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Preview: February 26, 2019, meeting

Our guest speaker will be Ben Bogner. His topic will be “Systematic Biases in the Rapid Sky Localization of Gravitational Waves.” What are gravitational waves, how can we detect them here on earth, and why do astronomers care? Bogner will take you through a crash course on gravitational wave theory, detection methods, and how a budding astrophysicist from Wichita collaborated with international and NASA scientists to probe the most up-to-date methods for finding gravitational waves.

Bogner graduated in December 2018 from Benedictine College in Atchison with a double major in physics and astronomy. He participated in two NASA internships as an undergraduate: one with NASA Langley Research Center and one with NASA Goddard Space Flight Center. He plans to use his research project and connections at NASA Goddard to support his pursuit of a Ph.D. in physics or astrophysics with a to-be-determined graduate institution. He plans to do research with NASA as a postdoctoral student for a number of years before going into academia as a university professor of physics and astronomy.


Hotspots: Gateway to Digital Radio

By Dale L. Puckett, KØHYD

Digital radios – DMR, D-Star, YSF, P25, NXDN – pick your protocol poison. These new radios populate the amateur radio landscape. They make worldwide contacts possible to amateurs everywhere.

Repeaters worldwide communicate using the Internet, making this new medium possible. Unfortunately, few repeaters exist to support these new communication protocols.

In Kansas we seem to be stuck in an analog morass, tolerating the noise and excessive bandwidth. Where repeaters do exist, they are most often not connected to the Internet. This limits communication to a local area.

No worries! There is a solution.

Ingenious hams invented hotspots to solve this very problem. With a hotspot you can have your own personal “repeater” that connects you to hams around the world.

The first hotspots were either “sticks” or dongles that you plugged into your computer. The sticks used your computer’s microphone and speakers to communicate.

The dongles were digital access points that were miniature radios. You talked to them with your digital handheld or mobile radio.

The access points used software in your computer to connect the small radio to the Internet. This was often problematic because the computer often went to sleep. This caused the software to quit and disabled communication.

Hotspots today use their own dedicated computer to connect you to the Internet. Most use a Raspberry Pi computer and a “hat.” The hat is a small circuit board holding a miniature digital radio. These radios usually have a range of several hundred yards.

Hotspots have two components, hardware and software. I use a ZumSpot which contains a small hat riding on a Raspberry Pi Zero W. The W stands for wireless. This board gives you a way to talk to your LAN and the Internet. Both boards together fit in a small compact case. The combination is highly recommended.

Jim McLaughlin, KI6ZUM, designed the ZumSpot hardware. José “Andy” Uribe, CA6JAU, wrote its firmware. ZumSpot descends from the Multi-Mode Digital Voice Modem (MMDVM), created by Jonathan Naylor, G4KLX.

The software of choice today is Pi-Star. It delivers access to your mode of choice when paired with a hotspot like the ZumSpot.

The ZumSpot/Pi-Star combination can link to DV repeaters, DMR talk-groups and reflectors. It also links to D-Star reflectors, YSF rooms, and QuadNet Smart Groups. This will keep you busy for hours, if not days on end.

You’re sold! OK! Where to start?

The best source for the official ZumSpot hardware is Ham Radio Outlet. You can buy either a bare board or a kit.

I recommend the kit. If you are a true hardware guru with tiny hands, go for the bare board. The kit includes a Raspberry Pi Zero W and a microSD card preloaded with Pi-Star. For a compact and very neat installation I recommend a C4Lab case.

When you complete the assembly of the kit, it’s time to install the Pi-Star software. It sounds scary, but actually it’s very straightforward. First you flash the Pi-Star software into a microSD card. You’ll need a card with at least 8 GB.

Then, you boot up the Raspberry Pi and create a WiFi connection using the Pi-Star software. You do this by connecting to Pi-Star.setup on your web browser.

Once you have the WiFi connection you reboot the hotspot and login to Pi-Star.local with your web browser. Pi-Star then gives you all the web forms you need to configure every mode you want to operate.

It sounds complicated. It’s the exact opposite. You’ll find two excellent sources of step-by-step instructions. The best source depends on your learning style. If you would like to follow someone else going through the steps, go to YouTube and search for Pi-Star setup. If you prefer written step-by-step instructions, point your web browser to pi-star.hamnotes.com.

I was able to configure my ZumSpot for both D-Star and DMR in less than an hour. It was a blast!

A DMR repeater is coming to WARC sometime in the future. In the meantime, why wait? Get your own hotspot, an inexpensive DMR handheld and get on the air now.

It’s opportunities like these that get me excited about amateur radio.

Let me know what you would like to see next in an email to kØhyd@arrl.net. Until next month! 73 de KØHYD.

Digital Ham Radio: What to Do?

By Dale L. Puckett, KØHYD

During the birth of the personal computer, clubs popped up across the nation. Many clubs were large. Several SIGs operated in each club. SIG stood for Special Interest Group.

Members using microcomputers based on Motorola’s processor architecture discussed projects in one room. Those owning machines based on other architectures met in other rooms. Then, they all got together and defined personal computing as we know it.

Fast forward now to the second decade of the 21st century. Can we apply parallels in amateur radio clubs like the Wichita Amateur Radio Club today? I’m pretty sure we can.

The microprocessors born in the 1970s became the personal computers of the future. These personal computers revolutionized almost everyone’s life.

These same microprocessors redefined amateur radio. They made efficient and effective operating techniques available to all. Logging software made it possible to maintain accurate records during contests. They also made it easy to chase awards. The evolution of cloud-based databases like Logbook of the World simplified the process even more.

Microprocessors gave us better control of things like our bandwidth and audio quality. They let us automate antenna tuning and any number of other processes.

Today microprocessors are making digital radio not only possible, but practical. WARC already maintains a Fusion repeater at Wesley Hospital. The board of directors and technical staff are busy investigating a digital mobile repeater.

Grounded Grid Editor Randy Fisher, KEØJYU, asked me to tackle the topic of digital radio in monthly installments. This first column is as much a survey of our readers as anything else. Where would you like to see us go in a column about digital radio? How detailed would you like it to be?

Would you like to see a SIG within WARC dedicated to digital radio? How granular should it be? Would you like one generic group that discusses and experiments with digital radio? Or, specific groups dedicated to D-Star, DMR and Fusion? Where does digital TV fit in the big picture?

We now stand on the threshold of exciting possibilities for all hams. To get a feel for the question “Why digital radio?” you only need to think about an earlier transition.

A mere decade ago broadcasters transitioned from analog to digital television. Before the transition if the analog signal was strong you got a good picture. If it was weak, you could see the picture but a field of snow almost hid the picture. With the new digital television you either received a perfect picture or no picture.

Likewise you can hear the difference between analog and digital radios. On our current analog repeaters if you drive into a valley, your signal weakens. Repeater listeners then begin to hear a lot of noise with your voice. On our digital Fusion repeater you will either hear a perfect audio signal or hear nothing.

There are many other reasons to champion digital radio. Take bandwidth for example. DMR repeaters allow two conversations on a single 12.5-KHz channel. Analog repeaters meanwhile deliver only one conversation on a 25-KHz channel.

The good news is that you don’t have to wait to start experimenting with digital radio. Even if there are no repeaters in your area you can communicate with hams around the world. To do this, you set up a hotspot that communicates over the Internet to a gateway that connects you to any repeater. Your digital radio, usually a handheld, talks to your hotspot and bingo – you’re on the air anywhere in the world.

I’ve been experimenting with a hotspot for several months now and it is a lot of fun. Working in this medium is different but it’s not hard. Once you understand the big picture about the various modes it becomes a simple question. What do you want to do?

So, what do you want to read here or in the Grounded Grid? Do you want to know how to configure your hotspot? Do you want to know how to create a code plug for your DMR radio? Do you want to know how to connect to a reflector on D-Star? Please let me know and I’ll do my best to give you an easy to follow path for success in digital radio.

Email your requests and ideas to me at kØhyd@arrl.net within the next few weeks. I’ll do my best to deliver results for you beginning with the next Grounded Grid.

An Introduction to Digital Ham Radio

By Dale L. Puckett, KØHYD

On most months the Wichita area ham luncheon on the second Saturday doesn’t feature a program.

September 8th was different.

Like in the movie, “Build it and they will come.” And on this Saturday afternoon, they did! Hams from Garden City, Great Bend, Arkansas City, Emporia and Topeka came. A special presentation about DMR was the dessert.

Chuck Kraly, KØXM, a leader in the Kansas City area’s Backyard Repeater Group (BYRG), and the technical support manager at BridgeCom Systems in Kansas City, spoke.

A ham since 1979, Kraly’s background allowed him to explain the what, why and when about DMR to the excited crowd. BYRG is deep into DMR deployment and Chuck has spearheaded the move.

Much like single sideband in the early 1960s, digital radio is the future of amateur radio in the 21st century. Today it takes many forms including DMR, D-Star and System Fusion. BYRG leadership believes DMR is best suited for amateur radio.

What is DMR?

So what is DMR? For one thing, it’s an acronym for Digital Mobile Radio. Developed by the European Telecommunications Standards Institute, it’s used worldwide.

DMR has three tiers. Amateurs today use the Tier II, which is a twoslot, 12.5-kHz wide peer-to-peer specification. The two slots give it a spectrum efficiency of 6.25 kHz per channel. Amateur repeaters talk to each other using the Internet. The IP Site Connect (IPSC) specification makes communications possible.

Amateurs encode the analog voice from their microphone using the DSVI AMBE+2™ vocoder. Most DMR radio manufactures have implemented licensed copies of this vocoder. The newer version delivers an improved voice quality over earlier versions. D-Star, for example, uses the earlier version.

There are three types of users working with DMR today. They are the individual ham, the repeater operator, and the network operator. It takes all three to make DMR function worldwide.

Another type of amateur DMR user implements a small device called a hotspot. Hotspots deliver worldwide connectivity when there is no DMR repeater in the area. Your DMR radio talks to the hotspot which in turn talks to the Internet. Amateurs use their personal LAN at their home QTH. On the road, they often connect their hotspot to the Internet using their cell phone.

The Future

In the next column, originally written for Grounded Grid, we’ll look at DMR and other digital modes in more depth. With DMR you can get your hands dirty and learn how it works as you program your radio, which is a great mode for DIY fans. It’s a great sport.

If computer programming scares you, never fear. BridgeCom is preparing a preprogrammed Anytone ATD868UV radio. This radio, declared the “must have” DMR radio by many amateurs, is dual band. KØXM will program the radio before it ships.

One last thing! Chuck made an exciting announcement near the end of his presentation. BYRG has received several dozen DMR repeaters from a donor. They are making them available to ham clubs in Kansas at no cost providing the club meets a simple set of criteria. With the blessing of the Wichita Amateur Radio Club membership and board we may soon see a DMR repeater in Wichita. We may even see a robust amateur DMR network spanning Kansas. I’m excited!

Talk to you on DMR!

Preview: December 18, 2018

We will have a musical program for our last meeting of the year. Troy and Joy Pulver will perform Christmas music on acoustic instruments. They played for us last December with The 37 Mile Band. Troy plays guitar and banjo, and Joy plays the hammered dulcimer. As always, please bring your spouse or another friend.

Also, please RSVP to Secretary-Treasurer Larry Cannon as soon as you can so we can let Spear’s Restaurant folks know how many tables to set up. Tell him if you are coming alone, 1, and if you are bringing your spouse or a friend, that will be 2. If you see a former Chapter 79 member invite him or her to join us again, and ask them to RSVP, too.

We are still taking nominations for all offices.You may make nominations for each office, but please be sure that the person(s) you nominate will serve if elected. You may nominate yourself (i.e., volunteer) for an office. We really need someone to be the vice president as that office has been vacant this year. We appreciate your help so we can vote at the December meeting and get a good start for 2019.

Minutes: October 30, 2018

President Harold Childress called the meeting to order at 1845, with nine members and four guests in attendance.

Minutes and financial report were approved as e-mailed.

Nominations for officers for 2019 were opened. Nominated were Harold Childress for president and Larry Cannon for secretary-treasurer. No nominations were made for vice president.

President Childress asked Secretary Cannon to send an e-mail to all members who were not in attendance at the meeting, asking for nominations for all offices.

The business meeting was closed at 1855.

Harold introduced Aaron Diller, NØQD, who presented an interesting and informative program about the Kansas Civil Air Patrol. A question-and-answer time followed the presentation. Aaron is the communications officer for Emerald City Composite Squadron, located in Wichita. He is also a flight instructor at Flight Safety International.

Please contact Bryon Cannon, Chapter 79 webmaster, if you have content to post on the chapter’s website.

Preview: October 30, 2018, meeting

QCWA Chapter 79 will meet at 6:30 p.m. October 30. Our speaker is expected to be someone from the Civil Air Patrol.

At this meeting we will have nominations of officers for next year.  Our officers are President, Vice President, and Secretary-Treasurer.  We need to nominate a complete slate of officers so we can function efficiently.

We especially need to nominate and elect a Vice President.  He chairs the meeting if the President is unable to attend the meeting.  He is also the person who secures a program for each of the meetings.  Throughout the year he will be happy to hear from members who are willing to present a program or who know of someone who will do a program for a meeting.

Self-nominations are allowed and even encouraged.  But if you are a bit shy, ask someone else to nominate you.  Please check ahead of time with anyone you wish to nominate to be sure they are willing to serve in an office.

Minutes: August 28, 2018

President Harold Childress called the meeting to order at 1900. Twelve members and three guests were in attendance.

Minutes and financial reports were approved as e-mailed. Motion by Joe Pajor; second by Henry Monton.

Harold said we have two more meetings this year, and asked members to start thinking about chapter officers for next year. We really need to elect a vice president, who is also the program chairman.

Please contact Bryon Cannon, Chapter 79 webmaster, if you have content to post on the chapter’s website. The URL of the web site is QCWA79.com. The secretary was asked to add the website URL to the e-mails of the meeting notice and minutes.

The business meeting was concluded at 1905.

President Childress introduced Coy Terry, WØZWS, who presented a very interesting program about delta loop antennas for 40 meters and how he phases two loops to add some directivity, which helps with the transmit and receive signal strength.

Coy is almost completely blind due to an eye disease he got in 2006, possibly related to his stay in the New Orleans Superdome after Hurricane Katrina. Although it is a condition that moves slowly, it will most likely result in total blindness.

Coy holds an Amateur Extra class operator license. He enjoys operating CW and building and putting up antennas. He has taught himself to solder but says he endured some burned fingers in the process. His wife, Pamela, helps him by reading meters and a few other things, but Coy says the words “can’t do it” aren’t allowed at his house.

Preview: August 28, 2018, meeting

Our speaker for the August 28 meeting will be Coy Terry, WØZWS.

After serving in the Army, Coy worked on oil rigs in the Gulf of Mexico. He performed maintenance and did all of the electrical work on the rig. While employed on the rigs, he experienced Hurricane Katrina; he was housed in the Superdome in New Orleans and then transferred to various states from there. He had an interesting experience while in Cheyenne, WY, which maybe he’ll tell us about.

In 1986 Coy earned his baccalaureate in astrophysics from Louisiana State University as a result of his interest in astronomy. He studied clusters and wrote articles for several astronomy magazines.

Coy’s eyesight started going bad in 2006, possibly related to his stay in the Superdome. It is a slowly developing condition which will most likely result in total blindness.

In 2013, Coy went for his first amateur radio license and tested through to Extra Class. About two weeks later, he traveled to Kansas City where he took the commercial broadcasting exam. By this time, Coy had to have someone read the questions to him as he could no longer see well enough to read. Even though visually challenged, he worked in the broadcasting field repairing broadcast equipment for a number of years.

In amateur radio, Coy has enjoyed reconditioning tube-type receivers and transmitters. Yes, he has even learned how to solder, after burning his fingers countless time. His other passion is in antenna design. Not content with only the technical aspects of amateur radio, he has earned several difficult-to-get awards. Coy is a very accomplished CW operator, which is his favorite mode.

No doubt, Coy will have some interesting tales to regale us with. Hope to see you there.

Minutes: June 26, 2018

There was no formal business meeting.

Attendance was 11 members, 1 guest.

Jerry Kahn, ACØRL, presented an interesting program about reforming electrolytic capacitors. Jerry explained that the plates inside of an electrolytic capacitor slowly lose their insulating oxide layer as it sits unused for a number of years. As the insulating oxide layer depletes, the capacitor’s internal resistance lowers, eventually to nearly zero ohms. Permanent damage will occur if a sufficiently high current is applied to an electrolytic capacitor with depleted oxide layers.

The safest way to reform an electrolytic capacitor is to apply a constant low current (5 ma maximum) to the capacitor, with its rated voltage. When the capacitor is fully reformed, the current drops off sharply to a leakage current value on the order of microamps.

The next meeting will be August 28, 2018.