|
 "If you have dark eyes and blonde hair.
and are under 30, you're due for some easy squeezing. Milligan's Appliance Center,
84 Main Street, is giving every girl between 16 and 30 who has these striking features
a newly patented orange squeezer, to introduce the new item ... Note: Any traces
of recent peroxide rinse will disqualify applicants." That is advertising copy offered
as an example effective promotional material in a 1947 edition of
Radio News. My first reaction was to think how something
like that would never fly today, but then I wasn't so sure. It seems there must
be anti-discrimination laws in this "offend nobody" climate today...
 Imagine having a serviceman of any sort
arrive at your house, fix your problem, and present you with a bill of $6 - parts
included. He would walk away satisfied that he had done a good job and was well
compensated for the work considering the effort invested in training and qualification.
$6 in 1932, per the Bureau of Labor Statistics'
Inflation Calculator is worth $135.97 in 2015 money - that's a
cheap service call even in today's economy. Further, the $14 stated as a day's earnings
is $317.26 in 2025, which equates to 50 (work weeks/year) x 5 (days/week) x $243.86
(/day) = $79,315 (/year) - not too shabby. Just between you and me, that's more
than I'm currently making per year running RF Cafe...
 Aegis Power Systems is a leading supplier
of AC-DC and DC-DC power supplies
for custom and special applications. Aegis has been designing and building highly
reliable custom power supplies since 1995. They offer a complete line of switch
mode power supplies and power converters for a variety of markets including defense,
industrial, aircraft, VME, and telecom. Supports military, aircraft, EV, telecom,
and embedded computing applications. Design and manufacture of custom power supply
solutions to meet each customer's exacting specifications. Please visit Aegis Power
Systems today. Manufactured in the USA.
 Oscillators were never my forte. My biggest
exposure to oscillators was unintentional oscillations in amplifier circuits ;-(
. This
Oscillator Quiz, published in the November 1962 issue of Popular Electronics
magazine, would embarrass me if I attempted to complete it. Therefore, I will simply
state that I highly regard your oscillator prowess if you do better than 50% on
it. I guessed correctly at a couple of the more familiar circuits, but cannot even
make an educated guess at most of them. Don't let the presence of vacuum tubes scare
you off; mentally replace them with a FET and move on...
 These letters represent an unfriendly exchange
between The Electrical Experimenter editor Hugo Gernsback and Dr. K.G.
Frank, of the Telefunken System of Wireless Technology, of Germany. Gernsback correctly
accused Dr. Frank of engaging in espionage for Germany and against the United
States of America, during World War I at a time we were not officially at war
with the Axis powers. He was arrested and interred for the duration of the war for
sending out "unneutral
messages" from the broadcast station at Sayville, Long Island, New York. See
"Radiobotage" in this month's (September 1941) editorial...
 "There's an interesting development in amateur
ballooning: using so-called
superpressure
balloons, which float high in the atmosphere indefinitely rather than simply
going up and up and then popping like a normal weather balloon. Superpressure balloons
can last for months and travel long distances, potentially circumnavigating the
globe, all the while reporting their position. You might imagine that an undertaking
like this would be immensely difficult and cost thousands of dollars. In fact, you
can build and launch such a balloon for about the cost of a fancy dinner out. You
just have to think small! That's why amateur balloonists call them pico balloons.
The payload of a pico balloon is so light..."
 Many of the words in this week's
crossword puzzle pertain to radar engineering. All the rest of
the words are related to technology, engineering, science, mathematics, aeronautics,
ham radio, chemistry, etc. There are no names of Hollywierd actors, shoe designers,
or romance novel titles. I will be glad to create a special edition crossword for
your newspaper, newsletter, etc. Enjoy...
 It's time to gather 'round for another story
about fictional radio service shop owner
Mac McGregor and his trusted sidekick technician, Barney. In this
episode, an errantly wired bypass capacitor on a chassis from one of the old AC/DC
radio sets caused Mac to get a 300-volt wakeup call when his hand brushed against
it. After explaining the situation to Barney and apprising him of the danger it
poses to an owner who unwittingly sticks his/her hand into the back of the cabinet,
Mac lists a few other common dangers to watch for. Radios that ran on either AC
or DC power were very common back in the early days because there were homes and
businesses that had both type systems wired in to the premises - in part due to
the famous battle between Thomas Edison's preferred DC electrical distribution system
and Nikola Tesla's preferred AC electrical distribution system. Another reason for
DC compatibility was that prior to the
Rural Electrification Act of 1936, many...
 An incredibly glaring example of the famous
admonishment* that those who ignore history are condemned to repeat it, Radio-Craft
editor Hugo Gernsback wrote in May of 1941, a full half year before the United States
of America officially entered World War II, about how current conditions regarding
domestic commercial radio broadcast stations were likely being used by German agents
to send coded messages to offshore vessels (ships, submarines, and aircraft).
In example, he cited, amazingly, an article he himself published in 1915 in
The Electrical Experimenter accusing Dr. K. G. Frank, of the German Telefunken
company, of conducting spy operations from the Sayville, NY, station on Long Island...
 Considering that not much more than a year
before this article was written that the transistor had been invented, it is impressive
that already Raytheon was producing a commercially available
CK703 "crystal triode." That nomenclature was a natural extension
of the preceding crystal diode already being widely adapted in circuit design. If
you have wondered how the transistor schematic symbol came to be as it is, you will
learn why here where the emitter and collector symbols actually both have arrows
on the ends that contact the base, indicating the "point contact" physical arrangement
of the semiconductor junctions. Shortly thereafter the arrow on the collector port
was eliminated, primarily, I suppose to avoid confusion when the E, B, and C labels
are not present...
 "CDimension recently unveiled a technology
that enables conventional semiconductor fabs to use ultra-thin semiconductor materials
to manufacture vertically integrated arrays of extremely small, fast, and efficient
"2D" transistors. It has the potential to change what's possible for both digital
and power devices. According to the company, it's already helping several chipmakers
explore how to apply their technology to produce digital and analog ICs that offer
dramatically higher logic densities, operating speeds, and energy efficiency..."
 Here are three more Radio Service Data Sheets
added to the online archive. As mentioned many times in the past, I post these for
the benefit of hobbyists looking for information to assist in repairing or restoring
vintage communication equipment. These particular radio models -
Emerson Model 20A and 25A,
Pilot Model B-2,
General Electric Model K-40-A - were featured in a 1933 edition
of
Radio-Craft magazine...
 Nationwide commercial
television broadcasting companies wasted no time stringing coaxial
cable and microwave towers from sea to shining sea once the NTSC format standard
was adopted and manufacturers had spooled up production after World War II.
Adoption of cable services was slow because a fee was involved, but once purely
cable channels started being added the perceived value increase convinced consumers
to open their wallets. Eventually cable eclipsed over-the-air broadcasts for all
but extremely rural areas that were not serviced by cable. Along came satellite
TV to take care of filling that void. Once a small, inexpensive, unobtrusive Ka-band
antenna replaced the huge S-band backyard parabolic dishes and subscription prices
dropped significantly, suburbanites and city dwellers picked it up. Soon, cable
companies were feeling the pinch as their customer bases shrunk. Not ones to sit...
 A lot of RF Cafe visitors might not be familiar
with some of the electronic waveforms presented in this
Oscilloscope Quiz by Popular Electronics magazine's ultimate quizmaster, Robert
Balin. The shapes are recognizable to anyone who has done a lot of design, troubleshooting,
testing, or alignments on analog circuits. Electronics repairmen were intimately
familiar with these - and much more complex - waveforms. Modulation of the z-axis
is especially cool as it varies the intensity of the waveform. I always roll my
eyes when, back in the day, a laboratory or medical facility in movies or on TV
had an oscilloscope display with a Lissajous pattern writhing on the display...
 "SpaceX is putting its longstanding focus
of sending humans to Mars on the backburner to prioritize
establishing a settlement on the Moon, founder Elon Musk said Sunday. The South
Africa-born billionaire's space company has found massive success as a NASA contractor,
but critics have for years panned Musk's Mars colonization plans as overambitious.
The move also puts Musk in alignment with U.S. President Trump's shift away from
Mars. "For those unaware, SpaceX has already shifted focus to building a self-growing
city on the Moon, as we can potentially achieve that in less than 10 years, whereas
Mars would take 20+ years. Difficulties in reaching Mars include the fact that "it
is only possible to travel to Mars when the planets align every 26 months..."
 Life for the blind has always been fraught
with obstacles that we who can see will never be able to fully appreciate. Society
has come a long way in accommodating the special needs of those with no or severely
reduced eyesight. Recent news stories report of experiments with electronic implants
that use implants set into the eye and couple somehow with the retina to send image
information to the person's brain. While in no way close to being able to be called
sight, it has at least allowed the guy or girl with training to detect and avoid
obstacles based on changes in scenery shading. We are probably a century away from
true bionic vision, incremental improvements will thankfully improve
the lives of our thusly challenged brethren. This article from a 1947 edition of
Radio News reports on efforts made by the New York Institute for the Educations
of the Blind to make amateur radio...
 everythingRF, a long-time supporter of this
website, is now, in addition to publishing e-books, putting out an
e-zine which provides
some insightful content, interesting products and expert interviews within the RF &
Microwave industry. Vol. 4, now available, includes articles on Next Gen Adjustable
Q-Band Gain Equalizers, Earth to Orbit:The Important Role of Antennas in NTN, Benefits
for Phased Array Systems Through SM Components, as well as product features, upcoming
industry events, and more.
Download it now.
 Have you ever heard of a
"globar" resistor? They have been around since the early days
of radio and were used, among other things, to protect vacuum tube heater elements
from burning up due to high inrush current when first turned on. Globars have a
negative temperature coefficient (NTC) of resistance so that, opposite of standard
carbon and metal film type resistors, they exhibit a higher resistance when cold
than when hot. Mac and Barney discuss their use in this episode of "Mac's Radio
Service Shop." You might be more familiar with the name "thermistor" for such devices,
but globars are unique elements in that their construction from non-inductive ceramic
material makes them useful at high power levels and high frequencies. Globar appears
to now be owned by Kanthal (aka Kanthal Globar). Interestingly, Keysight Technologies...
 Louis Garner was the semiconductor guru
for Popular Electronics magazine in the 1960s when he wrote this article
attempting to
demystify the proliferation of over 2,000 transistor types. He devised a "transistor
tree," tracing evolution from the obsolete point-contact transistor - unstable with
high gain but noisy - to advanced designs balancing cost, frequency, power, and
reliability. It covers pnp and npn basics, then details processes: grown-junction
(inexpensive, good high-frequency); meltback diffused (similar, better response);
alloyed-junction (popular for power); surface-barrier family (SB, SBDT, MA, MADT;
excellent high-frequency, low voltage); post-alloy-diffused...
 "Gentlemen,
ei*π
+ 1 = 0 is surely true, it is absolutely paradoxical; we cannot understand
it, and we don't know what it means. But we have proved it, and therefore we know
it must be truth." - Benjamin Peirce
(not to be confused with Captain Benjamin Franklin "Hawkeye" Pierce), 19th century Harvard mathematician.
ei*π
+ 1 = 0 i, BTW, is known as
Euler's identity
- engineers live by it.
 "Scientists have shown that
twisting a crystal at the nanoscale can turn it into a tiny, reversible diode,
hinting at a new era of shape-engineered electronics. Researchers at the RIKEN Center
for Emergent Matter Science, working with collaborators, have created a new technique
for building three-dimensional nanoscale devices directly from single crystals.
The approach uses a focused ion beam instrument to precisely carve materials at
extremely small scales. Using this method, the team shaped tiny helical structures
from a topological magnetic material made of cobalt, tin, and sulfur, known by its
chemical formula Co3Sn2S2..."
 I am constantly amazed when reading stories
about how easily Adolph Hitler rose to power in Germany by encouraging and exploiting
resentment of his countrymen over being forced, among other concessions outlined
in the Treaty of Versailles, to disarm militarily and make reparations for atrocities
committed in World War I. Part of the Nazi (National Socialist) party success
was extensive use of propaganda via print, radio, and the relatively new technology
of television. Government exercised complete control over the mainstream media (i.e.,
not "underground") by dictating content that promoted the proclaimed virtues of
Nazism and the Aryan race and the vices of just about every other form of government
and race. At the height of Hitler's reign of terror during the Third Reich era,
radio and television sets were only permitted to use crystals
tuned to state-sponsored...
 Manmade electrical noise (QRM) and natural
electrical noise (QRN) has been the nemesis of communications
- both wired and wireless - since the first signals were sent. While it is true
that over the last century the amount of "background" noise has increased significantly,
the ability of modern circuits to deal with (reject) it and/or accommodate (error
correction) it has pretty much kept up with the advancement. You might be tempted
to think that "back in the good old days" such problems did not exist, but operators
were plagued by poorly designed and inadequately filtered transmitters as well as
really deficient electrical service installation that spewed noise from transformers,
inadequately grounded transmission lines, lousy connections...
|
 • FCC
"Supercharge" Wi-Fi in 6 GHz Band
• Legacy
Memory (DDR2, 3, 4) in Demand but Scarce
• 2026 is
Year of 6G Slop
• FCC to
Exempt Amateurs from Foreign Adversary Reporting
• Continuing
Your Professional Education in 2026
• India Reaches
400M 5G Subscribers
in 3 Years
 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.
 This very extensive article on iron-core
inductors appeared in the November 1946 issue of Radio-Craft magazine.
The first part, published the month prior in October, was an introductions to terms
of
inductance and magnetism, while this one deals with actual design curves and
formulas. Iron core and air core inductors are the focus, and as you might guess
(due to the use of iron cores) the frequency range addressed is audio and relatively
low intermediate frequency (IF). In fact, separate treatment is given to coils operating
at DC (direct current) and AC (alternating current). Back in the day, not only were
most of the components inside a radio, television, record player, or other types
of electronics devices serviceable (i.e., replaceable), but the components themselves
were considered serviceable. That is, inductors, speaker coils, transformers, and
even some capacitors were often repaired or modified to fix non-working circuits
or to improve marginally functioning ones...
 Just as you will never get everyone to agree
on who was the first person to successfully fly a powered aircraft (Wright, Whitehead,
Curtiss, etc.), there will never be a consensus on
who invented the radio. Most people would probably agree that it was Guglielmo Marconi,
but this author makes a case for none other than Thomas Edison. I don't recall ever
hear anyone making that claim before, but before you dismiss the opinion, read on...
 This custom
Wireless Engineering themed Crossword Puzzle for September 11th, 2022, is brought
to you by RF Cafe. All RF Cafe crossword puzzles are custom made by me,
Kirt Blattenberger, and have only words and clues related to RF, microwave, and
mm-wave engineering, optics, mathematics, chemistry, physics, and other technical
subjects. 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., Reginald Denny or the Tunguska
event in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
 Anyone who has done a lot of
electronics troubleshooting - especially on a wide variety of hardware - knows
that proficiency depends on acquiring a 'feel' for how things ought to be. An oft-given
example is that bank tellers and store clerks are taught to spot counterfeit bills
not by showing them what all the different phony currency looks like, but what real
money looks like. That way, anything that does not look familiar is readily apparent.
The same philosophy has served technicians and engineers well since the beginning
of electrical and electronic circuits. The more senses that can be drawn upon to
facilitate troubleshooting, the more quickly you are likely to pinpoint the problem.
Depending on the symptoms of the failure, sniffing the assembly for toasted or cracked
components and looking for discolored areas is a good first step for catastrophic
scenarios. Broken wires and failed solder joints are very common causes, as are
partially plugged-in or contaminated...
 This week's crossword puzzle will keep you
busy for a while. Since 2000, 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. The jury
is out on whether or not this type of mental challenge helps keep your gray matter
from atrophying in old age, but it certainly helps maintain your vocabulary and
cognitive skills at all ages. A database of thousands of words has been built up
over the years and contains only clues and terms associated with engineering, science,
physical, astronomy, mathematics, chemistry, etc. You will never find a word taxing
your knowledge of a numbnut soap opera star or the name of some obscure...
 Sylvania Electric Products was born out of
Hygrade Sylvania Corporation in 1942, and continued until 1959 when it merged with
General Telephone to form General Telephone and Electronics (GTE). That puts this
1951 promotion in Radio-Electronics magazine smack dab in the middle of
their existence. Sylvania, like most major electronics products companies of the
era, made vacuum tubes, CRTs, incandescent lamps, radios, even proximity fuses for
warheads during World War II. In the 1960s and 70s, Sylvania produced semiconductor
components and computers. Brick-and-mortar stores, whose primary competitors were
mail-order businesses back then, were typically replete with sales promotions like
this one featured in Radio-Electronics. Sylvania is now part of the LEDVANCE
brand, owned by Chinese lighting company MLS. Is there any real American anything
left anymore? Here is the Archive.org page on Sylvania's history, and here is an
interesting piece on founder Frank Poor (who wasn't so poor following the company's
immense success)...
 At least 10 clues with an asterisk (*)
in this
technology-themed crossword puzzle are pulled from this past week's (7/2 - 7/6) "Tech
Industry Headlines" column on the RF Cafe homepage. For the sake of all the avid cruciverbalists
amongst us, each week I create a new technology-themed crossword puzzle using only words
from my custom-created related to engineering, science, mathematics, chemistry, physics,
astronomy, etc. 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...
 After getting out of the U.S. Air Force
in 1982, I was fortunate to get a job at the Oceanic Division of Westinghouse Electric
Corporation in Annapolis, Maryland. Most of the guys who worked in the area with
me were former electronics technicians from the armed forces. We spent most of our
days (and often evenings) building small quantity specialty systems for the U.S. Navy.
The facility was fairly small and was not set up for high volume production; that
was the purview of the much larger operation based adjacent to the Baltimore / Washington
International Airport (BWI), which built ground-based and airborne radar systems.
Whilst there, I did a lot of
wire-wrap assemblies that went into MIL-SPEC systems, primarily rack-mounted
equipment in helicopters and aboard ships deploying towed sonar systems. As such,
I received extensive training for performing soldering, wire-wrapping...
  Any time I see
an article that references causing limb movements by poking the brain with electrical
signals, I think of the old The Far Side comic. Artist Gary Larson drew quite
a few hilarious operating room scenarios.
Electrocution is of course not a laughing matter - unless it happens to someone else
and it is not serious and no harm is done. Then - and only then - can it be funny. I've
laughed at myself many times after receiving a good jolt due to stupidity. Sometimes
after such an experience I wonder how I never killed myself from getting zapped as the
result of being too lazy to turn off a circuit breaker before servicing a light switch
or receptacle. The sad thing is that I'll probably do it again some day...
 It's not often that you will see a full-page
ad promoting a particular element in the periodic table, but in 1950 that wasn't
the case. This advertisement for
Anaconda Copper Mining Company which appeared in a 1950 issue of The Saturday
Evening Post magazine extolled the virtues of element number 29 - copper (Cu , from
the Latin "cuprum"). Aluminum and iron were other popular topics of advertising.
If you do a search on the history of Anaconda, which is today owned by the Atlantic
Richfield Company (ARCO), what dominates is the harm done to workers and to the
environment. The short video below is one of the less vicious reports on the company's
operations in Butte, Montana and in Chile. COPPER... Time's Friendly Enemy Time
and copper get along well together - because of one simple reason: Copper chooses
to ignore time completely. For nature has given copper the great quality of almost
eternal youth - the ability to resist the slow but steady ravages of the elements,
for centuries if need be...
 Here is a different kind of crossword puzzle.
Called the "R-E
Puzzler," it has only Across words and clues - no Downs. Its sort of a crossword
puzzle with training wheels, or a crossword puzzle for the vertical word challenged.
Actually, not having cross-linking Down words can make solving it a bit more difficult
since only the one or two provided letters are available to assist in figuring out
the correct word. Other variations of this sort of word grid has the provided letters
spell out a word or phrase, but this one doesn't. Every word is related to electronics
or electrical principles. Bon chance...
 Hopefully, you are winding down operations
for the week and getting ready to celebrate Thanksgiving with a long weekend. This
trio of
electronics-themed comics from a 1946 issue of Radio-Craft magazine
will help get you in a jovial spirit, regardless of whether or not you're getting
the long weekend. I've mentioned many times that these comics make a good source
of levity for adding to your presentations. As you might have guessed if you are
familiar with Frank Beaven, he drew the top and bottom comics. He also drew the
middle one. Two of these comics are part of his "Radio Term Illustrated" series,
where magazine readers sent him suggestions for a theme that could serve, along
with his drawing, as a sort of double entendre. Enjoy!
 Poor
impedance matching between the source and load has been the cause of many poor
performance issues ever since the wavelength of the transmitted signal became less
than the length of the interconnecting line. A generally accepted rule of thumb
is that when the line is more than about a tenth of the wavelength of the highest
frequency, impedance matching is probably required lest standing waves cause problems.
An impedance mismatch causes part - or maybe all - of the incident signal to be
reflected back towards the source. That results in part of the signal not being
transferred to the load, and the rest is dissipated as heat and/or radiated as an
electromagnetic wave. In some circumstances the reflected signal can cause damage
to the source because the reflected voltage can be much greater than the output
circuit can withstand. VSWR is not just a concern for transmitters...
 Schemes for transmitting newspapers via airwaves
and cable had already been around for a couple decades by the time this piece
appeared in a 1968 issue of Radio-Electronics magazine. Large publishers
like the New York Times, Atlanta Journal and Constitution, Los Angeles Times, Chicago
Tribune, etc., wanted the ability to sell subscriptions to entities and individuals
who desired time-sensitive information even more quickly than an overnight airline
flight could provide a hard copy. The vision would ultimately need to wait for the
advent of the Internet before widespread, affordable service would be available
- primarily because the original vision of producing hard copies of entire newspapers
at remote locations was (and still is) impractical. Color television was overtaking
B&W as being dominant in households, and a lot of effort went into improving
picture quality. A big problem was inconsistent hue and brightness between sets,
even those of the same make and model. The IEEE and others convened committees to
investigate and remedy the issue. Analog signals complicated the problems, but even
today's LED and LCD displays show a huge variation between monitors
 At least 10 clues with an asterisk (*)
in this
technology-themed crossword puzzle are pulled from this past week's (1/29 -
2/2) "Tech Industry Headlines" column on the RF Cafe homepage (see the Headline
Archives page for help). A couple even include Super Bowl-related news. For the
sake of all the avid cruciverbalists amongst us, each week I create a new
technology-themed crossword puzzle using only words from my custom-created
related to engineering, science, mathematics, chemistry, physics, astronomy,
etc. Enjoy!...
 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...
 This entry level introduction of
differential calculus as it applies to electronic circuit analysis appeared
way back in a 1932 edition of Radio News magazine. It was written by none
other than Sir Isaac Newton himself (just kidding, of course). Author J.E. Smith
created an extensive series of lessons that began with simple component and voltage
supply descriptions and worked up through algebraic manipulations and on finally
to calculus. I remember not being the best math student in high school (OK, one
of the worst), but once I got an appreciation for the power of mathematics for analyzing
electronics, mechanics, physics, and even economics, my motivation level soared
to where I craved more of it and ended up receiving "As" in all my college math
courses. That is truly an indication that while not everyone can excel at math,
the proper environment can make a world of difference...
 This is pretty cool. If I owned a good receiver
(which I don't), I would definitely give it a try. In 1970 when this Popular
Electronics article was written, a lot of Hams were still using tube receivers
so the recommendation to let the equipment warm up for several hours prior to making
the fine frequency adjustments was good advice. Nowadays the warm-up time and stability
of receivers should permit 30 minutes or so to suffice (even ovenized frequency
references need time to stabilize when first powered up). Unless I missed it, the
author does not explicitly state that the frequency change measured over time is
due to gravity acting on the mass of the crystal reference, but I suspect that is
his intention since part of the experiment involves disconnecting the antenna and
shielding the receiver from outside interferers. Over a lunar month period (29.5
days) we experience a leap tide and a neap tide which maximizes and minimizes, respectively,
the vector sum... |
