See Page 1 |
2 |
3 |
4 | of the June 2023 homepage archives.
Wednesday the 14th
The veracity of claim of ownership to many
(maybe most) of the world's significant inventions is challenged either by others
who seek credit, or by historians desiring to "set the record straight." In this
1963 Radio-Electronics "Inventors
of Radio: Sir Oliver Joseph Lodge" article, author Dexter Bartlett says
that Sir Lodge was the first to build a coherer, not Édouard Branly. Interestingly,
Mr. Bartlett credits David Edward Hughes for the cohere prior to Branly as
well. Maybe the Bartletts and the Branlys had a long-standing family feud going
on, and he would sooner give credit to King George than to Branly ... but I digress.
Sir Lodge had many notable accomplishments, including a tuned wireless telegraphy
patent he sold to Marconi, portable antennas, and a triode detector circuit. See
patent US609154A "Electric Telegraphy," granted May 21, 1901...
Apollo 11 astronaut
Colonel Buzz Aldrin, the second man to ever
stand on the moon's surface - and the first ever to photograph another man standing
on the moon's surface - retired from the U.S. Air Force as a full bird colonel.
As the result of a distinguished career as a fighter pilot and test pilot, and after
earning a PhD in astronautics from MIT (thesis: "Line-of-sight guidance techniques
for manned orbital rendezvous"), and after flying as an astronaut in NASA's
Gemini space program, Buzz Aldrin was chosen as one of the three-member Apollo 11
crew (along with Neil Armstrong and Michael Collins). On May 5, 2023, at the Space
Systems Command Los Angeles Air Force Base, Buzz was honorarily promoted to the
rank of brigadier general (one-star) in the U.S. Space Command. Congratulations,
Brigadier General Buzz Aldrin!
Have you ever heard of a "globar"
resistor? They have been around since the early days of radio and were used,
among other things, to protect vacuum tube heater elements from burning up due to
high inrush current when first turned on. Globars have a negative temperature coefficient
(NTC) of resistance so that, opposite of standard carbon and metal film type resistors,
they exhibit a higher resistance when cold than when hot. Mac and Barney discuss
their use in this episode of "Mac's Radio Service Shop." You might be more familiar
with the name "thermistor" for such devices, but globars are unique elements in
that their construction from non-inductive ceramic material makes them useful at
high power levels and high frequencies. Globar appears to now be owned by Kanthal
(aka Kanthal Globar). Interestingly, Keysight Technologies (formerly Agilent Technologies,
formerly Hewlett Packard) has an old Educator's Corner document where the student
plots the resistance of a globar resistor against its temperature...
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...
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.
Tuesday the 13th
Take note of the unique Smith Chart superimposed
on the original soothsayer's crystal ball in this "Mysticism
in Output Matching" article, which appeared in Radio-Electronics magazine. That
is a rendition of the 3D Smith Chart* as developed by Dr. Andrei A. Muller
and his team. Having only been recently created, the 3D Smith Chart was not around
in 1963 when Herbert Ravenswood published his piece. In fact, although Phillip H.
Smith's original Smith Chart had been around since 1939, it does not appear anywhere
in the article. Mr. Ravenswood addresses the important difference between maximum
power transfer and maximum efficiency of power transfer. Audio frequencies are specifically
addressed (which might explain the absence of a Smith Chart) with regard to interfacing
the output of a power amplifier to a speaker, but the concept is similar when dealing
with RF frequencies. As with many articles on matching, the reactive part is not
dealt with, so really it is an article on resistance matching, not impedance matching
(unless there happens to be no reactive component)...
Being that the world's largest RF and microwave
trade show, IMS2023 (International Microwave Symposium - see
Exhibit Floor map) is happening this week in San Diego, CA, I thought this
Dilbert™ comic strip from May 6, 2012, would be a fitting subject for posting
on RF Cafe. Having been to a couple of the IMS shows and talking to exhibitors,
many seem to actually relate to Dilbert's experience. The main value of having a
presence there is often simply being seen in the realm of major players, which confers
a certain level of industry gravitas. So, even if spending a week at the show does
not directly result in new customers, at least some companies believe the cumulative
effect of a persistent presence will pay off in the long run. At least one major
RF/microwave manufacturer has concluded otherwise. Other
Dilbert resources here...
The early 1960s was evidently a good time
for printing quizzes in electronics magazines. Popular Electronics was
no exception. As I look through my collection I am finding quite a few. Here is
the latest, from the January 1963 edition, that tests basic knowledge of using analog
multimeters (digital types were not around yet). All are pretty straightforward;
however, be careful with question 9. At first I thought maybe it was a trick question,
but the key to arriving at the correct answer is noting that you are measuring a
low resistance. Be sure to consider the properties of a standard multimeter of the
era. Give it a try for yourself to see how well you fare. There was another
Electronic Measurement Quiz in the August 1967 issue of Popular Electronics...
everythingRF is providing live coverage
of events at the IEEE's IMS2023 show in San Diego, from June 11th to 16th. The symposium
will be conducting a technical conference along with a 3-day exhibition that includes
400+ exhibitors from around the world, showcasing their products and services. IMS
is the flagship event in a week dedicated to all things microwaves and RF. The week
also includes the IEEE MTT-S Radio Frequency Integrated Circuits Symposium (RFIC)
and the Automatic Radio Frequency Techniques Group (ARFTG). IMS will hold a competition
of the 50 top-ranked papers, as determined by the Technical Paper Review Committee
(TPRC), that will be invited to submit their paper to the IEEE Microwave and Wireless
Components Letters (MWCL) for publication. A
floor plan of the Exhibit Hall is available here.
In this article from a 1942 issue of QST
magazine, author T.A. Gadwa employs a
standing wave mechanism analogy that I don't recall having read before - that
of a dam on a river. The river is the transmission line with a lake as the source
(presumably) and then he imagines a dam load. The dam standing waves, per his description,
have phase and amplitude characteristics that depend on how tall the dam wall is
relative to the surface height of the dammed river. An extensive array of graphs
is provided showing how the current of the dam standing waves react to the dam transmission
line termination impedance. I always wonder when seeing electrical-mechanical parity
examples whether, as with this case, there are any dam magazine articles out there
that use an electrical transmission line to help fellow civil engineers...
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 17,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be.
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."
Monday the 12th
Take a look at the
variation in antenna design in the 1960s as presented in Radio-Electronics
magazine. There was a boom in television and FM radio happening at the time, and
antenna manufacturers were coming out with great new designs that promised to squeeze
out that last little bit of signal reception and interference rejection. While fundamentally
most of the antennas featured the standard array of straight, constant diameter
reflector and radiator elements, many also incorporated fancy flat metal patches,
spirals, and what resemble modern printed elements without the substrate. My guess
it was mostly a combination of marketing hoopla and an effort to avoid patent infringements.
There are not many TV and FM radio antenna models available today, but those that
are generally don't have all the extra features. Some of the modern compact TV antennas
made for receiving digital signals sport some fancy stuff, but they are fundamentally
log periodic or Yagi design. Ham antennas typically do not have all the extra gimmicks,
either. Aside from that, I have to acknowledge the amount of effort that went into
illustrating all 30 of these antennas. A EM analysis of each using the latest modeling
software...
When you think about wireless (radio) saving
the day for reporting trouble at sea, most of us (including, until now, me) think
of the
RMS Titanic incident that occurred on 14 April, 1912. Her telegraph operator,
Jack Phillips, managed to get off an SOS (actually "CQD" in the day) message that
was picked up by the ship Carpathia. In fact, this story of the SS Republic recounts
events on January 23, 1909 when the good ship collided with Italy's Florida. Radio
operator Jack Binns managed to get off a CQD message using backup batteries once
he discovered the ship's power had gone down. Jack Phillips had the dubious honor
of gaining celebrity for his heroic action a few year after Jack Binns. If I were
the owner of ocean-faring vessels in those times, I would be sure to always hire
radio operators named Jack! Mr. Binns wrote the foreword to Allen Chapman's...
The
International Microwave Symposium (IMS) 2023, the RF, microwave, and wireless
industry's premier trade show, is happening this week in San Diego, California.
It runs from Sunday, June 11th, through Friday, June 16th at the San Diego Convention
Center. Many of RF Cafe's generous sponsors have display booths set up on the Exhibit
Floor. Their locations are labeled on the layout shown above. Clicking on the image
will open a much larger version with legible print. While you are roaming, cruising,
and perusing, please be sure to stop by and say hello to them and thank them for
supporting RF Cafe. The matrix of company thumbnails on the left side represent
all that are currently on RF Cafe, though some are not attending the show. BTW,
be sure to see the Historical Exhibit for some amazing bits of our industry's development...
If you happen to be Estonian, you might
think of something entirely different than most RF Cafe visitors do when we hear
the word "getter."
In fact, you probably capitalize the word since it is the name of a pop singer from
your country, Getter Jaani. If you are a child living in Japan, you would probably
think of Getter Robo, an anime from a popular cartoon series. I suspect just about
everyone who visits RF Cafe knows getter as the silvery deposit (typically barium)
that resides inside vacuum tubes for the purpose of helping to maintain the vacuum
and to absorb pesky random molecules that might otherwise cause electrical noise
in the circuit. This article from a 1958 edition of Radio-Electronics magazine
discusses the purpose of getter. BTW, I had never heard of either of the other two
Getters, probably due to OGS (old guy syndrome)...
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 17,000 pages in the Google search index, RF Cafe returns in favorable
positions on many types of key searches, both for text and images. New content is
added on a daily basis, which keeps the major search engines interested enough to
spider it multiple times each day. Items added on the homepage often can be found
in a Google search within a few hours of being posted. If you need your company news to be seen, RF Cafe is the
place to be.
SF Circuits' specialty is in the complex,
advanced technology of PCB fabrication and assembly, producing high quality multi-layered
PCBs from elaborate layouts. With them, you receive unparalleled technical expertise
at competitive prices as well as the most progressive solutions available. Their
customers request PCB production that is outside the capabilities of normal circuit
board providers. Please take a moment to visit San Francisco Circuits today. "Printed
Circuit Fabrication & Assembly with No Limit on Technology or Quantity."
Sunday the 11th
This custom RF Cafe electronics-themed crossword
puzzle for June 11th contains words and clues which pertain exclusively to the subjects
of electronics, science, physics, mechanics, engineering, power distribution, astronomy,
chemistry, etc. If you do see names of people or places, they are intimately related
to the aforementioned areas of study. Being that "K" is the 11th letter of the alphabet,
it is used as the first and/or last letter of many words in today's crossword puzzle.
As always, you will find no references to numbnut movie stars or fashion designers.
Need more crossword RF Cafe puzzles? A list at the bottom of the page links to hundreds
of them dating back to the year 2000. Enjoy.
This assortment of custom-designed themes
by RF Cafe includes T-Shirts, Mouse Pads, Clocks, Tote Bags, Coffee Mugs and Steins,
Purses, Sweatshirts, and Baseball Caps. Choose from amazingly clever "We Are the World's
Matchmakers" Smith chart design or the "Engineer's Troubleshooting Flow Chart."
My "Matchmaker's" design has been ripped off by other people and used on their products,
so please be sure to purchase only official RF Cafe gear. My markup is only a paltry
50¢ per item - Cafe Press gets the rest of your purchase price. These would make
excellent gifts for husbands, wives, kids, significant others, and for handing out
at company events or as rewards for excellent service. It's a great way to help
support RF Cafe. Thanks...
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.
Friday the 9th
"A battle is developing over spectrum space."
That is the opening line in the News Briefs feature of Radio-Electronics
magazine in 1968. Spectrum crowding then is peanuts compared today's airwaves. The
Federal Communications Commission (FCC) began auctioning off spectrum in 1994 ("Auction 1"),
selling space in the Narrowband Personal Communication Service (PCS) band. Since
then, billions of dollars have been sucked out of the commercial sector (ultimately
paid by private users). Governments have an insatiable appetite for Other People's
Money (OPM, pronounced "opium"), and rule with the heavy-handed power authority
of all federal enforcement agencies - including the military. The sunspot maximum
for Solar Cycle 20 occurred around May 1969, with a monthly occurrence of 169.
The NOAA chart shows Solar Cycle 20 is one of the longest on record but far
from one of the most intense. The previous cycle peaked at 359 sunspots. We are
currently on the upward side of Solar Cycle 25, with a peak thus far of 112
sunspots. It looks a lot like Cycle 24...
Hallicrafters gave servicemen an opportunity
to earn some cash by writing about their font line experiences using radio equipment
built by Hallicrafters. The $100 top prize in 1944 is the equivalent of $1,705 in
2023 money (per the BLS Inflation Calculator) - not chump change in any year. Hallicrafters
was a premier manufacturer of radios for commercial, hobby, and military use before
World War II broke out. Once the United States was drawn in by the Imperial
Japanese Navy's December 7, 1941 surprise attack on Pearl Harbor, no time was wasted
converting the majority of production for electronics, transportation, and other
realms into almost exclusively war production. Hallicrafters was, of course, onboard.
Life took a sudden turn for many Americans as fathers, husbands, cousins, uncles,
and brothers went off to fight battles in foreign lands. Communications to and from
loved ones back home were difficult as priority was assigned to military channels,
but that didn't discourage thousands of servicemen from writing letters during moments
of discouragement or following victories. Many were penned from inside fox holes
and bunkers, or even while riding in a C-47 on the way to being air dropped into
a fire zone...
Note "equity" vs. "equality" - a significant
difference meaning a legally mandated result vs. an unbiased opportunity to achieve
a result. Marxism vs. capitalism. The Federal Communications Commission has released
an updated version of its
National Broadband Map, one that FCC Chairwoman Jessica Rosenworcel said reflected
a 'big' step in a new, iterative process that is meant to provide a more accurate
and up-to-date picture of broadband access across the United States. This version
of the map, as well as continued challenge-based refinements, will be used as the
basis for state allocations from the massive Broadband Equity, Access, and Deployment
(BEAD) funding program aimed at closing the digital divide, according to the National
Telecommunications and Information Administration. The executive-branch agency added
that it 'is confident that with this data as a baseline, we will be able to effectively
allocate [BEAD] funds by the end of June. We will continue to monitor the FCC's
updates to availability data to ensure that we make a well-informed allocation of
these vital funds.' The FCC released what it called its 'pre-production' maps..."
Leeds, which dubbed itself "The Home of
Radio," has been in New York since at least 1923. This advertisement appeared
in the December 1931 edition of QST magazine. Leeds is still in operation
today in Brooklyn under the name of Leeds Radio. They were one of the original "Radio
Row" companies. Looking at the ad is a step back ninety years into the past, but
the nostalgic waxing does not have to end there. If you want a trip back to the
beginning days of the World Wide Web, go to the current Leeds Radio website. It's
format-less text presentation with basic hyperlinks is circa 1992 when bulletin
boards ruled the day and the Mosaic browser was just giving web surfers their first
taste of a GUI. The only images I found on the Leeds website were a few scans of
old advertisements...
It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
Reactel has become one of the industry leaders in the design and manufacture
of RF and microwave
filters, diplexers, and sub-assemblies. They offer the generally known tubular,
LC, cavity, and waveguide designs, as well as state of the art high performance
suspended substrate models. Through a continuous process of research and development,
they have established a full line of filters of filters of all types - lowpass,
highpass, bandpass, bandstop, diplexer, and more. Established in 1979. Please contact
Reactel today to see how they might help your project.
Thursday the 8th
"Getting a hernia and not getting paid for
it?" That's the lead question in this Loral Distributor Products ad in a 1968 issue
of Radio-Electronics magazine. My response is to ask the obvious question:
Are there actually people who do get paid for getting a hernia? Hernia repair† surgeons
probably saw a lot of business from TV repair guys who did in-home service and had
to lug sets from the truck to and from the house and shop. Even with using a hand
truck the large console type TVs were a bear to move around. If you have seen some
of the electronics themed comics from magazines of the era (I've posted hundreds
of them), the often stressful life of mobile repair guys is a common topic. Loral
doesn't offer a solution to boat-anchor-heavy TV sets, but they do claim using their
capacitors will reduce the number of repeat service calls needed...
Innovative Power Products (IPP), with more
than 30 years of experience designing & manufacturing RF & microwave passive
components, is proud to announce its unique online
Interactive S-Parameter Viewer! This one-of-a-kind online viewer allows you
to scroll, zoom, point and select a sub-band. The viewer, still in beta, adds the
flexibility of showing out-of-band data as well as the value at each data point
just by hovering the cursor over the data point. Use the checkboxes to view individual
S-Parameters, or choose to view by groups: All Transmission, All Reflection, All
Isolation or All Parameters. You can view data in Log-Magnitude view, as a Smith
Chart, or as Unwrapped Phase...
Nuclear energy was a big topic in the 1960s
and 1970s as it was believed to be the future of electrical power generation for
the world (at least up until the 3 Mile Island, Chernobyl, and Fukushima incidents
occurred). Ships and submarines were being powered by reactors that allowed them
to run for months at a time without refueling, atmospheric emissions were practically
zero, and the fuel source was abundant (albeit not simple to obtain). Medical and
space applications were increasingly dependent on a greater knowledge of radiation
and its effects on humans, plants, animals, and electronics. Many people by that
time were working with and around radiation sources, so having knowledge of which
is and is not safe was paramount to responsible activities. Proper operation of
many types of equipment depend on adequate shielding from the effects of radiation.
Probably the two major discriminators...
Who says that supergenius astrophysicists
don't have a sense of humor? Certainly not me, and here's proof. A news story entitled
"Gravitational
Lensing of Supernova Yields New Value for Hubble Constant," tells an amazing
account of how a group of researchers exploited the phenomenon of gravitational
lensing (a relatively new discovery) by a recently discovered supernova to calculate
a more accurate value for the Hubble constant (H0). Here's the hilarious
part: One of the three primary research groups in the quest for ever-improved Hubble
constant values calls itself
H0LiCOW (H0
Lenses in COSMOGRAIL's Wellspring). "A study
of how light from a distant supernova was gravitationally lensed as it travelled
to Earth has been used to calculate a new value for the Hubble constant - an important
parameter that describes the expansion of the universe ... The lumpy distribution
of mass in the cluster created a complex gravitational field that sent the supernova's
light along several different paths towards Earth. When the supernova was first
observed in 2014, it appeared as four points of light. As the four points faded,
a fifth appeared 376 days later. This light was delayed by the longer path it had
taken through the cluster. During those 376 days the universe had expanded, which
means that the wavelength of the late arriving light was redshifted..."
Holy cow, another
nonconstant constant!
Here it is the year 2023, a full 92 years
after this editorial was published in ARRL's QST magazine, and nobody is
any more certain of the origin of the term "Ham" being applied to amateur radio
operators than they were in 1931. Being closer to the date of origin, though, might
have given editor Kenneth Warner a bit more insight. In fact, the term Ham is usually
uttered in a mildly pejorative manner; e.g., "he is such a ham." Per the QST's
editor's research, Ham might be a shortening of Hamlet, referring to Shakespeare's
play and the 2-bit actors who endlessly recited the lines in an attempt to impress
others. Analogously, a Ham radio operator would be a professional broadcaster wannabe.
However, Mr. Warner offers an even more plausible explanation that has the term
descending more directly from the craft of amateur radio operation. Read on to find
out...
It was a lot of work, but I finally finished
a version of the "RF & Electronics Schematic & Block Diagram Symbols" that
works well with Microsoft Office™ programs Word™, Excel™, and Power Point™.
This is an equivalent of the extensive set of amplifier, mixer, filter, switch,
connector, waveguide, digital, analog, antenna, and other commonly used symbols
for system block diagrams and schematics created for Visio™. Each of the 1,000 or
so symbols was exported individually from Visio in the EMF file format, then imported
into Word on a Drawing Canvas. The EMF format allows an image to be scaled up or
down without becoming pixelated, so all the shapes can be resized in a document
and still look good. The imported symbols can also be UnGrouped into their original
constituent parts for editing. Check them out!
Werbel Microwave is a manufacturer of RF
directional and bidirectional couplers (6 dB to 30 dB) and RF power dividers
/ combiners (2- to 16-way) with select models operating up to 26.5 GHz and
100 W of CW power (3 kW peak). All are RoHS and REACH compliant and are
designed and manufactured in our Whippany, NJ, location. Custom products and private
label service available. Please take a couple minutes to visit their website and
see how Werbel Microwave can help you today.
These archive pages are provided in order to make it easier for you to find items
that you remember seeing on the RF Cafe homepage. Of course probably the easiest
way to find anything on the website is to use the "Search
RF Cafe" box at the top of every page.
About RF Cafe.
Homepage Archive Pages
2024:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2023:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2022:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2021:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2020:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2019:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2018:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2017:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2016:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2015:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2014:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2013:
Jan |
Feb |
Mar |
Apr |
May |
Jun |
Jul |
Aug |
Sep |
Oct |
Nov |
Dec
2012:
1 |
2 |
3 |
4 |
5 |
6 |
7 |
8 |
9 |
10 |
11 |
12 |
13 (no archives before 2012)
|