Rock & Roll meets Ham and Radio

Bob Heil is a ham, K9EID.  He’s also the premier person in sounding good for many musicians.   His Amateur Radio experience has taken him into the Rock & Roll Hall of Fame. 

How?

Well….watch this!

About this website

The Amateur Radio Service frequency bands are the place on the usable radio spectrum where you as an individual can develop and experiment with wireless communications. Hams not only can make and modify their own equipment, but can create whole new ways to do things.

Discrete-Method Signal Analysis

 

 An Introduction to the The Fifth Pillar for Amateur Radio

 

William E. Sabin, WØIYH

 

 At the Dayton Hamvention in May 2008, ARRL President Joel Harrison, W5ZN, announced the formation of a Fifth Pillar for amateur radio, combined with the in-existence Four Pillars (Public Service, Advocacy, Education and Membership). The purpose of the new Pillar is to encourage and enhance math, science and engineering appreciation and skills. Individuals who are interested in and involved with, at various levels, the rapidly expanding modern-age technology developments in electronic hardware and software are the intended audience. This applies in particular for us as it pertains to the art and science of Amateur radio communications, not only at the “black box” and “operating” levels, all of which are very important, but equally important at the math, science, analysis and design levels.

 

This concept was encouraged by Dave Sumner, K1ZZ, in the August 2008 QST Editorial. QEX and other ARRL Technical staff members are very active in advancing the Fifth Pillar ideas. The new ARRL website wedothat-radio.org is dedicated to this effort. Traditional (“legacy”) methods are also respected, as they should be.

 

Many national governments, including the USA, are deeply concerned with inadequate awareness and education by the general public in the fields of math and science. Many nations are ahead in this respect. The Fifth Pillar effort is dedicated to adding to the improvements in deficiencies of this kind. This brief and simple example article is also dedicated to this effort.

A Modern Discrete-Method for Signal Analysis and Design

 

The modern personal home computer, in conjunction with an elegant and sophisticated mathematics calculation program, Mathcad Version 14.0 [Ref. 1], is employed in this brief article at an introductory level that is very user-friendly. This program is used to calculate, process and graph-plot a variety of signal-processing and very many other kinds of math problems. The so-called symbolic math methods {see the Mathcad User Guide, Chapter 13} are also used in modern math computing. This software is an outstanding tutorial tool for the advancement of the engineer’s and student’s math skills, which is considered to be an important goal in today’s advanced technology environment.

 

The signals and their analyses can be in the time domain or the frequency domain, and they can be linear in nature or non-linear. Signals, before and after processing, can be switched back and forth easily between time domain and frequency domain. A complete Mathcad 14.0 program, with perpetual usage, is attached to the new book Discrete-Signal Analysis and Design [Ref. 2].  This is a special and very generous Mathcad promotional offer by the PTC company.  The User Guide that is on the compact disk can be placed on the Desktop as an icon.

 

Example: A three-tone distortion simulation. [Ref 3.]

  A typical discrete-signal processing example will help to illustrate just a few of the basic ideas of Mathcad usage in the practical world of electronic design. This and similar examples can also be further explored with circuit simulation programs such as Multisim (student edition) by National Instruments (http://www.ni.com/academic/multisimse.htm) using accurate models of I.C.’s, transistors, diodes, tubes and many kinds of passive components. In addition to the three desired tones, a large undesired “out-of-band” signal that contributes to distortion products will be examined.

 

Time domain information can be converted to spectrum results. After modifying the frequency spectrum, for example by introducing a filter or a signal interference or random noise (additive or multiplicative), the modified time domain results can then be obtained. We can also begin with various spectrum shapes that achieve certain desired time-domain results.

  Certain communications waveforms use methods similar to this example, and laboratory test equipment (http://www.ni.com/analysis/) is used to perform discrete-time and discrete-frequency tests automatically. Pseudorandom data error rates can be evaluated.

Analysis of the Example.

 

 

Illustration A & B

Part (A) shows the time-domain input Vsig(n) and part (B) the time-domain output Vout(n) of an amplifying device that is perfectly linear. The device delivers only output signals that are proportional to those at the input, i.e.,Vout(n) = Vsig(n)^1.0 times a voltage gain constant Gv. The signals in Part (A) are at frequencies 4, 7 and 9. Another much smaller input at frequency 29 will be considered a little later. Observe also the DC bias Vdc on the device. This is called the “operating point.”

 

 

 

  Part (C) is the two-sided (positive-frequency and negative frequency) phasor spectrum of the output as calculated by the Discrete Fourier Transform (DFT) of the time-domain output (part B) of the device. Part (D) shows the same actual positive-frequency signals as the input. We get these positive-frequency signals by combining the positive-frequency phasors and the negative-frequency phasors. Chapter 2 of the Sabin book explains how this is done. Also, Chapter 1 discusses phasors vs signals.

  

 Part (E) introduces a nonlinearity, the exponent 1.5, which is often used in text books [see Sabin ch. 2], in the transfer function of the device. This creates distortion products in the form of new frequencies at the output Vout(n) that are not present in the input Vsig(n). In the signal spectrum Vout(k) of part (F) many, but not all, of the nonlinear output products are identified. For example, the term at (k) = 3 is due to the term at (k) = 4 interacting with the term at (k) = 7. The 1.5 exponent also increases the voltage gain, in this particular example, to Gv^1.5. Gv can also be a more complicated time-varying function of (n) such as [Gv(n)]^1.5.

 Another consequence of the nonlinearity is that the spectrum phasors, therefore also the signals, are “complex” and may possibly display items that have a real (Re) part, an imaginary (± j Im) part, a magnitude ( |  | ) and phase angle (Θ) with respect to some “reference” phase such as zero. The graphs of parts (F) and (G) would identify these. Mathcad can be instructed to calculate and plot all of these results.

 In part (G) the interfering “out-of-band” signal at (k) = 29 is greatly increased in amplitude so that distortion terms are emphasized. The ability of a strong out-of-band interferer to corrupt a desired signal spectrum is illustrated. In particular, the spurious product at (k) = 6 stands out. In addition to this large distortion term, there are many smaller distortion products that can degrade the desired weaker signals. Also 4, 7 and 9 are degraded slightly. This is very serious interference that can be difficult and expensive to repair, especially in wideband high-level systems where filtering of strong interfering signals is expensive. A tunable notch filter is sometimes possible for constant interferers, but costly high dynamic range equipment is often indicated. We see this effect in practical environments, for example in HF/VHF/UHF radio. We now see it also mathematically.

Beyond this simplified introduction, a much more complete study would be well-justified. For a closer look at the various related technologies for this and many other topics, visit the new ARRL website www.wedothat-radio.org.

 

Ref 1.

 Mathcad, version 14.0, PTC company, Needham, MA.(http://ptc.com/products/mathcad/)  The Mathcad program is very mature and has a history of fourteen versions in more than 25 years.

 Ref 2.

 Discrete-Signal Analysis and Design, by William E. Sabin, published in January 2008 by www.wiley.com Interscience Division, available from the ARRL Bookstore, item #0140 at http://www.arrl.org/catalog/, search: Sabin.

 Ref 3.

 Sabin, W0IYH. QEX, Nov/Dec 2008 “A Modern Discrete-Method for Signal Analysis and Design” pp 36-38.

 
 

Bill Sabin, W0IYH

About the author:

 

Bill Sabin received the call Sign W9YFA in 1941 in Covington, KY at age 15. This changed to W4YFA in 1946, and to W0IYH in Iowa (Collins Radio Company) in 1964. He holds BSEE and MSEE degrees from the U of Iowa. He retired from the Rockwell Collins Company in Cedar Rapids IA in 1990. He is co-editor of and contributor to, with E.O. Schoenike, three books on Single-Sideband and HF Radio. He is the author of more than 40 technical articles and portions of the ARRL Handbook (1995 to 2009 editions). In 1983 he received the annual ARRL Technical Excellence Award. He is a member of ARRL, Life Senior Member of IEEE, and member of the ARRL DXCC Honor Roll.

 

 

 

Bill Sabin W0IYH,  w.sabin@mchsi.com

Who ya gonna call? Hams!

Back in the early-mid 1900’s, hams were often accused of being the source of interference.  With the coming of better radios and TVs, complaints now are far more likely to actually be a CB radio, not a ham radio (they are very different things!) .  But when there is something happening that’s really wierd and nobody knows what to do, who are you going to call? 

One local TV station knew the answer – call in the hams!

VoIP

VoIP: Internet Linking for Radio Amateurs

Growing numbers of hams are using VoIP, or Voice Over Internet Protocol, in combination with their radios for long-distance communication spanning hundreds or thousands of miles. They’re using the Internet as the relay between their base stations, handhelds and mobile transceivers.
There are four primary VoIP systems used by hams: EchoLink, IRLP, eQSO and WIRES-II. Getting started can vary in complexity from beginners who just want to set up and try using these systems, to arrangements with plenty of technical “meat” for those who want to dig deeper and explore how the systems actually work.
VoIP possibilities, using Amateur Radio to provide communications across expanses where normal phone services are damaged in storms, has been extensively  used in the recent past following several hurricanes.  There is an ARRL book published to help hams get involved in this new area.  This may be the first book ever written about the developing ham radio applications of VoIP. Author Jonathan Taylor, K1RFD, is the creator of EchoLink and one of the top experts in Amateur Radio Voice Over Internet Protocol. (ISBN: 0-87259-926-4)

Radio Sport by John Donovan, K6YLG

Radio Sport

 

By John Donovan  K6YLG

 

John at his radio

 

 

You know you’re a true tech geek when you play at what they pay you to do at work—or in my case, write about.

 

 

 

 

 

In Portable Design magazine I spend a lot of time covering low-power wireless issues—from exploring evolving air interfaces to explaining how to design them into the next portable gadget. In my spare time I design and build low-power wireless transceivers that operate in the amateur radio (‘ham’) bands. Working exclusively below 30 MHz, I don’t worry whether my 5 GHz UWB signal can reach from my living room to my bedroom TV. I’m more concerned about whether Serge can hear my 5W 14 MHz signal in Tahiti or Joao in Brazil. Since local deed restrictions relegate me to using an attic dipole, that’s a neat trick.

 

“Daddy listens to static.” What’s that about? In an age when cell phones have made people blasé about international wireless communications, ham radio seems like a relic—and in some ways it is. Why would you spend time analyzing sunspot cycles, atmospheric ionization and the maximum usable frequency (MUF) for wireless communication between your home and Brazil when you can just pick up your phone can call someone there?

 

Cell phones are fine for point-to-point communications when you know who you’re calling. Ham radio is fun precisely because you never know who you’ll wind up meeting. It’s a mixture of science and serendipity—like sailing. Sure, you could fire up an engine and get somewhere faster and more predictably. But as in sailing you’re harnessing a force of nature—in this case the ionosphere—and working with it for the sheer joy of the adventure. The Germans refer to ham radio as “radio sport,” which seems a fitting term.

 

Still, there is a lot of science involved, and not just in analyzing propagation. Hams have long experimented with different data communications modes, inventing more than a few. I was only able to contact Serge and Joao with my tiny transmitter because I was using PSK31, a type of binary phase shift keying invented by Pete Martinez, G3PLX. PSK31 transmits 31.25 bits per second, using a binary code whose length varies with the popularity of the letter (‘e’ is two bits, ‘z’ is nine). This makes for a very efficient modulation protocol, well suited to low power stations.

 

If band conditions permit, you can switch to QPSK31—quaternary phase shift keying—which adds a second BPSK carrier that is 90 degrees out of phase with the first. The second channel carries redundant bits, so QPSK adds a convolutional encoder to generate one of four different phase shifts that correspond to patterns of five consecutive data bits. On the receiving end a Viterbi decoder sorts it all out. All of this magic is done using your computer’s sound card and Pete’s software. Plug your computer into a 5W transmitter, add a decent antenna, and you can get a lot farther than the nearest cell tower.

 

Hams have invented and are using a number of other interesting air interfaces. Whereas PSK31 uses anywhere from 2-12 symbols per text character, MFSK (multi-tone frequency shift keying) uses only one—but modulates an RF carrier with as many as 16 different tones; while slower than PSK31, MFSK signals are less affected by multipath errors. MT-63 uses 64 different tones, plus forward error correction; MT-63 is robust against selective fading. Olivia uses a two-layer code and Walsh Functions, making it readable even when the signal is 10 dB below the noise floor (“Can you hear me now?”). JT65 is a digital protocol optimized for the extremely weak signals found in earth-moon-earth (EME) communications on the VHF bands. When not bouncing signals off the moon, hams can communicate via one of several satellites—called OSCARs (Orbiting Satellite Carrying Amateur Radio)—that support VHF and UHF communications.

 

Ham radio has come a long way since I got started. I got my novice license just after my 11^th birthday. I got on the air using a WWII surplus BC-654 transceiver (AM and CW) that ran off a battery and dynamotor. One of my first contacts was the postmistress of Vladivostok. I ran out and bought a world map and started sticking colored pushpins into places I worked, reading up about them in the encyclopedia at the local library. Ham radio really opened up the world for me. Now my kids can read all about Vladivostok on Wikipedia and call there on their cell phones. Still, all the instant information available on the Internet doesn’t begin to substitute for the thrill of the hunt and the unplanned meeting with a stranger.

 

While I enjoy experimenting with digital RF designs, I’m basically into ham radio for one reason—because it’s fun.

 

This article originally appeared as an editorial in Portable Design magazine (www.portabledesign.com) in July, 2008

 

John Donovan, K6YLG, has been a licensed amateur radio operator for over 50 years. When not writing for Portable Design magazine or skulking about trade shows, he can often be found on the digital portions of the 20-, 30- and  40-meter ham bands. He’s also active in the Amateur Radio Emergency Services (ARES) in Williamson County, Texas.

ARRL Teachers Institute on Technology

The Teachers Institute on Wireless Technology (TI) is a week long, in-residence learning opportunity designed for motivated teachers and other school staff who want to learn more about wireless technology and bring that knowledge to their students. A variety of topics are covered during the 4 days of the TI including basic wireless technology literacy, electronics, and the science of radio; bringing space into the classroom; ham radio operation; introduction to micro controllers; and basic robotics.

The Teachers Institute is only the beginning of a participant’s exploration with wireless technology. The goal of the TI program is to equip each teacher with necessary foundational knowledge, and through hands-on learning, generate the inspiration for teachers to continue to explore wireless technology and adapt relevant content into their classroom instruction.

Just a few examples of some of the activities teachers who have participated in the Teachers Institute have initiated upon return to their classrooms include:

·         Using weather imagery gathered by the students for environmental studies.

·         Using TV remotes to control simulated “smart homes.”

·         Radio Direction Finding (RDF) activities to study how naturalist track wildlife.

·         School competitions during the School Club Round-up, a nation wide ham radio contest for schools.

·         Geography lessons using QSL card (postcards collected from ham contacts around the world).

·         A school wide space exploration curriculum including radio stations to receive signals from space and participation in the NASA Explorer School Program.

·         Radio contacts between participating schools.

·         Using radio in ESL classrooms to listen to live broadcasts from countries that use the languages as their native tongue.

 

More information about the Institute, including how teachers may apply for scholarships, is available at:

http://www.arrl.org/FandES/tbp/ti.html

 

Teachers also have a final exam!

As part of their activities, the teachers construct their own robotic vehicles which must navigate a maize, trail each other and even perform “synchronized carpet swimming.”

 

 

 

EETimes – Great SuitSat Article

Extreme design: SuitSat pushes engineers’ limits

by Patrick Mannion, TechOnline

An excellent feature article on the design and creation of SuitSat and Amateur Radio technology in space.

 http://tinyurl.com/6qvxqp

 

(This is DEFINITELY not your Grandfather’s radio!)

 

 

     

Project Blue Horizon Sets Record

2008 – A group of graduate students has broken the world amateur high-altitude balloon record in a recent near-space flight that exceeded 125,000 feet. The balloon launch was the capstone effort of Project Blue Horizon (PBH), an educational component of a three-year program known as Lockheed Martin’s Engineering Leadership Development Program.   PBH is a space-flight program that incorporates amateur radio (also known as ham radio) technologies. Onboard global positioning systems and amateur radio technology allow for monitoring of launch, ascent, descent and recovery, with high-resolution images 20 miles above the earth’s surface recorded.

Read more about it at:

http://www.scientificcomputing.com/Balloon_Makes_Near_space_Flight.aspx

Ham Satellites

Amateur Satellites?

Yes, We Do That Too !

Satellite-active hams compose a relatively small but growing segment of our hobby, primarily because of an unfortunate fiction that has been circulating for many years—the myth that operating through amateur satellites is overly difficult and expensive. Like any other facet of Amateur Radio,satellite hamming is as expensive as you allow it to become. If you want to equip your home with a satellite communication station that would make a NASA engineer blush, it will be expensive. If you want to simply communicate with a few low-Earth-orbiting birds using less-than-state-of-the-art gear, a satellite station is no more expensive than a typical HF or VHF setup. In many cases hams can communicate with satellites using present station equipment—no additional purchases are necessary.
Does satellite hamming impose a steep learning curve? Not really. You have to do a bit of work and invest some brain power to be successful, but the same can be said of DXing, contesting, traffic handling, digital operating or any other specialized endeavor. You are, after all, communicating with a spacecraft!
The rewards for the efforts are substantial, making satellite operating one of the most exciting pursuits in Amateur Radio. There is nothing like the thrill of hearing someone responding to your call from a thousand miles away and knowing that he heard you through a satellite. (The same goes for the spooky, spellbinding effect of hearing your own voice echoing through a spacecraft as it streaks through the blackness of space.)
No doubt this is beginning to sound like an impassioned Captain Kirk delivery. (“Answers! I need answers, Mr Spock!”) Let’s cut to the chase.

Satellites: Orbiting Relay Stations
While a repeater antenna may be as much as a few thousand meters above the surrounding terrain, the satellite is hundreds or thousands of kilometers above the surface of the Earth. The area of the Earth that the satellite’s signals can reach is therefore much larger than the coverage area of even the best Earthbound repeaters. It is this characteristic of satellites that makes them attractive for communication. Most amateur satellites act either as analog repeaters, retransmitting signals exactly as they are received, or as packet store-and-forward systems that receive whole messages from ground stations for later relay.
There is much more to learn and enjoy. I suggest that you spend some time at the AMSAT Web site at http://www.amsat.org. You’ll pick up a wealth of information there. Speaking of “picking up,” grab a copy of the ARRL Satellite Handbook (see your favorite dealer, or buy it on the Web at http://www.arrl.org/catalog/). Between these two resources you’ll be able to tap just about all the amateur satellite knowledge you’re likely to need.

New Amateur Radio Satellite Receives OSCAR Designation

Late May 2008, Bill Tynan, W3XO, announced that Amateur Radio satellite Delfi C-3 has been issued an OSCAR number: Delfi-C3 OSCAR-64 or Dutch OSCAR-64. The shortened version of either of these two designations is DO-64.

Delfi C-3 was successfully launched April, 28, 2008 from India aboard a Polar launch vehicle and was successfully commissioned, currently transmitting telemetry on the 2 meter amateur band. In addition to its 2 meter downlink, Delfi C-3 has an uplink on the 70 cm band. This newest amateur satellite was developed by a team of some 60 students and facility members from various polytechnic schools in The Netherlands. Delfi C-3 carries two experiments: one involving thin film solar cells developed by Dutch Space, and an autonomous wireless Sun sensor from the Dutch Government Research Institute (TNO).

According to Delfi C-3 Project Manager Wolter Jan Ubbels, Delfi C-3 has been duly coordinated through Region 1 IARU representative Graham Shirville, G3VZV, and that the satellite “meets all of the criteria necessary to be issued an OSCAR number.”

“AMSAT-NA is pleased to welcome DO-64 into the family of Amateur Radio satellites,” Tynan said. “We are hopeful that it will fulfill its intended mission of furthering education and increasing interest in the Amateur Radio space program. We congratulate all of those responsible for designing, building, testing and launching this new Amateur Radio satellite and look forward to its long and productive life.”
 . . . see you in orbit!