Absorptive Switch w/Decoder
Skyworks Solutions has introduced a new 0.02
– 4 GHz, high isolation, single pole four throw absorptive switch with 50 Ω terminations and excellent isolation
performance. The symmetrical SKY13392-359LF
is ideal for military communications, test and measurement and GSM/CDMA/WDCMA/LTE cellular infrastructure applications requiring
feedback, channel and filter-bank switching where very high isolation (>50 dB) and low
loss (1 dB) are needed. The device contains integrated logic.
for Noisy Well Pump
Here is an interesting story where the FCC issued
a citation of violation for
incidental radiation due to a malfunctioning well pump. The noise was evidently being generated by the motor and radiated
from the AC power wires. The interference was affecting local MF and HF amateur radio operation.
FCC investigators used direction finding equipment
to locate the source ('fox hunting' in Ham terms). The owner was threatened with a $16,000
fine unless corrected immediately, with up to $112,500 levied if he screwed around. Replacing the AC line filter did not
solve the problem, so he probably ended up replacing the entire pump. Being in Florida where the water tables are typically
near the surface, it was likely not a submersible type pump, so the entire assembly would have had the opportunity to radiate.
Submersible pumps use brushless induction motors deep within the metal casing lining the well hole
(a nearly ideal RF shield), but depending on the vintage of the resident's above-ground pump
it could be brushed, with arcing causing the problem.
Here are a few recent articles from our industry's
leading magazines that you might find useful.
- Choosing Optimal Cables &
Connectors, J. Browne
- Designing MRI Coils with Aid
of Simulation, A. Bitz,
J. Felder, T. Wittig
- Unused RF Spectrum May
Ease Wi-Fi Traffic Jams,
I. Sokol
- Manage Growing EM
Radiation Levels, J. Browne
- Input Third Order Intercept
Point for Crystal Filters
(p.22)
D. Layne
- Measuring the Thickness of
Coated Shields, K. Wyatt
for Long-Time Support
Linx Technologies'
RF modules,
remote controls, evaluation kits and master
development systems feature straightforward hardware configuration and clear documentation, making it simple for engineers
and hobbyists to integrate wireless features without the hassle and expense of engineering RF functionality from scratch.
They also offer design services including board layout assistance, programming, certification advice and packaging design.
"Wireless Made Simple"
Engineering Crossword
Take a break and
work this week's wireless engineering
themed crossword puzzle. All the words are pulled from a hand-built list of terms, names, and abbreviations that have
only to do with science, mathematics, and engineering. If you want a crossword with names of movie stars and obscure countries,
try the local newspaper. If you want to exercise your nerd knowledge, this is the one for you.
in Appreciation of Support
Since 1985, Apex Wireless has
offered consulting, engineering, and design services focusing on
high-performance, cost-optimized products that employ wireless RF transmitters, receivers, and transceivers. To complement
our RF design expertise, we work with local experts in DSP, ultra low power design, packaging, certification, and manufacturing.
Consumer, defense, aerospace, power, transportation, industrial, sports, and other industries served.
Powered Satellite Receiver
Have you ever heard of a 'nuvistor?' It didn't seem familiar
to me right away until after I looked it up.
Nuvistors
were high mu (high gain) tubes, manufactured originally by RCA, used in sensitive receiver front ends. They came in about
a dozen different varieties. This particular NASA-136 receiver for satellite reception uses a 6CW4 triode. Per Wikipedia,
"Most nuvistors are basically thimble-shaped, but somewhat smaller than a thimble, and much smaller than conventional tubes
of the day. Triodes and a few tetrodes were made. The tube is made entirely of metal and ceramic. Making nuvistors requires
special equipment, since there is no intubation to pump gases out of the envelope. Instead, the entire structure is assembled,
inserted into its metal envelope, sealed...
Many times I have extolled
the high quality of QST authors' knowledge and writing skills.
H. Ward Silver writes the "Hands-On Radio" column which usually features circuit and system design and theory topics. It often
includes, gasp, mathematics. His July 2013 article is titled "Phasors, Part One." It promises to be a good series. The last
paragraph says, "There is a final way to describe the signal - the exponential form in which it is represented as V ejΘ.
This form comes from the mathematics behind Euler's equation in which the coordinates
of our points are miraculously shown to be equivalent to ejΘ=cosΘ +j sinΘ. The serious
and beautiful math behind this equation lies at the heart of much electrical engineering and leads to the jaw-dropping Euler's
identity: ejπ = -1 which unites the two
most widely used transcendental number (e and π),
imaginary numbers (j), negation and unity. Not bad for a moving point in a simple circle, huh?" Beautiful. After reading
it Melanie asked why my eyes were suddenly red. "Allergies," I explained.
Digital Control Phase Shifter
PMI Model
No. PS-500M2G-8B-SFF
is a Stare-of-the-Art, 8-Bit Digitally Controlled Phase Shifter that operates over the 500 MHz to 2.0 GHz frequency
range. This model has a typical insertion loss of 10dB and offers 360 degrees of phase shift via 8-Bit TTL control.
The phase shift error is less than ±10 degrees and the amplitude error is less than ±1 dB. The switching speed is 500 nsec
maximum.
Polarity SMA Connectors
Linx Technologies'
new low-cost gold plated connectors are now available from Linx, adding new options to our already diverse connector line.
The gold jacks are available in SMA
and Reverse Polarity SMA styles
in straight or right-angle versions. In addition, the 50-ohm connectors are available as PCB mount or surface mount components
offering a variety of mounting options for your design.
on Your Wrist
By the time you read this it will
probably be too late to be an original owner of this very limited edition 'Codebreaker'
watch, made by the prestigious UK Bremont Watch Company. Each Codebreaker watch will incorporate a piece of pine wood from
the iconic Hut 6 and numbers from some rare, original punch cards used in wartime machines that carried out rapid analysis
of encrypted message systems to assist the Codebreakers.
Each watch will also have incorporated into its rotor, material from an original Enigma machine
rotor. Speaking of
Bletchley Park news, the WWII era
Electronic Delay Storage Automatic Calculator
(Edsac) restoration project recently reached a key milestone. Edsac is built of 3,000 valves
(vacuum tubes) spread across 140 separate shelves.
Identifies You and Helps QST
In the early 1930s, QST magazine
(ARRL's monthly publication) usually ran a line at the bottom of every page in the back half
of each issue that said, "Say You
Saw It in QST - It Identifies You and Helps QST." They even got the capitalization correct (all
lower case short prepositions and conjunctions, but I digress). The December 1933 edition was a bit different, however,
in that all the left-hand pages had the message translated into one of fourteen different languages while the right-hand
pages used English. I deemed that discovery cool enough to scan and post here. Since the only languages I speak with any
fluency are English and Pig Latin, I took the trouble of entering the English sentences into the Google Translator engine
for each language...
Radio Amateur Exhibit
The
1933 "Century of
Progress" World's Fair, held in Chicago, was a big deal on many fronts. Life in America and around the world was changing
rapidly due to the widespread introduction into homes a decade earlier of electrical and telephone service, indoor plumbing,
and associated appliances. The state of the art was a modern wonder. Transportation had been made affordable to many families,
and leisure time was becoming more abundant. If it were not for the advent of the stock market crash in 1929, economies
would be thriving because there was so much cool stuff to be had. Many people had taken up the hobby and/or profession of
wireless communications, so a display was included on the fairgrounds for the craft. An interesting consequence of a combination
of noisy (electrically) electromechanical wonders being promoted and the desire to demonstrate
working amateur radio equipment was a necessity to locate the two as far apart as possible...
Started June 26, 2013
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RF Xcvr MPMP Modules Control
The DTS Series
and EUR Series RF transceiver
modules combine a low power wireless transceiver with a powerful multipoint-to-multipoint protocol controller to form
an effective UART-to-antenna wireless communication solution. The modules use a wide band digital modulation technique known
as Digital Transmission System (DTS) and are capable of replacing wires in almost any RS-232/422/485 application. This system
has a higher output power, giving it a range of up to 1 mile / 1.6 km line of sight without having to limit duty
cycle, hop channels or the expense of a DSSS system.
Accurate Clock
The National Company, of Malden,
MA, which made this cesium-based
Atomichron in the mid-to-late 1950s, began life as a toy manufacturer. It had an output frequency at the
nominal resonance frequency of cesium - 9192.631830 MHz - and was accurate to better than a second in 600 years. The
unit was 7 feet tall and weighed 500 pounds. Modern cesium standards are more stable and are portable. As of January 2013,
the NIST-F1 cesium fountain primary frequency standard is accurate to within one second every 100 million years!
Threshold Detector
PMI Model
CDT-2M18-30-BB Options
DE, D is a threshold detector that operates over the 2 MHz to 18 GHz frequency range. This model has a low insertion
loss of 2.5 dB maximum and operates over an input power range of -30 to 0 dBm. The threshold level is adjustable
and the output signal is TTL positive logic. In addition to the threshold detector, this unit offers an analog detected
output voltage of 0 to 2.5 VDC.
to Write on Graphene 'Paper'
This new technology could be
a relatively simple and inexpensive method of creating permanent, high density records storage. Using an
electron beam, the
planar hexagonal carbon matrix of graphene
(2-dimensional by definition) is disturbed and replaced by a 3D clump of carbon atoms that
provide a discernable relief easily recognized as printing under a microscope. While the print could be similar to a normal
printed page, it might be more useful to encode the information in some other form that will require decryption to read.
Magnetic and optical digital storage media is notoriously non-permanent due to cold flow and migration of localized storage
domains. This process eliminates that problem.
and Contactless Ring
You have probably heard proposals for 'smart guns' that
will only fire when owners wearing special rings are in possession. Here is a near field communications
(NFC) ring that permits only its wearer to
use a cellphone, tablet, or other NFC-enabled device linked to its code. Doing so eliminates the need to enter a password
for access. According to an
NFC World report, the ring contains an IC that can store personal contact information as well allowing the
wearer to voluntarily "share" certain details about him/herself (why would you do that?) simply
via proximity contact. Initially, the ring will only work with Geak's devices, but plans are in the works for more widespread
adoption.
Offer eBook on RF Design
AWR Corporation announces
a new eBook,
RF Electronics: Design and Simulation, which is available free of charge to students, graduates, professors
and industry professionals through AWR's new
Professors in Partnership™ web portal. Developed by adjunct associate professor C. J. (Keith) Kikkert of James Cook
University School of Engineering and Physical Sciences, Townsville, Queensland, Australia, the book describes the use of
AWR's Microwave Office® and
AXIEM® software to design RF electronic devices for
applications such as amplifiers, radar, mobile phones, Bluetooth, and WLAN.
Most regular RF Cafe visitors will probably
not be too interested in this article, but there are a lot of people who build and/or repair vintage radio gear and search
the Internet for helpful information. Having built a couple
crystal radio sets as a kid, I've always been amazed at how a few picowatts of RF energy can be received,
processed, and heard through an ear plug without the need for external power from a battery. Speaking of crystal radios,
I remember one time while working as an electrician in Annapolis, MD, (prior to entering electronics)
I had a telephone handset for use in communicating with other electricians in a building I was wiring, and it picked up
the local AM radio station. A pair of the old style handsets...
"It's stupidity. It's worse
than stupidity: it's a marketing hype campaign." - GNU founder
Richard Stallman
on embracing Cloud Computing for its ostensibly "free" data storage on uncontrolled servers rather than on your local machine.
10 GHz Frequency Synthesizer
Phase Matrix's newest addition to the
QuickSyn® line of microwave frequency
synthesizers is a 10 GHz synthesizer housed in a very compact package, only 4 x 4 x 0.8 inches. The new synthesizer,
model FSL-0010, employs the revolutionary
phase-refining QuickSyn® technology. The new Quicksyn® Lite synthesizer is less than half the size of the full featured
10 GHz and 20 GHz QuickSyn® synthesizers, yet it performs with wide coverage (0.65 to 10 GHz),
fine resolution (0.001 Hz resolution), fast frequency switching
(100 μs), and exhibits instrument-grade spectral purity.
The folks at Rev Response have a pretty big collection of white papers on a very
wide range of subjects that are free for downloading. Well, not quite free - they do require you to sign in, but no $$$
is involved. I make a few pennies on each download, so you're helping to support RF Cafe if you participate. Here are a
few of the newer ones that might interest you:
- 2012
Laptop Buying Guide
-
Rapid Color 3D Modeling
and Printing
-
Your Guide to Create
Professional Documents
on Word
-
Scientific Instrument and
Medical Device Makers
Exploiting 3D Interactive
Technology
-
Bring Your Own Device (BYOD) Policy Guidebook
for June 23, 2013
Take a break and work this
week's engineering-themed crossword puzzle.
All the words are pulled from a hand-built list of terms, names, and abbreviations that have only to do with science, mathematics,
and engineering. If you want a crossword with names of movie stars and obscure countries, try the local newspaper. If you
want to exercise your nerd knowledge, this is the one for you.
Restoration Project
After searching occasionally for many
years for another Crosley 03CB radio in a location close enough to drive for pick-up, I finally saw one on Craigslist in
Harrisburg, PA, about 300 miles from my home in Erie, PA. Melanie and I picked it up yesterday. It needs - and will receive
- a total restoration for both the cabinet and the electronics, but it appears to be in better condition that my first pre-restored
Crosley 03CB. This
radio is Chassis #95. If you look at the photo of the first radio , you will notice that the tuning dial has no cover over
it. I never knew there was supposed to be a glass bezel in front of the dial...
Sent to Just 10 Addresses
Think the illegal alien problem
is just made up? Here is the IRS's own 2012 fraud report
showing more than $86 million sent to just 10 addresses. See
Figure 5 on page 17.
In Atlanta alone, a single address for 23,994 'Unauthorized' (aka Illegal) Aliens received payments totaling $46M. This
crap is costing our economy jobs by requiring working citizens to pay the tab for this. It also feeds into the massive fraudulent
voting scheme for one party and suppression of voting by the other party. We now have a politico-economic
oligarchy, folks. Congratulations.
Here are a few more useful stories on the tech job market and job hunting. Enjoy.
- 5 Negotiation
Tips from
Steve Jobs
-
Google Says GPAs Are
Meaningless for Recruiting
-
9 Qualities of Truly
Confident People
- TWC Offering New
Teleworker Support for
Businesses
-
13 Must-Have Mobile Apps
for Business
- 4 Extreme Habits of Highly
Successful
Remote Teams
I will be travelling on Friday with limited e-mail access. Responses will probably
be delayed for a few hours. I apologize for any inconvenience.
Here is a fairly
simple quiz on
AC circuit analysis. If you are not already comfortable with adding series and parallel circuits containing
resistors, capacitors, and inductors, you will appreciate the simple formula presented that will keep the sweat level down
;-) OK, pick up you pencils... now.
Electronics hobbyists
are always anxious to hear the announcement of a new device that is forecast to revolutionize the tech world. In the late
1950s something as relatively tame as a
crystal photocell satisfied that urge. Today it takes something like a negative refractive index metamaterial
to invoke the same sense of awe and wonder. Those were simpler times, but then again even today's beginners in the world
of electronics circuit designing and building have to start somewhere, and these types of circuits are as good as any place.
for the TV Industry
I wasn't able to verify Dr. Baker's
(VP of GE) prediction in 1957 of what the state of the television industry would be by 1960.
He said 10 million sets would be sold in 1960 vs. 7.5 million in 1957. Some recent sources claim there were as many as 52
million TV sets total by 1960, so he might have been right. Transoceanic scattering techniques were thought to be the method
of choice for television broadcasts, but we know that ultimately relay satellites would win out. It wasn't until 1962 that
the Telstar bird carried the first TV signals, however. "Truly portable" transistorized TVs would be appearing...
Here is a little insight into early
speech
processing research by the Bell Telephone Laboratories. 1957 was the early era of real-time digital processing where
the need to cram more calls into less signal space (bandwidth) led to sampled systems - 1:6 in the case of this advertisement
from Bell that appeared in Radio & Television News. Engineers of the day would be amazed at how the state of
the art has advanced since then, both in mathematical techniques and in miniaturized hardware.
from IEEE's JobSite
IEEE sends out an e-mail every week or
so with links to stories on job hunting. Here are a few of the most recent.
-
20 Questions to Ask
Yourself Before You
Relocate for a Job
-
The 10 Best Cities for
STEM Jobs Right Now
-
Didn't Get the Job?
You'll Never Know Why
-
Messages Galore, But
No Time to Think
MW & RF 2013 Survey Awards
AWR has won
in two categories in the first annual Microwaves & RF magazine "Best of Microwaves & RF"
awards. The company won the Best Training and Education category and was first runner up in the Best Supplier Industry Blog
category. The winners were determined through a recent survey that went out to readers of Microwaves & RF magazine
inquiring about their favorite online tools for keeping up to date within the microwave/RF industry.
for Long-Time Support
RFtronics develops both turnkey and custom solutions for
the RF telecom equipment designers and manufacturers. Currently,
our product line includes high power couplers, splitters / combiners and filters between 1 MHz and 3 GHz. They
have more than 20 years experience in the RF/microwave design and manufacture, with the agility of a small company and the
production capabilities of a larger-sized, high-volume manufacture. RFtronics will usually deliver prototype quantities
(less than 50 pcs) directly and for larger orders the design will be transferred to our manufacturing
partner.
Consequences to Follow?
A recent
NY Times article reported on a court ruling in favor of a couple interns who claimed they were not fairly paid for their work. Author
Steve Greenhouse points out that while it could be a victory for the litigants, ultimately it could bode poorly for internship
programs. Legal precedence is widely referenced and applied by legal teams, and is notoriously difficult to overturn. This
particular internship involved work on a movie production set, but expect the decision to ripple through to even engineering
and science business programs. An estimated 1,000,000 internships are hosted each year in America, a significant portion
of which could be eliminated out of an abundance of caution and fear of being sued. Is this another "careful what you wish
for, you might just get it" scenario?
Microstrip Lines and Slotlines, by Ramesh Garg, Inder Bahl, and Maurizio
Bozzi. Planar transmission line technology has
progressed considerably due to developments in UWB communications, imaging, and RFID applications. In addition, the simultaneous
demands for compactness of wireless electronic devices while meeting improved performance requirements, necessitates increased
use of computer-aided design, simulation, and analysis by microwave engineers. This book is written to help engineers successfully
meet these challenges. This book was used as the basis for
RF Cafe Quiz #50.
You might have read about the recent U.S. Patent and Trademark
Office (USPTO) law that changes policy from a 'first to invent' to a 'first to file' system. It was meant to reduce the amount of work required by patent
examiners and to reduce litigation by eliminating the heretofore potentially subjective nature of determining who was the
'real' inventor of an idea. Previously, if a person could prove via formal dated notes, witnesses, etc., that he was the
first to manifest an idea in the form of a working model, there was a good chance that an existing patent could be reassigned.
Now, it is almost purely a matter of who gets the earliest timestamp for having been received at the USPTO. This short piece
in Inc magazine discusses the new
patent filing issue.
in Appreciation of Support
Since 1994, leading
wireless electronics companies have relied on 3Gmetalworx to deliver cutting edge solutions for advanced
RF/EMI PCB-level shielding requirements.
From prototyping and design services to JIT manufacturing supply, our clients depend on us to provide a seamless service
pathway supporting entire product lifecycle. All shields can incorporate these features, as
well as your custom needs:▪Engagement tabs, trace/component relief, tuning/access openings, thermal relief.
Larry Wolfgang has a good article in the May 2013 edition of QST titled "Contributing to Science." In it he recalls a few examples of how amateurs have helped professional scientists and engineers advance the state of the art in wireless communications.
For instance Pat Dyer, WA5IYX, conducted an 11-year study of mid-latitude
sporadic E, and Dave Olean, K1WHS, built
a magnetometer to predict aurora to aid
in 144 MHz DX. Hams also discovered
trans-equatorial propagation. Mr. Wolfgang suggests that pursuing a meaningful scientific investigation
of your own or maybe by your club would be a worthwhile and satisfying endeavor. BTW, while writing this I happened upon
a resource for current QST articles on
EBSCO Host website, which is significant because non-members of ARRL cannot access their online editions.
Started June 18, 2013
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