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...
Simulation Program with Integrated Circuit
Emphasis (SPICE)
has been around since 1973. The basic computational engine has always been open
source. It began as a simple analog circuit simulator that took a structured text
file as the input net list and provided a text file output that contained the calculated
values that the user specified such as DC bias points, transient analysis, and AC
analysis. Online simulators are now going through the same kinds of growing pains
that the earlier iterations of PC-based SPICE simulators experienced. Most are really
clunky and always seem to be missing key features and/or easily accessed features
- like rotating components on the schematic or routing interconnect lines. Aspen
Labs, in a partnership with Digi-Key, has a free online analog circuit simulator
called PartSim that seems to have conquered most of the basics. Being able to save
and recall your work is a huge benefit...
Sangamo Electric Company was a "heap" big
name in capacitors in the realm in the middle of the last century. The company always
featured an American Indian in its electronics magazine advertisements, and usually
also included some form of "indian-ese" statements as part of the sales pitch. Of
course such marketing schemes would be vehemently raided and those responsible figuratively
"scalped," if you will pardon the gratuitous expressions. As with using names like
the Washington Redskins, the Atlanta Braves, the Chicago Blackhawks, and the Cleveland
Indians to appropriate and celebrate the bravery and might of the named peoples,
Sangamo implied quality, durability, and reliability of its products through an
association with American Indians. That does not matter to people who seek to create
discord amongst the population while, in many cases, seeking notoriety and financial
gain for themselves. Sangamo Electric was located in Marion, Illinois, an area where
a few other uses of Sangamo are used, but I could not find any direct reference
to a Sangamo tribe...
Usually, when I read about yet another launching
of rockets from Gaza into Israel, what comes to mind is the barrage of
V1 Buzz Bombs and ultimately the V2 rockets that Germany terrorized London with
during World War II. Although overall not very effective individually, they
did cause brief spells of horror for the localized group of people that were affected
through maiming, killing, or property destruction. The difference between the Nazi's
weapons and Hamas' weapons is that the Germans didn't depend on other terrorist
entities to supply them with their weapons of destruction; they were brilliant people
who had evil intentions of world domination. Hugo Gernsback writes here that the
initial plan for the V2 was to deliver an electromagnetic impulse that would disable
all electrical and electronic systems within 8,000 feet of its detonation point
- what we nowadays call an electromagnetic pulse (EMP) weapon. BTW, the 'V#' designation
stood for...
Syzygy is a great word for a Scrabble game.
If you use it on a Triple Word Score (TWS) space where the "Z" sits on a Double
Letter Score (DLS) space, it will net you 105 points. About the only way to do better
is to use all 7 letters on a TWS play, where you earn 50 bonus points added to your
word score (I've done it twice in the last year).
Syzygy is an astronomical term referring to an alignment of three or more celestial
bodies - not necessarily in exact alignment, but within a few degrees. Astrologers
(not to be confused with astronomers) have since their knuckles no longer dragged
on the ground exploited such scenarios to predict various events both good and bad.
That was even before they knew those "wandering" orbs (planet means "wanderer")
were different than the (seemingly) stationary points of light. Until Galileo turned
his rudimentary telescope on the planets, the only celestial objects with a discernable
disk shape were the sun and moon, and possibly the earth. But I digress. It was
long thought that the vector sum of gravitational influences was responsible for
certain phenomena on our planet, including weather, tides, and earthquakes...
If you think government bureaucracies meddling
in the affairs of private business is a relatively new phenomenon, think again.
Elected and unelected persons and agencies have since the inception of control over
the populace made it their business to dictate which pursuits of technology are
sanctioned and which are not. Often, the motivation lies in who within those bureaucracies
stands to benefit monetarily from the decision. In this story lamenting the painfully
and, in the author's opinion, unnecessarily long time experienced in bringing commercial
broadcast television to the marketplace - in 1935. One of the primary stumbling
blocks was the Federal Communications Commission (FCC) preventing companies from
televising paid commercials during programs because, in the FCC's view, picture
quality was not good enough to serve advertisers' interests. In the process...
Who says engineers and scientists have no
sense of humor? This is not an April Fools joke or an attempt to punk you into reading
the story. An Internet browser with strict parental control settings enabled might
even prevent this page from even being displayed. In actuality, the term "G-String
Transmission Line" was so dubbed by its inventor, Dr. George Goubau, as
a tribute to his own name - both first and last. Out of an abundance of caution,
I reference the Library of Congress' "G-String" entry for the good doctor and the
device's legitimacy. A drawing similar to Fig. 1 in this 1951 issue of
Radio-Electronics magazine can be seen on the chalkboard behind Dr. Goubau
in the LoC photo. To be honest, I do not recall ever having heard of the G-string
transmission line. Its enthusiastically, nearly evangelically extolled virtues must
not have panned out in real-world practice because we do not find G-strings...
Hugo Gernsback is not necessarily a household
name in 2020, but in the early to middle 20th century, he was fairly well known
in both the hard science and science fiction realms. He was a prolific author of
books and magazines in both areas, applying his profound knowledge of technology
and his ability to foretell the futures of many aspects of communications, mechanics,
electronics, and marketing and societal behavior to the aforementioned. If you are
a regular RF Cafe visitor, you have seen very many articles written by Hugo Gernsback
reproduced. This particular work of prognostication appeared in a 1947 issue of
his Radio-Craft magazine. It presciently claimed that a post-war boom in
consumer buying after half a decade of sacrifice of creature comforts for the good
of the country and world would feed a significant adoption of
FM radio
over...
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...
We take a lot for granted these days with
the seemingly unlimited availability of cheap stuff of all kinds - some of it complete
junk and other of it pretty darn good. That goes for electronics components and
complete products and test equipment, tools, automobiles, appliances, and utensils,
clothing, medical equipment - you name it. Something as simple as a
pistol-type soldering gun can be purchased at just about any hardware or home
store, and at a price that when adjusted back to equivalent money in the 1940s would
be amazingly cheap even then. For instance a Weller Soldering Gun kit from Lowes
sells for $39.48 today (less when on sale), which would have been $3.44 (per the
BLS Inflation Calculator) in 1947 when this article showing how to build your own
appeared in Radio-Craft magazine. If a soldering gun could have been purchased
for a mere $3.44 in 1947, there would have been no need to publish such an article
because its cheapness would have obviated...
Have you heard about this? I hadn't. If you
think the only goal in Afghanistan is to stamp out the Taliban, think again. An
article in the October 2011 issue of Scientific American details the extensive
mineral surveys that have been carried out there in the last year or so. Afghanistan
is home to what may be the largest cache of
rare earth elements
in the world, with a potential to replace China as the largest extractor (~90%)
of those atoms that lie in the lanthanide and actinide regions of the periodic table
- the two rows that are typically pulled out of the chart. China, you may have heard,
is severely restricting the export of rare earths - wanting to keep it for themselves
- thereby triggering a near panic. Prices are rising so alarmingly that reopening
mines in the U.S. has once again become profitable in spite of the crippling regulations
that years ago closed down operations here (huge loss of jobs and tax revenue) and
forced us to become reliant on offshore supplies...
As with my hundreds of previous
engineering and science-themed crossword puzzles, this one for May 3, 2020,
contains only clues and terms associated with engineering, science, physical, astronomy,
mathematics, chemistry, etc., which I have built up over nearly two decades. Many
new words and company names have been added that had not even been created when
I started in the year 2002. 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, if you don't already know, might
surprise you.
E-flite's Blade CP radio controlled electric
helicopter comes from the factory with a 4-in-1 electronics unit that contains a
6-channel receiver that performs the functions needed for motor control, piezoelectric
gyroscope, BEC (battery eliminator circuit), and ESC (electronics speed control).
It also includes a dual-gimbal transmitter with an idle-up switch for transitioning
to aerobatic mode where both positive and negative pitch can be commanded to the
rotor head. My Blade CP has always flown well, but from the very beginning it has
been prone to sudden, uncommanded control movements (glitches). The results have
varied from slight jerkiness in the flight to a sudden high speed climb-outs (really
bad when inside).
"On the
way back to your home state, don't let the door hit ya' where the good Lord split
ya'. Oh, and we'll be sending you a tax bill in appreciation for your selfless sacrifice
in caring for our citizens." That is basically the sentiment of New York's governor,
who after literally begging
out-of-state healthcare workers to come to NY City amongst the Chinese COVID-19
breakout, has declared that his financially mismanaged and cash-strapped state
is going to collect income tax from the aforementioned good Samaritans.
Phased
vertical stacks of two or more antennas were fairly common in the television
realm - especially once color broadcasts became more dominant in the 1950s. Up to
3 dB per additional antenna is possible, but due to various non-ideal physical
parameters (summed phase angle, imperfect antenna geometry, etc.), realized gain
is typically in the 2.5 to 2.8 dB range. Higher signal to noise ratios were
needed to guarantee good color separation with the National Television System Committee
(NTSC) and stereo channel audio separation with the advent of Multichannel Television
Sound (MTS). As you might expect, companies appeared claiming to have invented physics-defying
antennas that "outperform all present antennas." This particular "Super 60"
model from All Channel Antenna Corporation further claims to outperform antennas
that use a mechanical rotator (see my Alliance U-100 Tenna-Rotor) by virtue of its
9-position electronic phase switching...