See Page 1 |
2 |
3 |
4 | of the April 2023 homepage archives. Friday the 14th
 In 1969 when this news item appeared in
Radio-Electronics magazine, any temperature of
superconductivity above absolute zero (0 K) was considered a major accomplishment.
Dreamers dreamed of room temperature (RT) superconductivity from the time it was
first predicted theoretically in 1911, but not even the people telling us we would
be driving anti-gravity cars by the turn of the century thought we'd get there anytime
soon - and we didn't. High temperature superconductivity is defined today as occurring
at 77 K or above. Some exotic compounds have exhibited superconductivity under
extreme pressures at temperatures as high as about 250 K (-23 °C, 10 °F).
Unfortunately, we are still nowhere near the point that practical industrial or
commercial applications are possible...
 A few days ago Bob Davis sent me a link
to a YouTube video documentary, "Transistorized," of the development of the transistor.
It was originally produced in 1989. Narrator Mr. Ira Flatow begins by saying
that the story behind the transistor, arguably one of the most important inventions
of the 20th century, was one of "clashing egos
and top secret research." Anyone familiar with the collaborative effort of Drs.
John Bardeen, William Shockley and Walter Brattain, at Bell Telephone Laboratories
(aka Bell Labs) knows of the strain between them at times. I will not attempt to
embellish the huge amount of information presented; you will get all you want to
know from the film. As you might expect, in addition to the "Transistorized" video
there are other videos telling the story of the transistor's history. A couple really
good ones are also embedded below. One covers Japan's successful climb to the top
of the electronics product food chain based on their early adoptation of transistor...
 You probably know that it was Scottish engineer
Robert Watson−Watt who pioneered the first successful radar systems. During World
War II, America benefitted from improved magnetron designs from Great Britain
to help build both ground-based air defense radars and, later in the war, airborne
radars. This article from a 1972 issue of Popular Electronics magazine
reports on state-of-the-art (at the time)
marine radars from England for pleasure boats. In 1972, a radar with a 16-mile
range was priced at around $2,000, which is equivalent to a little more than $14,000
in 2023 dollars. By comparison, you can now buy a compact microprocessor-controlled
color marine radar (Si-Tex) with a 27-mile range for a mere $1,900 from Amazon...
 "A
mixed-signal printed-circuit-board (PCB) design requires basic understanding
of analog and digital circuitry to minimize, if not prevent, signal interference.
Modern systems consist of components that are operational with both digital and
analog domains, and they must be carefully designed to ensure signal integrity all
throughout the system. PCB layout - an important part of the mixed-signal development
process - can be intimidating and component placement is just the beginning. Other
factors must be considered, too, including board layers and how to properly manage
them to minimize interference caused by parasitic capacitors that can be unintentionally
created between the PCB's interplane layers. Grounding also is an integral process
in the PCB layout design of a mixed-signal system. While grounding is a frequently
debated topic..."
 Here is another addition to the growing
collection of radio service data sheets for vintage radio sets. Most people will
have no need for them, but for the few who have one of these old sets and want to
restore or service it, this information can mean the difference between owning a
non-working conversation piece or a functional piece of America's history. This
Radio Service Data Sheet for for the
Stromberg-Carlson No. 29, 9-tube superheterodyne receiver appeared in a 1932
issue of Hugo Gernsback's Radio-Craft magazine. Note that its name derives from
"number of its design feature." All 29 are delineated, including Optosynchronic
(Visual) Tuning, and a Mono-vision Dial and Tuning Meter. The photo thumbnails are
just two of many for a very fine example of a Stromberg-Carlson No. 29a claiming
to be in its original finish, with no rework having been performed on the cabinet
or electronics. A full list of all radio service data sheets is at the bottom of
the page...
 The RFCafe.com website exists partly on the support
of its visitors by way of a small percentage earned with your
Amazon.com purchases, which typically works out to less than
$20 per month. That does not even cover the domain registration and secure server
fees for RFCafe.com. If you plan to buy items via
Amazon.com, please click on this link to begin your shopping
session from here so that I get credit for it. Doing so does not cost you anything
extra. Thank you for your support.
 LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
Thursday the 13th
 In the joke-telling realm, probably the
most oft-adopted axiom is to "know your audience." Another is that if you need to
explain a joke, you have failed in your attempt at humor. In this case, a little
insight into the mindset of the era (from a 1960 Radio-Electronics magazine)
might help you appreciate the
electronics-related comics messages since we don't typically think in the same
terms today. The page 42 comic leverages the huge obsession many technophiles
had with stereo equipment. Believe it or not, really powerful public address (PA)
systems were a big deal, too, as the page 95 comic intimates. Given that almost
no consumer products use voltage supplies of high enough voltage and/or frequency
to impart an RF burn to a serviceman, the page 122 comic probably also portrays
a foreign concept. Now that you are privy to the motives behind the comics, feel
free to laugh accordingly...
 This is part 2 of "Phase-Noise
Modeling, Simulation, and Propagation in Phase-Locked Loops," appearing in
Microwaves & RF magazine. "As noted in Part 1, phase-locked
loops (PLLs) are ubiquitous in today's high-tech world. Almost all commercial and
military products employ them in their operation and phase (or PM) noise is a major
concern. Frequency (or FM) noise is closely related (instantaneous frequency is
the time derivative of phase) and is generally considered under the umbrella of
phase noise (perhaps both might be considered 'angle noise'). Amplitude (or AM)
noise is another consideration. Part 1 discussed brief theory and typical measurements
of phase noise along with the analysis (modeling, simulation, and propagation) thereof,
and showed the method used by most computer-aided-design (CAD) applications. Part
2 digs into the design of a hypothetical PLL frequency synthesizer to be used for
analysis. To demonstrate the concepts and methods reviewed in Part 1, we design
a hypothetical single loop 8- to 12-GHz/50-MHz step (channel spacing) integer synthesizer
with a 25-MHz reference (50 MHz being the smallest achievable step..."
 Achieving clean oscillations above about
300 MHz (1 meter wavelength) from standard glass and metal vacuum tubes
is difficult due to interelectrode capacitances and self-inductance of internal
wires and grid plates. Generating high power for applications like radar and long
distance communications was made possible with the invention of klystron, magnetron,
and ring oscillator tubes during World War II years. The UHF radio band spans
from 300 MHz to 3 GHz, and it is the upper end of the band where the wavelength
is short enough (3.93 inches | 10.0 cm for 3 GHz) to provide adequate spatial
resolution for radar. The
ring oscillator, unlike a magnetron with a solid chunk of metal with machined
cavities and coupling windows, uses separate high power tubes with tuned coaxial
lines between sections to isolate mutual inductance and capacitance loading effects
that would otherwise limit the upper frequency of operation...
 Anritsu Company expands its
Field Master™ MS2080A, a multi-functional spectrum analyzer that combines nine
instruments into a single solution, to operate up to 6 GHz. With extended frequency
coverage, the MS2080A addresses growing congestion in the 6 GHz spectrum caused
by rapid growth in satellite services; cellular, commercial and LMR networks; radio
location services; and industrial scientific and medical networks. The compact and
portable spectrum analyzer provides insights into interference and intermodulation
that degrade network performance through its best-in-class performance and features,
bringing distinct benefits to base station installation and maintenance (I&M)
applications. At 6 GHz, the MS2080A features fast sweep speed of 45 GHz/s
for greater insight over wider spans. It also has advanced user features, such as
AM/FM audio demodulation, and best-in-class RF performance, including ±1 dB
amplitude accuracy. Additionally, it supports a cable and antenna analyzer...
 There are still many old-timers and beginning
nostalgic collectors out there who nurse heirloom and otherwise procured vacuum
tube radios - like this
Hoffman Model A500 Radio / Phonograph console - back to health (operating
condition) and/or keep them in good health. While it is possible to purchase schematics,
parts lists, and service instructions from many different models, there are still
some that have escaped the scanners of those publishers. I could not find any photos
of a Hoffman A500, I did find this page from Sams Photofacts. For those kindred
spirits in search of such reference materials, I happily scan, clean up as necessary,
and post this collection (see complete list at bottom of page). I have dozens more
that will eventually be added over time, so check back later or send me an e-mail
if I have an issue of Radio News, Radio-Craft, etc. known to contain
the information you need...
 With more than 1000
custom-built symbols, this has got to be the most comprehensive set of
Visio Symbols available for RF, analog, and digital system and schematic
drawings! Every object has been built to fit proportionally on the provided
A-, B- and C-size drawing page templates (or can use your own). Symbols are provided
for equipment racks and test equipment, system block diagrams, conceptual drawings,
and schematics. Unlike previous versions, these are NOT Stencils, but instead are
all contained on tabbed pages within a single Visio document. That puts everything
in front of you in its full glory. Just copy and paste what you need on your drawing.
The file format is XML so everything plays nicely with Visio 2013 and later...
 Please take a few moments to visit the
everythingRF website to see how they can assist
you with your project. everythingRF is a product discovery platform for RF and microwave
products and services. They currently have 267,269 products from more than 1397
companies across 314 categories in their database and enable engineers to search
for them using their customized parametric search tool. Amplifiers, test equipment,
power couplers and dividers, coaxial connectors, waveguide, antennas, filters, mixers,
power supplies, and everything else. Please visit everythingRF today to see how
they can help you.
Wednesday the 12th
 When Arthur C. Clarke talks, people
listen (to paraphrase the old E.F. Hutton commercial). Mr. Clarke
wrote many books and papers about space technology and was a popular commentator
on space-related issues. He also made several predictions about the future of technology
that proved to be remarkably accurate, such as the use of geostationary satellites
for telecommunications. Clarke famously published his "Extra-Terrestrial Relays:
Can Rocket Stations Give World-Wide Radio Coverage?" in a 1945 issue of Wireless
World magazine. Nearly a decade later he penned this "The
Resonant Sky" article for the August 1963 edition of Radio−Electronics
magazine. The former essay predated the 1957-1958 International Geophysical Year
(IGY) atmospheric studies which laid the groundwork for space exploitation, while
the latter followed on the successful orbiting of a few satellites. Basically, everything
Clarke presents here has come to fruition, albeit a bit later than he thought it
might take...
 "Delivering expertise - application oriented
presentations - based on day to day testing challenges It is common for electronics
engineers to face challenges when trying to achieve their testing goals. During
this two-day "Oscilloscope
Days" event, experts from Rohde & Schwarz and our partners will deliver
the latest updates of fundamentals and test features of the neXt-generation Oscilloscope,
with online theoretical and practical sessions on the following topics: Oscilloscopes
and Probing Fundamentals Power Electronics Power and Signal Integrity EMC This FREE
virtual event will be streamed in English, French, German, Spanish and Brazilian
Portuguese..."
 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. Because the list is so extensive, no attempt has been
made to clean it up...
 Tech and outsourcing companies continue
to
exploit the H-1B visa program at a time of mass layoffs. The top 30 H-1B employers
hired 34,000 new H-1B workers in 2022 and laid off at least 85,000 workers in 2022
and early 2023. The H-1B program is the largest U.S. temporary work visa program,
with a total of approximately 600,000 workers employed by 50,000 employers. The
program's intent is to allow employers to fill labor shortages for jobs that require
a college degree, by providing work authorization for migrant workers in fields
like accounting, journalism, health and medical, and teaching. Most H-1B workers,
however, are employed in occupations like computer systems analysis and software
development. Visas for new workers are capped at 85,000 per year, but many employers
are exempt from that annual cap, including universities and their affiliated nonprofit
entities, nonprofit research organizations, and government research organizations.
Approximately 130,000 temporary migrant workers will receive new H-1B visas...
 I am constantly amazed when reading stories
about how easily Adolph Hitler rose to power in Germany by encouraging and exploiting
resentment of his countrymen over being forced, among other concessions outlined
in the Treaty of Versailles, to disarm militarily and make reparations for atrocities
committed in World War I. Part of the Nazi (National Socialist) party success
was extensive use of propaganda via print, radio, and the relatively new technology
of television. Government exercised complete control over the mainstream media (i.e.,
not "underground") by dictating content that promoted the proclaimed virtues of
Nazism and the Aryan race and the vices of just about every other form of government
and race (particularly Jewish). At the height of Hitler's reign of terror during
the Third Reich era,
radio and television sets were only permitted to use crystals tuned to state-sponsored
channels; to be caught possessing crystals for other frequencies meant certain death
- often at the hands of the infamously cruel Gestapo. A large portion of the German
population had no idea what the true status of the war was...
 With more than 1000
custom-built stencils, this has got to be the most comprehensive set of
Visio Stencils available for RF, analog, and digital system and schematic
drawings! Every stencil symbol has been built to fit proportionally on the included
A-, B-, and C-size drawing page templates (or use your own page if preferred). Components
are provided for system block diagrams, conceptual drawings, schematics, test equipment,
racks (EIA 19", ETSI 21"), and more. Test equipment and racks are built at a 1:1
scale so that measurements can be made directly using Visio built-in dimensioning
objects. Page templates are provided with a preset scale (changeable) for a good
presentation that can incorporate all provided symbols...
 The
Wireless Telecom Group,
comprised of Boonton, Holzworth, and Noisecom, is a global designer and manufacturer
of advanced RF and microwave components, modules, systems, and instruments. Serving
the wireless, telecommunication, satellite, military, aerospace, semiconductor and
medical industries, Wireless Telecom Group products enable innovation across a wide
range of traditional and emerging wireless technologies. A unique set of high-performance
products including peak power meters, signal generators, phase noise analyzers,
signal processing modules, 5G and LTE PHY/stack software, noise sources, and programmable
noise generators.
Tuesday the 11th
 Irwin Math - what a great last name. My
preferred last name list also includes Piper, Cessna, Rockett, Wright, Goddard,
Einstein, Marconi, Hertz, Coulomb, Ampere, Edison, de Forest. That is not to
disparage other worthy names like Bell, Moore, and Franklin, it's just that the
latter are common enough that they would not likely illicit an association with
an accomplished scientist. If I can't have fame in common with a great person, at
least the name would be somewhat of a consolation. ...but I digress. This "Digital-to-Analog
Fundamentals" article authored by Mr. Math appeared in a 1967 issue of
Radio-Electronics magazine. With the advent of transistors and a growing selection
of integrated circuits, digital signaling and processing was getting a lot of attention.
Univac-size vacuum tube computers were being compacted into a small fraction of
the volume, consuming a small fraction of the power, and requiring a small fraction
of the maintenance. History shows that rapid progress ensued in both digital circuitry
and the application thereof...
 Here are the schematic and parts list for
Zenith model 5R080 and 5R086 radio/phonograph combos, from a 1947 issue
of Radio News magazine. It must have been a fairly popular set because
many have been sold on eBay; in fact, that's where I got the photos shown here.
The schematic page from the Sam's Photofact also came from an eBay listing. Note
where it says that unless otherwise noted, all resistors values are ±20%. I suppose
when your phonograph turntable uses a metal chain drive mechanism, precision isn't
a huge concern. There are still many people who restore and service these vintage
radios, and often it can be difficult or impossible to find schematics and/or tuning
information; that's why I keep a running list of all the data sheets I find to facilitate
searches...
 "The phenomenon known as
electromagnetic interference (EMI) occurs when any device with electronic circuitry
becomes exposed to an electromagnetic (EM) field. The broad electronic spectrum
is being used by an ever-growing number of these devices, many of which will have
EMI issues affecting their performance. EMI will lead to poor operation, malfunctioning,
and can even ultimately stop circuitry from working at all. Needless to say, system
circuit designers need to design their architectures to prevent EMI disturbances
that can negatively impact their electronics. Man-made or even natural EMI sources
can be minimized or even blocked with electrical shields. The choice of using higher-quality
electronic components can help as well. Error-correction methods may reduce EMI
effects, too..."
 National Radio News magazine was published
bi-monthly by the folks at the National Radio Institute (NRI). NRI used to be a
major training center for electronics technicians beginning in the early part of
the 20th century. This article was provided for them by the Federal Communications
Commission (FCC) as a synopsis of
radio frequency spectrum allocations at the time. Compare a 1940 spectrum allocation
chart (just a simple description here) to one for 2016 and you will see a remarkable
difference in not just the number of bands, but in the extension of the frequency
range. This link produces the FCC Online Table of Frequency Allocations (July 1,
2022) document, and this one is a more user-friendly equivalent graphical U.S. Frequency
Allocations chart published by the U.S. Department of Commerce's National Telecommunications
and Information Administration (NTIA) Office of Spectrum Management, using 2016
data, which appears to be the most recent...
 New Scheme rotates
all Banners in all locations on the page! RF Cafe typically receives 8,000-15,000
website visits each weekday.
RF Cafe is a favorite
of engineers, technicians, hobbyists, and students all over the world. With more
than 17,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be.
 Amplifier Solutions Corporation (ASC) is
a manufacturer of amplifiers for commercial & military markets. ASC designs
and manufactures hybrid, surface mount flange, open carrier and connectorized amplifiers
for low, medium and high power applications using Gallium Nitride (GaN), Gallium
Arsenide (GaAs) and Silicon (Si) transistor technologies. ASC's thick film designs
operate in the frequency range of 300 kHz to 6 GHz. ASC offers thin film
designs that operate up to 20 GHz. ASC is located in an 8,000 sq.ft. facility
in the town of Telford, PA. We offer excellent customer support and take pride in
the ability to quickly react to evolving system design requirements.
Monday the 10th
 The more things change, the more things
stay the same. That old saying will live on forever. Radio-Electronics
editor Forest Belt discusses in a 1967 issue of the magazine the debate between
those companies and customers who are
Pay-TV proponents and those who are Pay-TV opponents. Although you can read
the entire article to draw your own conclusions, basically it boils down to whether
being required to pay hard-earned money for commercial-free programs and movies
will improve the quality. You can probably make a similar argument being made at
every stage of broadcast entertainment on cable, Internet, and smartphones. Personally,
I gave up on 99.9% of all programming newer than around 1985, so I have no dog in
the hunt, so to speak. Mr. Belt presciently states regarding current-day airings,
"Viewers therefore disparage the quality of programs they now get on TV (while watching
them insatiably), call the commercials lousy, and grumble that TV is the country's
great time-waster..."
 These days, I'm always a bit hesitant to
publish or do Internet research on items mentioning chemical compounds any more
toxic than rubbing alcohol, lest some digitally eavesdropping government agency
send storm troopers with fully automatic weapons to my house at 5:00 am to
drag my family and me out onto the lawn while in our pajamas. This article reports
on early plans of the Vanguard satellite launch platform for America's first orbiting
satellites. Although the main focus is on the electronic steering and stabilization
systems, it mentions the fuel composition of nitric acid and unsymmetrical dimethylhydrazine
(that sentence alone is probably enough to at least put me on some sort of surveillance
list). Less exotic fuel constituents like LOX (not to be confused with the fish
used on bagels), kerosene, and liquid hydrogen, which powered most of the
man-carrying booster stages, might similarly likely raise a flag even when taken
in context with the article's thesis...
LadyBug Technologies was founded in 2004
by two microwave engineers with a passion for quality microwave test instrumentation.
Our employees offer many years experience in the design and manufacture of the worlds
best vector network analyzers, spectrum analyzers, power meters and associated components.
The management team has additional experience in optical power testing, military
radar and a variety of programming environments including LabVIEW, VEE and other
languages often used in programmatic systems. Extensive experience in a broad spectrum
of demanding measurement applications. You can be assured that our Power Sensors
are designed, built, tested and calibrated without compromise.
 Website visitor R. Carson Vizina, owner and
chief miracle worker of
Riddim
Restoration, recently wrote to inquire whether I had a resource for repairing
or replacing a damaged glass radio dial bezel for a Packard Bell AM/FM radio he
is working on. Unfortunately, I do not know of anyone who can make a new dial plate,
'thou surely there is someone out there who does custom silkscreen printing, but
the cost would probably be prohibitive. I suggested that he might try an automotive
window repair kit. I have used the Rain-X method on two windshields and it does
an amazing job of "disappearing" the crack. Use a hair dryer after injecting it
onto the surface facilitates it flowing into the narrowest parts of the crack. Please
contact Carson if you have a suggestion. Zenith Chair Side Record Player Vacuum
Tube Stereo Ventura 65amps Magnavox Portable Record Player After perusing his RiddimRestoration.Rocks
website and seeing the amazing audio components he has restored, I offered to post
a description of it on RF Cafe. As the old saying goes, a picture is worth a thousand
words, so rather than me attempt to do Carson's handiwork justice with a written
description, feast your eyes on about 7k worth of words to the right. When asked
to provide a short blurb on Riddim Restoration, he responded thusly...
 You might wonder why an article entitled
"Winning
the National Radio Control Meet" for model airplanes would appear in the ARRL's
QST magazine. The answer is that back in 1940 when it was published, a
Ham license was required to operate a radio control (R/C) transmitter. There were
no license-free bands for hobbyists as there are now. In fact, it wasn't until 1976
that the FCC suspended their requirement for registration as an operator, which
has returned in the form of an FAA "drone" (aka USAS) pilot directive. The author,
William E. Good, was the twin brother of Walter A. Good, both of whom held
doctoral degrees in and physics and Ham licenses, and were referred to as "the fathers
of radio control." The photo of Bill shows his station identification (W8IFD) displayed
on the transmitter enclosure, as required by the FCC. They were born in 1916 and
won the R/C championship in 1949, at the age of 33. In the early days, R/C operators
built (and often designed) their systems, including the electronics and mechanics.
They were the pioneers that took the figurative arrows while forging the frontiers
of this hobby. A couple notable items mentioned in the article are the needing a
QSA "5" level signal (the highest quality of reception) in order to assure reliable
control of the aircraft, and of how Hams helped advance the design of small internal
combustion engines. Also, Fig. 4 shows the rudder escapement located in the
vertical fin, with the wound rubber there as well...
RF Cascade Workbook 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 (click here for screen capture). 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...
 KR Electronics has been designing and manufacturing
custom filters for military and commercial radio, radar, medical, and communications
since 1973. KR Electronics' line of filters includes lowpass, highpass, bandpass,
bandstop, equalizer, duplexer, diplexer, and individually synthesized filters for
special applications - both commercial and military. State of the art computer synthesis,
analysis and test methods are used to meet the most challenging specifications.
All common connector types and package form factors are available. Please visit
their website today to see how they might be of assistance. Products are designed
and manufactured in the USA.
Sunday the 9th
 This custom RF Cafe
electronics-themed crossword puzzle for April 9th, Easter Sunday, contains words
and clues which pertain exclusively to the subjects of electronics, science, physics,
mechanics, engineering, power distribution, astronomy, chemistry, etc. It'll keep
you busy while the kids hunt for Easter eggs. If you do see names of people or places,
they are intimately related to the aforementioned areas of study. As always, you
will find no references to numbnut movie stars or fashion designers. Need more crossword
RF Cafe puzzles? A list at the bottom of the page links to hundreds of them dating
back to the year 2000. Enjoy.
 This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
 Since 1996, ISOTEC has designed, developed
and manufactured an extensive line of RF/microwave connectors, between-series adapters, RF components
and filters for wireless service providers including non-magnetic connectors for
quantum computing and MRI equipments etc. ISOTEC's product line includes low-PIM
RF connectors components such as power dividers and directional couplers. Off-the-shelf
and customized products up to 40 GHz and our low-PIM products can meet -160 dBc
with 2 tones and 20 W test. Quick prototyping, advanced in-house testing and
high-performance. Designs that are cost effective practical and repeatable.
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
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