|
 Not surprisingly, there is a website dedicated
to only the
Regency TR-1 transistor radio and its history from development
through retail sales. As reported in this January 1955 issue of Radio and Television
News, The TR-1 was the world's first commercially available, fully transistorized
portable radio. A complete schematic and functional description is provided. It
used four germanium transistors and operated on a 22-1/2 volt battery, which provided
about twenty hours of listening pleasure. The unit weighed eleven ounces and cost
$49.95...
 This is a must-read article for all persons
interested in the history of wireless communications. Seriously. Stop what you are
doing and read it. I guarantee the vast majority have never heard of this challenge
to the veracity of
Mr. Guglielmo Marconi's bestowed title of "father of wireless
telegraphy." Most of us are at least passingly familiar with challenges to Samuel
Morse's, Thomas Edison's, and a few other notables' claims to being the first at
a particular technical breakthrough, but herein, as penned by of
Lieutenant-Commander Edward H. Loftin, is a first-hand account
of multiple successful challenges by the U.S. Patent Office against...
 ConductRF is continually innovating and
developing new and improved solutions for RF Interconnect needs. See the latest
TESTeCON RF Test Cables
for labs. ConductRF makes production and test coax cable assemblies for amplitude
and phased matched VNA applications as well as standard & precision RF connectors.
Over 1,000 solutions for low PIM in-building to choose from in the iBwave component
library. They also provide custom coax solutions for applications where some standard
just won't do. A partnership with Newark assures fast, reliable access. Please visit
ConductRF today to see
how they can help your project!
 This nomograph from a 1959 issue of
Radio & TV News magazine simplifies matching a source (sending - s) impedance
(Zs) and a load (receiving - r) impedance (Zr) using a
quarter-wave transmission line. To use it, locate your Zs value on the left
vertical scale and your Zr value on the right scale. Lay a straightedge across these
points; the intersection with the center vertical scale reveals the required surge
impedance - also called characteristic impedance - (Z0). Surge impedance is the
ratio of voltage to current for a wave traveling along an infinite transmission
line, dictated by the physical geometry and dielectric properties of the cable,
defined as Z0 = sqrt (L/C), where L is inductance per unit length and C is
capacitance per unit length. The quarter-wave transformer relies...
 Here is a batch of
electronics-themed comics that appeared in the January 1949 edition
of Radio & Television News. The scene seen (hey,
homonyms) on the page 138 comic was commonplace in the 1940s when televisions
were relatively new and not every household had a set. The scenario repeated itself
in the 1960s when color sets were hitting the consumer market. Now, people can watch
TV on their smartphones while not at home so gathering 'round the television display
in a store is relegated pretty much to little kids watching the Disney movies that
seem to always running on them. There is a growing list of other comics at the bottom
of the page...
 December
1942 was just a year into America's "official" involvement in World War II.
Already, both wired and wireless communications had made major advances and were
indisputably vital in both the logistical and strategic aspects of troop movement,
supply chains, fighting battles, and evacuation of wounded personnel. It also played
a large part in propaganda campaigns. This was all true for both Axis and Allied
forces. Ham radio operators provided a huge boost to the Signal Corps
because they came at least partially trained for the jobs. These dozen and a half
photos from the field exhibit the state of the art at the time. Maybe you'll
recognize a father, grandfather, or uncle in one of them. For that matter, you might
even recognize a mother, grandmother...
 Exodus Advanced Communications, is a multinational
RF communication equipment and engineering service company serving both commercial
and government entities and their affiliates worldwide. Exodus'
AMP20026 is a rugged 2.0 to 6.0 GHz solid state amplifier delivering a
minimum of 200 W with clean, stable 53 dB gain. It offers excellent gain
flatness, a 20 dB control range, and full protection circuitry. Built for EMI/RFI,
lab, CW/pulse, and EW environments, it delivers instantaneous bandwidth, superb
reliability, rack mount configuration...
 In April of 1952 when this article appeared
in Radio & Television News magazine, the
bipolar junction transistor (BJT) had only made it out of the
experimental laboratory of Messrs. Bardeen, Shockley, and Brattain at Bell Labs
a mere three years earlier in December of 1948. It did not take long for commercial
production to begin. Along with being a great primer for anyone new to transistors,
herein is also some background on how the now ubiquitous BJT schematic symbol was
created. Interestingly, only Dr. William Shockley is mentioned, making me wonder
whether the contributions of Dr. John Bardeen, and Dr. Walter H. Brattain was
not widely publicized early on. Not to worry, though, because all three were duly...
 Mac's Service Shop captures here a moment
of technological transition in 1961 where a new "Loud-speaking
Telephone" impresses his right-hand man, Barney. The device utilizes vacuum-tube
amplifiers and a bulky external control box to allow hands-free communication, enabling
Mac to work while handling customer inquiries. Mac, ever the mentor, contrasts this
tube-based unit with the emerging technology of transistorized speakerphones, which
eliminate the need for external control boxes, external power supplies, and warm-up
times. The 1961 "Loud-speaking" setup, occupying significant space under a workbench,
has been completely replaced by modern smartphones and integrated VoIP systems...
 As with all
RF Cafe
crossword puzzles, this one uses only words pertaining to engineering, science,
mathematics, mechanics, chemistry, astronomy, etc. 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., Hedy Lamarr or the Bikini Atoll). The technically inclined cruciverbalists
amongst us will appreciate the effort. Enjoy!
  The microwave klystron was invented in 1937
by brothers
Russell and Sigurd Varian. If you have been in the microwave design
business for a couple decades, you undoubtedly recognize the company name of Varian
Associates, especially if you worked in the aerospace or defense electronics business.
There is a video on YouTube of a segment on Varian done sometime around 1990 by
Walter Cronkite. There is also a historical piece on Varian Associates on the Communications &
Power Industries website. This circa 1952 article covers the fundamentals of klystron
operation and reports on the increasing use of klystrons in high frequency application
- including by amateur radio operators exploring...
 Werbel Microwave began as a consulting firm,
specializing in RF components design, with the ability to rapidly spin low volume
prototypes, and has quickly grown into a major designer and manufacturer with volume
production capacities. The
WMRD02-7.2-S is a resistive splitter that covers up to 7.2 GHz with ultra-wide
bandwidth. This design is useful when there are many low power signals within a
wide spectrum. By design, the nominal insertion loss and isolation is 6 dB,
hence it is often referred to as a "6 dB splitter." Its small size makes it
easy to integrate into compact systems. Designed, assembled, and tested in the USA.
"No Worries with Werbel!"
 Contributors to the Wikipedia article on
the
Yagi–Uda antenna credit Japanese professor Shintaro Uda primarily for the antenna's
development, with Hidetsugu Yagi having played a "lesser role." Other sources assign
the primary role to Yagi. Regardless, history - and this article's author, rightly
or wrongly, has decreed that this highly popular design be referred to commonly
as the Yagi antenna and not the Uda antenna. I don't recall seeing advertisements
for "'Uda" television or amateur radio antennas. Harold Harris, of Channel Master
Corporation, does a nice job explaining the fundamentals of the Yagi antenna. Another
Yagi article appeared in the October 1952 issue of QST magazine...
 Established in 1990,
dB Control supplies mission-critical,
often sole-source, products worldwide to military organizations, as well as to major
defense contractors and commercial manufacturers. dB Control designs and manufactures
high-power TWT amplifiers, microwave power modules, transmitters, high- and low-voltage
power supplies, and modulators for radar, ECM, and data link applications. Modularity
enables rapid configuration of custom products for a variety of platforms, including
ground-based and high-altitude military manned and unmanned aircraft. Custom RF
sources and receivers, components and integrated microwave subsystems as well as
precision electromechanical switches. dB Control also offers specialized contract
manufacturing and repair depot services.
 The production of high-performance transistors
necessitated new methods to achieve extreme purity levels, far beyond standard industrial
capabilities. To reach the required purity of
one part in ten billion, engineers adopted zone melting, a sophisticated technique
pioneered by W. G. Pfann. In this process, radio-frequency heating coils melt a
narrow zone of a semiconductor rod, which is then moved along the crystal to sweep
impurities to one end. Beyond purification, zone melting allows for the precise,
uniform introduction of "dopants" like antimony or indium, which are essential for
creating p-type and n-type semiconductor characteristics. By refining these methods
through continuous processing and floating-zone techniques, manufacturers significantly...
 Here's another advertisement that you probably
wouldn't see in a contemporary RF / microwave engineering magazine. For that matter
you probably wouldn't see it on a contemporary RF / microwave engineering website
... except on RF Cafe where political correctness gets no respect.
Adson Radio & Electronics was located on Fulton Street in New York City,
just a block from the 911 Memorial. the original building might have been destroyed
when the...
 My first thought when seeing the cover for
this edition of Radio-Craft magazine was that it was an April Fools gag,
but it turns out the "hat" being worn by the radio receiver's designer is a
loop antenna for AM reception. Ya' know, he does look like he
could be a suicide bomber. In a way it is the opposite of a tinfoil hat in that
this headgear invites electromagnetic energy around the wearer's head rather than
shielding it. Back in 1936, being seen in public donning a contraption like this
radio would have been akin to Google Glass today - you'd be a superhero to fellow
nerds, and just be confirming your otherworldly nerd status to non-nerds...
 Vreeland Corporation was an early radio
manufacturer located in Hoboken, New Jersey, with multiple patents on file for innovative
circuits. The
Vreeland band selector system mentioned here was originally filed
in the U.S. Patent and Trademark Office in August of 1927 and had not been awarded
by the time of this November 1929 article in Radio-Craft magazine. In fact,
it wasn't until five years later, in 1932, that the patent was finally assigned.
The official description reads in part, "The general purpose of the invention is
to receive the component frequencies of such a band with such uniformity as to avoid
material distortion of the modulated wave, and to exclude frequencies outside of
the band which the system is designed to receive. Another purpose of the invention
is to provide means for shifting the position of the band...
 In this 1959 Radio-Electronics
magazine promo, Bell Telephone Laboratories showcased its advanced
radio-inertial guidance system, a technological breakthrough enabling precise
long-range missile flight. Developed for the Air Force's Ballistic Missile Division,
this innovation proved its efficacy by guiding a Thor-Able nose cone to a precise
target five thousand miles away, allowing for a successful aerial and maritime recovery.
The system utilized a missile-borne transmitter to feed continuous data to ground-based
radar and a Remington Rand Univac computer, which calculated real-time steering
corrections. By keeping the primary command equipment on the ground...
 It's Friday afternoon as I post this installment
of
Mac's Radio Service Shop from a 1952 edition of Radio &
Television News magazine - the perfect way to burn off the last few minutes
of your work week while waiting for the shift-ending whistle to blow. John T.
Frye authored many of these stories that used main characters Mac McGregor, proprietor
of Mac's Radio Service Shop and sidekick technician Barney to set up a situation
and dialog whereby the highly experienced Mac imparts sage advice to Barney regarding
things electronics in nature. Topics range from safely troubleshooting a high voltage
power supply to tracking down noisy capacitors and how to treat customers equitably.
Today's lesson is on the employment of "repurposed" (a term not yet invented in
1952...
 Thomas Edison applied on November 4, 1879
to the U.S. Patent and Trademark Office for a patent on his "Electric-Lamp." Patent number 223898 A was awarded on January
27, 1880. Remember those years. While searching for technical headlines today, I
ran across an article in the New York Times where they point out the first-ever
mention of electric lights in their newspaper. Per the article "The Arrival of Electric
Light," The New York Times first wrote of the technology on April 15, 1858.
On that day, "Our Own Correspondent" in Havana described celebrations of Holy Week
that included "an electric light" cast across the harbor...
 This is part 5 in a series that began in
the October 1951 issue of Radio & Television News magazine. Previous
articles dealt with
crystal diodes in AM and FM radios, and this article shift gears
by moving into television applications. Crystal diodes were and are still used in
frequency generation, envelope detection, frequency mixing, and AC signal rectification.
Vacuum tubes could be used for the latter three applications but many physical issues
such as size, weight, power consumption, and heat dissipation proved to be major
drawbacks as designers strived to reduce the size of electronics assemblies, make
them more energy efficient, lower the cost of manufacturing, increase reliability,
and decrease weight...
 This article from a 1959 issue of Radio-Electronics
magazine details a simple, effective method to
convert a standard dipole antenna into a unidirectional, broadband performer
by bending it into a circular loop and terminating the ends with a non-inductive
resistor. By utilizing a cross-shaped support frame with TV standoff insulators,
a builder can easily construct this antenna for the 6-meter band or higher. The
design is noted for its impressive front-to-back ratio and surprising operational
versatility across a wide frequency range, even maintaining performance when improperly
sized. Offering increased gain at harmonic...
 As evidenced in these mid-last-century magazine
advertisements,
Sylvania Electric marketing moguls learned early what sells products
by exploiting the nature of their audience. The cartoon-style ads shown here appeared
in social publications like Look, Life, and Collier's, where both men and women
- many of them numbnuts - are the expected audience. Compare these with the type
of ad run by Sylvania in a "serious" magazine like
Radio-Craft...
|
 • FCC Expands
Use of Broadband Spectrum
• UK's
Fractile Chip Facility Gets £100m Expansion
• Choosing an
Antenna for Compliance Testing
• Huawei
Wins 8 GLOMO Awards at MWC Barcelona
• Smartphone
Shipments to Fall 7% in 2026
 The
RF Cafe Homepage Archive
is a comprehensive collection of every item appearing daily on this website since
2008 - and many from earlier years. Many thousands of pages of unique content have
been added since then.
 In the days before just about every multimeter
had a built-in
diode and transistor tester, there was not much - if anything - available for
the hobbyist. Some of the vacuum tube test sets, like my 1961 vintage B&K Dyna-Quik
Model 650, surprisingly included diode and transistor test sockets. This article
for a "non-destructive" type - as opposed to the popular "destructive" type -
homebuilt transistor tester appeared in a 1971 issue of Popular Electronics
magazine. It can identify PNP vs. NPN, measure DC gain, and measure leakage
current. The tester will verify diode integrity as well. There's also a bonus
"Parts Talk" comic on the page at no extra cost...
 Back in the 1970s while taking flying lessons,
I used to enjoy watching the
Civil Air Patrol run through its exercises at
Lee Airport,
in Edgewater, Maryland. For some reason, I never bothered to look into joining.
I wish I had. A few years later while in Basic Training (BT) for the USAF at Lackland
AFB, Texas, there were a couple guys in my squadron who had been long-time members
of the CAP and guess what? They only had to spend the first two weeks in BT, just
long enough to do all the paperwork processing, take a few of the classroom sessions,
get shots, examinations, a head shave, and to have uniforms issued. Then, immediately
before leaving for technical school, they got to sew a stripe onto their shirtsleeves
as an Airman 1st Class. High school ROTC guys got to do the same thing. I don't
know if the Air Force still has that policy; you might want to check it out if you're
planning on joining...
 "Fair
Trade" was a policy established in the post-WWII era in response to what
consumer retail groups considered business-ruining cost cutting by dealers who offered
to sell products at or barely above cost in order to steal profit from other stores.
So-scheming stores planned to make up for the low profit margin with high sales
volumes. Doing so drove a lot of the local competition out of business, leaving
the crafty dirty dealers to later raise prices. Stores that had manufacturer-sanctioned
service shops often got screwed because they were obligated to repair items like
TVs and radios that were bought from another dealer who did not do service work.
Profit margins on repair work - at least from honest shops - were typically very
low, so the owners depended on new product sales...
 Most of the time the
tech-themed comics which appeared in vintage electronics industry magazines
reflected popular issues of the day. In 1961 when these five comics appeared in
Radio-Electronics, home stereo systems and television performance woes
(with the need for repair and/or adjustment) were at the top of the list. Less domestic
issues like the fledgling satellite technology, digital computer systems, vehicle
navigation, and medical instrumentation often made the cut as well. The page 48
and 81 comics address stereo, page 99 does satellites, page 116 covers medicine,
and 121 hits on TV. A saying in the world of humor is that in order to be successful,
there needs to be some truth in the gag in order to be truly funny. Sometimes the
truth element is subtle and might even require the targeted audience to be privy
to not so widely known information. Such is the case with a couple of these...
 Since the International Microwave Symposium
(IMS 2020) is completely virtual this year, I figured maybe re-posting my coverage
of the Microwave
Museum display of vintage industry research and development items would fit
right in. The photos were taken during my attendance at IMS 2009 in Boston,
MA. At the time, they were the only photos of the collection on the WWW. It had
a very nice display of items from the early days of radio and radar. According to
the IMS 2009 website, the items are "memorabilia from the first IMS held in Boston
50 years ago." Most displays were glass cases, so it made getting useful photographs
difficult because of glare and reflections. You will see some of that in the images
here. More information can be found on the National Electronics Museum website...
 According to authors Neal Jensen and Alexander
Burawa,
magnetic reed switches were developed as recently as 1940 at the Bell
Telephone Laboratories to replace the expensive and power-hungry traditional
solenoid-based relays. Development cost was reportedly $100 million ($750M in
2018 dollars). I would have guessed reed switches were invented half a century
earlier, given how fundamental their concept and construction is. Maybe there
was no perceived urgency back when power efficiency was not such a big concern
given the wattage used by vacuum tube circuits that often employed the relays.
As in increasing number of homes and businesses had telephones installed and
party lines (shared by two or more users) gave way to private lines, the
physical...
 One sure giveaway to the age of a picture
is the presence of a wheat penny, a buffalo nickel, or a Mercury dime. This 1957
advertisement in Radio & Television News magazine for
Channel Master antennas has all three. It shows a walking Liberty half dollar
as well. Quarters haven't changed much over the years, with George Washington's
head on the obverse side since 1932. The wheat penny design ended in 1959 when the
Lincoln Memorial was put on the reverse side in its place. Thomas Jefferson's head
has been on the nickel since 1938. Theodore Roosevelt's head was ensconced on the
obverse of the dime in 1946. John F. Kennedy was placed on the half dollar obverse
in 1964. This ad is about antennas, not coins, though. For a lot, if not most, of
RF Cafe visitors, there has always been cable and satellite television. For some,
TV has always been available on their smartphones...
 This custom made
Science & Scientists theme crossword puzzle for February 20th 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!
 Honestly, I don't remember why I scanned
this advertisement for
Sarkes Tarzian recorder tape that appeared in a 1962 edition of Popular Electronics
magazine. Maybe it was to illustrate how far personal recording technology has come
in the half century since the ad ran. Today's recorders are in the form of a very
small digital device the size of a pack of gum (or any smartphone can be used),
and not only is the miniature recorder capable of storing longer sessions, but the
quality of the recording is almost certainly better. The cost of a digital recorder
is about the same in inflated dollars as a spool of tape was in 1962...
 If the history of radar intrigues you, then
you will not want to miss this article titled "Radar:
The Silent Weapon of World War 2," from the October 1945 edition of Radio
News magazine. There are a couple dozen photos of early radar equipment installations
on land, ships, and aircraft. Radar pioneers Dr. A. Hoyt Taylor, Chief Consultant
and Chief Coordinator of Electronics at Naval Research Laboratory, and Leo C. Young
are pictured reminiscing over the "scope" of radar's history beside the first radar
set at the Research Laboratory. In 1922, while experimenting with communications
equipment for the Navy, the two men made the initial discovery of distortion in
radio reception caused by the intrusion of objects between the transmitter and receiver.
Working from this discovery, they and a number of associates made great strides
forward into the vast sphere of scientific fields covered by the word "radar" today...
 One aspect of advertising on the RF Cafe
website I have not covered is using
Google AdSense.
The reason is that I never took the time to explore how - or even whether it is
possible - to target a specific website for displaying your banner ads. A couple
display opportunities have always been provided for Google Ads to display, but the
vast majority of advertising on RF Cafe is done via private advertisers. That is,
companies deal with me directly and I handle inserting their banner ads into the
html page code that randomly selects and displays them. My advertising scheme is
what the industry refers to as a "Tenancy Campaign," whereby a flat price per month
is paid regardless of number of impressions or clicks. It is the simplest format
and has seemed to work well for many companies. With nearly 4 million pageviews
per year for RFCafe.com, the average impression rate per banner ad is about 225,000k per
year (in eight locations on each page, with >17k pages)...
 This custom RF Cafe
electronics-themed crossword puzzle for March 19th 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.
 Here is your custom made
Filter-themed crossword puzzle for April 3rd, 2022. Clues for words relevant
to the theme are marked with an asterisk (*). 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 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!
 National Union Radio Corporation, located
in Orange, New Jersey, had been producing radios since its formation in 1929 when
this Radio Service Data Sheet for its
Model G-619 "Presentation" tabletop set appeared in a 1947 issue of Radio-Craft
magazine. That they survived the Great Depression which began in the year of their
founding is a testament the tenacity of its management, design staff, and production
workers. This 5-tube radio had a very nice mahogany case with a unique reverse-lettering
dial glass plate. A few years ago I posted an advertisement by Union Radio from
a 1945 issue of Radio-Craft appealing specifically to women engineers and technicians
because of the severe shortage of men available while serving in the armed forces
during World War II...
 Here for radio hobbyists are a dozen
handy-dandy 'kinks,' otherwise known as tricks, shortcuts, or clever ideas, that
could prove useful while working in the lab at work or in your shop at home. One
kink that might be worth trying calls for immersing an aluminum panel in a
water-lye solution to achieve "a professional-looking finish." A satin look
results. A Google search on etching aluminum turns up many other methods.
Admittedly, most of these ideas would not ...
 A lot of us still use older test equipment
at home and even in the company lab. As discussed in this 1972 article from
Popular Electronics magazine, the displayed rise time on an oscilloscope display
is not necessarily that
true rise time of a signal - particularly when the speed approaches the rated
bandwidth of the equipment. In that case, it is necessary to mathematically compensate
for the rise times of each individual component used for making the measurement.
Hooking the o-scope probe tip to the calibration point on the front of the instrument
and adjusting the probe's trim capacitor for a flat response is not always good
enough. Most modern o-scopes can calculate and apply corrections automatically,
negating the need for a manual correction. If your application is not super critical
from a timing standpoint, then you do not need to bother with correction, but it
is worth keeping rise time measurement inaccuracies in mind just in case you run
into an otherwise...
 If I have ever heard of a "trigistor"
(aka "dynaquad") before seeing it in the 1960 Radio-Electronics magazine article,
I don't remember it. It is a p-n-p-n silicon switch device that is essentially the
same as a thyristor in that conduction can be turned on or off with separate control
signals that can be removed once the switching action is initiated. According to
the Wikipedia entry for the thyristor, it was first introduced in 1956, not so long
before this article. The Howard W. Sams Transistor Circuit Manual, 1961, by
Allan Lytel provides information on not just the "trigistor," but also the "binistor,"
another bistable on/off silicon switch. Other process control devices such as unijunction
transistors, avalanche diodes, silicon controlled rectifiers (SCRs), and cryostats
(used for temperature control) are discussed. The electronics industry was in the
early stage of transition from vacuum tubes to solid state devices...
 One of the photos in this 1958 Radio &
TV News magazine article on the
Jodrell Bank radio telescope shows what appears to be the largest multi-conductor
cable connector I have ever seen. It looks like a early Photoshopping of a DB-9
connector with a heavy metal back shell. The cable bundle is three to four inches
in diameter. Rather than use slip rings to transfer the control, data, and power
signals from the base to the steerable 250-foot diameter parabolic dish of the Jodrell
Bank radio telescope (now called the Lovell telescope), a single massive cable does
the job. The science of radio astronomy was barely three decades old at the time
it was built. It was in 1931 that Karl Jansky first determined that radio signals
were coming from our Milky Way galaxy. He eventually ended up working for Bell Labs
in Homdel, New Jersey, where he built a radio telescope to investigate background
noise in the 10-20 meter wavelength band, where Bell planned to use its microwave
relay system... |
