 Tuesday the 7th
 This Radio Service Data Sheet covers
General Electric Models 102, 102W, 107, 107W, 114, 114W, 115, and 115W receivers.
Most - if not all - electronics servicemen had subscriptions to these magazines
because they were a ready source of not just these service sheets, but because of
the extensive articles offering advice on servicing radios and televisions. In fact,
many electronics manufacturers had a policy of supplying service data only to bona
fide shops. A large list is included at the bottom of the page of similar documents
from vintage receiver schematics, troubleshooting tips, and alignment procedures.
They were originally published in magazines like Radio-Craft, Radio and Television
News, Radio News, etc. I scan and post them for the benefit of hobbyists who restore
and service vintage electronics equipment...
 RF Superstore launched in 2017, marking
the return of Murray Pasternack, founder of Pasternack Enterprises, to the RF and
microwave Industry. Pasternack fundamentally changed the way RF components were
sold. Partner Jason Wright manages day-to-day operations, while working closely
with Mr. Pasternack to develop RF Superstore into a world class RF and
microwave
component supplier. RF coaxial connectors & adapters, coaxial cable &
cable assemblies, surge protectors, attenuators. Items added daily. Free shipping
on orders over $25. We're leading the way again!
 Riddle me this, Riddler: When is a war not
a war? "As Russian forces push for territorial gains in eastern Ukraine, they're
turning to a military capability they've largely forgone during the war but is expected
to give them an edge:
electronic warfare. After earlier failing to topple Ukraine's government, Russia's
military has focused its offensive on the country's eastern Donbas region, which
is home to a large population of Russian speakers. New reporting shows Russian forces
are increasingly intercepting the Ukrainian military's communications while jamming
navigation and guidance systems. 'They are jamming everything their systems can
reach,' an official with the Aerorozvidka, a Ukrainian agency that develops unmanned
aerial vehicles and other military capabilities, told the Associated Press in a
report published Friday. 'We can't say they dominate, but they hinder us greatly..."
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...
 Lotus Communication Systems began in 2009,
setting up CNC machine shop and RF/microwave assembling and testing lab in Middlesex
Country, Massachusetts. Lotus is committed to highest quality and innovative products.
Each RF/microwave module meets
exceedingly high standards of quality, performance and excellent value, and are
100% MADE IN USA. Lotus' RF/microwave products cover frequency band up to 67 GHz.
Lotus also offers an COTS shield enclosures for RF/microwave prototyping and production.
All products are custom designed. We will find a solution and save your time and
cost. Lotus has multiple 4 axis CNC machines and LPKF circuit plotters.
Monday the 6th
 These
electronics / technology themed comics from vintage hobby and trade magazines
were not originally colorized since color printing was typically reserved for front
and rear covers and maybe monotone color for higher priced advertisements. Even
shades of gray were rare, so varying line widths and tiny dotted fill areas were
used to give depth to an image. Similar techniques are still used today in newspaper
weekday comics that are not colorized. Accordingly, the color in these comics was
added by yours truly in order to make them more appealing. Feel free to use them
in your presentations and office cubicles, but please include an attribute to RFCafe.com.
BTW, the cow in the comic is using a Handy-Talkie, not a cellphone. Note the source
of the upsetting commercial in the other comic is a radio, not even a TV. Finally,
the germanium vs. germanium gag was popular back in the early days of semiconductors...
 Axiom Test Equipment allows you to
rent or
buy test equipment,
repair
test equipment, or sell or trade test equipment. They are committed to providing
superior customer service and high quality electronic test equipment. Axiom offers
customers several practical, efficient, and cost effective solutions for their projects'
TE needs and is committed to providing superior customer service and high quality
electronic test equipment. For anyone seeking a way to offload surplus or obsolete
equipment, they offer a trade-in program or they will buy the equipment from you.
Some vintage items are available fully calibrated. Please check out Axiom Test Equipment
today!
 The
Semi-Automatic Ground Environment (SAGE) system was designed and built to monitor
the flights of both intercontinental ballistic missiles and hostile aircraft - if
they were ever to occur, which, thankfully, they did not. Nuclear bombs were of
particular interest since they could be launched not just from the USSR, which was
the only other nuclear power in 1956, but also from offshore aircraft carriers and
submarines. This was the beginning of the era when school kids participated in practice
drills of getting under their desks in the event of an attack. I remember doing
it in the mid 1960s while in grade school. Some of the equipment described here
represents the earliest computerized digital technology, including magnetic core
memory. This 1956 issue of Popular Electronics magazine reports on the
system. According to the Wikipedia entry, SAGE did not go into full operation until
1958...
 Rohde & Schwarz just published a new
Worldwide Spectrum Allocations poster and is making is available a no cost either
as a high resolution PDF file for
download or a paper version for hanging on your wall. "The national and international
spectrum allocations have undergone over 4,000 changes since the World Radio Conference
2012 (WRC-12). Following the most recent WRC-19 and publication of the ITU Radio
Regulations Articles Edition of 2020, we have updated the Worldwide Spectrum Allocations
Poster to reflect these changes. Among the many changes included in the new poster
are the new frequency allocations for 5G communications (5GNR FR1 and FR2), new
GNSS frequency allocations, and separate allocations legends for Mobile Satellite
Earth-to-Space and Space-to-Earth communications for easier identification..."
 With today being the 78th anniversary (June 6,
1944) of the
D-Day
invasion of Normandy (aka Operation Overlord) and other beachheads on the coast
of France, I thought posting this advertisement from the July 1944 edition of
QST magazine would be apropos. This issue of the magazine probably arrived
in ARRL member's mailboxes within a couple weeks of the miraculously successful
invasion of Omaha Beach, Utah Beach, Gold Beach, Juno Beach, and Sword Beach. When
you consider that in those days - and also not so long ago for that matter - the
lead time for going to the printing presses was measured in months, the fact that
this ad made the final cut for the next month's issue (July) is noteworthy. Accordingly,
I duly make note. Back in the 1980s, there was a big push for commercial-off-the-shelf
(COTS) equipment to be used in military equipment in order to save money. It was
the era of $600 hammers and $7000 coffee makers manufactured by defense contractors.
The Project On Government Oversight (POGO) was created to address concerns. Anyway,
donations of equipment and components from private citizens...
 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 12,000 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. I also re-broadcast homepage
items on LinkedIn. If you need your company news to be seen, RF Cafe is the
place to be.
 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.
Sunday the 5th
 This custom made
RF & Microwaves theme crossword puzzle for June 5th is provided compliments
of RF Cafe. All RF Cafe crossword puzzles are custom made by me, Kirt
Blattenberger, and have only words and clues related to RF, microwave, and mm-wave
engineering, optics, mathematics, chemistry, physics, and other technical subjects.
As always, this crossword puzzle contains no names of politicians, mountain ranges,
exotic foods or plants, movie stars, or anything of the sort unless it/he/she is
related to this puzzle's technology theme (e.g., Reginald Denny or the Tunguska
event in Siberia). The technically inclined cruciverbalists amongst us will appreciate
the effort. Enjoy!
 TotalTemp Technologies has more than 40 years
of combined experience providing thermal platforms.
Thermal Platforms
are available to provide temperatures between −100°C and +200°C for cryogenic cooling,
recirculating circulating coolers, temperature chambers and temperature controllers,
thermal range safety controllers, space simulation chambers, hybrid benchtop chambers,
custom systems and platforms. Manual and automated configurations for laboratory
and production environments. Please contact TotalTemp Technologies today to learn
how they can help your project.
Friday the 3rd
 When the
FCC
forbade amateur radio operators from transmitting during the years encompassing
World War II (with a few exceptions), many Hams who were very active in the
hobby went a bit stir crazy and began looking for other pastimes. They could still
listen to other broadcasts, but no CW or phone transmissions were allowed. Author
Chester Cunningham recounts here his chosen replacement avocation - aviation. His
humorous story demonstrates one way Hams, whose curtailed radio activities resulted
in equipment that had atrophied as a result of nonuse and hard to find replacement
parts (all resources went to the war effort), were able to convince their XYLs of
expenditures needed to resurrect the shack. Note that in 1943 the cost per hour
to rent an airplane solo (w/o instructor) was $7 per hour. If my memory serves me
correctly, in 1978 I was paying about $18 per hour to rent a Piper Colt solo, and
$24 per hour w/instructor at Lee Airport in Edgewater, Maryland. Per the BLS's Inflation
Calculator, $7/hour in 1943 is the equivalent of $96/hour in 2016 ($116 in 2022)...
 Exodus Advanced Communications is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Power amplifiers ranging
from 10 kHz to 51 GHz with various output power levels and noise figure
ranges, we fully support custom designs and manufacturing requirements for both
small and large volume levels. decades of combined experience in the RF field for
numerous applications including military jamming, communications, radar, EMI/EMC
and various commercial projects with all designing and manufacturing of our HPA,
MPA, and LNA products in-house.
 Could this be the world's first publically
documented rack-mounted AC power strip? The
National
Company of Cambridge, Massachusetts, which began life as the National Toy Company,
ran a long series of advertisements in QST and other electronics magazines
that were heavy on text and light on pictures - definitely not the norm in advertising.
This one, number 62, from a 1939 issue describes, along with a reference frequency
oscillator, how their engineering team fabricated what we now call an AC power strip
for use in an equipment rack. According to the sketch provided, there does not appear
to be an On/Off switch and almost certainly not any form of surge protection as
is common (maybe even required by UL) for modern power strips. Someone at National
should have patented the idea; their heirs would be rich today.
 "Chinese scientists are working on a plan to
save the only radio telescope operating on the far side of the moon from major noise
problems that are stopping its attempts to explore the universe. Making observations
from the far side of the moon has long been a goal for astronomers because the radio
environment there is so much cleaner than the Earth's. An instrument on board the
Chang'e 4 lander was intended to scan the universe free from radio interference
from Earth but the reality is proving trickier Scientists knew radio noise from
the lander would be a problem, but now need another solution after their initial
precautions did not prove effective..."
 I have to admit that when I saw this large
advertisement for the
Sarkes
Tarzian company in Radio & TV News magazine, I didn't recall ever
having heard of the company. According to Wikipedia, "Sarkes Tarzian (1900-October
1987) was an American engineer, inventor, and broadcaster... He attended the University
of Pennsylvania and received an undergraduate degree in 1924 and a graduate degree
in 1927. Tarzian worked for the Atwater Kent company and then for RCA... He founded
the manufacturing company Sarkes Tarzian Enterprises in 1944, and was involved in
early experiments in VHF audio broadcasting in 1946. Tarzian was a member of the
Rotary Club. In 1949 he started television station WTTV in Bloomington. He sold
that station in 1978. The Sarkes Tarzian company was an important manufacturer of
radio and television equipment, television tuners, and components. Its FM radio
receivers helped to popularize the broadcast medium..."
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...
 Innovative Power Products (IPP) has over
35 years of experience designing & manufacturing RF & microwave passive
components. Their high power, broadband
couplers, combiners, resistors, baluns, terminations
and attenuators are fabricated using the latest materials and design tools available,
resulting in unrivaled product performance. Applications in military, medical, industrial
and commercial markets are serviced around the world. Products listed on website
link to detailed mechanical drawings that contain electrical specifications as well
as performance data. Please take a couple minutes to visit their website and see
how IPP can help you today.
Thursday the 2nd
 We have long known that activity on our sun
affects electromagnetic communications. Energetic particles, primarily electrons,
explode from the sun's surface (coronal
mass ejections and flares) and are hurled at blazing speeds towards the earth
at an average speed of around 424 km/s (263 mi/s). They begin affecting our
upper atmosphere about four days later by ionizing atoms, thereby altering electrical
conduction properties. This in turn determines how and whether electromagnetic signals
either pass through the atmosphere into space or get refracted (bent) back down
toward Earth. Long distance communications in particular are effected, but often
even local communications are impacted as well. Some events have little effect,
some cause minor disruptions in communications, some cause local communications
blackouts, and some are significant enough to cause entire power grids to fault
and shut down. Frequency and intensity of the CMEs and flares is correlated with
the well-established 11-year (approximately) cycle between solar maximums...
 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.
 Did I ever tell the story about a manager
I had at a major defense electronics firm who thought he could make an
NPN transistor by wiring two diodes in series with the anodes tied together?
He reasoned that since a bipolar junction transistor consisted of three alternating
layers of n-type and p-type silicon, the device could be affected per his scheme.
That was in the mid 1980s when I was still a technician (working diligently on my
BSEE degree at night). Needless to say the engineers who worked under him were not
too impressed with the guy's technical prowess (nor his managerial prowess, as I
remember it). I didn't consider myself qualified at the time to judge him one way
or the other, so the fact that he was a good guy made him OK in my book. This article
from the year I was born (some doubt the 'born' claim) reports on the advancements
during the first decade of the transistor era. It was just before Christmas of 1948
that Mssrs. Brattain, Bardeen, and Shockley announced to the world their universe-changing
invention...
 Deadbeat customers have been a problem since
time immemorial. Said dirt bags ask you to perform a service and/or provide a product
and then either try to cheat you out of full payment or refuse to pay at all. Back
in the days when repairmen made in-home visits for radio and television sets, evidently
the problem could be really bad. Art Margoli wrote this article for Radio &
TV News magazine in 1957 describing methods he devised to handle, and most
importantly avoid, uncomfortable situations and stave off ugly confrontations with
customers. One such scheme was to have customers sign a "cognovit
note," which is an extraordinary document by which a debtor authorizes his or
her creditor's attorney to enter a confession in court that allows judgment against
the debtor. Of course litigation would probably cost more than the bill was worth
and therefore would not likely be pursued, but the cognovit note appeared intimidating
with sufficient legalese to give pause to the seasoned feckless homeowner. If you
are in business for yourself and have similar issues, maybe something here will
work for you...
 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 2003, Bittele Electronics has consistently
provided low-volume, electronic contract manufacturing (ECM) and turnkey PCB assembly
services. It specializes in board level turnkey
PCB assembly
for design engineers needing low volume or prototype multi-layer printed circuit
boards. Free Passive Components: Bittele
Electronics is taking one further step in its commitment of offering the best service
to clients of its PCB assembly business. Bittele is now offering common passive
components to its clients FREE of Charge.
Wednesday the 1st
 The meaning of the title of this
Mac's Radio Service Shop story, "Whose Ox Is Gored?," is perfectly obvious to
me, having grown up in an era when the saying was commonplace. However, my guess
is that a lot of people have never heard it, and it makes no sense. A search for
the origin of the idiom turned up lots of guesses, but no definite source. Some
say it came from a writing by Martin Luther, others say from the Bible, but all
agree that it basically means the assessment of a situation (usually a wrong having
been done) depends on the individual's point of view. In this case, Mac points out
to Barney how the annoying inattention to detail provided by mechanics during servicing
of his car are not so different from the "little" things Barney himself has let
slip by because he did not believe they were important enough to be of concern.
This appeared in a 1950 issue of Radio & Television News magazine...
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. We are pleased to present
the new
Exodus AMP2065B-LC, 6.0−18.0 GHz, 300 watt, TWT replacement solid
state power amplifier (SSPA). Exodus AMP2065B-LC is designed for replacing aging
TWT technology. A broadband, rugged EMC Class A/AB linear design for all modulations &
industry standards. Covers 6.0-18.0 GHz, produces >300 W with a minimum
55 dB gain. Excellent flatness, optional monitoring parameters for Forward/Reflected
power, VSWR, voltage, current & temperature sensing for superb-reliability.
Exodus Quiet-Cool technology in our compact 8U-chassis...
 The
APS−42, as described in this 1948 issue of Radio News magazine, was
truly a break-through x−band airborne search radar system born out of the lessons
learned from its predecessor: the APS−10 search radar developed during World War II.
This very compact radar system is contained within a volume of about 3 feet on a
side (not including the cockpit controls and displays. The close proximity of the
receiver front-end to the antenna made for a very low noise figure and, consequently,
high sensitivity. Interestingly, there is not a whole lot of information available
on the Internet for either radar. In fact, this article is probably the most information
source available on the APS−42...
 As of this writing, AR RF/Microwave Instrumentation
is now offering a few wall posters designs at no charge. Among the themes are "RF and EMC
Formulas and Charts," "Mathematical Tools of the Trade," and "Radiated And Conducted
Immunity Test Requirements & Solutions." Posters by AR RF/Microwave Instrumentation
Wall posters used to be a common sight decorating engineering labs and engineers'
and technicians' cubicles, but since the smartphone boom began, fewer and fewer
of them have been made available. Even with apps for just about every imaginable
topic available literally at your fingertips, sometimes it is handy to look at a
large size printed chart for quick reference. If you would like one of these posters
you had better put in your request now because they could be gone at any time...
 Hobbyists in the technical realm have in
many ways contributed mightily to the advancement of professional scientific knowledge
and practice. This is partly because many hobbyists are also career technologists,
but the majority are tinkerers, experimenters and otherwise participants who come
from all walks of life geographically, economically, professionally, and socially.
Just as with university and corporate laboratories, some of the discoveries are
the result of structured, preconceived plans of action and designs of experiments
with certain goals in mind; many, however, are due to serendipitous events that
are recognized by their participants as being significant. Such is the case of "TV
DX" as related in this 1958 Radio-Electronics magazine story. TV DX
is the use of unique opportunities in the atmosphere's ionization state to facilitate
signal transmission and reception at distance much greater than normally experienced.
Data collected by amateurs were, during the era of over-the-air VHF and VHF television
broadcasting, included in studies and theories created by professional scientists
and engineers to help better understand and predict communications phenomena - both
for exploitation and for interference avoidance. The same is true today for other
areas...
 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 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...
 Windfreak Technologies designs, manufactures,
tests and sells high value USB powered and controlled radio frequency products
such as RF signal generators, RF synthesizers, RF power detectors, mixers, up /
downconverters. Since the conception of WFT, we have introduced products that have
been purchased by a wide range of customers, from hobbyists to education facilities
to government agencies. Worldwide customers include Europe, Australia, and Asia.
Please contact Windfreak today to learn how they might help you with your current
project.
|