Every once in a while an RF Cafe visitor
writes to let me know that he or she found one of the vintage electronics magazine
articles I post regularly useful. It helps to validate my efforts, which is critical
for motivation to continue. A couple days ago Mr. Dave Jones (N1UAV), sent
me a note about the stacked television antenna project he undertook after finding
to Stack TV Antennas to Increase Signal Strength and to Reduce Ghosts" article
from the November 1965 issue of Popular Electronics magazine. His location
about 90 miles outside of Nashville, TN, is a challenge for trying to receive a
good signal from a television station from both an attenuation and multipath signal
degradation perspective. Dave began with a single antenna, but was not happy with
the performance. The results of adding the second antenna is amazing ...
Sometime around 1980, while stationed at
Robins AFB, Georgia, I finally succumbed to the peer pressure of other more sophisticated
audiophiles in the barracks and bought a "real" stereo. Unlike my roommate who had
a full compliment of rack-mounted gear, my meager enlisted military pay only allowed
for a mid-grade instrument. The solution was a
Sansui TA−300 Integrated Tuner Amplifier. It put out a whopping 30 watts per
channel, but unlike my existing radio (a Readers Digest 800−XR), those 30 watts
were nearly distortion free when driving good speakers. Having only the pathetic
5 W speakers that came with the 800-XR, I designed a set of speakers rated
for 60 W, and built the enclosures myself in the base woodshop. Unfortunately,
in preparation for a household move about 20 years ago, I sold the Sansui and the
As you already know if you are planning
to be at the International Microwave Symposium (IMS) this year, it is being held
from June 2nd through the 7th in Boston, Massachusetts. The last time the IMS show
was in Boston venue was 2009,
and RF Cafe was there. It was my very first IMS show. The entire day was spent taking
photographs and meeting as many RF Cafe website advertisers as possible. I also
got to visit with a few people from companies I used to work for. The
National Electronics Museum had a very nice display set up showcasing
the evolution of the Microwave industry. Up until a couple weeks ago, Melanie and were planning on returning this year
to the IMS show, but some family matters have required some extensive travel lately ...
Knowing that I am an avid consumer of literature
pertaining to time and astronomy, Melanie picked up a book at the library for me
The True Story of a Lone Genius Who Solved the Greatest Scientific Problem of His
Time, by Dava Sobel. When Christopher Columbus discovered America, his
intended target was, if you recall, the Indies. His original charter was to find
a direct westerly pathway from the Atlantic coast of Europe to the immensely
profitable trade production region of the Indies as an alternative to to sailing
around the treacherous
Cape of Good Hope at the southern tip of Africa. How could such an experienced navigator
have missed his mark by so far, you might reasonably ask? Didn't Columbus know how
to use a sextant, or at least have a navigator who could? The answer to the second
question is, "no." The answer to the first question is complicated ...
Just about everyone who has worked in the
radar field for a long time is familiar with the name of
Dr. Robert M.
Page. He was the first to come up with the concept of monopulse radar, and he
invented the familiar Plan Position Indicator (PPI) radar display and the RF duplexer
which allows one antenna to be connected to both the transmitter and the receiver.
Amazingly, I recently received an e-mail from Dr. Page's son, John Page. An
interest in his father's career combined with insight that only growing up under
the loving care of Dr. Page can provide has afforded him some unique tidbits
of information that many (most, per John) historical accountings omit. Rather than
me summarizing his letter, you will want to read it yourself as presented below.
World War II aficionados will particularly appreciate the information. John
pays homage to his father's co-workers ...
If you were around here in 2014, you might
recall my publishing a paper titled, "Drone-Based Field
Measurement System™ (dB-FMS)™." Since then, I have seen a few companies doing
and many more); others are coming online all the time. Those people have actually
implemented working systems that seem to perform very well. I'm not saying they
got the idea from my article because more than one person can have a brilliant idea
;-). It's just good to know that my idea had some merit in the real world ...
February 11, 2019
Hello. My name is Kirt, and I'm a
vintage wired and wireless communications publication addict. This affliction
has had a hold on me for going on two decades now. Call it my middle age crisis.
At sixty years old, there is no sign of abatement in enthusiasm. Nearly every day
I still find myself reading and commenting on articles and advertisements from mid-last-century
magazines, newspapers, and catalogs. Maybe I'm hopeless and will never be able to
kick the habit. I'm not alone, though, based on some of the feedback received from
RF Cafe visitors. for that reason and others, maybe, in truth, I've grown comfortable
with my addiction. While perusing a few vintage newspaper editions from the World
War II era looking for relevant stories, I ran across this November 1, 1940
(exactly 78 years ago) special section in the Harrisburg Telegraph titled,
"Radio Industry Marks 20th Anniversary." It contains many stories ...
November 1, 2018
It is probably safe to say that most people,
especially today, believe that the United States was suddenly and unexpectedly thrust
into involvement in
World War II on December 7, 1941, when the Japanese navy launched a surprise
attack on Pearl Harbor. The fact is the U.S. was "unofficially" engaged for over
a year beforehand by "lending" both equipment and personnel to British, Russian,
Chinese, French, and other militaries as part of their effort to drive back invading
German, Italian, and Japanese Axis forces. World War II actually began in the
Fall of1939 with Hitler's invasion of Poland. Americans, being safely separated
from the front lines by the Seven Seas, knew little of and were concerned little
about the goings on "Over There." Once the call to arms was sounded with the Pearl
Harbor attack, the country quickly and enthusiastically converted to full wartime
mode. Manufacturing plants ...
In all my years of repairing and restoring
old radios, I have never had the occasion to re-string a
dial cord. There are many variations on dial cord construction and diameter,
but there are even more variations in that way the path around the tuning shaft,
tuning elements, and indicator dials are implemented. Larger radios with lots of
room in them are relatively easy to re-string and usually take a fairly straightforward
path, but smaller portable multiband radios like my 1970's-vintage
Realistic Patrolman−50 are a bit of a challenge, as I found out recently. A
Web search on recommendations for how to replace dial cords results mostly in frustrated
handymen who have seemingly given up on the job. It is easy to understand why, especially
on a ridiculously complicated routing scheme. My only guess as to the need for the
multiple pulleys and specific number of wraps around each is because of the need
to maintain very solid contact while tuning four separate variable capacitors ...
Late in 2016, news outlets began reporting
on American and Canadian diplomats stationed at their respective embassies in Cuba
complaining of dizziness, nausea, headaches, ringing in the ears, and other seemingly
sound-related illnesses. Similar reports have come out of China as well. At the
time, doctors and scientists investigating the phenomenon thought maybe some sort
sonic beam was being directed at the personnel. Certain people were affected
while others nearby experienced no such phenomena, leading researchers to believe
that the presumably sonic beams were highly concentrated and directional. Some of
the targeted personal were diagnosed as having suffered mild traumatic brain injury
with likely damage to the central nervous system ...
In 2010, I posted a short piece about where
to look on the Web to learn what upper management, board members, and large investors
were doing with
insider company stock trades. At the time, the MSN Money website had a tool
where you could enter a company's stock symbol and get a readout of who was buying
and - more often that not - selling stock. That web page is gone, but I found the
same information on InsiderCow.com. The dollar amounts are truly staggering to people
like you (likely) and me (definitely). Numbers reported are sale values, not profit
to the stock holder. Many of the stocks were issued as either grants or options,
but even outright purchased stocks are included as well. Regardless, prepare to
have your jaw drop if you have never seen this type of data before. Some of the
more familiar technology companies have been selected for examples ...
While not quite the equivalent of an Elvis
sighting, I was utterly surprised to see an open
Radio Shack store in the Ashtabula Towne Square Mall during a recent trip to
Ohio. As you can see in the photo, it is a shell of a store, with products on display
only along the walls. Do you remember the days when every shopping mall and plaza
had a Radio Shack crammed full of stereos, radios, calculators, antennas, computer
accessories (and the TRS-80), toys, and of course a huge portion of the store dedicated
to electronic project components? I had a "Battery Club" card for a couple decades,
and a current catalog was always on my bookshelf. If, as the old saying goes, "Misery
loves company," then the good folks at the Ashtabula Radio Shack can at least take
some solace ...
Old Farmer's Almanac (OFA) has been on my annual need-to-buy list for as long
as I can remember. It is chock full of useful data for sunrise and sunset times*,
high and low tide times, crop planting days, first and last frost days, and significant
astronomical events. There are stories of interest on topics ranging from canning
your garden's harvest to how to view a solar eclipse. - often from noted authors,
but also from lay people. I also enjoy the monthly "on this day" type tidbits and
the homey short story relating to the time of year. After 225 years of continuous
publication, it still features the hole in the upper left corner to facilitate handily
hanging it on the wall of your shed -- or outhouse. I gave a 1961 edition of the
Old Farmer's Almanac found on eBay to Melanie as a birthday present this year ...
Electronic Counter was found in a second-hand shop sitting in with a bunch of
random electronic gear. The "HP" on the front panel piqued my attention, so I carried
it to the counter and asked the nice lady to plug it in, figuring if the front panel
lit up and none of the smoke that makes electronics work leaked out, I'd buy it.
It did, it didn't, and I did, respectively. The outside condition is pretty good,
with most of the scratches being on the top and bottom. Some oxidation is present
on the bare aluminum chassis components, but a little ...
If you grew up in the era of rooftop television
antennas, then there is a good chance you are familiar with the electromechanical
antenna pointing systems that were often installed as well. Alliance, Channel Master,
Cornell Dubilier, Radio Shack, RCA, Winegard, and others made low cost, light-duty
for television antennas. Ham radio antenna rotators were/are more robust in
order to handle higher weight and wind loads. Many television antennas also cover
the FM radio band (88-108 MHz), allowing them to do double duty. Being an unapologetic
technology renaissance man, I recently purchased (on eBay) a vintage Alliance Model
U−100 Tenna−Rotor that was unused in the original ...
The manned space program has unarguably provided
mankind with many new and innovative tools, medicines, electronics, materials, physics,
materials, appliances, and mathematics. Know officially as "spinoffs," products
like the portable heart defibrillator unit, the portable vacuum cleaner, freeze-drying
food processors, powdered lubricants, memory foam, quartz clocks and battery-powered
inventions have not found an application in your basement or garage, however, because
their purpose is too specialized. Take, for instance, the ZeRT, or Zero Reaction
You might have noticed that since last November
the engineering and science themed daily RF Cafe header images have been much larger
than those which graced the pages in the past. The change was motivated mainly by
a desire to make them more viewable on the tiny screens of mobile phones. It also
gave me the opportunity to include more information. In the process, I took the
occasion of being on each daily
and technology history page to check on the validity of the long ago included
hyperlinks to pages which validated dates of events. Use Wikipedia was avoided because
of the joke-worthy reputation it had for bogus ...
To be or not to be - that is the question:
Whether 'tis nobler in the mind to suffer the slings and arrows of outrageous bi-annual
clock shifts, or to take up arms against a sea of contradicting justifications for
and against its existence for DST, and by opposing, end it. Twice each year, a majority
of the western world is subject to a manmade disruption in circadian and habitual
cycles with an inane one-hour clock change on and off of "Daylight
Saving(s) Time" (DST). Some historians claim that Benjamin Franklin joked about
DST in the 18th century, but it was New Zealander George Hudson who proposed the
modern day clock ...
Have you ever started a relatively simple
investigation into a trivial matter, only to find yourself going down the metaphorical
"rabbit hole" even after finding the original answer? Such was the case for me when
someone sent me an e-mail with a signature that included his
amateur radio call sign. The first three characters, KB3, matched mine and that
got me wondering on what date his call sign was granted compared to mine. Let us
say for example* the writer's call sign was KB3PGM and mine is (actually) KB3UON.
I looked them up in the FCC's ULS self-serve license ...
If, as the saying goes, "Misery loves company,"
then you will appreciate the following. Whilst perusing the December 2017 issue
of NASA's Motion Design supplement to their Tech Briefs publication,
I ran across the image to the right in an article titled, "Trends in Hydraulic Filtration"
(areas of interest are quite diverse here at RF Cafe).
After reading the caption stating that the holes were "fire holes," the first thing
that came to mind was
Sure enough, upon going back and reading more of the story (provided by Argo-Hytos),
I found ...
Another era, sadly, has come to an end. H. Ward
Silver (aka Ward Silver, NØAX) has announced the end
of his monthly column, "Hands-On
Radio," in QST magazine. The title of each column was enumerated as
"Experiment #nnn," followed by the subject. To wit, "Experiment #179 Maxwell's Equations
- The Wave Emerges" is Mr. Silver's final column, appearing in the December
2017 QST. "Hands-On Radio" topics ranged in intensity from relatively simple
discussion on calculating power dissipation in resistors, capacitors, and inductors
to more heady treatises on subjects like electromagnetic fields within coaxial cable
and waveguide to Maxwell's equations. Mathematics, too ...
One of my favorite old-time
radio personalities, Paul Harvey, had a trademarked feature titled The Rest of the
Story. For those of you not familiar with the format, Mr. Harvey would begin his
story talking about particular life aspects of a person that, while remarkable,
usually had no connection with the person's eventual claim to fame. The listener's
challenge was to guess who the person was before it was revealed at the very end,
followed by, "... now you know --- the rest [emphasis] of the story." As far as
I know the story of FM radio inventor
Edwin H. Armstrong was never a subject, although it certainly met the criterion.
I've already let the figurative cat out of the bag, so you already know my subject ...
From May 9th through the 11th in the year
of our Lord 1958, the very first "Jamboree on the Air" (JOTA) was held by the Boy Scouts of America
(BSA). The American Radio Relay League (ARRL), in conjunction with the BSA, is promoting
this year's 60th anniversary event occurring from October 20-22. As you might imagine,
quite a lot has changed over 59 years in terms of equipment, but the basics in terms
of encouraging and assisting the next generation of licensed Hams remains as always
the primary goal of organizers. The Boy Scouts, of course, join in for the fun and
learning experience. Jamboree on the Air events, held in October, do not coincide
with the National Scout Jamboree, held in July ...
Nikola Tesla was born in 1856 in Smiljan,
Austrian Empire, and died in 1943 in New York City. His life is so amply documented
far and wide that regurgitating the information in books and blog posts would be
a waste. Most of what you find there is second-hand, having gone through the filter
of an author's preferences. I like to search for stories on various topics in their
original publications; e.g., scanned newspaper and magazine archives. A hunt for
early stories on Nikola Tesla turned up many 19th century examples from the Newspapers.com
website. It is interesting that back in the day, men like Nikola and Edison were
referred regularly to as "electricians." The oldest article I found on Nikola Tesla
appeared in the July 1, 1889 edition of The Pittsburgh Dispatch, titled "The
Electric Fiend" ...
It's finally here - the
Great North American Solar Eclipse of 2017! The amateur astronomy community
has been anticipating and preparing for the event for a couple years. Astronomy
magazine dedicated the entire August issue to providing detailed information on
viewing suggestions along the entire path. Traffic from the Pacific Coast of Oregon
to the Atlantic Coast of South Carolina will probably be a challenge as people vie
for positions as close to the centerline as possible. Those who manage optimal locations
will see about 2 minutes and 40 seconds of total darkness. Others within the 68-mile-wide
path of totality will see from a fraction of a second up to the full extent. According
to a calculator on the Vox website, we will only see a 76.2% eclipse, which will
barely darken our skies ...
Hmmm.... let us see what made the front page
of the July 1, 1948 edition of Murray Hill, New Jersey's, The Madison Eagle newspaper:
"Man Found Dead, Wedged in Drain on Park Edge," "Lawyer Fined $50 on Zone Charge,"
and Sandra Dean Stevenson had been born two weeks earlier. Oh, also included was
Replaces Vacuum Tube" and "Local Man Invents New Device in Electronics for Bell
Lab; Could Revolutionize Radio." Page 10 ran, "Bell Laboratory Releases Data on
Newly Invented Transistor." It is widely known that Drs. Brattain, Shockley, and
Bardeen formerly announced on December 23, 1947, within the walls of Bell Labs ...
We have all been treated to a seemingly endless
series of headlines portending rising ocean levels and the ensuing drowning of costal
cities due to
ice in the polar regions. This phenomenon ostensibly is brought on by the exponential
increase in carbon emissions from developing third-world countries as well as established
first-world countries in the post World War II era ... or was it post Vietnam,
or maybe post Gulf War? The reference keeps changing, but it definitely began occurring
since at least 1990, right? There is a problem, though. In the early and mid 1970s
climate scientists began warning us of an approaching ...
For some inexplicable reason, it seems that
of the many articles I read dealing with antenna and feedline efficiencies, rarely
receive side of the equation addressed. Yes, transmit power is expensive and
there is a legitimate reason to reduce losses when converting power amplifier output
to in-the-air power, especially for DX operations. However, it doesn't do much good
to launch the full permissible 1,500 watts PEP and make a contact on the other side
of the world if your system cannot receive a reply because of the excessive line
loss and/or mismatch loss between your antenna and your receiver. Antennas and feedlines
are reciprocal elements so if ...
Friends, former employees, and fellow lovers
of all things electronic, we are gathered here today to remember and honor our lifelong
friend and enabler of our hobby and passion,
- once a Tandy company, as we are familiar with it. Radio Shack has lingered in
failing health for a decade, all the time keeping a brave face on its dwindling
number of stores. Caretakers attempted a variety of infusions and transplants in
an attempt to save the American stalwart electronics retailer. Alas, a confluence
of poor management ...
For Mother's Day this year, the kids and I
got Melanie a 23andMe DNA testing kit. She has spent a fair amount of time over
the years researching the family lineage which, in case you care, traces back primarily
to Germany and Switzerland. Along with some of the online ancestry websites, she
searched the U.S. Census database for immigration and early American household information
(number of people, ages, names, occupations, etc.) The entire
1930 Census form consisted of a single page seeking basic information on whether
you own or rent, value of the home, live on a farm or not, color or race, ...
Long-time RF Cafe visitor and occasional
contributor Gary Steinhour, KF6U, recently sent me a note saying he had acquired
a very used
DX-60B amateur radio transmitter and was in the process of restoring it. Gary's
first transmitter as a freshly minted Ham over 50 years ago was a DX-60, so this
was an effort to satisfy a nostalgic emotional attachment. The project is complete
now, and boy does it look nice! Gary provides a brief account here ...
If you have ever seen the result of a lightning
strike on electronic equipment, then you know how devastating it can be - often
total destruction that includes molten metal. Woe be unto any human operator who
happens to be in contact with it at the time of the strike. Unprotected antennas
are begging for contact. Shortly after leaving a company where I worked on a Tx/Rx
system for a phased array weather radar I got word that the indoor equipment rack
took a major hit because the guy who maintained the site forgot to reconnect a
rod system cable after moving it during ...
Miscellaneous Earlier Smorgasbords and Factoids: