in the February 1948 issue
of Radio News magazine. I refer to it as drive-by because there was no
description or maintenance verbiage provided. It most certainly was considered a
portable radio since there is a handle on the top of the case, and a protective
cover flips down for access to the dial. Also, the schematic shows battery power,
which does not automatically mean portable because even in 1948 there were still
many households in rural areas which did not have commercial electric service and
relied on storage batteries. The Rural Electrification Act (REA) was passed in 1936
to remedy the issue, but due to World War II, total implementation was delayed...
 It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols"" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
 The leading website for the PCB industry.
PCB Directory is the largest directory of
Printed Circuit Board (PCB)
Manufacturers, Assembly houses, and Design Services on the Internet. We have listed
the leading printed circuit board manufacturers around the world and made them searchable
by their capabilities - Number of laminates used, Board thicknesses supported, Number
of layers supported, Types of substrates (FR-4, Rogers, flexible, rigid), Geographical
location (U.S., China), kinds of services (manufacturing, fabrication, assembly,
prototype), and more. Fast turn-around on quotations for PCB fabrication and assembly.
Thursday the 17th
 Stop me if you've heard this story before.
Back in the early-mid 1980s I worked as an electronics technician at the Oceanic
Division of Westinghouse, in Annapolis, Maryland. There was an older engineer there
that dated back to the days of vacuum tube design who - and I'm not making this
up - thought that a transistor could be made by connecting diodes together so their
circuit resembled the NPN or PNP junctions inside a transistor. That is, connect
the diodes anode to anode or cathode to cathode, respectively. He was amazed to
learn of how the transistor actually worked. If I recall correctly, it wasn't long
thereafter that he retired. This "Four-Layer
Diodes & Controlled Rectifiers" from a 1961 issue of Radio-Electronics
magazine would have really had him confused with three PN junctions rather than
only two. To be fair, though, there are very few engineers using solid state devices
that could tell you how to bias a vacuum tube...
 "Maybe not
completely - but some proactive work can help identify when PIM problems are likely.
Interference from
passive intermodulation often doesn't show up as a major issue until a new site
starts taking on significant amounts of traffic, or perhaps when a popular new device
adds new spectrum support. But PIM really shouldn't come as a surprise, according
to Tom Bell, who is senior director of interference products at ConcealFab. The
company has been working since 2016 specifically on developing methods to identify
and mitigate passive intermodulation. 'I refer to dealing with PIM as equivalent
to the seven stages of grieving - and it always starts with denial. 'How can this
be?'' he says jokingly. He goes on to say that the industry has a process for site
builds that it has been following, largely unchanged, for decades. 'But what we're
finding is that practices that were used to build sites historically, aren't good
enough any more. And that means there's a lot of change required in the organizations
to adapt,' he said. Identifying PIM and its cause at any particular site is actually
the easy part..."
 Only John T. Frye can turn an episode
of an electronics technician / tinkerer attempting to devise a method of blowing
up mosquitoes with sonic waves into a lesson in solving television and radio servicing
issues by listening to the audio and interpreting CRT test patterns, as applicable.
Mac's young apprentice is introduced to the recently released troubleshooting volumes
- called "Pict-O-Guides"
- published by RCA which presents a set of uniquely distorted television test patterns
(recall the Indian head test pattern) with an explanation of which circuit likely
cased the problem(s). I note that Barney was told to take the Pict-O-Guides home
to study them on his own time rather than while on the clock...
 Sam Benzacar of Anatech Electronics, an
RF and microwave filter company, has published his August 2023 newsletter that features
his short op-ed entitled "LMDS
is Back as 5G Fixed Wireless Access." In it, Sam discusses how Fixed Wireless
Access (FWA) is fundamentally a remake of the 1990s scheme called Local Multipoint
Distribution Service (LMDS). I remember when it was considered a big deal, coming
at the beginning of the wireless access era, concurrent with affordable cell phone
service. LMDS was eventually abandoned due to technical difficulties (lack of sufficient
range at available power levels), and then the bursting of the tech bubble in 1999
was the final blow. As always, Sam's knowledge of all facets of the communications
industry is apparent, having been acquired first-hand as an active participant along
the way...
 This posting is one of more than 220 pages
of
electronics-themed comics from vintage electronics magazines like Radio &
Television News, Radio Craft, Electronics World, Popular
Electronics, and others. It is rare to find a comic in a trade magazine these
days, probably due to fear of offending the sensibilities of some person who is
a member of Generation Snowflake, causing him/her/it to curl up in the fetal position
in a Safe Space. Some people have no sense of humor unless it is directed against
a preferred foe. Being of an emotionally hardier generation, I can laugh at ribbing
directed at me as long as it is done without malice...
 Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
Wednesday the 16th
 This story from the April 1938 issue of
Radio-Craft magazine reports on a ground-breaking (at the time) new television
system, written by none other than the inventor himself -
Allen B. Du Mont. Television in the era was still largely in the experimental
phase with various schemes for transmitting, receiving, and displaying still vying
for dominance as the national / international standard. The now-familiar NTSC (National
Television Standards Committee) standard, which ultimately passed over the Du Mont
system, was adopted in 1941. Most communications historians are of the opinion that
the "Phasmajector" developed by Du Mont was unquestionably superior from a
technical and practical perspective for an end-end television system based on relatively
low manufacturing costs, high reliability of fielded systems, and ease use. Politics,
it is said, is responsible for the inferior standard adopted in its stead - the
aforementioned NTSC. Your time taken to read the article is time well spent if you
appreciate irony...
 "As
discussed in Part 1 of this "7
Pillars of 5G/6G RF System Design" series, customer service providers (CSPs)
manage telecommunication systems as a business that yields profitable activity.
The determining factor upon which they focus is the total cost of ownership (TCO).
TCO is a numerical value driven by direct and indirect components. The direct elements
include: Number of base stations to serve a given region. Does the carrier choose
fewer base stations with more power, or more base stations with lower power to cover
a service area? The electric bill. What are the power costs to a base-station operator,
and how can they be managed? What power profiles are expected at peak traffic and
low traffic periods? Reliability. How long will the equipment operate before maintenance
schedules dictate replacement..."
With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
 Empower RF Systems is the technological
leader in RF & microwave power amplifier solutions for EW, Radar, Satcom, Threat
Simulation, Communications, and Product Testing. Our air and liquid cooled amplifiers
incorporate the latest semiconductor and power combining technologies and with a
patented architecture we build the most sophisticated and flexible COTS system amplifiers
in the world. Solutions range from tens of watts to hundreds of kilowatts and includes
basic PA modules to scalable rack systems.
Tuesday the 15th
 When this "Communications
on 450,000,000 MC" article appeared in a 1961 issue of Radio-Electronics
magazine, MC (megacycles) was still being used rather than MHz (megahertz). Ditto
for kC. Cycles per second (cps) were used in place of Hertz (Hz), and concepts like
GC (GHz) and TC (THz) were rarely seen. Picofarads (pF) were designated as micromicrofarads
(μμF). 450,000,000 MC is 450 terahertz, which is 6.66*10-7 m, or 666 nm
(6660 Å). That is deep-red/near-infrared. Aside from using rubies, many early
lasers were made from rear earth materials like YAG and neodymium, or from gases
like CO2 and He-Ne. Semiconductor lasers were decades off. The first ruby laser
was demonstrated just a year earlier by Theodore Maiman at Hughes Research Laboratories.
Lasers were moving out of the science fiction realm and into laboratories. Now,
they're ubiquitous....
 Innovative Power Products (IPP), with more
than 30 years of experience designing & manufacturing RF & microwave passive
components, has, over the past four quarters, had a product return rate of just
0.1%, making our quality score 99.9%, and an on-time delivery rate of 87.4%. Therefore,
our
Customer Satisfaction rating for the last four quarters is 95.7% (based two
parts on quality and one part on on-time delivery*). At Innovative Power Products,
our goal is to provide our customers with the highest quality products along with
competent and courteous customer service in order to exceed their expectations...
 News was a bit slow to spread prior to the
Internet. Unless you worked in a newsroom with a ticker machine clacking away all
day heralding breaking headlines from around the world, your access was relegated
to the discretion of media editors and producers. Items like the
passage of radio pioneer Guglielmo Marconi on July 20, 1937, due to a heart
attack would surely have been broadcast on radio shows and printed in major newspapers,
but long lead times for magazines meant a three or four month delay for publications
as in this October 1937 issue of Radio-Craft. This story appeared along
with a separate editorial by Hugo Gernsback. Not to tarnish the man's name, but
you might be interested in this article which included mention of Marconi's fascist
political bent, even embracing Mussolini's faction in the 1920s. There is a link
to a New York Times quote where he claimed to be the "first fascist in
the field of radiotelegraphy." Should the world therefore, as is the trendy Cancel
Culture practice, reject and abandon any invention associated...
 For nearly
two decades, a collaborative effort between amateur and professional astronomers
has been scanning the night sky for massive bodies whose trajectories cross the
Earth's orbital path, thereby creating a potential collision someday. Software compares
images of the entire sky (acquired in small areas) to look for newly appearing and/or
moving points of light. As with amateur radio, which has contributed mightily to
the knowledge of wireless communications, so too have amateur astronomers significantly
pioneered the field (pun intended) of primarily visual wavelength astronomy. Indeed,
they routinely discover asteroids, planet and moon impacts by asteroids and meteorites,
and even novae missed by professionals. Panoramic Survey Telescope and Rapid Response
System (Pan-STARRS) does
the heavy lifting for finding near-earth objects (NEO), but NASA has a dedicated
program called Near-Earth Object
Observations (NEOO) Program. It includes devising methods to divert the trajectory
of a massive body capable of potentially devastating damage on impact. To do so,
an explosion is used to jolt the object enough to alter its orbit. It requires detection
while far enough away that a small nudge will create an acceptable margin of safety.
NASA recently tested its method on asteroid Dimorphos. Control room operators cheered
when the onboard camera show it making a direct hit. Score one for science.
It did alter the orbit, while also blowing off hundreds of smaller chunks, some
of which are now themselves NEO's. Oops. Q: Of all the asteroids out there,
why would they select one whose trajectory crosses Earth orbit, not knowing what
might happen if something went wrong? It took a rocket scientist to do that.
 Many people find their way to RF Cafe as
a result of a Google (or other) search about electronics, so even though regular
visitors might find this primer on
Ohm's law to be a redundant review (is that phrase redundant?), it will be valuable
to the aforementioned people. Electronics technology has moved forward at lightning
speed in the last century, but the fundamentals of Ohm's law remain unchanged -
at least in the Newtonian physics realm. Indeed, we would be in trouble if voltage
no longer equaled the product of current and voltage (E = I x R).
National Radio-TV News magazine was published monthly (1928 - 1980) by
National Radio Institute, a correspondence school that did business from 1914 through
2002. A bonus electronics-themed comic is included...
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be seen, RF Cafe is the place to be...
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
About RF Cafe.
Homepage Archive Pages
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13 (no archives before 2012)
- Christmas-themed
items
|
