See Page 1 |
2 |
3 |
4 | of the February 2023 homepage
archives. Tuesday the 28th
 "What's
Your EQ?" (Electronics Quotient, a la IQ - Intelligence Quotient) was a feature
run in Radio-Electronics magazine for a couple years in the early 1960's.
It was a quiz for challenging your knowledge of basic electronic circuit functions.
Most of them are relatively simple exercises in voltage division, resistor-capacitor
(RC) and resistor-indictor (RL) time constants, resonant frequency, and transformer
input/output ratios (voltage and/or current and/or power). Sometimes, the first
step in solving the poser is to rearrange the schematic into a more familiar configuration.
Also, read the wording carefully to determine whether parts of the circuit can be
ignored. Answers are at the bottom of the page. Note that I do not agree with the
magazine's answer for the "How Much Voltage?" circuit. My solution is presented
below with the rest of the answers.
 For many years, Texas Instruments has offered
a free Spice-based circuit simulator called
TINA-TI. The UI is very intuitive and I use it fairly often. "TINA-TI provides
all the conventional DC, transient and frequency domain analysis of SPICE and much
more. TINA has extensive post-processing capability that allows you to format results
the way you want them. Virtual instruments allow you to select input waveforms and
probe circuit nodes voltages and waveforms. TINA's schematic capture is truly intuitive
- a real 'quickstart.' We bet that you won't. TINA is a product of DesignSoft exclusively
for Texas Instruments. This complimentary version is fully functional but does not
support some other features available with the full version of TINA." Full commercial
versions of TINA are available
from DesignSoft beginning at around $160.
 Assuming the 10 enumerated advantages of
a gridless vacuum tube may be added to the 17 enumerated disadvantages of a gridded
vacuum tube, there are 27 reasons, per author Henri Dalpayrat why one should consider
abandoning the "old style" tubes for his revolutionary concept. Part 1 of this
2-part series discussed the unavoidably negative features of a gridded vacuum tube.
Part 2, presently, extolls the wonders of a
gridless vacuum tube. Chief among the features is the use of "compressor bar"
elements that are situated parallel to the electron flow rather than in series with
it. Another major difference is the cathode element running vertically up the center
of the tube and the cathode wraps around it. If I had to draw a comparison of gridless
versus gridded vacuum tubes with semiconductor devices, the former more closely
relates to a field effect transistor (FET) and the latter to a bipolar junction
transistor (BJT). I say that because the compressor bars' action on the electron
flow is to change the concentration (density), effectively having the ability to
cut off the current...
 "A new technique produces
X-ray images in colour quickly and efficiently using a specially-structured
device called a Fresnel zone plate (FZP). The technique could have applications
in nuclear medicine and radiology, as well in non-destructive industrial testing
and materials analysis. X-rays are frequently used to determine the chemical composition
of materials thanks to the characteristic 'fingerprint' of fluorescence that different
substances emit when exposed to X-ray light. At present, however, this imaging technique
requires focusing the X-rays and scanning the whole sample. Given the difficulty
of focusing an X-ray beam down to small areas, especially with typical laboratory
X-ray sources, this is a challenging task, making images time-consuming and expensive
to produce. Single exposure and no need for focusing and scanning The new method,
developed by Jakob Soltau and colleagues at the Institute for X-ray Physics..."
 In this series, author Yardley Beers discusses
propagation effects, modulation systems, and receiver techniques. Part 1 of
this 3-part article entitled "Influence of the Antenna of the Choice of Wavelength
for Best Communications," appeared in the February 1952 issue of the ARRL's
QST magazine. This second part concerns "Propagation,
Modulation, and Receivers." I have also posted Part 3, which subsequently
appeared in the August 1952 edition. A particularly interesting topic included in
this installment is that of using a form of pulse modulation in FM broadcasting
in order to exploit the "capture effect" whereby a signal in the presence of noise
will tend to suppress the noise. I don't think modern stations use that method,
possibly because of incompatibility with stereo channels and data added for digital
readouts...
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...
 SF Circuits' specialty is in the complex,
advanced technology of PCB fabrication and assembly, producing high quality multi-layered
PCBs from elaborate layouts. With them, you receive unparalleled technical expertise
at competitive prices as well as the most progressive solutions available. Their
customers request PCB production that is outside the capabilities of normal circuit
board providers. Please take a moment to visit San Francisco Circuits today. "Printed
Circuit Fabrication & Assembly with No Limit on Technology or Quantity."
Monday the 27th
 Servel is not a name that immediately comes
to mind (and probably not at all) when thinking of companies who manufactured refrigerators
or any other household appliances. However, they were rather prominent in the in
the early 1940's when this "Wartime Message" appeared in a 1942 issue of Life
magazine. So, too, was Crosley, a name which lives on today, and they still make
refrigerators (manufactured by Westinghouse). Unique about
Servel refrigerators was that they operated off of natural gas. It might seem
strange that a cooling - even freezing - process can be accomplished via a flame,
but such is the case. In fact, Melanie's parents had a gas-powered refrigerator
and a gas-powered chest freezer at their house on a mountaintop in West Virginia,
where they got free natural gas from a well a gas company operated from their property.
But I digress... The motivation for posting this piece is that Servel was one of
hundreds of American companies that spent some of their hard-earned their advertising
money to promote the sacrificial efforts of fellow citizens (many of whom were former
employees or relatives of current employees). It was a time when major companies
were owned and run by patriotic Americans...
 "IEMI from high-power microwave sources
and EM pulses can generate significant threats to electronic systems in civil and
infrastructure. Thus, inclusion of methods that recognize and reduce IEMI in designs
is more critical than ever. Before we can define
intentional electromagnetic interference (IEMI), which will also be referred
to as 'sabotage' in this article, let's begin by characterizing electromagnetic
waves. A mechanical wave can be defined as a vibration or disturbance in matter
through some medium (such as a solid, liquid, gas, or plasma). Sound waves occurring
in the air are mechanical waves. A changing magnetic field induces a changing electric
field and vice versa - these two are linked. The two changing fields ultimately
will form electromagnetic waves. Electromagnetic waves aren't like mechanical waves;
they don't need a medium to propagate. Thus, electromagnetic waves have the ability
to travel not just through air and solid materials, but through the vacuum of space
as well..."
 The geographic center of the 48 contiguous
(conterminous) states in America is located about 2.6 miles northwest of the center
of Lebanon, Kansas (39° 50' N, 98° 35' W). That is about 85 miles from
the FCC's (Federal Communication Commission) first central
frequency monitoring station at Grand Island, Nebraska. I have driven by that
spot a couple times while traveling on Interstate 80. Grand Island is probably not
much bigger today than it was in 1932 when this story was published in Radio-Craft
magazine, although it boasts being the state's 4th largest city (population 48,000).
"Island" must have a different definition in Nebraska than in the rest of the world
;-) Because of its remoteness - 6 miles from town to minimize electrical noise -
a diesel generator (chosen to eliminate ignition noise) was installed on-site to
provide the necessary 3-phase, 240-volt power for equipment. Great care was taken
to shield cables and motors and eliminate unnecessary metal structural components.
Engineers who designed and operated this and other early monitoring stations had
no previous data to reference. They were creating the standards and technical foundations
on which future generations would build...
 "The
shortest electron pulses ever made in the lab have been claimed by researchers
in Germany. By firing ultrashort laser pulses at a tungsten nanotip, the team created
electron pulses just 53×10-18 seconds long and then characterized the
pulses using a new technique. When a short, intense laser pulse is fired at a material
it can cause the emission of an extremely short pulse of electrons. These electrons
are then driven back into the material before re-emerging - a process that can provide
important information about the material's properties. The challenge in doing such
experiments is knowing how long the electron pulses are and characterizing the electrons
that are emitted. Now, Eleftherios Goulielmakis and colleagues at the University
of Rostock have developed a new technique to create and study ultrashort electron
pulses. In their experiment, an intense laser pulse is fired at tungsten nanotip
that is just 70 nm in diameter at its apex. This causes the emission of a pulse
of electrons from the tip..."
 Magazines usually provided at least a brief
description on the circuit functionality for each of the radio models presented
in schematic format. The January 1947 issue of Radio News published schematics
and parts lists for six sets, including this for the United models 980744 and 980745
"Sonomatic,"
but not a word about any of them accompanied it - just the schematic and PL. These
are AM radios designed for Buick automobiles, and the series ran for more than a
decade. One thumbnail image is the SAMS Photofact from an eBay auction, and the
photo thumbnail is from an eBay auction. I post this type of information as part
of my ongoing effort to make the information available to those who repair and/or
restore vintage vacuum tube radio sets...
 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 16,000 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.
 Alliance Test Equipment sells
used / refurbished
test equipment and offers short- and long-term rentals. They also offer repair,
maintenance and calibration. Prices discounted up to 80% off list price. Agilent/HP,
Tektronix, Anritsu, Fluke, R&S and other major brands. A global organization
with ability to source hard to find equipment through our network of suppliers.
Alliance Test will purchase your excess test equipment in large or small lots. Blog
posts offer advice on application and use of a wide range of test equipment. Please
visit Allied Test Equipment today to see how they can help your project.
Sunday the 26th
 This "X" marks the spot with this custom
RF Cafe
electronics-themed crossword puzzle for February 26th. It contains words and
clues which pertain strictly to the subjects of electronics, mechanics, power distribution,
engineering, science, physics, astronomy, chemistry, etc. If you do see names of
people or places, they are directly 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...
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
Friday the 24th
 Amongst the topics addressed in this "The
Electronic Revolution" article in a 1968 issue of Radio-Electronics magazine
is "thermoelectron
cells that convert solar radiation into electric current at an efficiency of
86%." Having not seen the term before, but guessing it was based on a heating effect
rather than a radiation effect, I looked it up and found thermoelectron is "a negative
ion, or electron, emitted from a body at high temperature." That is akin to "thermionic"
emission, such as what happens when a vacuum tube's heater element spews electrons.
Such technology, along with the "Electronic Automated Revolution," "The Instant
Newspaper," computers, and lasers are why editor Hugo Gernsback declares, "The Great
Accomplishments of Electronics Are Still to Come..."
 Providing full solution service is our motto,
not just selling goods. RF & Connector Technology has persistently pursued a management
policy stressing quality assurance system and technological advancement. From your
very first contact, you will be supported by competent RF specialists; all of them
have several years of field experience in this industry allowing them to suggest
a fundamental solution and troubleshooting approach. Coaxial RF connectors, cable
assemblies, antennas, terminations, attenuators, couplers, dividers, and more. Practically,
we put priority on process inspection at each step of workflow as well as during
final inspection in order to actualize "Zero Defects."
 When I first saw the title "What
Wives Think About Ham Radio" of this 1966 QST magazine article, I thought it
was going to be a comical parody on how wives (YL's) of Ham radio operators (OM's)
viewed their husbands' hobby. It turned out to be a report on a nationwide survey.
Many of wives of Hams were themselves licensed operators which, at the time, required
Morse code proficiency in addition to radio theory and regulations. In 1966 the
average cost of a Ham shack layout was about $1,000, which is equivalent to $9,093
in 2023 dollars according to the BLS's Inflation Calculator. As with most electronics
equipment, the quality and features have evolved significantly in the intervening
decades, so you get a lot more capability for your investment today. If you believe
the author presents results honestly, the general attitude was that wives would
rather have their hubbies engaged in an educational at home or with like-minded
men than at a bar or sporting event. A majority also thought that spending on Ham
equipment activities was not at the expense of essential family needs...
 "Can heat be channeled similar to how circuits
control the flow of electricity? Possibly yes, according to a new study, if a new
kind of quasiparticle could effectively be harnessed to make a practicable heat
switch. Nearly every piece of technology today could be a case study in electricity
being channeled toward productive purposes. With the right materials, heat could
be made to be have like a different kind of current. However, says study senior
author Joseph Heremans, a physicist and engineer at Ohio State University, 'Unlike
electrical current,
heat flows
everywhere and is much harder to control.' Yet, even an imperfect heat switch
could still have major technological impacts. For instance, more than 70 percent
of the energy that humanity uses originates in heat, such as combustion engines.
Heat switches can boost the efficiency of entire classes of heat engines, such as
solar thermal power plants..."
 This is the schematics and parts list set
for
vintage Emerson vacuum tube radio models 501, 502, and 504, as they appeared
in the November 1947 issue of Radio News magazine. I scan and post these
for the benefit of hobbyists and historians seeking such information. As time goes
by, there is less and less likelihood that records of these relics from yesteryear's
archives will be made available. To the left is the cover page for the Sam's PhotoFact
data packet. To the lower right are example of the Emerson Model 502 that appeared
on eBay at one time. As with all historical information, it takes someone with a
personal interest in preserving the memories in order to fulfill the mission, and
I am glad to be a small part of that cadre...
/jobs.htm">![Engineering Job Board - RF Cafe]() RF
Cafe's raison d'être is and always has been to provide useful, quality content for
engineers, technicians, engineering managers, students, and hobbyists. Part of that
mission is offering to post applicable /jobs.htm">job openings. HR department employees and/or managers of hiring
companies are welcome to submit opportunities for posting at no charge. 3rd party
recruiters and temp agencies are not included so as to assure a high quality of
listings. Please read through the easy procedure to benefit from RF Cafe's high
quality visitors...
 Aegis Power Systems is a leading supplier
of AC-DC and
DC-DC power supplies for custom and special applications. Aegis has been designing
and building highly reliable custom power supplies since 1995. They offer a complete
line of switch mode power supplies and power converters for a variety of markets
including defense, industrial, aircraft, VME, and telecom. Supports military, aircraft,
EV, telecom, and embedded computing applications. Design and manufacture of custom
power supply solutions to meet each customer's exacting specifications. Please visit
Aegis Power Systems today. Manufactured in the USA.
Thursday the 23rd
 There aren't many people using
transistor substitution boxes these days because circuit simulator software
is readily available to reasonably predict which type will serve the intended purpose.
However, back in 1960 when this article appeared in Radio-Electronics maga
zine, substitution boxes for not just transistors, but also capacitors, resistors,
and sometimes inductors were used quite often when prototyping and/or troubleshooting
circuits. I used resistor and capacitor substitution boxes all the time in the early
and mid 1980's while working as an electronics technician at Westinghouse Oceanic
Division, in Annapolis, Maryland. That was my first place of employment after separating
from the USAF. Prior to moving into the engineering lab, I built electronics assemblies
for U.S. Navy sonars used on torpedoes, ship hulls, and towed vehicles, including
printed circuit assemblies, cable harnesses, chassis assemblies, and piezoelectric
transducers. Occasionally, I was tasked to build component substitution boxes for
the engineering lab and the test equipment repair / calibration (metrology) group.
Little did I know at the time that in the near future I would be using some of the
equipment I built...
 Yep, that's a
Lockheed U-2 wingtip in
that photo! That's 1955 technology (upgraded, of course), same year as the still-in-service
B-52 Stratofortress.
"The multi-ton payload that defense officials had claimed was attached to a
Chinese spy balloon that floated across North America earlier this month looked
like a oversized, suspended satellite, according to a photo released by the Pentagon
on Wednesday. The image, taken from the cockpit of an Air Force U-2 spy plane, shows
two large panels dangling from a balloon several times larger than the payload itself.
'The majority of the balloon, including the payload, was recovered,' Sabrina Singh,
a Pentagon spokeswoman, said during a briefing Wednesday in which she confirmed
the photo's authenticity. Defense officials said the surveillance equipment suspended
from the balloon, which the Pentagon said earlier this month belonged to the Chinese
government, was designed to spy on sensitive U.S. military sites. It resulted in
a 1,500 square meter debris field after an Air Force F-22 shot it down off the coast
of South Carolina..."
 Here is an interesting article that was
probably much needed in its day (1956 Popular Electronics magazine) when
many hobbyists were building and repairing their own electronic equipment. Being
able to measure and identify
unknown transformer winding parameters is key to both troubleshooting and determining
whether a particular transformer is applicable for your need. Even professional
repair shops often scavenged transformers from scrapped chassis for use in equipment
brought in for service. The process can be extended to multiple winding transformers.
Now you, too, can confidently tackle the unknown transformer and determine its construction...
 Quantic PMI, a leading supplier of custom,
high-reliability MIC/MMIC components and subsystems for applications in space, military,
communications, commercial and consumer electronics systems for more than three
decades, introduced six new products this month of February in their extensive line
of
RF and microwave components. Included amongst them are a 0.8 to 2.5 GHz
two-way power divider; an absorptive, high speed, SP3T, absorptive switch for 8.0
to 12.0 GHz; a hybrid coupler with a frequency of 5.6 to 5.8 GHz; a highpass
filter with a passband of 26.5 to 40.0 GHz; an absorptive, SP6T pin diode switch
for 2.0 to 20.0 GHz; a switched filter bank with a frequency range of 30 to
600 MHz; and an absorptive, SP6T pin diode switch for 2.0 to 20.0 GHz...
 The June 1949 issue of Radio & Television
News magazine had four television-themed comics. Television at that time was
a relatively new home appliance, so there was a huge amount of interest in the technology.
It hadn't really been all that long since the public got used to hearing sound (aka
"talkies") in the movie theater, so the mystique that surrounded television made
it the subject of a lot of puns and jokes. 1949 was a mere four years after the
end of World War II, and the post-war economic boom was primed by a surplus
of left-over electronic components along with lots of available talent both in the
areas of design and assembly. There is a growing list of other comics at the bottom
of the page. Over time, I am colorizing many of them, as with these...
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 16,000 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.
 Berkeley Nucleonics Corporation (BNC) is
a leading manufacturer of precision electronic instrumentation for test, measurement,
and nuclear research. Founded in 1963, BNC initially developed custom pulse generators.
We became known for meeting the most stringent requirements for high precision and
stability, and for producing instruments of unsurpassed reliability and performance.
We continue to maintain a leadership position as a developer of custom pulse, signal,
light, and function generators. Our designs incorporate the latest innovations in
software and hardware engineering, surface mount production, and automated testing
procedures.
Wednesday the 22nd
 It is understandable if, based on this article's
title, "Holes and the Service Technician," you thought maybe it had to do with semiconductors.
Silicon was beginning to overtake germanium as the substrate of choice it appeared
in a 1963 issue of Radio-Electronics magazine. Electron conduction seemed
intuitive to most people involved in electronics; however, the concept of hole conduction
caused a lot of head scratching. But, I digress. This article discusses how to
create various types of holes in metal. It might seem like a no-brainer task,
if you have ever needed to make precisely shaped and dimensioned holes in metal,
you know it is not always such a simple task - especially in soft sheet metal. Achieving
a truly round hole - especially of large diameter - in an aluminum chassis requires
securely clamping the work piece to the table and using a sturdy drill press. Otherwise,
you almost always get an oblong hole. A machinist at Westinghouse showed me one
day back in the 1980's how he would get the chassis secured and drill press positioned,
then place a couple layers of paper towel on the metal before lowering the drill
bit onto the chassis. It helped fill the space between drill bit flutes to prevent
it from "walking" before both sides of the bit had a bite on the metal. It works
like magic, even when using a hand drill. To this day I still do that...
 "As devices get smaller and more powerful,
the risk of them overheating and burning out increases substantially. Despite advancements
in cooling solutions, the interface between an electronic chip and its cooling system
has remained a barrier for thermal transport due to the materials' intrinsic roughness.
Sheng Shen, Professor in the Department of Mechanical Engineering at Carnegie Mellon
University has fabricated a flexible, powerful, and highly reliable material to
efficiently fill the gap. 'At first glance, our solution looks like any ordinary
copper film, but under a microscope the novelty of our material becomes clear,'
explained Lin Jing, PhD student. The material, composed of
two thin copper films with a graphene-coated copper nanowire array sandwiched
between, is extremely user-friendly. 'Other nanowires need to be in-situ grown where
the heat is designed to be dissipated so that their application threshold and cost
is high..."
 In typical
Carl & Jerry style, the teen experimenters ("makers" or "DIYers" in contemporary
lingo) spent another summer vacation day cobbling together an electromechanical
contraption or even purely electronic device with a specific goal in mind. Whether
designing and building a circuit for tracking down the cause of strangely acting
synchronized wall clocks ("The Crazy Clock Caper") or devising a system for catching
a vandal in the act of vandalizing ("Geniuses at Work" - this story), creator John T.
Fry provides a mix of developing personalities, describing the task at hand, and
maintaining a degree of suspense regarding how the adventure will end.
 Innovative Power Products has been designing
and manufacturing RF and Microwave passive components since 2005. We use the latest
design tools available to build our baluns, 90-degree couplers, directional couplers,
combiners/dividers, single-ended transformers, resistors, terminations, and custom
products. Applications in military, medical, industrial, and commercial markets
are serviced around the world. Products listed on the website link to detailed mechanical
drawings, electrical specifications, and performance data. If you cannot find a
product that meets your requirements on our website, contact us to speak with one
of our experienced design engineers about your project.
 "Reconfigurable
antennas - those that can tune properties like frequency or radiation beams
in real-time, from afar - are integral to future communication network systems,
like 6G. But many current reconfigurable antenna designs can fall short: they dysfunction
in high or low temperatures, have power limitations, or require regular servicing.
To address these limitations, electrical engineers in the Penn State College of
Engineering combined electromagnets with a compliant mechanism, which is the same
mechanical engineering concept behind binder clips or a bow and arrow. They published
their proof-of-concept reconfigurable compliant mechanism-enabled patch antenna
today..."
 This advertisement for transformers, coils,
chokes, and rotary converters from
William Bayliss Ltd., on Sheepcoat Street in Birmingham, England, appeared in
the March 9, 1932 edition of The Wireless World magazine. I only have this one edition,
but will work on getting more soon. William Bayliss London Ltd. was a British manufacturer
of scientific instruments, founded in London in 1919 by Sir William Maddock Bayliss,
a well-known physiologist and Fellow of the Royal Society. The company specialized
in the production of laboratory equipment, including microscopes, balances, and
other precision instruments used in scientific research and education. One of the
company's most significant contributions to science was the development of the Bayliss-Tate
apparatus, a device used to measure the concentration of oxygen in blood. This instrument
was based on the discovery made by Bayliss and his colleague, Ernest Starling, that
the oxygen-carrying protein hemoglobin in blood changes color depending on the amount
of oxygen it is carrying. The Bayliss-Tate apparatus was widely used in medical
research and diagnosis for many years...
 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...
 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.
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.
About RF Cafe.
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