|
 Before there were electric generators onboard
airplanes to power communications equipment, aviators relied on storage batteries
to operate their radios. Before that, there were no radios at all aboard airplanes.
Although Wilbur and Orville Wright first piloted their Wright Flyer in 1903, by
the end of the decade airplanes were becoming a common sight across the country
and across the civilized world. By the middle of the second decade experiments were
being done with airborne radio. They were heavy vacuum tube units with heavy
lead-acid batteries. Antennas sometimes hundreds of feet long needed to be
reeled out and in once at altitude. The earliest transmitter (for 2-way
communications) were spark gap types, meaning of course Morse code was the
medium...
 Werbel Microwave began as a consulting
firm, specializing in RF components design, with the ability to rapidly spin low
volume prototypes, and has quickly grown into a major designer and manufacturer
with volume production capacities. The
WMHPC-80-520M-6dB-N is a high-power coupler that operates over the 80 to
520 MHz band, covering FM radio, upper VHF and lower UHF applications.
Conservatively rated for 100 watts CW. Useful for amplification and signal
distribution applications including radio and television broadcasting, public
safety and emergency broadcasting and distributed antenna systems. Mainline loss
1.2 dB typical, directivity 24.5 dB. Assembled and tested in USA. "No Worries
with Werbel!"
 Whoa, it's a good thing I read these articles
prior to publishing them, lest some uninitiated soul be lead to the wrong conclusion!
Keep in mind that this article was written in 1932, prior to the development of
the quantum mechanical model of the atom, but on the other hand, Ernest Rutherford
and Niels Bohr developed their model in 1913, so the information was available.
The
Rutherford-Bohr model of the atom suggested a nucleus comprised
of positive masses called protons, each of which carries a charge of +1 unit, and
neutrons with no net charge. Surrounding the nucleus were orbiting masses called
electrons, each of which carries a charge of -1 units. Accordingly, the net charge
of an atom was the sum of protons and electrons, with unionized atoms having a net...
 I have always found it annoying when an
author uses a symbol or subscript in an article without explaining or somehow making
obvious what it is. In this "Resistivity:
Some Definitions" piece from a 1969 issue of Electronics World magazine,
the author's stated purpose is to define terms related to resistivity, which he
does well, but there are a couple instances where subscripts for resistivity, rho
(ρ), are left for the reader to figure out.
ρsp, ρs,
and ρv have been replaced with
ρspecific, ρsheet,
and ρvolume , respectively, where needed.
Sure, a careful reading of the surrounding content clarified the intent, but you
are not supposed to work that hard. Otherwise...
 Carl and Jerry found the appearance and
construction of 2400 megacycle transmitters and receivers to be quite odd compared
to the equipment they were used to dealing with. It's sometimes hard to believe
such an attitude of wonder when our world today is utterly filled with wireless
devices operating in the 2.4 GHz ISM band. Author John T. Frye could never
have imagined that such a reality would would exist half a century after his story
of the pair of teenage electronics sleuths. Unlike our postage stamp size integrated
assemblies that cost a few dollars, they speak of "special ultra-high-frequency
"light-house" tubes with...
 Say goodbye to Earth-based astronomy if
this trend continues! Elon Musk's Starlink 10,000-satellite constellation pales
in comparison to this ambitious, dominating system. Isn't it amazing how Green warrior
funders are willing to ignore things like and nuclear power plants when it serves
their financial and influence purposes? "China
files to launch 193,448 satellites. The CTC-1 filing is for a single notional
Non-Geostationary Orbit (NGSO) system. The CTC-2 filing is still at the Advanced
Publication Information stage. CTC-1 and CTC-2 are early-stage ITU regulatory filings
but don't authorize launches. [They] form part of a single strategic effort to secure
spectrum and orbital priority for a future next-generation Chinese megaconstellation..."
 In an effort to promote entry of women and
girls into the amateur radio hobby, Short Wave Craft magazine ran a few
contests for Best "YL" Photos. Amazingly - and maybe there are still instances
of it today - many (if not most) of the YLs featured had built their own equipment.
In 1935, most people built their own equipment, so that is not too surprising. The
winner for this month was a 16-year-old young lady i.e., "YL") who in fact built
her rig. Another winner was an 83-year-old grandma who was born before Marconi,
Maxwell, and Hertz did their best work! The third winner was a girl who earned her
Ham license at age 6, which back in the day required sending and receiving 5 words
per minute (WPM) in Morse code...
 Coaxial cable is the most familiar form
of
RF transmission line for most people these days. Up until 2009
when the U.S. switched to digital television (DTV), there were still a fairly large
number of people who had the old 300 Ω twin lead cable running from roof-top
antennas to TV sets. Over-the-air reception has petered off precipitously since
then. Coaxial cable is undoubtedly more convenient and forgiving regarding routing
since proximity to structures - particularly metallic components - than twin lead.
Good quality 300 Ω twin lead cable (~30¢/foot today)...
 Certainly my high school, Southern Senior
High (class of '76), in Harwood, Maryland, had a JROTC program in the 1970s, but
I have no recollection of it. Maybe because of the Vietnam War, not as many ROTC
groups were being formed. In fact, I don't think there was anything about ROTC in
my yearbook. This 1962 Carl and Jerry adventure titled "ROTC
Riot" took place at the semi-fictional Parvoo University, where the electronics
and technology pair was attending for electrical engineering. ROTC upperclassmen
were famously difficult to tolerate due to their attitude of superiority -- and
desire to do unto others as was done unto them...
 Mrs. Helen McKee knew exactly what she was
signing up for when she agreed to marry Mr. McKee. After all, she met and got familiar
with the guy over the air during some rag chewing sessions. This story is a humorous
(and true) account of what life can be like for the spouses of enthusiastic Ham
radio operators. We all hope for such an understanding "significant other." Melanie
has certainly endured and supported a lot of
my pastime endeavors
over the past 32 years. It's a short read, so take a break and put a smile on your
face...
 "SatVu has released a 3.5m high-resolution
thermal image revealing near-real-time activity inside one of the USA's largest
data centres. The image provides a heat-based look at cooling systems, substations
and high-load infrastructure of the data centre of a bitcoin mining company in Rockdale,
Texas. Demand for AI, cloud computing and crypto mining has made data centres some
of the world's most energy-intensive facilities. They are expanding fast, often
outpacing the ability of regulators, grid operators, analysts and communities..."
 As mentioned many times in the past, some
things never change regarding the
basics of electricity and electronics. Resistance, inductance,
and capacitance are examples. When first starting out in this science, an effective
introduction to the fundamentals can often determine whether a person sticks with
it or finds another area of interest to pursue as a hobby and/or vocation. Analogous
examples of voltage and water pressure, resistance and the diameter of a water hose,
inertia in a spinning mass opposing a change in rate and an inductor opposing a
change in current, etc., are presented along with some good sketches of...
 How is this for a prescient prediction from
the early 1960s? "As a result of modular and
integrated circuitry techniques, all future circuit design work,
regardless of degree, will become the responsibility of the component manufacturer
instead of the equipment producer." Texas Instruments' (TI) Jack Kilby is credited
with designing the first integrated circuit in 1958. The first commercial IC, Ti's
Type 502 flip-flop, had just hit the market in early 1960, and already pundits were
prognosticating and ruing the disappearance of circuit designers. Maybe it was concerns
over job security that they seem to favor forever building every circuit...
 Werbel Microwave is a manufacturer of RF
directional and bidirectional couplers (6 dB to 50 dB) and RF power dividers
/ combiners (2- to 16-way) with select models operating up to 26.5 GHz and
100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are
designed and manufactured in our Whippany, NJ, location. Custom products and private
label service available. Please take a couple minutes to visit their website and
see how Werbel Microwave can help you today.
 John R. Collins' 1967 Electronics World
magazine "Advances
in Magnetic Materials" article captures the essence of magnetic materials leaping
from incremental tweaks to revolutionary shifts, like grain-oriented steels that
aligned crystals to slash transformer losses and shrink massive power gear for aviation
and grids. Alnico alloys ditched bulky speakers for sleek permanent magnets, while
ferrites -- ceramic wonders -- tamed high frequencies with non-conductive ease,
spawning compact motors, tools, and early computer memories. Superconductors, then
lab novelties generating intense fields with zero resistance, hinted at sci-fi applications
from particle physics to space. Fast-forward to today, and they've exploded, proving
Collins' "quantum jumps" birthed today's...
 Crowded frequency bands have been a problem
since the beginning of radio because technology is constantly not only filling available
bandwidth, but also pushing the frontiers higher. The advantage of going higher
in frequency is that required bandwidths for existing modulation schemes represent
a smaller percentage of the center frequency. For example, an 802.11b WiFi signal's
22 MHz bandwidth represents roughly 1% of its 2.4 MHz center frequency.
802.11a does 20 MHz at 5 GHz for 0.4%. Extend that center frequency up
to 50 GHz and the channel occupancy is a mere 0.04%. That means for the same
total band occupancy of 1% as with 802.11b, you can fit in 25 equivalent slots.
The problem with going higher in frequency is that components...
 "Researchers have used a new nanowire fabrication
technique to produce flexible electronics virtually impervious to electromagnetic
interference. Developed at Glasgow University [that's "UoG" in the image], the method
involves imprinting ultra-thin nanowires onto bendable and transparent polymer substrates.
A process called
interfacial-dielectrophoresis (i-DEP) uses electrical fields to arrange the
nanoscale materials with high accuracy, enabling the creation of precise patterns.
The Glasgow team used i-DEP to create gaps in the nanowire network that act as capacitors..."
 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).
Enjoy...
 San Francisco Circuits (SFC) has been a
trusted U.S. provider of advanced PCB manufacturing and assembly solutions for R&D
innovators, prime contractors, and integration experts. SFC has published a white
paper entitled, "PCBA
Press Fit Connector Reliability: Strain Thresholds and Best Practices," to help
inform you on issues that can mean the difference between success and failure. "Press
fit connectors are common in high-density PCB designs - powering 5G infrastructure,
electric vehicles, aerospace systems, and advanced medical devices. Their ability
to deliver high I/O counts without the heat risks of soldering makes them indispensable
for modern electronics. But here's a hidden risk: If strain during insertion isn't
properly managed, it can lead to latent solder joint..."
 As a case in point about my claim with today's
earlier post featuring
Bob Berman's factoids on astronomy, this article from a 1956 edition
of Popular Electronics illustrates how vital electronics are in the various
fields of science. It has only been fairly recently that astronomers have been 'looking'
at stars and planets outside of the visible wavelengths. Renditions of the sky in
both shorter and longer wavelengths show in some regions a vastly different universe.
Earlier this year, a comprehensive mapping of the entire known universe in the microwave
realm revealed the largest contiguous feature ever detected - dubbed "The Cold Spot"...
 Of the scores of Mac's Service Shop stories
I have read and posted here on RF Cafe, this is the first that deals with a subject
near and dear to author John Frye - the plight of handicapped people. If you don't
know, Mr. Frye had been confined to a wheelchair for most of his life. "Electronics
and the Handicapped" is essentially the story of his life, though he does not
say so. Mac: "When I was a kid growing up in a little Arkansas town, I knew a crippled
boy whose dad ran the local garage." Guess where John grew up? His father owned
a machine shop, and made gadgets to help his crippled son. "I had never heard the
term 'respo' until you told me about a month ago it was the nickname for a victim
of respiratory polio." He had polio at 18 months old...
 Very few items from my early days here on
Earth have escaped destruction or disposal. A couple dozen household moves in the
last half century have been responsible for some of it. Oddly, one thing that survived
is a box full of old letters and greeting cards - dating back to the late 1960s.
Melanie has been scanning her and my items for a more permanent record, and ran
across this letter of praise written from the administrator of the
Annapolis Vocational Technical Center, where I studied for the electrical trade
in high school. The linked page has information on the AVTC and my time there...
 "With $800 of off-the-shelf equipment and
months' worth of patience, a team of U.S. computer scientists set out to find out
how well geostationary satellite communications are encrypted. And what they found
was shocking. Close to half of the communications beamed from satellites to the
ground that the researchers were
able to listen in on were not encrypted. This included sensitive data including
cellular text messages, voice calls, as well as sensitive military information,
data from internal corporate and bank networks, and the in-flight online activity
of airline passengers. The research team, led by Aaron Schulman and Nadia Heninger,
then set out to find out which companies and government agencies were failing to
encrypt data in order to contact them and disclose the vulnerabilities..."
 This is one of the earliest examples I have
seen (and I've seen many) of an electronics article that was written in a conversational
tone rather than in the heretothen[sic] stoic, all-business type prose. In fact,
you would be hard pressed to discern it from a contemporary article in QST
magazine. Author Davis describes his process of interfacing 52 Ω coaxial
cable to his multi-element beam antenna. The
gamma match has the advantage in such an application of being
usable when the center of a driven element is directly grounded to the antenna boom. Most
other types of feed systems...
|
 • FCC
to Delete Obsolete Part 97 Rules in February
• 2026
6G predictions
from Keysight
• DRAM Cannot
Keep up with
AI Demand
• 2025 Began Changing
Rare Earth Supply
Chains
• AT&T
Drops DEI for $1B Spectrum Deal
 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 topic -
power
supply filter design - that never goes out of style. It was originally published
in a 1952 issue of QST magazine. Without bothering to worry about source
and load impedances, this brief tutorial on the fundamentals of power supply filter
design using series inductors and parallel capacitor combinations. Author Gabriel
Rumble offers a rule-of-thumb type formula for guessing at a good inductor value
based on peak-to-average expected current. This is by no means a comprehensive primer
on power supply filter design and is directed more toward someone new to the concept
of removing or reducing noise and AC ripple from the output of a DC power supply...
 Forgive me if I sound like a broken record
(a scratched record, actually), but when selecting articles for posting here on
RF Cafe, I like to include ones that are directed toward newcomers to the field
of electronics as well as for seasoned veterans. This piece from a 1958 issue
of Radio & TV News magazine entitled "Basic Electronic Counting," is a prime example in that it introduces
the concept of binary numbers. We've all been there at some point in our careers.
A big difference between now and when this article appeared is that in 1958, almost
nobody was familiar to binary numbers, and fuggetabout [sic] octal and hexadecimal.
Only those relatively few people designing and working with multimillion dollar,
vacuum tube-based digital computers installed in universities, megacorporations,
and government research facilities...
 Each week, for the sake of all avid cruciverbalists
amongst us, I create a new technology-themed crossword puzzle using only words from
my custom-created lexicon related to engineering, science, mathematics, chemistry,
physics, astronomy, etc. This week's puzzle contains a
special holiday message (clues with asterisks) to all RF Cafe
visitors. You will never find among the words names of politicians, mountain ranges,
exotic foods or plants, movie stars, or anything of the sort. You might, however,
see someone or something in the exclusion list who or that is directly related to
this puzzle's theme, such as Hedy Lamarr or the Bikini Atoll, respectively. Enjoy!...
 Well-known radio communications futurist,
visionary, and inventor Mohammed Ulysses Fips, I.I.R.R.E.E., published an article
in the April 1946 issue of Radio-Craft magazine. He described a portable,
compact, fully functional two-way radio disguised to look like an ink pen - the
"Radio
Pen." It measured approximately 3/4" in diameter and about 6" in length. Like
early cellphones, the antenna was not a conformal internal job, but need to be extended
externally for use. When I first saw the Radio Pen, it reminded me of the ones used
by playboy spy Napoleon Solo and nuclear physicist spy Illya Kuryakin in the old
television series "The Man from U.N.C.L.E." Whilst on assignment tracking down a
THRUSH bad guy or girl, the master spies would covertly remove the cover of their
pen communicators, attach it to the bottom of the pen, and initiate contact back
at U.N.C.L.E. headquarters using the "Open Channel D" code phrase...
 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 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...
 The
Crosley Model 567 "Chairside" chassis was an out-of-the-box concept in the day
when nearly all radios were of the familiar tabletop or floor console variety. At
least for now, I am going to only scan and post Radio Service Data Sheets like this
one featuring the Crosley Fiver Chassis "Chairside" Model 567 radio in graphical
format, rather than run OCR on them to separate the textual content. There are still
many people who restore and service these vintage radios, and often it can be difficult
or impossible to find schematics and/or tuning information. I will keep a running
list of all data sheets to facilitate a search...
 Declaring any kind of straight LC tank circuit
to be high stability is a bit of a stretch when compared the Q available simply
by adding a crystal, even in 1958. Tone modulation was an early method for achieving
remote control of model airplanes, boats, and cars. The number of channels with
these
tone modulation systems is two times the number of modern proportional
systems in that moving the rudder left took one channel and moving it right took
another. Up and down elevator likewise took two channels. Therefore, this four
channel system is only two channels by today's terminology. Technology evolved
into fully proportional ...
 Here is a humorous "Kool-Keeping
Kwiz" that appeared in the June 1970 issue of Popular Electronics magazine.
Your answers to questions will determine whether you are a truly cool technophile,
or you are just a maniacal misanthrope who happens to know something about radios
and regulations. This would probably have been more aptly printed two issues earlier
as an April Fools' joke...
 Bell Telephone Laboratories was largely responsible
for designing and building a
communications system that was the envy of the world. Innovation on the part of Bell
engineers, manufacturing staff that produced the equipment, and technicians who serviced
the systems deserve the credit as do management types who made funds and opportunity
available to the aforementioned. As the number of telephone service subscribers grew
and reliability became even more vital to business, law enforcement, and national defense,
new methods had to be devised. In the late 1950s, Bell introduced the concept of wireless
microwave links at 11 GHz (X band)...
 Selenium rectifiers were the first widely
used replacements for vacuum tubes in commercial electronic equipment. Since amplification
was not possible - that came in late 1948 with the invention of the transistor,
compliments of Shockley, Brattain and Bardeen - diode action in AC-DC power supplies
was its primary application. Typical reverse breakdown voltage is in the neighborhood
of 20 volts and current handling capability depends on the interface surface area.
Cost kept the selenium rectifiers from being widely adapted early in their history
(1933), but by 1946 when this article was published in Radio-News magazine
it had dropped enough to make their use economical. Eliminating one or two vacuum
tubes in a radio or television power supply made the sets more efficient and increased
reliability since the selenium rectifiers rarely suffered failures if designed into
the circuit correctly...
 A while back ago I posted a write-up on the vintage
Alliance Model U-100 Tenna-Rotor that I installed in the garage attic with a
Channel Master CM5020 VHF / UHF / FM antenna atop it. There are not many television
antenna manufacturers around anymore; their numbers have been decreasing continually
due first to the advent of cable-delivered TV and now with Internet-delivered TV. The
"cord-cutter" movement is helping to give over-the-air television broadcasting a rebirth
due to the outrageous cost of subscription programming. Anyone contemplating installing
a television antenna today has the same concerns as those back in 1959 when this Channel
Master advertisement appeared in Electronics World magazine - gain, directivity,
bandwidth, ruggedness...
 "The situation is one that is difficult,
if not wholly impossible to eradicate, because of all modern, 20th Century machine
age products, the radio receiver of today undergoes more violent and more radical
changes than almost any other single item we can think of." That was the lament
of electronics inventor, publisher, and industry visionary Hugo Gernsback in 1939!
He wrote in the February issue of Radio-Craft magazine of the practice
of
electronics component manufacturers vastly overproducing products and then,
when they are quickly obsoleted due to newer better ones entering the market space,
selling at below cost in hopes of recovering at least some of their investment.
For a man who otherwise encouraged, welcomed, and participated in the pushing forward
of technological frontiers, the attitude seem strangely at odds with his raison
d'être. "This 'dog eat dog' process has gone on ever since and will probably go
on for a long time to come." He had no idea ... or maybe he did...
 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)...
 Electronics wizard, repairman, and experimenter
extraordinaire Mac McGregor, as sort of alter ego of author John T. Frye, provides
a brief lesson on electrostatics for his repair shop apprentice wing man Barney
(I don't think his last name was ever mentioned). In this 1973 Popular Electronics
magazine article, Mac had built two types of
electroscopes - one using a pair of pith balls suspended from silk strings and
another that was a cobbled-together version of a gold leaf electroscope. His motive
was two-fold. First and foremost was to accommodate his own interest in electrostatics,
and second to hopefully engender enough curiosity in Barney to cause him to do a
dive into science books to learn more. Given the potentially lethal levels of electrostatic
charge that builds on TV picture tubes they worked around, gaining a healthy respect
for an electrostatic charge...
 Here is an advertisement by
Western Electric from the August 25, 1945, edition of the Saturday Evening
Post magazine. As with many of the advertisements of the era, this ad refers
to the company's contribution to the war effort during WWII. "How communications
help tighten the ring," accompanies a map of the Japanese islands. All forms of
battlefield and shipboard communications benefitted from the innovations of Western
Electric scientists, engineers, and assembly line workers. These days Western Electric
manufactures special purpose audio frequency vacuum tubes and amplifiers to use
them. They're not cheap. Back in 1945, Western Electric was a major manufacturer
of telephone and telegraph equipment for Bell Telephone, Western Union, and America
Telephone & Telegraph (AT&T). Dr. Lee de Forest, inventor
of the Audion amplifier tube, worked for Western Union...
 Part 1 of this 3-part article, titled
"Influence of the Antenna of the Choice of Wavelength for Best Communications,"
appeared in the February 1952 issue of QST magazine. Unfortunately, I do
not yet own that edition. However, I do have Part 3, which subsequently appeared
in the August 1952 edition. It will eventually get posted here. QST does
not have a publicly available archive, but if you happen to be an ARRL member, you
can access Part 1 after signing in. In this series, author Yardley Beers discusses
propagation
effects, modulation systems, and receiver techniques. A particularly interesting
topic included in this installment is that of using a form of pulse modulation in
FM broadcasting in order to exploit the 'capture effect' whereby a signal in the
presence of noise will tend to suppress the noise. I don't think modern stations
use that method, possibly because of incompatibility with stereo channels and data
added for digital readouts...
 1976 is the year I was emancipated (aka graduated)
from high school, and this issue of The Old Farmer's Almanac (OFA) happens to be
from that year. For as long as I can remember, the OFA has included a set of
Mathematical Puzzles in its annual publication. They range in difficulty from
1 (very easy) to 5 (sometimes quite difficult). Having been a faithful buyer and
reader of the OFA for as long as I can remember, I have spent many hours toiling
with some of the more challenging examples. In fact, there were a lot which I never
did figure out and needed to look up the answers in the back (come to think of it,
I experienced the same dilemma with my college engineering textbooks). Because quite
a few of the Mathematical Puzzles are worthy of an engineer's cerebration, contemplation,
and deliberation, all I have will be eventually posted here on RF Cafe. Enjoy!
In 2010, I posted a short piece about where to
look on the Web to learn what upper management, board members, and large investors were
doing with
insider company stock trades. At the time, the MSN Money website had a tool where
you could enter a company's stock symbol and get a readout of who was buying and - more
often than not - selling stock. That web page is gone, but I found the same information
on InsiderCow.com. The dollar amounts are truly staggering to people like you (likely)
and me (definitely). Numbers reported are sale values, not profit to the stock holder.
Many of the stocks were issued as either grants or options, but even outright purchased
stocks are included as well. Regardless, prepare to have your jaw drop if you have never
seen this type of data before. Some of the more familiar technology companies have been
selected for examples... |
