American Microwave Corporation
(AMC) uses a state-of-the-art clean room to manufacture all of it's products, as well as a fully automated machine shop.
AMC is a leader in the design and manufacturing of DC to
40 GHz solid state control components for commercial and military grades. Products include PIN diode switches,
PIN diode attenuators, detector log video amps (DLVAs), tunnel diode amps, wideband detectors, power dividers & couplers,
and bias "Ts."
to the Transistor Museum website, "The Philco
Surface Barrier Transistor (SBT) was the 'hottest' transistor around until the late 1950s.
This device performed very well at high frequencies and was used extensively in radio and computer circuits. Hobbyists were
delighted to find such an inexpensive high frequency device... [Edwin] Bohr authored many well-remembered transistor construction
projects in the 1950s/60s." Many of Bohr's construction articles featuring SBTs were published in Radio Electronics
magazine, and this was one of them from 1957. The manufacturing process is described where jet streams of an electrolyte
were shot at both sides of the germanium crystal to etch it as required - Neanderthal in nature compared to today's...
Please visit RFIC Solutions in appreciation of their helping to deliver RF Cafe. RFIC Solutions offers
RFIC/MMIC, Analog, Mixed-Signal, Digital IC and module, RF system
design services, RF prototype board development and RF testing up to 60 GHz. The RFIC team of 40+ staff, mostly engineers
has delivered more than 30 million RF ICs for Wireless LAN, Cordless & Cellular Phone & wireless apps. The RFIC
team has extensive RF industry knowledge with many years of background in designing and deploying Wireless Systems.
Hittite Microwave Corporation, the world class
supplier of complete MMIC based solutions for communication & military markets, has announced a new GaAs pHEMT MMIC
power amplifier and an analog variable gain amplifier that are ideal for Ka-band VSAT, high capacity microwave radio and
radar systems in the 27.5 to 31 GHz frequency range. The HMC7441 is a three-stage
GaAs pHEMT Power Amplifier which operates
between 27.5 and 31 GHz. The amplifier provides 23 dB of gain and +34 dBm of saturated
output power at 25% PAE from a 6 V supply and output IP3 of +38 dBm.
Pasternack Enterprises is searching for
a talented Copywriter with RF/Microwave knowledge and industry experience to develop and maintain an extensive range of
information for the Company. Writing projects will be varied and challenging including the development of content for the
Company’s website landing pages, product descriptions, marketing-related emails, press releases and news pages as well as
copy for technical reference materials such as white papers and glossaries. Our successful candidate will become an integral
part of our professional team of RF engineers and marketers. This position requires strong technical and product knowledge
Headquarters Allied Powers Europe" - is that a cool sounding title or what? As an aficionado of World War II movies
and paraphernalia, such terms bring to mind a consortium of countries and countrymen desperately working and sacrificing
together to fend off ruthless aggressors to preserve their cherished ways of life. The North Atlantic Treaty Organization
(NATO) was formed in 1949, just a few years after the end of WWII in order to formalize an
agreement to basically cover each other's butts. To attack any one member was to attack all members, thereby reducing the
chance of onslaught. Part of the strategy included developing and implementing what would be the most
radio communications in existence at the time. Because of the great distances that needed to be covered, both over-the-horizon
tropospheric forward scatter and line-of-sight radio relay links were essential...
Hittite Microwave Corporation, the world class supplier
of complete MMIC based solutions for communication & military markets, announced a new Gallium Nitride
(GaN) MMIC power amplifier product which offers significant performance, size and durability
advantages for communications, test instrumentation and radar systems operating in the 6 to 18 GHz frequency range. The
HMC7149 is a 10 W GaN MMIC Power
Amplifier which operates between 6 and 18 GHz. The amplifier typically provides 20 dB of small signal gain, +40
dBm of saturated output power.
Anatech Electronics has published its November
2013 newsletter. As always, it includes both company news and some tidbits about relevant industry events, regulations,
and standards. This month Sam Benzacar offers his takes on the subjects of analog
voltage-tuned filters, legacy products, reverse microwaves,
high-tech feature phones.
Applied Computational Sciences
has been supporting RF Cafe since 2008. ACS designs, develops and sells Electronic Design Automation (EDA) software tools for RF and microwave
engineering applications. ACS's main product is the LINC2 linear circuit simulator and RF Tools products. Visual System Architect
provides a block diagram level system simulator, and AMP Pro simplifies amplifier design. Bundles on multiple
packages are available. All products run under Windows.
Calculator watches stopped being a sign of nerd chic a long time
ago. If your wrist has been crying out for a device that declares to the world, "I am a hopeless technophile... and proud
of it!," then this wearable o-scope-in-a-watch might
be just the fashion statement revolution you have been waiting for. For a $99 pledge, you can receive one of the first prototype
as part of Gabriel Anzziani's Kickstarter project (hurry - only one left as of this writing).
Per the website, "The Oscilloscope Watch has all the features of a modern watch (time, calendar,
alarm, etc...) combined with all the features of the popular
(Oscilloscope, Waveform Generator, Logic Analyzer, Protocol Sniffer, Frequency Counter). The
$60k goal has been met and exceeded. Its open source code...
TEC has been
helping deliver RF Cafe since 2009. "Test Equipment Connection Corporation is your single source
test & measurement solution. We offer over 300
test equipment manufacturers including Agilent, Tektronix, Anritsu, Rohde & Schwarz, Advantest and Fluke, plus thousands
of new, used, 2nd hand, and refurbished test equipment products. We buy and sell bench top, general-purpose test and measurement
equipment. $2,000,000 is budgeted each month for the purchase of surplus equipment."
In 1957, only a top-of-the-line automobile
deserved a radio containing 13 discrete transistors and four crystal diodes. Only buyers of such a top-of-the-line vehicle
could afford the luxury offered by an electronic marvel that promised instant-on music with superior sensitivity and selectivity
over the vacuum tube models that lesser humans endured.
Model 7268085 was up to the task as it populated the dashboards of Cadillac's Eldorado Brougham. Modern day radios use
a single IC (e.g., NXP SAA7706H) for performing all reception, filtering, amplification, and
tuning functions, with superior performance compared to the Delco without all the interstage tuning transformers, Rs, Ls,
and Cs. Most of the rest of the circuitry in your car radio is for microprocessor control of the user interface and that
AWR Corporation, the innovation leader in high-frequency
EDA Software, will be exhibiting in Booth A505 at the 2013 Microwave Workshops and Exhibition from November 27 to 29 in
Yokohama, Japan. Software demonstrations of the AWR Design Environment™ will inform and educate attendees about key features
and applications. AWR will participate in the MWE Workshop #08 on Verification of Accuracy for Electromagnetic Simulators for Canonical Problems on
November 28th. AWR will present "Introduction to Analyst, AWR's 3D FEM EM Simulator," on November 29th.
Linx has been helping to
deliver RF Cafe since 2008. 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. We also offer design services including board layout assistance, programming, certification advice and packaging
I just added Twitter and LinkedIn buttons
to RF Cafe in the horizontal bar underneath the top menu area. By clicking on them, you activate your account and can automatically
send the page URL to your followers. If possible, I would appreciate your trying one or both buttons to make sure they are
working properly. For some reason they do not seem to be incrementing even though I have sent out multiple Tweets and LinkedIn
messages when new items are posted on the homepage (like this one). Each web page is supposed
to have its own unique, independent set of counters, so maybe also try at least one page other than the homepage. Thanks
for your help!
Here is another of the
Electronic Sticklers challenges from Popular Electronics (see May
Sticklers). These are fairly basic circuit analysis problems that often can be solved by inspection, but sometimes
a pencil and paper are necessary. Re-drawing the circuit in a different configuration to make the connections more obvious
often helps when solving total resistance, capacitance, inductance, etc., as in question #1. In this case, though, you need
to be able to recognize a common configuration to be able to simplify the circuit; otherwise, you'll be writing and solving
mesh equations. #2 has a simple answer and a more elaborate possibility. #3 and #4 are simple inspection problems.
Chances are if you are reading this, you don't really need
Electronics for Dummies. However, Christmas is coming and you might considering picking up a copy
to gift to a tech-challenged friend or boss, or maybe to a relative, that always gets the tell-tale deer-in-the-headlights
stare whenever you start explaining what you do for a living or hobby. The "for Dummies" series is well-known for helping
to make complex concepts understandable for laymen.
BRL Test, Inc. is a leading dealer of new and reconditioned
test and measurement equipment. We buy, sell, rent, lease, repair
and calibrate all types of general purpose test and measurement equipment. BRL Test is your one stop source for over fifty
different manufacturers and thousands of different models – specializing in Agilent, HP, Tektronix, Fluke, Anritsu, and
Rohde & Schwarz. All equipment is calibrated per order at an ISO9001:2000 Registered and A2LA Accredited facility
(Z-540 & 17025), so you have the added reassurance you are receiving high quality equipment
ready to work right out of the box.
Before there were CFL light bulbs with
complicated electronic circuits for generating the requisite high voltages without a transformer, there were just the familiar
straight fluorescent bulbs that use a simple ballast arrangement and a built-in switch in the bulb base. As with compact
fluorescent (CFL) lights, very few people understood how they worked. Most knew that the 8-foot-long
T-12 bulbs made a really cool implosion sound when they broke - usually intentionally (by people
like me) since the glass tubes were amazingly tough. I remember many moons ago, between high school and the time
I enlisted in the USAF, while I was an apprentice electrician working on a renovation job at a public school, a co-gofer
and I spent weeks wiring fluorescent fixtures all throughout the building. We worked atop a tall scaffolding that was on
wheels, pulling ourselves around the room by grabbing the suspended ceiling grid. When the foreman wasn't around, we relieved
our utter boredom...
PMI Model No. TD-30T-SHS-218-2G4G-PECL is
a high speed, LVPECL logic output threshold detector designed to operate from 2.0 to 18.0 GHz, but optimized for 2.0 to 4.0 GHz.
This detector has a propagation delay of 15 ns max and has a LVPECL output.±15 Vdc supply, SMA connectors.
lot of time can be wasted when performing Internet searches. With tens of thousands of pages likely containing at least
some reference to whatever it is you are looking for, drilling down into data to retrieve relevant web pages can be difficult
or impossible. Fortunately, if you know about a few handy special search
formats, you can increase your likelihood of success greatly. Here are a few I use quite often. Search terms are not
case sensitive, but note that the OR operator is. You may combine any or all of these special operators as long as the syntax
rules are followed. If you don't want to remember all the special search formats, simply type in "advanced search" to get
a search page with all these options implemented. BTW, one of the best tricks I've discovered...
The eleventh hour of the eleventh day of the eleventh month - November 11th, at 11:00
am - that is when the armistice (cease fire) began in 1918, unofficially ending World War I.
This Veteran's Day tribute is by Canadian citizen Terry Kelly. It was written after an experience he had on Veterans Day
in 1999. Terry went blind at an early age, but has excelled as an athlete and a musician. "A Pittance of Time" is done in the
finest Celtic tradition.
"Right now, there are about a thousand satellites operating in space. Of those, just
two were designed to be serviced in orbit: the Hubble Space Telescope and the International Space Station." -
Benjamin Reed, PM of NASA's
Satellite Servicing Capabilities Office, regarding work in progress to built automated robotic satellite service platforms
for repair and refueling satellites not originally designed to be serviced.
U.S. Coast Guard Office of Contract
Operations intends to award a non-competitive sole source purchase order to Rohde & Schwarz, for
receivers (with options) and
decoding software (with options). The statutory authority permitting Other than Full and Open
Competition is 10 U.S.C. 2304(c)(1) as implemented by FAR 6.302-1, Only One Responsible Source and No Other Supplies or
Services Will Satisfy Agency Requirements. Together, the products can be used for capture, analysis, classification, demodulation
and decoding of digital and analog IF signals.
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.
Apex Wireless handles the complete design and production cycle, or any part of it - electrical, mechanical, packaging, sourcing,
certification, and management.
The N2YO website provides real-time mappings of many satellites,
including the ESA's Gravity Field and Steady-State Ocean
Circulation Explorer (GOCE) platform, which, as I write this, is deciding whose front
lawn to fall onto. The only thing about the satellite's destiny known for certain is that sometime between Sunday afternoon
and Monday morning, it will come plunging to Earth in a fiery re-entry, hopefully burning up into small enough chunks to
not cause any damage on the ground. If you or anyone you know is hit by a piece of the debris, take comfort in knowing that
you can probably sue your country's government for damages. "Basically, governments are responsible for their own spacecraft,"
RF Engineering crossword puzzle
is a bit larger than normal, so you'll need to budget a little more time in the corporate reading room to complete it. As
usual, only words related to engineering, science, mathematics, physics, etc., are used. If you want to de-throne those
folks in management and sale of a know-it-all attitude for being able to complete the 'other' crosswords that use movie
star and fashion designer names, leave a copy of this puzzle in a strategic location in the men's and women's resting areas.
Simpson Electric is a name most
RF Cafe visitors are probably familiar with as being the maker of high quality analog multimeters, with the Simpson
260 line being the most famous (it is still manufactured today). Not as many people, however,
know that Simpson also used to make
This article from Popular Electronics was written by a Simpson Electric engineer whose job was, in part, to respond to questions
asked by users. It covers basic operations like how to calibrate the display, adjust
the horizontal time base
and vertical amplitude scales, and how to synchronize the display with the input signal. Some explanation of how to interpret
periodic and pulse type waveforms is provided as well as tips on how to avoid overloading and possibly...
the innovation leader in high-frequency EDA Software, is co-hosting with CST and National Instruments a complimentary series
on high-frequency design, simulation, and
test workshops in Brazil and Argentina this month. The workshop brings to South American designers hands-on insight
into the world of simulation for RF and microwave circuits and systems as well as 3D electromagnetic analysis using AWR
and CST software. Attendees will also be introduced to the National Instruments’ PXI platform for RF measurements.
has released new designs for a 800-2500 MHz 10 dB directional coupler, a 728 to 734 MHz cavity bandpass filter,
and a 1710 to 1785 MHz/1805 to 1880 MHz cavity duplexer, and a 2412 MHz cavity bandpass filter for Wi-Fi
Hotspots. All can be ordered directly through their AMCrf web store.
About once a month I scan the Internet
for useful articles on career news and tips. Here are a few new ones.
Branding Mistakes You
Know You Were
Demand for Engineering
Jobs Grows in 2013
"Onshoring" Firms for Visa
- 5 Job
Search Tips for
Corporate Recruiters Insist
There Really Is a STEM
Tips to Use LinkedIn
Effectively for Job Hunting
10 Job Search Tips for
How's the Engineering Job
Market? Depends on Whom
Dr. Fornetti personally provided
the copy of Conquer Radio Frequency
that was used to create this quiz, and has authorized me to include it in the monthly Book Drawing. His video to the right
provides a great introduction to the book and to the very well-done set of instructional videos featured on the included
DVD. AWR's Microwave Office software is used throughout the tutorials. A live, narrated, step-by-step process is fully captured
on-screen so you see how to create the circuit schematic, set up the component parameters for simulation and optimization,
specify graph and table types and how to designation input files, configure input stimulus, and how to interpret the results
of the simulation. It is an excellent way to familiarize yourself with where to find everything in MWO's menu and toolbar
(ECOs) were a real breakthrough in achieving frequency stability in harsh environments that
included mechanical vibration, temperature excursions, power supply variations, and load changes. Use of vacuum tubes made
the task even more challenging. Such oscillators were necessarily very expensive compared to less sophisticated designs.
Henry E. Rice Jr., W9YZH, introduced his "Rice Variarm" model (aka the Millen Model 90700)
at a breakthrough price of just $29.50, which in 2013 money equates to $469.89 per the U.S. BLS
That is a lot of moola for amateur radio operators even today. The arm sticking out of the case is for adjusting the frequency.
new car today generates 15 gigabytes (109) of information
per hour - a number that's climbing as sensors proliferate. A little back-of-the-napkin figuring suggests that 250 million
such vehicles would produce around 2000 exabytes (0.002 yottabyte) per year, most of which
never leave the car. But that's changing." So said Frank Markus in the September 2013 edition of Motor Trend magazine. His
article titled, "You Car's Contribution to the 'Big Data' Cloud," does
a nice job in explaining the immense amount of digital data generated by a new car's computer system. The numbers include
everything from tire pressure sensors sending metrics via Bluetooth to fuel injection and entertainment systems. Smart headlights,
auto-dimming rear view mirrors, self-parking algorithms and gesture sensing make it easy to believe the numbers. Coming
soon to a vehicle near you is a personal health vital signs...
The late 1950s and early 1960s were the dawn of the Space
Age, beginning unofficially with the launch of Sputnik. Popular Electronics put a lot of effort into educating
the public on advances in
electronics, including not just the spaceborne platforms, but also ground tracking and communicating equipment. Much
hardware was launched into orbit in the early years without giving much thought to the hazards or space debris. Failures
in the form of explosions scattered chunks widely, but fortunately most were low enough to have their orbits degrade and
re-enter the atmosphere. One interesting tidbit reported in this article that I didn't know was that the TV camera lens
on the TIROS 2 weather satellite was defocused during launch (due to positional shifting from
vibration and G forces, I suppose) and crippled the image quality severely.
Skyworks Solutions today announced
that HTC and Samsung are ramping
SkyOne™, a highly customizable, fully optimized front-end solution, in several of their recent smartphone
launches. The SkyOne™ platform, which integrates all RF and analog content between the transceiver and antenna, reduces
complexity, size and time-to-market for customers with demanding architectures for advanced mobile applications. Utilizing
Skyworks’ full technology portfolio and advanced multichip module capabilities including proprietary shielding and packaging,
SkyOne™ is the world’s first semiconductor device to condense multiband power amplifiers and high throw switches along with
all associated filtering, duplexing and control functionality into a single, ultra-compact package.
RF test engineer Joe Cahak, owner of Sunshine
Design Engineering Services, recently had a photovoltaic panel system installed on his southern California home. After much research and running through
return on investment (RoI) calculations, he made the decision to invest in a state-of-the-art
system by Semper Solaris in San Diego. If you have not looked into modern PV technology, you might be surprised - as was
I - to learn that rather than all the panels feeding their DC outputs into a common AC inverter that handles phasing issues
with the street service, instead each panel has its own inverter and phase matching circuit so everything simply feeds into
a 2-pole circuit breaker. Doing so eliminates single point failures and allows graceful degradation if necessary rather
than taking down the entire system. Joe has provided a very nicely done write-up on the system and its installation.
A project is underway by Defense
Advanced Research Projects Agency (DARPA) to provide a real-time map (RadioMap) of where over-the-air broadcasts are occurring.
The idea is to create a Google Maps type graphical interface where a network of 'sensors' that includes special purpose
and otherwise deployed devices will report to a central data collection point to provide situational awareness for where
and when (and by whom in some cases) specific frequencies are being occupied. Proposals are
being accepted for companies wanting to contribute to the program, so this might be a great opportunity for makers of software
defined radios (SDR) to build functionality into systems for accommodating such detection
announces its launch of the high performance, low cost
RM Global Positioning
System receiver modules. Using the built-in MediaTek MT3337 chipset, The RM module can simultaneously acquire on 66
channels and track on up to 22 channels, providing standard NMEA data messages through a UART interface. A simple serial
command set can be used to configure optional features. The RM receiver module is a cost-effective GPS solution. It offers
no-frills, basic operation in a compact 15 mm by 13 mm package.
No, this is not a phone or GPS device. It is a handheld digital oscilloscope
(DSO) with a 1 MHz bandwidth, 2.8" color LCD, max sample rate of 1 Msps with 12 bits of resolution, and a USB
interface (not needed for operation). For a mere $70 you get the
DSO201 and a test probe. For $162 you can get a 4-channel version (DSO203) with a 72 MHz analog bandwidth. Here is a
YouTube video demonstrating both o-scopes' capabilities.
Electronic mail did not start out as we know it today,
whereby anyone with access to an Internet-connected device can compose and send a typed message to a similarly equipped
receiver. The first electronic mail message was sent (and received) on November 1, 1960, between
post offices in Washington, D.C., and Chicago, Illinois. This article from Popular Electronics takes you on a step-by-step
tour of how the
Speed Mail system worked, including its dedicated shortwave radio links between participating cities.
Great care was taken in an attempt to assure message confidentiality by having the letter opened and scanned automatically
inside a sealed machine on the transmit end and then printed and placed in a sealed envelope on the receive end. Knowing
what we know now about government snooping, you have to wonder if a copy of each message was routed...
RF Cafe visitor sent me a link to an article showing how most of what we buy at a grocery store is under the auspices of
a mere 16 conglomerates. It
is amazing - and scary - just how much corporate consolidation has occurred in the last couple decades. News reports mention
all the bankruptcies, buyouts, and mergers throughout each year, but unless you are paying attention to such matters, it
is easy to not notice what is happening. Did you know, for instance, that Pepsico owns and therefore controls among other
companies Kentucky Fried Chicken and Pizza Hut, Aunt Jemima and Cap'n Crunch, Doritos and Ruffles, Dole and even - believe
it or not - Pepsi. Proctor & Gamble owns Mr. Clean and Bounty, Tide and Ivory, Cover Girl and Olay, Charmin and Old
Spice. Kraft controls Ritz and Planters, Jell-O and Cool Whip, Dr. Pepper and Sunkist, Certs and Chiclets, Oscar Meyer and
Honey Maid. The list goes on and on...
This opportunity is open to either new EE/EET
electronics graduates, experienced RF / wireless technicians with 1 year min experience seeking a full or part time job,
or current EE/EET students seeking a paid internship or a part time / co-op job. The RF test and general engineering technician
will work primarily in product test where RF amplifiers are tested and tuned prior to shipment. No experience is necessary
and all training will be provided, however, it is necessary that the applicant be proficient in basic electrical concepts
and circuits. In addition to RF test the job involves assisting design engineering with parts purchases, light electronic
assembly (prototyping) and engineering documentation and database update tasks.
Since our inception in 1996 in Korea, ISOTEC has been a leading
manufacturer of RF and Microwave Connectors such as SMA, MCX,
SSMB, etc., and RF Components such as Attenuators, Terminations, etc., for wireless service providers, etc. We provide recognized
and trusted products and service to our customers in more than 30 countries worldwide. ISOTEC offers also an extensive product
mix with RF Filters and Multiplexers etc. ISOTEC is ISO9000 and ISO14000 certified factory.
of us have heard tell of people sticking a penny in a screw-in
glass fuse holder slot in an old fuse panel when either a replacement fuse is not available or when the correct amperage
fuse keeps blowing. Neither reason is acceptable under any conditions, but the latter reason to avoid replacing a fuse that
keeps blowing is especially stupid. Fuses blow and circuit breakers trip usually because something is wrong and needs attention.
This installation of EDN's "Tales from the Cube" feature shows how truly stupid people can thwart virtually any
measure of safety when it comes to electricity.
"Everyone is born a genius, but the process of living de-geniuses them." "I'm not
a genius. I'm just a tremendous bundle of experience."
- R. Buckminster
This appeared in the
November 2013 edition of The Good Life, a local
newspaper of northern Michigan. Each monthly edition is chock full of not just news and advertisements, but also scores
of jokes and riddles. "Okay, I'm five-foot-three and pleasingly plump. Recently, after I had a minor accident, my mother
accompanied me to the emergency room. The ER nurse asked for my height and weight, and I responded in a serious tone, 'Five-foot-eight,
125 pounds.' While the nurse pondered this information, my mother...
Bonus riddle: How do the guys in a close-knit group
of technology refer to each other?
Every Sunday I create a
crossword puzzle using a
word list that I personally created and added to during over a decade of making puzzles. All of the words are related to
engineering, science, mathematics, chemistry, astronomy, etc. There are no numbnut clues about movie stars or clothing designers.
You've heard of 'Litz' wire, right? It's
the twisted bundle of multiple enamel or otherwise coated wire used for making couplers, antennas, and at frequencies
up to about a couple MHz. Congratulations, but did you know the full name for it is 'Litzendraht?' Neither
did I until after reading this article. 'Litzendraht' is the German word meaning 'braided wire' or 'woven wire.' Litz by
itself means braided or woven. So, technically if you call it Litzendraht wire, you are being redundant since it is the
same as saying woven wire wire. That might save you some embarrassment one day if you happen to be working around a German
techie. Litzendraht is used in order to exploit the skin effect at high frequencies where the majority of the current is
conducted on the wire's surface. Using multiple insulated wires enables greater current carrying capability than an equivalent
diameter single solid wire. While dispensing trivia, note also the use of the term 'B. & S.' gauge for wire...