Today in Science History -
John Sargrove was to the production of radios what Henry Ford was to
automobiles. At the time this "Robot Makes Radios" article appeared in a 1947
issue of Radio-Craft magazine, Sargrove had recently put his
Electronic Circuit Making Equipment (ECME) fully automated assembly line
into operation. Applying knowledge from two decades of developing methods of
crating inductors, capacitors, resistors, and interconnecting conductors using
controlled deposition of various materials on flat substrates, he was able to
build 2-tube AC/DC radios at a rate of up to three per minute, with only two
ECME operators - one at the input and one at the output. The only manual
assembly required was the installation of a potentiometer-switch, a transformer,
The U.S. Federal Communications Commission
Map for the continental United States in 1975, and it is still the most current
version. No doubt more modern ground conductivity equipment and methods could produce
a more detailed and accurate map, but for general purposes, this suffices. When
more precise local soil conductivity measurements are required by electric utilities,
communications installations, etc., teams of technicians and/or engineers are dispatched
to obtain measurements. Many moons ago (early 1990s) while doing a short stint at
the Potomac Edison Electric Company in Hagerstown, Maryland, our electric substation
guys had some pretty impressive measurement gear that used probes pounded into the
ground in multiple locations to gets resistance (conductivity) readings between
them. Where the soil conductivity is not sufficient to meet specifications with
simple ground rods and/or meshes, chemical agents...
RF Cascade Workbook 2018 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. 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 2018 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. An intro video takes you through the main features...
If subjects pertaining to electronics - particularly
vacuum tubes - are like music to your ears, then this poem entitled "What Is It?,"
from the February 1943 edition of QST, should suit you just fine. The rhyming
words are supplied by author Frank Judd; you just need to supply the harmony. You
might recognize paraphrasing of other familiar works such as Longfellow's "Paul
Revere's Ride." Poems like this one were actually quite common back in the day.
In fact if you look through the list of articles that I have posted from vintage
QSTs, you will find about a dozen...
Nova Microwave is a leader in technically differentiated
electronic and radio frequency Ferrite Circulators and Isolators that connect, protect and control
critical commercial and military wireless telecommunications systems. Our staff
is dedicated to research and development of standard and custom design quality Ferrite
Circulators and Isolators from 380 MHz to 26.5 GHz. Available in single
or multi-junction topographies, the Nova Microwave product line of is specifically
designed for use in varied environmental and temperature extremes.
If you had to guess, what would you say the
image to the left represents? Part of a printed spiral inductor? How about a printed
antenna for near field communications (NFC)? Need a hint? OK, the object is part
of a project that Alexander Graham Bell, his cousin Chichester Bell, and Charles
Sumner Tainter worked on in their Volta Laboratory Associates labs. No, it's not
a neatly wound coil of telephone cable. It is a section of an audio
etched on a glass platter in November of 1884. After being stored at the Smithsonian
Museum for 130 years, this and a few other recording media was lent to the scientists
at Lawrence Berkeley National Laboratory with hopes that they could apply newly
invented noninvasive, non-contact techniques to scan the disc and use software algorithms
to recover the data. Thomas Edison had introduced his phonograph to the world in
Since 2003, Bittele Electronics has consistently
provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly
services. It specializes in board level turnkey
PCB assembly for design
engineers needing low volume or prototype multi-layer printed circuit boards.
Passive Components: Bittele Electronics is taking one further
step in its commitment of offering the best service to clients of its PCB assembly
business. Bittele is now offering common passive components to its clients FREE
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 with antennas sometimes hundreds of feet long that 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. That's right,
the pilot - often alone without an assistant - sent messages by tapping out dits
and dahs using a straight key strapped to his thigh. Moving into the 1920s, radio
telephony had become standard equipment aboard transport and military aircraft.
Much of it early-on was battery powered...
NorthEast RF provides quick-turnaround
antenna testing services for IOT and M2M
devices. Either passive antenna measurements, or OTA cellular device pre-compliance.
We supply 2D | 3D antenna patterns along and antenna efficiency measurements in
a report along with a data file for use with a pattern viewer. The near-field antenna
test system is ideal for either free space or verification of body worn devices
using our selection of human head and hand phantoms. NorthEast RF's comprehensive
antenna testing services include linear | circular polarized antenna measurements
and OTA cellular device pre-compliance. Antennas can be rapidly evaluated and optimized
using our fast near field spherical system. Test results supplied in data file with
pattern viewer software. Turnaround time is usually 3-days. Please take a few minutes
to see how they can help your project.
"A high-resolution paramagnetic resonance
detection method based on the diamond nitrogen-vacancy (NV) color center quantum
sensor was proposed and experimentally implemented in a study led by academician
DU Jiangfeng from CAS Key Laboratory of Microscale Magnetic Resonance of University
of Science and Technology of China (USTC) of the Chinese Academy of Sciences (CAS).
The researchers obtained the
single-spin paramagnetic resonance spectrum with kilohertz (kHz) spectral resolution.
The study was published in Science Advances. A major development trend of electron
paramagnetic resonance spectroscopy is to get as accurate information as possible
from as few samples as possible, which requires enhancing..."
San Francisco Circuits (SFC), a provider
PCB fabrication and assembly, announces they are fully compliant with the National
Institute of Standards and Technology (NIST) Special Publication 800-171 requiring
companies to adhere to specific guidelines to protect data and information pertaining
to federal or state agencies. Being in compliance ensures proper data handling is
in place for maintaining the trust of partners, vendors, contractors, and customers–especially
when federal or state agencies are involved. The federal government requires companies
to be compliant with 800-171 to protect Controlled Unclassified Information (CUI).
CUI is sensitive information relevant to the interests of the United States government...
Bill Schweber's article on the Electronic
Design website entitled, "Watch
Out, MEMS Switches - Much-Smaller NEMS Relays Are Coming After You!" shows once
again that every new paradigm-changing miracle product and method is eventually
trumped and rendered obsolete. "Using phase-change materials, researchers have devised
a nanoscale metal-contact on/off switch that doesn't use a flexure element and is
far smaller than its MEMS-based counterparts. There's no doubt that devices based
on MEMS (microelectromechanical systems) processes and technologies have radically
changed the world of sensors and solid-state functions. Since they became commercially
viable in the 1980s beginning with analog airbag impact-acceleration sensors...
Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products such
as RF signal generators, RF synthesizers, RF power detectors, mixers, up / downconverters.
Since the conception of WFT, we have introduced products that have been purchased
by a wide range of customers, from hobbyists to education facilities to government
agencies. Worldwide customers include Europe, Australia, and Asia. Please contact
Windfreak today to learn how they might help you with your current project.
This week's custom RF Cafe crossword puzzle
celebrates the 244th anniversary of the signing of the
Declaration of Independence, and uses as a background the John Trumbull painting.
Clues marked with an asterisk (*) are part of the theme. Each week for two decades,
for the sake of all avid cruciverbalists amongst us, I have created a new technology-themed
crossword puzzle using only words from my custom-created lexicon 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, find someone or something in the otherwise
excluded list directly related to this puzzle's technology theme...
As I have written often, Hugo Gernsback was
one of the electronics industry's most prolific authors, inventors, and innovators.
In this 1947 article in his Radio-Craft magazine, he proposes using
components in place of leaded resistors. In fact, he sold printed resistive
cards through his Radio Specialty Company (Rasco) that could be cut into whatever
size was needed to achieve the required amount resistance based on a certain ohms/square
value. He also mentions creating printed inductors on Bakelite and even fashioning
variable-coupling transformers with a pair of inductor plates sliding relative to
each other, similar to capacitive "variometers" used for tuning RF circuits. Not
to neglect the possibility of capacitors, Gernsback suggests possibly spraying a
thin conductive coating on paper and then rolling multiple layers into a tubular
form, achieving a smaller form factor per unit capacitance...
Copper Mountain Technologies has released
the new Compact S5045 and M5045 VNAs with a frequency range from 9 kHz to 4.5 GHz.
Featuring a dynamic range of 130 dB typ. and measurement speed of 70 µs,
Compact VNA offerings will effectively replace the functionality of the recently
discontinued S5048, while delivering improved performance. The S5045 will come with
the advanced software features engineers expect from CMT's S Series Compact VNAs.
The M5045 will join the M Series line of Compact VNAs and include standard VNA software
features in an economical package that excludes a number of advanced software features...
"SES, leader in global content connectivity
solutions, announced its selection of two U.S. satellite manufacturers, Northrop
Grumman and the Boeing Company, to deliver four new satellites as part of the company's
accelerated C-band clearing plan to meet the Federal Communication Commission's
roll-out 5G services. Northrop Grumman will deliver two flight-proven GeoStar-3
satellites, each equipped with a high-quality C-band payload to deliver the superior
customer experience that end users are accustomed to. The two satellites - SES-18
and SES-19 - will be designed, assembled and tested in Dulles, Virginia. The Boeing
Company will deliver a pair of highly efficient all-electric 702SP satellites. The
two satellites - SES-20 and SES-21 - will be manufactured and assembled in Los Angeles,
Dog Days of Summer,
contrary to what many people believe, is named not to describe the hottest, most
humid, most oppressive period of the year, but marks the astronomical point in time
following the heliacal rising of the star system
Sirius, aka the Dog Star in the
constellation Canis Major.
40 days later, on August 11th, the Dog Days end. That also happens to be middle
of summer (not midsummer),
which is on or about August 6th. Never having been a proponent of summer, the end
of the Dog Days has always meant we're closer to the end of summer than to the beginning,
and autumn is on the way.
RF Cafe's raison d'être is and always has
been to provide useful, quality content for engineers, technicians, engineering
managers, students, and hobbyists. Part of that mission is offering to post applicable
job openings. HR department employees
and/or managers of hiring companies are welcome to submit opportunities for posting
at no charge. 3rd party recruiters and temp agencies are not included so as to assure
a high quality of listings. Please read through the easy procedure to benefit from
RF Cafe's high quality visitors...
Do you remember seeing a cool Doodle on
the Google search page and would like to find it again? Would you like to see not
only the Doodle that piqued your interest, but ALL of the Doodles that Google has
ever published? You can do that, but what might be more useful would a page full
of all the technology- and science-related Doodles (click large image below) or
some other specific topic. Fortunately, there is an easy way to find what you want
by going to the Google website and typing "google doodles"
into the search box, or just go to www.google.com/doodles. Once you get there, enter
the specific event that interests you. Since some events have Doodles in more than
one year, add a year to your search to narrow down returns...