Phenomena
Image response, harmonic of the IF, direct
IF response, harmonics of the oscillator, combination of the IF, heterodyne oscillator
radiation, cross modulation within the receiver, cross modulation external to the
receiver, same channel beat, adjacent channel beat and
monkey chatter are all sources of radio interference addressed
in this article that appeared in a 1946 edition of Radio News. I don't
know about you, but I've never heard of the term 'monkey chatter.' According to
the troubleshooting table it is, "Unintelligible modulation superimposed upon desired
station, having the character of 'inverted speech'." Recommendations on how ...
on PCB w/NI AWR Software
NI-AWR-Antenna-Design-PCB-3-31-2015.htm" >
NI (formerly AWR Corporation)
has released two new antenna design application examples using
NI AWR Design Environment™ software titled ‘Design and Simulation
of a 2.4 GHz/5.6 GHz WLAN Antenna on PCB Technology' and ‘Design and Simulation
of an ISM Band Antenna on PCB Technology.' Both application notes were co-authored
with Dr. Volker Muehlhaus of Muehlhaus Consulting & Software GmbH NI-AWR-Antenna-Design-PCB-3-31-2015.htm"
...
and mmWave Components
Pasternack-USB-Microwave-mm-Wave-Components-3-30-2015.htm" >
Pasternack, a leading manufacturer and supplier
of RF, microwave and millimeter wave products, releases their brand new lines of
USB controlled microwave and millimeter wave components
which includes amplifiers, attenuators and PIN diode switches. The new components
from Pasternack are controlled and powered by a convenient USB 2.0 port with driverless
installation, meaning no external power supply is required. The attenuators and
PIN diode switches require an easy-to-use downloadable software program which interfaces
with any Windows computer. The company is releasing two models each of the amplifiers
Pasternack-USB-Microwave-mm-Wave-Components-3-30-2015.htm" ...
"The history of science teaches only too plainly
the lesson that no single method is absolutely to be relied upon, that sources of
error lurk where they are least expected, and that they may escape the notice of
the most experienced and conscientious worker." -
Sir John William Strutt, Lord Rayleigh
The Electronic Beach Buggy
You can go into Walmart or Radio Shack
(though not for much longer) and pick up a pretty
decent handheld
metal detector for under $100 these days, but in the 1950s even
a rudimentary metal detector was a rather large and heavy contraption. So unwieldy
were they that most had a belt clip and shoulder straps to help support and manipulate
them. That was the situation facing teen electronics aficionados
Carl and Jerry as they pondered how to leverage their combined
technical prowess to facilitate a thorough combing of the nearby Lake Michigan beach
area for treasures of coins, watches, jewelry, cigarette lighters, and other metallic
objects given up as lost by weekend seekers
...
McWatts Comic Strip
McWatts was an electronics-themed comic that
appeared in Popular Electronics back in the 1950s. Artist Carl Kohler's main character
is a stereotypical Joe Sixpack (actually a Joe McWatts)electronics
hobbyist who dreams up unique ways to deal with situations. This edition shows McWatts
in a scenario where, presciently enough, he experiences having his radio controlled
airplane treated to what modern day 'drone' pilots are experiencing on a more and
more frequent basis - being shot down. In this case the hostile fire came from some
kids with slingshots. Fast-forward to 2015 and we are now seeing reports of people
using shotguns and rifles to down the privacy-invading craft being piloted by unqualified
pranksters. Back in the McWatts era, getting 'shot down' was much more likely
...
(USB 3.1) w/Agnostic Connector
Have you seen the new
USB 3.1 'SuperSpeed' cables
yet? Finally, both ends of the cable can be identical ('Type-C')
so you don't need to have a special adapter to connect between dissimilar types.
Another bonus is that there is no 'up' and 'down' orientation because the pinouts
are symmetrical. In an apparent violation of the law of averages there seems to
be a much greater than 50% probability of attempting to plug existing USB connectors
in upside down on the first attempt - for either end. To make matters worse, I have
mistakenly plugged the squarish end of the peripheral device end into the telephone
jack hole ...
Hunting Advice for Q1 2015
The first third of the year is gone now. If
one of your New Year's resolutions was to explore alternative
career options
and you have not even started yet, you had better get going. Sorting through all
the friendly advice online, around the office, and at the bowling alley can be rough,
so I have taken the liberty of finding a few for you. One article admonishes you
not to be a Sisyphus. A sissy-what? If you're not up on Greek
mythology, this will educate
...
-
GE Icon Jack Welch Warns
Which Common Pitfalls Will
Keep You from Getting
Ahead
-
Want People to Accept Your
LinkedIn Requests?
-
I Switched to a Standing Desk,
So Now You Should, Too,
(satire
and comic relief) <more>
R/C System
If
you are relatively new to
radio control (R/C)
operation, whether for the latest 'drone' craze (technically
multi-rotor aircraft), model cars, model boats, helicopters, or airplanes
- or even robots, then you might be interested in discovering a little about the
systems which pioneers in the sport had to work with. In the mid 1950s when this
article appeared in Popular Electronics magazine, multi-rotors and helicopters
were not even in the list of model types. As with radios and television sets, before
the convenience and performance increase brought about by the advent of solid state
components, R/C modelers struggled with vacuum tube equipment, too. If you are old
enough to remember needing to re-tune your radio or TV occasionally due to
…
By now, most people involved in science and
engineering have seen the iconic photos of cosmic rays and other subatomic particles
leaving a signature of their presence as streaks in a
cloud chamber. Invented by Scottish physicist Charles Wilson,
the cloud chamber is a sealed volume containing super-saturated water vapor that
can be ionized by energetic particles passing through it. The result is a tell-tale
whitish line that can be straight arced, or even a spiral, depending on the nature
of the particle. First developed in the early part of the 20th century, many particles
predicted by researchers were detected and identified. Many unexpected particles
were also encountered that gave physicists reasons to sharpen their pencils and
develop new theories to explain. Similar research and discoveries
...
I don't know about you, but I really miss
the hard-wired
POTS (Plain Ordinary Telephone System)
days of remote communications. Unless the conversation was with an overseas telco
system, there was never a noticeable delay where both parties were constantly either
'stepping' on each other's words or having to consciously wait before speaking to
make sure the other guy has finished. Whether it be cellphone-to-cellphone or cellphone-to-VoIP,
nearly every conversation is annoying. Sometimes when one party is on the POTS line
with either a cell or Internet connection it can go well, but if you want a hassle-free
conversation (assuming the person you're talking to is not
a PiTA), you
...
c1946
Who among us has not ordered electronic components
or hardware from Newark Electronics? Now known officially as "Newark element 14"
(silicon?), and before that Newark Electronics, the
company began life as Newark Electric Company, as shown in this 1946 advertisement
that appeared in Radio-News. In the days before Digi-Key and the Internet, Newark
and Allied were the standards for me when ordering stuff in the lab. Weekly long
distance phone calls (remember when they were called that?)
to Newark were the routine. Unless a project was really hot, standard U.S.
Post Office delivery was used since at the time UPS and FedEx were deemed by the
bean counters
...
with System Antennas
Narda-Intros-Remote-Analyzer-System-Antennas-3-26-2015.htm" >
The new generation of
NRA RX 19” Remote Analyzers from Narda Safety Test Solutions
automatically detect and take into account the calibration data of Narda's own brand
of antennas and RF cables, so monitoring and safety measurements in electromagnetic
fields can now also be made without the need for conversion calculations. Narda
Safety Test Solutions has added the “Antenna Control” option to the RX version of
the Narda-Intros-Remote-Analyzer-System-Antennas-3-26-2015.htm" >NRA Remote Analyzer.
This allows direct use of all Narda antennas and cables. The antenna factors and
calibration data are detected and automatically taken into account by the NRA RX
devices, so that the measurement results are Narda-Intros-Remote-Analyzer-System-Antennas-3-26-2015.htm"
...
See poll archives.
Clutch Head Screw Ad
Clutch head screws were one of the original
'security' or 'tamper-proof' type fasteners. United Screw and Bolt Corporation undoubtedly
hoped their patented design would become the new standard in screw heads and drivers.
Clutch head screws are still available today, but many do not include the round
shape in the middle of the 'bowtie' shape. Fortunately for Mr. Henry Phillips, his
eponymous screw head design, first introduced a decade earlier than when this advertisement
appeared in Radio News, won out in the battle to replace the straight slot
screw type. Any kind of screw head that captures the driver to prevent it from slipping
off the head
...
Infographic
Jordan O., of Ohio U.'s
Russ College of Engineering and Technology, contacted me
about their newest infographic titled
Beyond the Kite & the Key -
Amazing Electrical Experiments That Furthered Engineering Innovations. Says
Jordan, "While we may not know what the next revolutionary engineering achievement
is, the future of engineering truly depends on accomplishments laid out in it's
past. Without Franklin and his kite or Bell and the wire, our modern knowledge of
electrical engineering would cease to exist." "The graphic incorporates landmark
experiments that sparked electrical engineering progress. It represents a timeline
of ..."
Cryogenic Product Development
XMA-Corporation-Announces-Cryogenic-Products-3-23-2015.htm" >
XMA Corporation, an industry leader in microwave
and RF component technology, announced further developments of their
CRYOGENIC product family of XMA-Corporation-Announces-Cryogenic-Products-3-23-2015.htm" >attenuators,
adapters, and terminations, expanding performance parameters into the 4 Kelvin
(-273.15°C) temperature range. Technical advancements
with thin film design and fabrication at XMA, allows performance levels to reach
new milestones with Millimeter and Microwave RF products. XMA Corporation, powered
by Omni Spectra®, now offers a complete line of CRYOGENIC
RF, coaxial passive components that range from XMA-Corporation-Announces-Cryogenic-Products-3-23-2015.htm"
...
Formulas Page Updated
Part of my reason for suspending private
advertising on RF Cafe was to free up time to update a lot of the website content.
All of the existing data is still valid of course, but I have been wanting to add
to it for a long time. Since I also am fiddling around with writing an app for cellphones,
this effort will serve a dual purpose in providing fresh fodder for the app as well.
Please take a look at the newly updated
Inductor &
Inductance Formulas page.
Depending on which news story you believe,
both AM and FM (and TV for that matter) over-the-air
broadcasting is dying out at an increasingly rapid rate. Between recordable podcasts,
wired Internet connections, and the growing ubiquity of Wi-Fi connectivity, a large
majority of people in the civilized world are getting their broadcasts via the Web.
If you 'follow the money' in broadcast advertising, the lion's share of dollars
have shifted to online venues, simultaneously draining revenue from local stations.
When this story was written in 1946, OTA radio was king for real-time and free reception
of information - particularly in a mobile environment. A dilemma arose in the form
of RF spectrum allocation in border regions
...
Showcased at EDI Con 2015
NI-AWR-Design-Environment-Software-EDI-Con-2015-3-23-2015.htm" >
NI (formerly AWR Corp)
will be showcasing NI AWR Design Environment™ software in its Booth
#315 at the Electronic Design Innovation Conference 2015 being held April 14-16
in Beijing, China. Additionally, NI AWR Design Environment software will be
showcased in four 20-minute talks as well as one 40-minute workshop during the week. These
NI AWR software presentations and demonstrations include: NI AWR Design Environment
V11 – What's New, Microwave Office for MMIC, RF PCB and Module Design NI-AWR-Design-Environment-Software-EDI-Con-2015-3-23-2015.htm"
...
Debug an Oscillating Amplifier
Ed Troy, owner of
Aerospace
Consulting, LLC, was kind enough to offer a few of his articles for posting
on RF Cafe. This fourth paper discusses the benefits of modeling and simulating
an amplifier circuit as part of an effort to troubleshoot an oscillating amplifier
design. It comes to us in a timely manner after my recent Notable Tech Quote highlighting
the often uttered "Amplifiers are oscillators that don't and oscillators are amplifiers
that do" aphorism. The amazing accuracy of modern high-end simulators makes such
exercises useful for many types of troubleshooting efforts
...
Guerrilla Marketing for Job Hunters 3.0:
How to Stand Out from the Crowd and Tap Into the Hidden Job Market using Social
Media and 999 other Tactics, by Jay Conrad Levinson. That's a long title. "New
chapters integrate using social media and social networking tools like Facebook,
Twitter, LinkedIn, and ZoomInfo in your job search, along with case studies from
successful guerrilla job hunters that detail what works in today's hyper competitive
job market with commentary from America's top recruiters." According to the current
unofficial RF Cafe Poll (on the homepage), 1/3 of
visitors are at least considering looking for a new job. This book gets the highest
rating from readers for usefulness - even higher than the well-known
What Color Is Your Parachute? 2015.
Enterprise-E Control Line Stunt
Model Maiden Flight
In case you care - my
Enterprise-E finally had its maiden flight today,
and all went very well. The electric power system seems very appropriately fitted
and provides way more than enough thrust. There is a lot of control surface throw
available so the first flight was a bit shaky for the first few times around the
circle, but the craft settled down after I got accustomed to it. Three flights were
put in and I brought her home unscathed - that's success in anyone's book! A short
video is posted on the web page
…
In a continuing effort to provide archival
material for researchers and for anyone seeking information on a particular radio
restoration project, these Radio Service Data Sheets for the
Crosley "Chief" Model 132-1 and
Zenith Model 430/440 radios from a 1933 edition of Radio-Craft
are being posted. An Internet search will show that there are many people engaging
in such activities. Restoring my
Crosley Model 03BC console radio would have been more difficult
if not for others who have done similar work to assist the 'community.' I generally
despise the phrase "giving back" because it is usually uttered by people that really
owe nothing to anyone, but somehow feel
...
Here is a nice article on various types of
power measurement instruments and their uses. The calorie wattmeter,
calorimeter wattmeter, photometric wattmeter, thermo-ammeter, RF voltmeter, reflectometer,
in-line meters, and slotted line are covered. Suggestions for selecting the proper
instrument for measurement and operation is touched upon. Although the article was
written in 1963, many of these instruments - or close descendants of them - are
still in use today.
High Isolation Amp
Architecture
Guerrilla-RF-Awarded-Patent-High-Isolation-Amp-Circuit-3-23-2015.htm" >
Guerrilla RF, a leading provider of high performance
MMICs, today announces that the USPTO has issued Patent No. 8,970,296. The company's
first issued patent, expiring in 2033, prevents amplifiers from turning on in the
presence of large RF input signals – leading to exceptional isolation and minimal
impact to their on-state performance.
Guerrilla Armor™ also fits in the same form factor
as the company's existing, best-in-class noise figure LNAs, requiring no additional
components and resulting in substantial cost and size savings. “Guerrilla Armor™ solves a unique issue found in high speed wireless
data Guerrilla-RF-Awarded-Patent-High-Isolation-Amp-Circuit-3-23-2015.htm" ...
"Don't engage [these] people, and don't humor
the idiots. Stupidity can't be regulated, no matter how good the rules are. Just
turn the big knob. Every rig has one." -
Riley Hollingsworth, K4ZDH, former FCC Special
Council for Enforcement, speaking about changes in FCC violation enforcement policy
changes. Printed in February 2015 QST magazine. Watch entire speech at
FARC meeting on video.
for January 2015
anatech-march-2015-newsletter.htm" >
Anatech Electronics, a manufacturer of RF and
microwave filters, has published its anatech-march-2015-newsletter.htm" >March
2015 newsletter. As always, it includes both company news and some tidbits about
relevant industry happenings. This month, Sam Benzacar discusses the increasingly
important issue of passive intermodulation (PIM) distortion products that originate in metal-to-metal contacts
where dissimilar compositions are involved. New modulation schemes place PIM requirements
into the -165 dBc realm, which is a difficult goal. Connector interfaces to
cables and components are major sources of PIM interference. Being a major manufacturer
of connectorized filters anatech-march-2015-newsletter.htm" ...
on RF Cafe
(for those who dislike 3rd-party)
Since stopping all
private advertising
at the end of 2014, I have been contacted by many companies wanting to be represented
on RF Cafe, but do not wish to use 3rd-party advertising. Many are not comfortable
with the perceived complexity and/or potentially high cost of that venue. My primary
motivation for stopping private advertising was a combination of the time taken
to manage all the advertising clients (up to 80) and
the hassle of chasing down payments. I much prefer spending my effort adding valuable
content to the website. Doing so redounds positively both to RF Cafe and to its
advertisers. In order to be accommodating, if you are interested in presenting your
products and/or services to RF Cafe visitors in a very positive manner, please take
a look ...
Names and Model Numbers
Many people have provided resources on the
Internet that made my life easier, and I have been amazed at being able to find
photos and descriptions of very esoteric subjects for which I figured there was
no chance of finding anything. In appreciation, there are times I post stuff that
probably almost nobody will ever need, but maybe there is one guy
(or gal) out there who will breathe a sigh of relief
when finally finding the needed data. This list of
radio trade names and model numbers appeared in a 1933 edition
of Radio-Craft magazine. Page scans are provided at the top, and since
search engines do not yet OCR images to be able to index their textual content,
I have also included my OCR results at the bottom
...
Support Broadband CATV
RFMW-MiniRF-Splitters-Support-Broadband-CATV-3-19-2015.htm" >
RFMW announces design and sales support for MiniRF's
low cost, 2-way splitter, model
MRFSP0014. Covering the CATV bandwidth of 5 to
1002 MHz, the MRFSP0014 is designed for applications that require small, low cost
and highly reliable surface mount components. Typical insertion loss is 0.5 dB with
isolation of 30 dB. Amplitude balance measures 0.2 dB with phase balance of 1 degree.
The MRFSP0014 can handle a maximum input power of 33dBm and comes in a 0.15 x 0.15
x 0.115", surface mount RFMW-MiniRF-Splitters-Support-Broadband-CATV-3-19-2015.htm"
...
Every time I see one of these article on
'modern'
medial electronics it makes me think of the Star Trek IV
movie titled, "The Voyage Home," wherein Dr. McCoy (aka 'Bones')
intervenes as a 20th century brain surgeon is about to operate on Chekov - "My God
man, drilling holes in his head is not the answer!" The 1948-vintage electrocardiograph
featured in this piece looks like it was built from parts salvaged from World War II
field gear. Having a doctor attach wires to you is scary enough, but back when the
probes were powered by instruments using circuits with 200-300 volts of plate
bias in them would add an extra level of anxiety. BTW, have you ever wondered how
'star dates'
...
Crossword Puzzle
This week's crossword puzzle, as is the case
with all RF Cafe crossword puzzles, has only words and clues related to science
and engineering. Time for generating the puzzle is short today, so, so is the puzzle.
Enjoy.
Radio Service Men
The Star Radio Company, in Washington, D.C.,
was lauded in its day for pioneering the use of humor in its print advertising.
I searched for more info on the company, but all I could find was a Library of Congress
photo of a display of automatic washers and ironers - considered as high tech in
the day as any
vacuum tube radio. My grandmother had one of those wringer washing
machines back in the 1960s. The wringer mechanisms were real safety hazards, hence
the old quip about there not having been so much excitement around the house since
granny got her
...
for 1st Day of Spring 2015
The vernal equinox is in the air, as they
say, and hope springs eternal. Poets use Springtime metaphorically to elicit the
idea of ushering in new life, new ideas, new commitments. To wit: "No [vernal equinox]
nor summer [solstice] beauty hath such grace as I have seen in one autumnal [equinox]
face" - John Donne, ... "O, wind, if winter [solstice] comes, can [vernal equinox]
be far behind?" - Percy Bysshe Shelley, ... The concept can easily be extended
to finding a new career situation, either because you are tired of the same old
rote routine, tired of being misused, feel underused, want to
...
-
The Mr. Spock Test: Are
You Making Illogical Career
Choices?
-
Should You Take a Transition
Job?
-
Take the Sting out of Short-
Term Jobs on Your Résumé
-
An Easy Way to Make Sure
You Never Stagnate in Your
Career
<
more >
Robert P. Balin created many electronics-related
quizzes for
Popular Electronics. I have posted many of them here on RF
Cafe, and will post more in the future. Most of the Popular Electronics
quizzes were pretty easy for anyone who has been in the electronics realm for a
few years. This quiz, by contrast, is a real head scratcher. I was only able to
get two out of 10 answers correct. It would take someone who is a physics historian
to even come close to acing it - or I'm really just lacking in knowledge
...
System Sets BW Benchmark
X-COM-IQC500B-RF-Record-Playback-System-BW-Benchmark-3-19-2015.htm" >
X-COM Systems, a subsidiary of Bird Technologies,
today introduced the
IQC5000B RF record and playback system designed
for applications such as electronic warfare, interference analysis, surveillance,
and spectrum monitoring and management. In the industry's smallest form factor,
the IQC5000B has the widest instantaneous bandwidth, 4 Tbytes of removable, high-speed
solid-state data storage, and other features tailored for the most demanding applications.
The IQC5000B builds on the success of its “A” predecessor, with higher performance
and X-COM-IQC500B-RF-Record-Playback-System-BW-Benchmark-3-19-2015.htm" ...
Looking for an RF
Technician
Defense Engineering Corporation in looking for
a full time RF technician with at least 5 years experience, specifically in the
area of testing in an anechoic chamber environment. Responsibilities will include
maintaining, implementing and operating an indoor range anechoic chamber test facility
measuring antennas, radomes, and multiple RF systems. Experience collecting and
reducing data in a compact range anechoic chamber environment including antenna
patterns and radar cross section measurements is preferred. The job location is
in Dayton, Ohio at Wright Patterson Air Force Base ...
Automotive ignition noise issues are rarely
experienced these days since not many people even listen to broadcast radio anymore,
and those that do tend to prefer FM stations. Portable music devices rule the world
both in and out of the car, with Bluetooth or phono jack connections to the dashboard
stereo making it easy to bring your own entertainment and use just the amplifier
portion of the box. Back before such conveniences existed,
magneto, point, and condenser ignition systems wreaked havoc with
radio reception. AM was particularly vulnerable because the noise was introduced
inband and could not be readily filtered out. FM helped matters, but even then it
was not uncommon to detect a background crackle in the audio that changed in frequency
with the engine rotation speed; noise on the
...
Capacitors & Capacitance
Formulas Page Updated
Part of my reason for suspending private
advertising on RF Cafe was to free up time to update a lot of the website content.
All of the existing data is still valid of course, but I have been wanting to add
to it for a long time. Since I also am fiddling around with writing an app for cellphones,
this effort will serve a dual purpose in providing fresh fodder for the app as well.
Please take a look at the newly updated
Capacitor &
Capacitance Formulas page.
According to Radio-Craft magazine
founder and editor
Hugo Gernsback, during the Roaring Twenties era in the U.S. -
and around much of the world for that matter - interest in the burgeoning field
of radio communications led to as many as half a million new entrants into the field
each year. As the novelty of the still-mystical wireless craft wore off and/or enthusiasts
discovered the technical aspects were too challenging, the numbers ebbed to a quarter
of the peak. The Stock Market crash in the Fall of 1929 didn't help matters, either.
By 1933, Gernsback was writing, "The radio beginner these days is in a paradise
...
When Designing RF Systems
Ed Troy, owner of
Aerospace
Consulting, LLC, was kind enough to offer a few of his articles for posting
on RF Cafe. Ed has more than 30 years in the electronics communications design field.
This third paper demonstrates why using a highly capable software simulator for
system design work is essential because of its ability to predict and facilitate
mitigation of system-generated problems prior to building and testing the prototype.
Case in point are spurious spectral components generated by the local oscillator
and SSB to PM conversion created in a frequency doubler circuit
…
Enhances PCB Performance
RFMW-Rosenberger-40-GHz-Edge-Connector-3-17-2015.htm" >
RFMW announces design and sales support for the
Rosenberger
02K243-40ME3, 2.92mm female, clamp-on, RFMW-Rosenberger-40-GHz-Edge-Connector-3-17-2015.htm" >PCB
edge launch connector. Perfect for prototyping or production design where frequencies
up to 40GHz are required, this Rosenberger connector is compatible with SMA and
3.5mm connectors. The 02K243-40ME3 body is brass with gold over nickel plating and
the center contact is beryllium copper, gold over nickel plated. The 02K243-40ME3
dielectric is PEEK and PTFE. RFMW and Rosenberger will recommend an optimized PCB
layout for customers RFMW-Rosenberger-40-GHz-Edge-Connector-3-17-2015.htm" ...
Radiometric Remote Sensing
Microwave Radar and Radiometric Remote Sensing,
by Fawwaz Ulaby and David Long. Artech House publishing graciously supplied a copy
of this amazing book to RF Cafe for review. Not only is it utterly packed with explanations,
drawings, and graphs, but also an extensive collection of publically-available
(i.e., you don't need to buy the book for access)
online interactive
calculators, graphs, and other RF-related resources. The authors and many contributing
provide much more than just data specifically related to
Microwave Radar and Radiometric Remote Sensing.
This 2¼" thick tome has just north of 1,000 pages.
Some of the earliest examples of
communications via light waves include signaling systems used
my mariners to send and receive simple coded messages in ship-to-shore and ship-to-ship
modes. Doing so involved candles or bonfires, depending on how far the signals needed
to be sent. Costal lighthouses have served an optical communications function for
centuries. Even Paul Revere relied on optical communications from the Old North
Church in Boston during his "Midnight Ride" to warn colonists of the impending British
invasion - "One [lamp] if by land, and two [lamps] if by sea." In the 1930s, Elman
B. Myers designed and exhibited the first widely publicized light wave communication
system that modulated a powerful
...
Advertisement
Did you know RCA (Radio
Corporation of America) used to manufacture and sell oscilloscopes? The
Model 155-C oscilloscope was promoted quite aggressively in the
mid 1940s as a breakthrough instrument. A quick Google search shows that not many
survived, and they are not particularly sought-after by vintage test equipment collectors.
It seems the quality of the metal chassis was not very good, although the electronics
get high marks. You can pick one up on eBay occasionally for fairly cheap. Oscilloscope
Museum has an example of an RCA 155-C oscilloscope (lots
of links on the page to images, manual, etc.
...
Launch of RF Pro Touch
Red-Oak-Canyon-RF-Pro-Touch-Low-Cost-RF-Signal-Generator-3-13-2015.htm" >
Red Oak Canyon is pleased to announce the launch
of the RF Pro Touch, a portable touchscreen-driven, calibrated RF generator
that makes testing circuits or prototype electronic products with RF content easier,
faster and more convenient. This innovative new signal generator implements all the
attenuator, Red-Oak-Canyon-RF-Pro-Touch-Low-Cost-RF-Signal-Generator-3-13-2015.htm" >RF
sweep and modulation features of other calibrated generators, but is packaged in
a small, 12-oz case making it easier to haul RF sources to out-of-reach locations.
The RF Pro Touch can output frequencies between 35 MHz and 4.4 GHz, and
power levels from 10 dBm to -55 dBm. It's internal rechargeable battery
Red-Oak-Canyon-RF-Pro-Touch-Low-Cost-RF-Signal-Generator-3-13-2015.htm" ...
Amplifiers Cum Oscillators
"Amplifiers are oscillators that don't and
oscillators are amplifiers that do." - R.F. Anon. This adage is akin to another
that says, "If you want an oscillator, design an amplifier. If you want an amplifier,
design an oscillator." In case the concept is not familiar with the dilemma, both
refer to frustration pre-computer simulation designers often had
(and some still have) with unintentional constructive
feedback causing an amplifier to oscillate and unintentional destructive feedback
preventing an oscillator from oscillating.
Test Cables up
to 3 GHz
Pasternack-Intros75-Ohm-Test-Cables-3-GHz-3-16-2015.htm" >
Pasternack, a leading manufacturer and supplier
of RF, microwave and millimeter wave products, announces the release of their newest
line of
75 Ohm test cables with operation up to 3 GHz.
These rugged cable assemblies are specially designed to withstand the rigors of
test lab use and applications in Pasternack-Intros75-Ohm-Test-Cables-3-GHz-3-16-2015.htm" >75
ohm communications systems. Technicians commonly rely on these high frequency test
cables in technologies such as cable TV, MoCA 2.0 and MoCA 1.1
(Media over Coax Alliance) and DOCSIS. Pasternack's
new series of high performance 75 Ohm test cables are available in two configurations
including a type-N male to type-N male or a type-N male to type-F male Pasternack-Intros75-Ohm-Test-Cables-3-GHz-3-16-2015.htm"
...
Articles for March
16
It's been quite a while already since I last
posted links to engineering articles from our favorite microwave and RF magazines.
There are lots of new author names in the list, as well as a few familiar favorites.
-
BER Test Method Uses
Real Data, J. Beaudet
-
Small Cells Challenge
Measurement Capabilities,
P. Dillien
-
How Cops Are Finding "Grow
Ops" with AM Radios,
K. Wyatt
-
A Data-Acquisition System
on a Chip, M. Rowe <more>
Try Googling 'cyclodos' and 'cyclophone' and see what you come up with. I found that Cyclodos
is now a German company which makes apparel from recycled inner tubes and tents
(among other things), and cyclophone is a weird bicycle-mounted
contraption for blasting sound while peddling down the street. In 1946, the terms
cyclodos and cyclophone referred to modulator and demodulator tubes, respectively,
for pulse-time modulation applications. Fortunately, the science of pulse modulation
quickly evolved past such devices. This article goes into quite a lot of detail
on the beginnings of pulse modulation techniques developed for radar systems during
World War II. It is very informative without going
...
