|
 Details of ancient Parthian
electrochemical batteries unearthed near Baghdad by archaeologist Wilhelm Konig,
dating over 2,000 years, was reported in this 1964 Popular Electronics
magazine article. Housed in earthenware jars sealed with asphaltum (bitumen), they
featured a copper cylinder soldered with 60/40 tin-lead alloy - identical to modern
electronics, prior to PB-free mandates - encasing a corroded iron rod for electrodes,
enabling electroplating of gold, silver, and antimony via electrolytes like copper
sulphate, ferrocyanides, or lye. GE engineer Willard F.M. Gray replicated them successfully
for Pittsfield's Berkshire Museum, using iron rods for series connections. More
cells surfaced in a Seleucia magician's hut and Berlin Museum...
 It seems most of the articles we see on
the subject of attenuator pads are based on signal reduction in terms of decibels
for units of power. Although it is a simple matter to convert power decibels to
voltage decibels, it would be more convenient if you are working with voltage to
have formulas and tables of values based on voltage ratios. This article does just
that. As a reminder, the decibel representation of a ratio is always 10 * log10 (x).
If you have a voltage ratio of V1/V2 = 0.5, then
10 * log10 (0.5) = -3.01 dB. If you have
a power ratio of P1/P2 = 0.5, then 10 * log10 (0.5) = -3.01 dB.
Does that mean that -3.01 dB of voltage attenuation is the same as 3.01 dB
of power attenuation...
 This might be a perfect application for
QuentComm. "Researchers led at the University
of Science and Technology of China (USTC), have achieved a major milestone in quantum
communication. For the first time, they demonstrated a key component required for
scalable quantum repeaters, which later allowed them to carry out device-independent
quantum key distribution (DI-QKD) across 100 kilometers. The results, published
in Nature and in Science, represent important progress toward building a functional
quantum internet. The work also reinforces China's position at the forefront of
quantum research and technology..."
 This Radio Service Data Sheet for the Clarion
"Replacement" Chassis, Model AC-160 A.V.C. Superhet is an example of the dozens
of similar schematic and alignment instruction sheets that have been posted on RF
Cafe over the years. Obtaining technical information on most things, even readily
available items, prior to the Internet era was often very difficult - if not impossible.
Service centers had what was need provided by manufacturers and distributors, but
if you wanted to find a part number or service data on a refrigerator, radio, lawn
mower, garage door opener...
 Remember the test patterns that used to
be broadcast by over-the-air broadcast stations that were used to align the electron
beam defection circuitry in CRT-based televisions? That pattern of squares, circles,
parallel and radial lines was generated by a special tube called a "Monoscope" on the transmitter end. Focus, 4:3 picture aspect ratio,
linearity, frequency response, and contrast and brightness were all tweaked to optimize
the pattern on the TV receiver circuitry. Of course not all sets were capable of
obtaining a perfect alignment due to inferior design and/or a scheme by the manufacturer
to provide a lower cost model with the tradeoff being a poorer picture - that it
the type of TV we always had in our household as...
 Anritsu has been a global provider of innovative
communications test and measurement solutions for more than 120 years. Anritsu manufactures
a full line of innovative components and accessories for
RF and Microwave Test and Measurement
Equipment including attenuators & terminations; coaxial cables, connectors &
adapters; o-scopes; power meters & sensors; signal generators; antenna, signal,
spectrum, & vector network analyzers (VNAs); calibration kits; Bluetooth &
WLAN testers; PIM testers; amplifiers; power dividers; antennas. "We've Got You
Covered."
 Dave Harbaugh created a great many electronics-themed
comics back in the 1960s for magazines like Popular Electronics, QST,
"73", and others. His "Hobnobbing
with Harbaugh" series usually depicted hobbyists and technicians in a state
of surprise and/or dismay over some event while in the act of pursuing his passion
(electronics, that is, not a woman). Although I have never run across any evidence
of it, I wonder how many of the scenarios are derived from personal experience.
Many do not have captions. I have to admit to being stumped at what he is trying
to convey in the comic where the guy is staring into the back of the TV while his
wife...
 Competition amongst countries and businesses
existed long before the advent of radio receivers. Here is an interesting story
which demonstrates how international politics and corporate policies has been part
of the electronics industry since its inception. In order to circumvent what were
considered to be outlandish patent licensing fees, Danish engineer Carl Arne Scheimann
Jensen developed a new "gridless" type of vacuum tube (aka valve) which was called
the "Renode." Rather than using a screen grid in the path between the
cathode and plate, the Renode employed two sets of beam concentrator and deflector
plates on either side of the electron beam's path to modulate the conduction. According
to measurements it provided a slight improvement in both linearity and selectivity...
 "Sixth-generation wireless networks, or
6G, are expected to achieve terabit-per-second speeds using terahertz frequencies.
However, to harness the terahertz spectrum, complicated device designs are typically
needed to establish multiple high-speed connections. Now research suggests that
advanced topological materials may ultimately help to achieve such links. The experimental
device the researchers have made, in fact, achieved 72 gigabits-per-second data
rates, and reached more than 75% of the three-dimensional space around it. Current
solutions typically achieve only one or two of these features at a time and often
rely on complex
antenna arrays or mechanical steering..."
 This week's
RF & Microwave Companies crossword puzzle includes the names
of all my current advertisers and a few others that will be familiar to many of
you. These kinds of puzzles take a particularly long time to create because of needing
to force words into certain positions. That leaves the software with fewer options
for fitting the other words. All the words in RF Cafe crossword puzzles are relevant
to engineering, science, mathematics, etc., stored in a hand-built (over more than
two decades) lexicon of thousands of terms and clues. Enjoy...
 Mystery stories were broadcast on radio
stations in the days before television - and for quite a while after TV was available
for that matter. Families gathered around the living room radio set in excited anticipation
of the next adventure of shows like "The Shadow," "Amos 'n' Andy," "Tales of the
Texas Rangers," "Dragnet," and "The Green Hornet." During that era, it was common
also for electronics magazines, which focused largely on radio communications, to
experiment with printed dramas that had a radio-centric theme. Here is the first
of a series tried by Radio-Craft magazine in the late 1930s. A couple decades
later the Carl & Jerry adventures were run in Popular Electronics,
but other than that I don't recall seeing a lot of these things...
 Diode characteristics and their applications
have not changed fundamentally since this article was published in 1952. Sure, the
die are smaller, power handling and frequency range has increased, package styles
are greatly expanded, and the cost per unit is way down, but if you are looking
for some basic diode information, you will find it here in this 4th installment
of a multi-part series in Radio & Television News magazine. Don't let
the vacuum tubes in schematics scare you off and think that it makes the story irrelevant
for today's circuits. For purposes of illustration substitute a transistor's collector
(or drain) for the tube's plate, a transistor's base (or gate) for the tube's screen
grid, and a transistor's emitter (or source) for the tube's...
 The term "drone"
these days for most invokes the image of a little plastic spider-looking thing with
propellers mounted at the ends of the arms - usually with a toothless bumpkin at
the controls. Those same people often think drones are relatively new devices. People
with a just a little more information automatically classify all radio control (R/C)
models, be they traditional fixed-wing aircraft or helicopters, as drones. Pilots
of the aforementioned models are even likely, per observers, to have all their teeth
and bathe regularly. I happen to be one of the latter type R/C modelers and while
I no longer possess all 32 teeth I had at birth, I do bathe regularly. Drones have
been around since World War I where they were used for target practice by ground-based
mark...
 "If you have dark eyes and blonde hair.
and are under 30, you're due for some easy squeezing. Milligan's Appliance Center,
84 Main Street, is giving every girl between 16 and 30 who has these striking features
a newly patented orange squeezer, to introduce the new item ... Note: Any traces
of recent peroxide rinse will disqualify applicants." That is advertising copy offered
as an example effective promotional material in a 1947 edition of
Radio News. My first reaction was to think how something
like that would never fly today, but then I wasn't so sure. It seems there must
be anti-discrimination laws in this "offend nobody" climate today...
 Imagine having a serviceman of any sort
arrive at your house, fix your problem, and present you with a bill of $6 - parts
included. He would walk away satisfied that he had done a good job and was well
compensated for the work considering the effort invested in training and qualification.
$6 in 1932, per the Bureau of Labor Statistics'
Inflation Calculator is worth $135.97 in 2015 money - that's a
cheap service call even in today's economy. Further, the $14 stated as a day's earnings
is $317.26 in 2025, which equates to 50 (work weeks/year) x 5 (days/week) x $243.86
(/day) = $79,315 (/year) - not too shabby. Just between you and me, that's more
than I'm currently making per year running RF Cafe...
 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.
 Oscillators were never my forte. My biggest
exposure to oscillators was unintentional oscillations in amplifier circuits ;-(
. This
Oscillator Quiz, published in the November 1962 issue of Popular Electronics
magazine, would embarrass me if I attempted to complete it. Therefore, I will simply
state that I highly regard your oscillator prowess if you do better than 50% on
it. I guessed correctly at a couple of the more familiar circuits, but cannot even
make an educated guess at most of them. Don't let the presence of vacuum tubes scare
you off; mentally replace them with a FET and move on...
 These letters represent an unfriendly exchange
between The Electrical Experimenter editor Hugo Gernsback and Dr. K.G.
Frank, of the Telefunken System of Wireless Technology, of Germany. Gernsback correctly
accused Dr. Frank of engaging in espionage for Germany and against the United
States of America, during World War I at a time we were not officially at war
with the Axis powers. He was arrested and interred for the duration of the war for
sending out "unneutral
messages" from the broadcast station at Sayville, Long Island, New York. See
"Radiobotage" in this month's (September 1941) editorial...
 "There's an interesting development in amateur
ballooning: using so-called
superpressure
balloons, which float high in the atmosphere indefinitely rather than simply
going up and up and then popping like a normal weather balloon. Superpressure balloons
can last for months and travel long distances, potentially circumnavigating the
globe, all the while reporting their position. You might imagine that an undertaking
like this would be immensely difficult and cost thousands of dollars. In fact, you
can build and launch such a balloon for about the cost of a fancy dinner out. You
just have to think small! That's why amateur balloonists call them pico balloons.
The payload of a pico balloon is so light..."
 Many of the words in this week's
crossword puzzle pertain to radar engineering. All the rest of
the words are related to technology, engineering, science, mathematics, aeronautics,
ham radio, chemistry, etc. There are no names of Hollywierd actors, shoe designers,
or romance novel titles. I will be glad to create a special edition crossword for
your newspaper, newsletter, etc. Enjoy...
 It's time to gather 'round for another story
about fictional radio service shop owner
Mac McGregor and his trusted sidekick technician, Barney. In this
episode, an errantly wired bypass capacitor on a chassis from one of the old AC/DC
radio sets caused Mac to get a 300-volt wakeup call when his hand brushed against
it. After explaining the situation to Barney and apprising him of the danger it
poses to an owner who unwittingly sticks his/her hand into the back of the cabinet,
Mac lists a few other common dangers to watch for. Radios that ran on either AC
or DC power were very common back in the early days because there were homes and
businesses that had both type systems wired in to the premises - in part due to
the famous battle between Thomas Edison's preferred DC electrical distribution system
and Nikola Tesla's preferred AC electrical distribution system. Another reason for
DC compatibility was that prior to the
Rural Electrification Act of 1936, many...
 An incredibly glaring example of the famous
admonishment* that those who ignore history are condemned to repeat it, Radio-Craft
editor Hugo Gernsback wrote in May of 1941, a full half year before the United States
of America officially entered World War II, about how current conditions regarding
domestic commercial radio broadcast stations were likely being used by German agents
to send coded messages to offshore vessels (ships, submarines, and aircraft).
In example, he cited, amazingly, an article he himself published in 1915 in
The Electrical Experimenter accusing Dr. K. G. Frank, of the German Telefunken
company, of conducting spy operations from the Sayville, NY, station on Long Island...
 Considering that not much more than a year
before this article was written that the transistor had been invented, it is impressive
that already Raytheon was producing a commercially available
CK703 "crystal triode." That nomenclature was a natural extension
of the preceding crystal diode already being widely adapted in circuit design. If
you have wondered how the transistor schematic symbol came to be as it is, you will
learn why here where the emitter and collector symbols actually both have arrows
on the ends that contact the base, indicating the "point contact" physical arrangement
of the semiconductor junctions. Shortly thereafter the arrow on the collector port
was eliminated, primarily, I suppose to avoid confusion when the E, B, and C labels
are not present...
 "CDimension recently unveiled a technology
that enables conventional semiconductor fabs to use ultra-thin semiconductor materials
to manufacture vertically integrated arrays of extremely small, fast, and efficient
"2D" transistors. It has the potential to change what's possible for both digital
and power devices. According to the company, it's already helping several chipmakers
explore how to apply their technology to produce digital and analog ICs that offer
dramatically higher logic densities, operating speeds, and energy efficiency..."
 Here are three more Radio Service Data Sheets
added to the online archive. As mentioned many times in the past, I post these for
the benefit of hobbyists looking for information to assist in repairing or restoring
vintage communication equipment. These particular radio models -
Emerson Model 20A and 25A,
Pilot Model B-2,
General Electric Model K-40-A - were featured in a 1933 edition
of
Radio-Craft magazine...
 A lot of RF Cafe visitors might not be familiar
with some of the electronic waveforms presented in this
Oscilloscope Quiz by Popular Electronics magazine's ultimate quizmaster, Robert
Balin. The shapes are recognizable to anyone who has done a lot of design, troubleshooting,
testing, or alignments on analog circuits. Electronics repairmen were intimately
familiar with these - and much more complex - waveforms. Modulation of the z-axis
is especially cool as it varies the intensity of the waveform. I always roll my
eyes when, back in the day, a laboratory or medical facility in movies or on TV
had an oscilloscope display with a Lissajous pattern writhing on the display...
|
 • Fund Opens
Defence Contracts to UK Startups
• Global
Trade Holds Its Ground
• FCC
"Supercharge" Wi-Fi in 6 GHz Band
• Legacy
Memory (DDR2, 3, 4) in Demand but Scarce
• 2026 is
Year of 6G Slop
• FCC to
Exempt Amateurs from Foreign Adversary Reporting
 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.
 I love these old
electronics company advertisements from the World War II era. It represented
a time when minor differences between citizens were put aside for the good of the
country (yours and mine). Nationalism had not yet been redefined by one-worlders
to mean that you hated the rest of the world, but rather that you had pride in your
country of birth - or legally adopted new country - and were willing to sacrifice
for the common good to preserve your way of life. The U.S. and Great Britain were
indisputably the leaders in technical invention amongst the Allied powers. Germany
and Japan led the Axis powers tech realm. That's not to say others didn't contribute
and were not vital to success. Naval aviation represents to me the assimilation
of all great technologies inclusive of ships, aircraft, electronics, weaponry, communications,
strategy, discipline, community living, isolation, navigation, and maintenance -
all in a limited space...
 The September 1932 issue of Radio Craft
contained an article titled, "Radio a la Cortlandt Street!," the original "Radio
Row" located at the corner of Cortlandt and Washington Streets in Manhattan. It was
a mecca of new and used electronics components and assemblies. After World War II
there was a huge supply of surplus parts and equipment made available to the public as
a means to clear out inventory and also as a "thank you" to the citizens who voluntarily
donated critically needed panel meters, tuning capacitors, connectors, and other items
to the War Department. That really helped the market boom. Post-war electronics
magazines were chock full of ads by dealers selling surplus electronic and
mechanical supplies...
 According to the National Bureau of Standards'
(now National Institute of Standards, NIST) website, In October 1949, Congress authorized
$4.5 million for "the construction and equipment of a radio laboratory building
for the National Bureau of Standards," for the planned new location of
WWV in Ft. Collins, Colorado. WWV was initially established in 1919 in
Washington, D.C., later moved to Beltsville, Maryland, then finally relocated to
Ft. Collins, Colorado, in 1955. Construction began on the facility in 1951
and was dedicated in September 1954 by President Dwight D. Eisenhower. This item
from the June 1945 issue of Radio News magazine reports on the Colorado location,
with WWV's addition of a 15 MHz time standard broadcast...
 Grammar and formatting standards have changed
over time. As technology evolves and society devolves, things like abbreviations,
use of capital letters, the "verbization*" of
nouns, interchanging of homophones (e.g., "their" and "there"), and the growingly
popular offense of eliminating the space between a number and its associated unit
(e.g., "914MHz" vs. "914 MHz") are becoming more prevalent. Look at nearly
any press release or datasheet from a component manufacturer in the past few years
and you will notice the number-unit change (I correct many of the ones I post on
RF Cafe). Some publishers (NPR) are particularly offensive at taking liberties
(aka laziness) and others (New York Times) are stalwart standard bearers
(good for them). I see many examples during my daily search for technical headlines.
We have gotten accustomed to many changes, and some have been around so long that
most people have never seen the former usage. Since I post a lot of articles from
vintage editions of the ARRL's QST magazine, I though it might be instructive
to include this list of common abbreviations used in the 1930s through 1960s (the
years I post). Most notable is the use of periods between letters and lower case
vs. upper case letters as with "a.m." (AM), "db" (dB), and "r.f." (RF)...
 This full-page advertisement by
CBS
Tubes caught my eye because of the vast array of vacuum tube shapes and sizes.
Most people, even back in the era of tube-based electronic equipment, think of the
standard 12AX7 type rounded top, cylindrical glass package with a plastic or phenolic
base and some metal pins sticking out of the bottom. Television and radio sets were
full of them, and those are what you or your parents or grandparents would yank
from the chassis and take to the local drug store or electronics shop to plug into
the big tube tester that was commonplace back then. However, as this photo shows
there was a great variety of special glass and inner electrode configurations. If
you have ever attended the MTTS (IMS) show, you might have seen the equipment display
provided by the National Electronics Museum...
 A While back I posted a page pointing to
the many laboratory wall charts offered by Keysight Technologies (formerly Agilent,
formerly Hewlett Packard). I mentioned how unlike modern charts that are full of
color, the old ones were usually a single color or black & white. Here is an
example from American Amphenol which appeared in a 1945 issue of Radio News
magazine. Something like this would make a really cool decoration for today. I just
looked on eBay and didn't see an
Amphenol Tube Socket Wall Chart for sale, but that would probably be the bet
place to latch on to one eventually...
 Narrow-band frequency modulation (NFM) was
a relatively new technology in 1947, having been advanced significantly during World
War II. Amateur radio operators were just getting their gear back on the air
after having been prohibited from transmitting for the duration of the war (see
"War Comes," January 1942 QST). Few were probably thinking about adopting
and exploiting new modulation techniques, but for those who were and recognized
FM as the path to the future of radio, QST published this fairly comprehensive
treatment of both frequency modulation (FM) and phase modulation (PM). Mathematically,
FM is the time derivative of PM. Both modulation schemes vary the carrier frequency
in some proportion to the baseband signal. Author Byron Goodman provides some insight
into the techniques...
 Here are a couple more
electronics-themed comics from the March 1967 issue of Popular Electronics
magazine for your TGIF enjoyment. The comic on page 100 especially appeals to me since
I am finishing the installation of a Channel Master CM-5020 antenna. It has been a long
time since I installed a traditional style TV antenna - about 40 years ago when I put
a Radio Shack antenna on the roof of my mother's house. The entire 109" long by 100"
wide antenna, including mounting hardware, weighs only 11.5 pounds and presents
a wind resistance of 30 pounds. This is Channel Master's best antenna.Gain
is 10 dB at VFH and 16 dB at UHF. I plan to use it for FM radio as well. A
vintage Alliance Tenna-Rotor will make it steerable...
 One of the first things you learn in school
when studying transistors is the
three classes of amplifier circuits: Class A, where the conduction angle
is a full 360°; Class B, where the conduction angle is 180°; and Class C,
where the conduction angle is less than 180°. There is a fourth hybrid Class AB,
which conducts more than 180° but less than 360°. Class A is generally considered
the simplest configuration to produce a linear operation, where the output signal
is exactly the same multiple in voltage as the input signal. For example if the
gain of the amplifier is 100, then a 0.01 V input produces a 1 V output,
a 0.1 V input produces a 10 V output, and a 1 V input produces a
100 V output. Perfect linearity produces no distortion in the output, with
no spectral components not present in the input. Why wouldn't you want to use a
Class A amplifier all the time, you might ask? The answer is that it is the
least efficient configuration. In order to conduct through a full 360°, a DC bias
is required to place the output halfway between the maximum peak-to-peak output
voltage so that the transistor is never turned fully on or fully off...
 Nearly everyone has seen photos and/or videos
of the Operation Crossroads nuclear weapons tests at the Bikini Atoll from shortly
after the end of World War II. Upon the ships were penned various species of
animals - goats, pigs, rats, guinea pigs, etc. - along with radiation and mechanical
measurement equipment. The goal was to determine exposure levels to nuclear and
electromagnetic radiation, as well as to severed physical forces. That was for both
the ship and its "crew." A Fat Man type fission bomb was detonated underwater (90-foot
depth), as opposed to the air drop type. Many sources provide details of the entire
operation, including the findings. Given the extreme complexity and risks involved
in using bombs, laboratory facilities were constructed to simulate exposure from
bombs. This "Death-Ray
Chamber Tests Atom Effects" story from a 1953 issue of Popular Mechanics
magazine describes one method used by the Naval Medical Research Institute...
 On the May 13, 2005 episode of The Tonight
Show, Jay Leno held a Morse code vs. SMS speed contest between two Ham Radio operators
using Morse code and two Millennials using their smartphones for texting (SMS).
At least one member of the audience thought texting would win. Watch the video to
see if she was right. Mr. Chip Margelli (K7JA) did the sending. He declares, "Let
me assure you that we never saw that message before I flipped the blue card over.
Each message, in rehearsal, was different. The character count was the same as the
one during dress rehearsal, though, to account for the time slot. And they put the
card on the table "upside down" creative to how I flipped it, as you can see on
the video." Mr. Ken Miller (K6CTW) did the receiving...
 Last week Melanie and I drove down to Greensboro,
North Carolina, to attend our daughter's wedding. The weather was typically hot
there, but not out of the norm. All went well at the small ceremony. Both bride
and groom showed up, as did the minister and necessary witnesses. After the blessed
event was over, we headed back northward to our humble abode in Erie, Pennsylvania.
Our route upon exiting NC is I81 for a few miles in Virginia, then north onto I77,
up to Rt. 19, then I79 all the way home up and down mountains for a few hundred
miles. Our 2011 Jeep Patriot has never had any mechanical issues, but then it only
has 81k miles on it and is kept in the garage. That day, though, the transmission
overheating idiot light illuminated while on I81 - not a particularly hilly stretch.
The outside temperature there was about 80 °F. I had noticed a slightly higher
pitch sound from it while going uphill, but didn't think anything of it until the
light came on. (On-Trak
Automotive Services)...
 Here is another of the "Electronic Sticklers" challenges from Popular Electronics
magazine - good for ratcheting down at the end of the week. These are fairly basic
circuit analysis problems that often can be solved by inspection, but sometimes
a pencil and paper are necessary. Re-drawing the circuit in a different configuration
to make the connections more obvious often helps when solving total resistance,
capacitance, inductance, etc., as in question #1. In this case, though, you need
to be able to recognize a common configuration to be able to simplify the circuit;
otherwise, you'll be writing and solving mesh equations. #2 has a simple answer
and a more elaborate possibility. #3 and #4 are simple inspection problems...
 No matter how proud I was of my family name,
I do believe I would refrain from using "Kluge" as a company moniker. Maybe the
word did no connate the same meaning in 1946 when this advertisement for the
Kluge Electronics "California Kilowatt" Amateur Radio Station appeared in Radio-Craft
magazine. An extensive WWW search turned up no examples of any surviving Kluge "California
Kilowatt" Amateur Radio Stations. One QRZ website discussion supposed that none
were ever manufactured. Per Wikipedia: "A kludge or kluge (klooj) is a workaround
or quick-and-dirty solution that is clumsy, inelegant, inefficient, difficult to
extend and hard to maintain." It has an interesting etymology. I found references
to the term "California Kilowatt" meaning a transmitter putting out more than the
legal power limit. California Kilowatt is also nowadays the name of a Canadian rock
band...
 A few years ago I was in a second-hand shop
in Erie, Pennsylvania, and happened to spot a Hewlett-Packard model HP 5212A Electronic
Counter stashed in a cardboard box with a bunch of other electronic stuff. It was
a little dirty, but otherwise appeared to be in pretty good condition. I took it
to the counter and asked the lady what she'd take for it, and we agreed on $15,
provided when I plugged it in the front panel display would light up and no smoke
came from the chassis. It did and it didn't, respectively. Once at home, I fired
it up and ran some functional tests on it, and all seemed to be working properly.
After performing some major clean-up to nearly like-new condition, I decided it
should go to someone who could put it to good use, so it went up for sale here on
RF Cafe. Believe it or not, the best offer received was $125. It deserved more respect
than that, but the guy was a collector of vintage test equipment, so at least it
went to a loving home. This 1962 "The
Counter as a Test Instrument" article in Electronics World magazine article
shows both the HP 5212A (300 kHz) and the HP 5243L (500 MHz)
electronic counters...
 Even if you have no use for building a "twin
lamp" standing wave indicator for a twin lead transmission line (solid
or open ladder type), this article makes an interesting read for its theoretical
description of how the device works based on current phases in the circuit. A pair
of flashlight bulbs and couple feet of wire is all that is needed. When operating
properly, the "twin lamp" indicator indicates by virtue of whether one or both bulbs
are illuminated whether there is a significant standing wave present on the line.
Author Charles Wright warns that the VSWR level cannot be reliably determined based
on relative brightnesses of the two bulbs; it is meant for use as a best case indication
for tuning and/or as a gross fault indicator...
 Phase noise measurements quantify the short term
stability of a frequency source. That is because phase and frequency are mathematically
related by a differential function [ω(t) = dΦ(t)/dt] so they are directly
connected. Phase noise also includes amplitude instability due to atomic scale
effects like FM flicker noise (1/f3), white noise (1/f2), PM flicker
noise (1/f), and possibly even voltage supply noise (typically discrete spurs).
When the frequency source is used as a local oscillator in a frequency converter
(up- or down-), the amount of instability (jitter) is modulated onto the
transmitter or received signal. While not usually a major concern in analog
systems, in high speed digital communication systems phase noise can degrade the
ability of the receiver to correctly determine the difference between a "1" and
a"0." That is because...
 This is another Radio Service Data Sheet
that appeared in the March 1936 edition of Radio-Craft magazine. I post
this schematic and functional description of the Crosley Model 515 (Fiver) 5-Tube
2-Band Superhet radio manufacturers' publications for the benefit of hobbyists
and archivists who might be searching for such information either in a effort to
restore a radio to working condition, or to collect archival information. An extensive
list of similar radio service data sheets from many different electronics magazines
of the day is at the bottom of the page... |
