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 For the sake of all the avid
cruciverbalists amongst us, this
technical-term-themed crossword puzzle contains only words and clues related
to engineering, mathematics, chemistry, physics, and other technical words. As
always, this crossword contains no names of politicians, mountain ranges, exotic
foods or plants, movie stars, or anything of the sort unless it/he/she is
related to this puzzle's technology theme (e.g., Hedy Lamarr or the Bikini
Atoll)...
 Sam Benzacar, of Anatech Electronics, an
RF and microwave filter company, has published his May 2026 Newsletter that, along
with timely news items, features his short op-ed titled "The
Math of LEO No Longer Adds Up." Sam runs the numbers on Low-Earth-Orbit satellites,
and assesses future plans. "SpaceX now operates more than 10,000 Starlink satellites,
roughly two-thirds of everything in orbit. The next-largest operator, OneWeb, has
fewer than 700." They roam the nighttime sky, with small dots of light tracking
across our already light-polluted skies. The ITU coordination process now confronts
filings for more than a million LEO spacecraft, with half a million projected to
be in orbit by 2040. Now that Internet coverage and even Direct-to-Device (D2D)
networks...
 Meteor scatter communications is an excellent
example of where hobbyists - in this case amateur radio operators - have contributed
mightily to technology. It could be argued that a big part of the reason for such
occasions is that many people involved in science type hobbies are employed professionally
in a similar capacity, and their extracurricular activities are a natural extension
of what pays for the pastimes. It seems amazing to me that
meteor
scatter as a means of achieving upper atmosphere reflections of radio signals
went undiscovered until 1953, but evidently that is the case. Meteor scatter is
a very popular form of amateur radio challenge...
 "Make the most of your time at
Dayton Hamvention® with the free ARRL Events phone app. Hamvention is the world's
largest annual gathering of radio amateurs, and will be held May 15-17 in Xenia,
Ohio. There is a lot to do and see. Use the ARRL Events app to make sure you don't
miss a beat and plan out your visit now. The ARRL events app is produced by ARRL
The National Association® for Amateur Radio in partnership with Dayton Hamvention.
The app includes Hamvention's full program, so you can browse and schedule forums,
preview the extensive list of exhibitors, and find affiliated events. During the
event, attendees can use..."
 Here's a topic that never goes out of style.
Without bothering to worry about source and load impedances, this brief tutorial
on the fundamentals of
power supply filter design using series inductors and parallel
capacitor combinations. The author offers a rule-of-thumb type formula for guessing
at a good inductor value based on peak-to-average expected current. This is by no
means a comprehensive primer on power supply filter design and is directed more
toward someone new to the concept...
 Werbel's new
WMC-0.5-2-6dB-S, 6 dB directional coupler provides precision attenuation
where it matters most. It covers 500 MHz to 2 GHz with broadband flat coupling response,
high directivity, and excellent return loss performance. The device covers the upper
portion of the UHF band as well as L band in a single unit measuring just 3.60 x
0.60 x 0.38 inches. Minimized reflections increase accuracy of the measurement.
Mainline insertion loss of 1.2 dB (typical) includes coupling factor. The 6 dB coupling
ratio gives an approximate 75/25% splitting ratio and may be used as such to distribute
signals unequally where required, often to make up for asymmetrical losses elsewhere
in a system...
 Connecting a diode backwards across a solenoid
coil to shunt potentially damaging current and/or voltages when the supply is turned
off is a common trick for saving connected circuitry. Depending on the magnitude
of the magnetic field and how quickly the field collapses, some really high voltages
can be produced. In fact, the ignition coil and point (now
solid state) system in exploits exactly that principle to turn the 12 volts
from your car battery into 20-40 kV for firing the spark plugs. Engineers that
designed this early
cyclotron
had limited options for what to use given the state of the art in the early 1940s,
and chose to keep the generator permanently connected to the coil (no switch) so
that if the controller failed, the coil's energy...
 In the opening scene of "Gladiators," Quintus
remarks to Maximus (Russell Crowe), "A people should
know when they've been conquered." Such truth is applicable to society today regarding
ubiquitous surveillance. Less than two decades ago the media was
filled with stories of outrage over the discovery of some new form of monitoring
and reporting system having been installed on highways, in shopping malls, along
sidewalks, even bathrooms. Since the 9/11 terrorist attacks, anything goes with
government snooping. Count the numbers of freedoms you have lost and the inconveniences
suffered because of those 19 men with no identifiable common cause
(wouldn't want to profile). This story from 1956 shows
how long stealth installation...
 I wonder why today's editions of the ARRL's
QST magazine does not have a column dedicated to the "YL" (Young Lady,
or female in general) contingent of the amateur radio realm? Ham radio, as most
-if not all - historically male-dominated hobbies has fairly significant outreach
efforts to try attracting women into activities. My Model Aviation magazine
has a monthly column written by a lady whose enthusiasm for model airplanes equals
that of most males - and she's funny to boot! - but it is not dedicated to female
modelers. If there is a girl or woman present at a competition, she is almost guaranteed
to receive coverage...
 The December 1947 issue of Radio News
and the February 1954 issue of Radio & Television News published these
electronics-themed comics. Humor evolves over time, which is apparent when you
look over these and many of the other comics from these vintage electronics magazines.
The AVC comic is the best, IMHO. For those of you not around in the olden days of
vacuum tubes, tapping on a tube would often make it work properly again, either
because of a dirty contact in the socket or crud that had accumulated on the screen
grid. I give this batch a score of about 7 out of 10, but you might think otherwise.
There is a growing list of other comics at the bottom of the page. Enjoy...
 How RF circuits work have long been referred
to as "black magic,... even sometimes by people who fully understand
the theory behind the craft. To me the ways in which a transmission line - be it
coaxial cable, microstrip, or waveguide - can be manipulated and controlled with
various combinations of lengths and terminations is what most qualifies as "magic."
Sure, I know the equations and understand (mostly) what's happening with incident
and reflected waves, etc., and how the impedance and admittance circles of a Smith
chart graphically trace out what's happening, but you have to admit there's something
wonderfully mystical about it all...
 I remember hearing a long time ago about
"The Thing"
- a passive bugging device discovered within a wooden Great Seal gifted to the U.S.
Embassy in Moscow. This 1962 Electronics Illustrated magazine feature explores
the ingenious, battery-less Soviet listening device. Far from a conventional electronic
bug, this passive device utilized a specialized resonant cavity and a diaphragm
that modulated an external 1600 MHz radio beam, essentially acting as an echo-based
microphone that was incredibly difficult to detect. While the article highlights
the device's diabolical simplicity and sensitivity, it contains no mention of the
U-2 incident or Gary Powers; notably, historical records clarify that Ambassador
Lodge displayed the device in 1960 to expose Soviet espionage...
 Based on beleaguered wife Sylvia Kohler's
mention of GE's Electronics Park in this story (surely a fable... or not), she and
unintentional antagonist, superheterodyne hubby (aka "Happy Boy," but we know him
as Popular Electronics cartoonist
Carl Kohler) probably lived in the Syracuse, NY, area. Electronics
Park existed during the hey days of General Electric when the sprawling campus ,
just north of I-90, designed and manufactured a plethora of both household and military
electronics products. GE's Electronics Laboratory ("E-Labs") was the company's pride
and joy. Today, a tiny portion of Electronics Park is still occupied by Lockheed
Martin, who bought that GE division in the 1990s, and the rest belongs the city.
But I digress... enjoy the story (her reason for referring to hubby as a Superheterodyne
is highlighted)...
 Multielement quad antennas are as popular
today as they were in 1967 when this article appeared in the ARRL's QST
magazine. That is not to say they are common. This particular design is for the
10-, 15-, and 20-meters bands, all three
of which are still in use today. If you build a multielement quad as shown here,
you might want to find a substitute for the bamboo frame members; aluminum tubing
is pretty cheap, but if you use metal, you'll need to use insulators at the connection
points. Formulas are provided for determining element lengths and director and reflector...
 This Radio Service Data Sheet from a 1932
issue of Radio-Craft magazine provides schematics and parts lists for
Silver-Marshall Model 727-DC Battery-Operated Superheterodyne
receiver. Most - if not all - electronics servicemen had subscriptions to these
magazines because they were a ready source of not just these service sheets, but
because of the extensive articles offering advice on servicing radios and televisions.
In fact, many electronics manufacturers had a policy of supplying service data only
to bona fide shops. A large list is included at the bottom of the page of similar
documents from vintage receiver schematics, troubleshooting tips, and alignment
procedures...
 There is something about these proposed
shorthand circuit symbols that reminds me of the IEEE digital
logic symbols using the distinctive shape (the traditional format) versus the newer
rectangular shape format. The set is quite extensive when all the different flavors
of combinatorial blocks - flip-flops, timers, counters, shift registers, encoders,
decoders, etc. - are included. My personal preference, you might guess, is the original
format with distinctive shapes. Although I do not do a lot of digital work, it is
easier for me to follow the signal flow and mentally perform the logic operations
with the distinctive shapes. But I digress. This article from a 1947 issue of
QST magazine introduces...
 Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas. "We've Got You
Covered."
 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...
|
 • Top
5 Companies Granted U.S. Patents in 2025 (one American)
• Shape-Shifting
Semiconductors Activated by Light
• UK Teachers Say
AI Eroding Critical Thinking
• FCC
Approves Charter's $34.5B Acquisition of Cox
• Amazon
Might Buy Globalstar
 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.
 Here's a gimmick that never really caught
on. In the 1960's, Antenna Specialists promoted their Model M-148 Co-Ax Omni Antenna
"with
visual RF indicator." This 1966 Popular Electronics magazine ad is a prime example.
That indicator was a neon light bulb at the tip which lit up when the transmitter
was keyed on. Not only would this novel feature let you know when your transmitter
was broadcasting, but it would also "guide mobiles visually to your 10-20." OK,
maybe at night, but it certainly wouldn't have been bright enough during the day
to even see. Alas, the public evidently didn't impress the buying public as much
as it did the designers. Maybe it had something to do with operators not wanting
to waste transmitter power for the purpose of lighting a neon bulb. Oh well, nice
try...
RF Cascade Workbook is the next phase in the evolution of RF Cafe's long-running
series, RF Cascade Workbook. Chances are you have never used a spreadsheet
quite like this (click
here for screen capture). It is a full-featured RF system cascade parameter
and frequency planner that includes filters and mixers for a mere $45. Built in
MS Excel, using RF Cascade Workbook is a cinch and the format
is entirely customizable. It is significantly easier and faster than using a multi-thousand
dollar simulator when a high level system analysis is all that is needed...
 One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 225,000k per
year (in eight locations on each page, with >17k pages)...
 A 720-line HDTV display is made up of 1,280 vertical
lines and 720 horizontal lines of pixels, which gives a total of 921,600 pixels. A 1080-line
HDTV has 1,920 vertical lines and 1,080 horizontal lines, for a total of 2,073,600 pixels.
In 1969, a 230 vertical line by 230 horizontal line
electroluminescent (EL) flat-screen television display with 52,900 pseudo-pixels
was considered a big deal - and it was since it was the starting point for digital flat-screens
of today. Interestingly, while the "pixel" distribution was square, the actual display
retained the standard 4:3 aspect ratio, meaning horizontal element width was 33% greater
than the vertical element. Since each EL element was addressed individually, there was
no ability of a picture element to be shared by adjacent "pixels," so displaying a circle
would result in a very pixelated picture...
 This custom RF Cafe
electronics-themed crossword puzzle for December 17th contains words and clues
which pertain exclusively to the subjects of electronics, science, physics, mechanics,
engineering, power distribution, astronomy, chemistry, etc. Given that today is
the 17th day of the month, many words in this crossword start or end (or contain)
the 17th letter, "Q." Related clues are marked with an asterisk (*). You might expect
a few Ham radio-related words and abbreviations in this one. If you do see names
of people or places, they are intimately related to the aforementioned areas of
study. 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...
 Much more than just a self-serving video
of my new R/C airplane flight agility, this model represents a plethora of modern
electronics. Although the radio control system in this plane is a standard narrow
band FM variety on 72.170 MHz (as opposed to my 2.4 GHz, spread spectrum
system), the motor is a state-of-the-art 3-phase brushless model (E-flite 450)with
a sensorless electronic
speed control (E-flite EFLA331, 20 A). Power for both the radio and the
motor is supplied by a 3-cell (11.1 V) lithium polymer (Li-Po) battery rated
at 2,100 mAh with a 15C discharge current capacity. There was a time not so
long ago when no one though that electric power could ever provide a equivalent
to the nitro methane gulping internal combustion engines, but the time has come.
This all-electric setup is fairly small in size, but there are much larger motors...
 Here is a
vacuum tube chart everybody needs. Well, not really, but surely somebody out
there in the RF Cafe audience will find it useful. By "audience" I mean most likely
a hobbyist who is restoring or repairing a vintage tube-type radio, television,
piece of test equipment, etc., and has never even heard of RF Cafe, but finds exactly
what he/she needs as the result of a Google (Bing, Yahoo, whatever) search. If it
seems like you can find information on just about anything you need on the Internet
these days, it is at last partly because of efforts like mine that uses a lot of
personal time and some personal funds to establish and perpetuate the reality. Others
of you contribute in different ways; this is mine. A helpful way to make it worthwhile
is to visit websites of companies that advertise on RF Cafe. A lot of great products
and services are offered, and it doesn't cost you a penny to investigate...
 Radio Shack was opened in 1921 by brothers
Theodore and Milton Deutschmann, then was bought by Tandy Corporation in 1962, reportedly
for $300k. As well as being an outlet for hobbyists to buy common electronics parts,
Radio Shack sold its own line of electronics like radios, calculators, and stereo
systems under the brand name Realistic. A lot of people don't like Radio Shack the
same way many don't like Walmart - usually for no good reason. I first started shopping
at Radio Shack in the mid 1970s when I needed parts to build a homebrew stereo radio
receiver from an article in Popular Electronics magazine (if I remember
correctly). I still like going in the store and looking around, occasionally actually
buying something. Do you remember the Free Battery card they issued where you could
get one free battery per month? How about the vacuum tube testers that were in the
stores until the late 1970s? When our TV would crap out...
 "These pulses speed toward the moon at the
fantastic speed of light… through the ionosphere and on into the unknown void surrounding
the earth's atmosphere." Hard as it might be to imagine nowadays, in 1946 there
was no empirical data regarding the Earth's upper atmosphere other than the few
instrumented sounding rockets that had been launched for studies. Orbiting man-made
communications satellites were still a decade away when engineers at the Evans Signal
Corps Engineering Laboratory in New Jersey made the first
Earth-Moon-Earth (EME, aka "moon bounce") signal bounce using a massive radar
and antenna that blasted 10 MW EIRP pulse at the lunar surface. It was a big
deal then; it's no big deal today. Amateur radio hobbyists routinely conduct EME
communications from the comfort of their home-based Ham shacks, using equipment
vastly superior to and less expensive than the 1946 setup...
 A couple years ago a house two streets away
had an estate sale after the elderly gentleman who owned it passed on. There was
a lot of old
amateur radio gear for sale, and most of it had been bought early in the morning,
right after the beginning of the sale according to the man's daughter who was on-hand.
The newspaper notice mentioned the Ham equipment. In the back yard was a nice 40-foot
crank-up tower that was a bit weather-worn, but otherwise appeared to be in good
condition. She said that was the first item sold. I didn't ask how much she got
for it. The house was to be sold, and they were glad to have the tower gone before
listing it on the market. I have wondered in the past when seeing a "For Sale" sign
in the lawn of a house with one or more radio towers in the yard how much they would
impact the sale price. Some Hams would plan to take...
 Anyone who watched the
WKRP in Cincinnati
sitcom back in the 1970s has to remember what was one of the funniest episodes ever.
Here is the 4 minutes that made Prime Time history. In this Thanksgiving episode,
station owner Arthur Carlson decided he would surprise the community with good deed
- that doubled as a promotional stunt for his radio station - by dropping turkeys
from a helicopter for lucky shoppers at the local shopping mall. Watch the disaster
unfold as Les Nessman reports live, and then see Carlson's final comment that is
still used or alluded to in many comic routines. Posting this video is an RF Cafe
tradition. Have a Happy Thanksgiving!
 The U.S.
Telstar 1 communications satellite launched atop a Thor-Delta rocket on
July 10, 1962. It was the first satellite to relay television shows and live broadcasts,
telephone calls, and telegraph messages - all analog of course - for both domestic
and international purposes. Electronics World magazine editor W.A. Stocklin
used his editorial space in the November issue to salute the engineers and scientists
that made it possible - which includes all those who paved the way for Telstar I.
Planning and development was performed by a consortium of companies and government
agencies. Bell Telephone Laboratories built the hardware. AT&T (a spin-off of
Bell Telephone Company) actually owned Telstar I. Note that in 1962 the unit
prefix "pico" was not in common use, so it mentions micromicrowatts rather than
picowatts. Similarly, publications of the era (and before) used micromicrofarads
(μμF) rather than picofarads (pF)... Sunday 17
 For two decades, I have been creating custom
engineering- and science-themed crossword puzzles for the brain-exercising
benefit and pleasure of RF Cafe visitors who are fellow cruciverbalists. This November
17, 2019, puzzle uses a database of thousands of words which I have 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 location like Tunguska, Russia, for reasons
which...
 There's no hiinggthe truth about how well
I did - or didn't do - on this "the truth about how well I did - or didn't do -
on this "R-E
Puzzler" from the October 1967 issue of Radio-Electronics magazine, because
contrary to the publisher's promise, a solution was never published in a later issue
(I looked for it in the six subsequent issues and could not find it). Therefore,
the R-E Puzzler Solution posted at the bottom of this page shows the answers I was
able to figure out which, embarrassingly, results in a score of only 17/25 = 68%.
I'm pretty confident of being able to get all of them if I spent more time, but
that's it for about 30 minutes worth of cogitating. If you know more of the words,
please send me an e-mail and I'll add them to the solution. Thanks...
 Erie Technological Products, located in
my adopted hometown of Erie, Pennsylvania, was a re-branding of Erie Resistor Company
as the concern had begun manufacturing a wide variety of discrete electronic devices
- resistors, capacitors, feed-through filters, silicon rectifiers. The Erie Resistor
complex on 12th Street in Erie occupies a huge amount of real estate on both sides
of the road. The overhead foot bridge can be seen in this photo. The buildings have
long been vacated and stand with many others as reminders of the thriving manufacturing
center that Erie once was. We still have a good bit of manufacturing here, but nothing
like back in the hey days of the last century. |
