RF Cafe Software
About RF Cafe
1996 - 2016
BSEE - KB3UON
RF Cafe began life in 1996 as "RF Tools" in an AOL screen name web space totaling 2 MB. Its primary purpose was to provide me with ready access to commonly needed formulas and reference material while performing my work as an RF system and circuit design engineer. The Internet was still largely an unknown entity at the time and not much was available in the form of WYSIWYG ...
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These items are an archive of past Topical Smorgasbord items that have appeared on the RF Cafe homepage. In keeping with the "cafe" genre, these tidbits of information are truly a smorgasbord of topics. They all pertain to topics that are related to the general engineering and science theme of RF Cafe. Note: There is also a huge collection of my 'Factoids' (aka 'Kirt's Cogitations') that might interest you as well.
"It's Déjà Vu All Over Again"
That is probably Yogi Berra's most famous line, and is the first thing that came to mind today when I read in the local newspaper where GE Transportation here in Erie, Pennsylvania, plans to layoff 950 production and 100 management employees. An additional 200 "temporary" layoffs could also occur. Rumors have been in the works for a couple years regarding an eventual total plant closing, since a new plant with the same capability (and more) was being established in Fort Worth, Texas. The Erie location is totally unionized, and Texas is a Right-to-Work state (union membership not mandatory). In an effort to be "globally competitive," labor rates must be kept as low as possible - for everyone, not just production workers. Texas also has no income tax, which helps keep wages low as well. Property taxes in Erie are quite high, typical of the Northeast...
FITSAT-1 CubeSat Flight over Erie, Pennsylvania
I stayed up late last night (early this morning, actually) to watch the FITSAT-1 CubeSat satellite flash its Morse code "HI DE NIWAKA JAPAN" message via super-bright LEDs over eastern North America. It was scheduled to pass just south of my location in Erie, Pennsylvania, at 1:14 AM, with a lights-on intensity great enough to be easily seen with binoculars. FITSAT-1 is a project conceived of and built by professors and students at the Fukuoka Institute of Technology (FIT) in Japan. In addition to the LED visual display, the satellite also carries several Amateur Radio payloads including a CW beacon on 437.250 MHz, a telemetry beacon on 437.445 MHz and a high-speed data downlink on 5,840.0 MHz. The CubeSat Project was developed by California Polytechnic State University and Stanford University's Space Systems Development Lab. It creates launch opportunities for universities previously unable to access space. A CubeSat...12/12/2012
Learn Almost Anything for Free"Learn almost anything for free." That is the tag line of the Khan Academy. While the claim is a bit of a stretch, especially when you need to delve below surface level, they do have over 3,300 videos on everything from math to physics, finance, and history. According to their website, in August 2004, Sal Khan began remotely tutoring his cousin, Nadia, who was struggling with unit conversion. Soon, Sal also began tutoring her brothers as well. He became so popular that he started recording videos and posting them on YouTube. More and more people kept watching, and Sal has continued to make videos ever since. Khan eventually drew the attention of Google ($2 million grant) and Bill Gates ($1.5 million grant). The rest, as the saying goes, is history. RF Cafe visitors might be particularly interested in subjects like circuit analysis (4 lessons), capacitance, magnetism (12 lessons), electric motors, electrostatics, Doppler, optics, and fields. You might also like watching the video lessons on momentum and torque, friction, gravity, thermodynamics (5 lessons), Newton's laws , and fluids (12 parts)...
Tax Day 2013: RF Cafe's *Fair Share*
Tax Freedom Day for this year is April 18 - five days later than last year. Today, April 15, is the day in America by which half the population gets to pay its *fair share* to the government in the form of income taxes (the other half pays no income taxes). Oh, excuse me, it is when we are "asked" to pay our fair share. Don't you love the "asked" term ...as if we have the option of refusing without going to jail? Six envelopes are pictured here that contain various tax mailings for Melanie and me: one each to the IRS for income tax and Q1 estimated income tax, state income tax and Q1 estimated income tax, local income tax and estimated income tax, plus a local services tax. The local services tax is just for the 'privilege' of working - I kid you not. After paying federal, state, and local income taxes, sales taxes on all we bought (including gasoline), utility taxes, taxes on savings, property taxes, school taxes, etc., etc., etc., our total 'fair share' works out to 37.6% on adjusted gross income. So, more than a third of my income was paid in taxes. Just our federal adjusted gross tax alone worked out to 26.6% of adjusted gross. By comparison, according to Whitehouse.gov, "The President's effective  federal [adjusted gross] income tax rate is 18.4%..."
PartSim Online Analog Circuit Simulator
Simulation Program with Integrated Circuit Emphasis (SPICE) has been around since 1973. The basic computational engine has always been open source. It began as a simple analog circuit simulator that took a structured text file as the input net list and provided a text file output that contained the calculated values that the user specified such as DC bias points, transient analysis, and AC analysis. Component models started with relatively simple definitions. If you wanted a graph of the response, it was in the form of text characters with a standard 80-column division on the y-axis and the x-axis was as many divisions as it needed to be to cover all the points calculated (often printed out on fan-fold paper in a pin printer). Yes, I personally used those versions in the mid 1980s. As time progressed, improvements were added to the computational engine to handle a wider range of component models including digital and RF/microwave. More parameters were added to component models to yield a better agreement between simulation and laboratory measurements. Lagging...12/20/2012
Is a Picture Still Worth a Thousand Words?
The old adage about a picture
being worth a thousand words is validated often with charts and graphs made for science, engineering, and finance. This chart illustrates levels
of collaboration between 25 countries on scientific papers published in 2011 in a select group of journals. Author John Sexton uses color and
line width to indicate origin and volume between countries. Circumferential length is relative volume overall. He also includes a similar chart
showing internal collaboration within the 10 countries with the highest scientific paper output. Per Mr. Sexton, in 1996 about 25% of scientific
articles were authored by people in two or more countries; today it is 35%. Non-commercial "Big Science" projects like the Large Hadron Collider
(LHC) at CERN, with multinational funding, contribute largely to the increase. Aptly pointed out is how global access to and...
RF Cafe Communications Central
How much do you pay every month for all of your personal communications? That includes, but is not limited to, smartphones with data plans, land lines, Internet, cable TV or satellite TV, wireless tablets and computers. Life in 2013 practically requires some degree of connectivity, but many people are paying for way more of it than necessary. I absolutely need a high speed Internet connection because of publishing RF Cafe (14 Mbps for $44.90 per month). Since most of my personal communications are via e-mail, phone service is not a high priority so my cell phone is a TracFone that I pay under $100 per year to use (mainly when away from home). Since there is no time for TV, any watching is done via the Internet - it doesn't matter if shows are a week or month old - so no cost there. I like using an old-fashioned telephone with a handset at home, so a landline is also used. Up until a couple months ago I was paying the local phone company $27 per month for basic local service (no long distance, caller ID, messaging, etc.).
How to Draw a Circle with a Square
"Squaring the circle" may as yet be
an unattainable goal for even the best mathematicians, but the November 2012 edition of The Family Handyman magazine had a tip for how to use
a square (of the framing type) and two nails draw a circle. This is what it said: "Make a Circle with a Square - Here's a tip for laying out small
circles or parts of circles. Tack two nails to set the diameter you want, then rotate a framing square against the nails while you hold a pencil
in the corner of the square. You might need to rub a little wax or some other lubricant on the bottom of the square so it slides easily. Don't
ask us why this process works; all we know is that it does." They're either very honest or they don't think the average reader would understand
the explanation. The Pythagorean theorem is the key, of course, for explaining the reason. For any right triangle: a2 + b2 = c2,
where 'a' and 'b' are the lengths of the two perpendicular sides, and 'c' is the length of the hypotenuse...
PartSim Online Analog Circuit Simulator
Each year the Foundational
Questions Institute (FQXi) holds an essay contest inviting writers to submit missives addressing the question chosen by the FQXi board as being
particularly thought-provoking. In their words, "FQXi catalyzes, supports, and disseminates research on questions at the foundations of physics
and cosmology, particularly new frontiers and innovative ideas integral to a deep understanding of reality, but unlikely to be supported by
conventional funding sources." The 2011 question was "Is Reality Digital or Analog?" Scientific American magazine, being one of three
partners, published the runner-up entry in the December 2012 issue: University of Cambridge professor of theoretical physics professor David
Tong's paper argues that the world is in fact fundamentally analog.
Professor Tong actually tied for second place, but for some reason SciAm does not tell us whether the other second place paper supported an analog or digital viewpoint. For that matter, it did not say which side the winning paper came down on. Strange. I looked it up on the FQXi website. First place went to Jarmo Makela, who believes reality is digital in nature based on a personal discussion with Isaac Newton in his London home in the year 1700. When...
What's Fair About an Internet Sales Tax?
You have probably heard and/or seen the scuttlebutt about Congress trying to push through an Internet sales tax, ostensibly in order to level the playing field for brick and mortar businesses versus online businesses. You can be sure the effort has nothing to do with fairness and everything to do with politicians' insatiable appetite for tax money. They have been salivating over the possibility of reaping that new revenue source for years. The plan is to require online sales from out-of-state buyers to have sales tax collected and remitted to the appropriate state revenue department. Local businesses are per the claim disadvantaged because they must collect their home state's sales tax, which supposedly causes buyers to prefer Internet vendors in order to avoid such taxes. As one who has purchased many items over the Internet in the last 15 years, I can't think of many times when avoiding sales tax was the prime motivation for my decision. It was usually because either the item I wanted was not...
What Does Your Daily Commute Cost You?
How far do you commute
each day for the privilege of doing your part to push back the frontiers of technical ignorance and to boldly go where no engineer - or technician
- has gone before (split infinitive by
Roddenberry, not me)? Do you know what the cost equates to you each
year? This handy-dandy poster by the folks at Streamline Refinance lays out some gruesome numbers. Those with a weak stomach probably should
pass on viewing this one. Here's a hint at what you will see: See that big $795 in the thumbnail image? That's the average
cost per year for commuting -- per mile! Yessiree, if you live just 10 miles from work,
you're losing nearly $8k per year, depending on you automobile type, on gas, tires, maintenance, devaluation, and loss of your personal time
(which is valuable, after all). Back in the early 1990s I drove 45 miles each way to Comsat, which took about
65 minutes due to miserable traffic. That's 130 minutes round-trip, or 2 hours and 10 minutes
(about the run time of an average movie) each day. Figuring two weeks vacation and 10 holidays, that leave 48
weeks x 5 days/week = 240 days per year of commuting. 240 days...
PartSim Online Analog Circuit Simulator
Every week while sitting in the studio where Melanie takes her cello and piano lessons, I usually read
technical and hobby magazines, but lately I have been studying the ARRL General Class License Manual in preparation for taking the
written exam in a couple months. Last week a lady saw the book title and remarked, "I didn't know
ham radio people
were still around." Wow. It would be tempting to blame her for being ignorant, or to blame the ARRL (American Radio Relay League) for not adequately
getting the word out, but the reality is that the mass media does not consider Ham radio's contribution to be significant enough to cover in
news stories. Amateur radio operators perform a mighty service in times of trouble, but they do it so efficiently and effectively- without actively
seeking credit - that their efforts are lost in the noise. Ham radio operators have been on the front lines of national and civil defense since
World War II and even a bit before...