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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.

Preview: June 26, 2018, meeting

Jerry Kahn, ACØRL, has prepared a very interesting and informative program for our June meeting: “A Modern, Simple, and Safe Method of Reforming Electrolytic Capacitors.”

The DOD, NRC, and manufacturers of capacitors recommend periodic reforming to keep electrolytics ready for use and to restore electrolytics that have gone through extended periods of disuse.

Bring an old, undamaged, electrolytic capacitor (or two or three) to the meeting. Once they are smoked, the magic is gone.

Jerry is an Amateur Extra Class operator, first licensed in 1991. He holds a GROL with Ships Radar Endorsement. He served in the United States Navy as an avionics tech, working on FLIR, RADAR, flight, and weapons systems. He worked in marine electronics.

Jerry attended DeVry University in electronics engineering technology. He worked for Logical Devices in QA, test, and product engineering.

He started his current technology business, VeriStitch, Inc., and Stitch Dynamics, in 1993, serving the personalization and decorative industry. His customer list includes Lands’ End, Neiman Marcus, J.C. Penney, Vera Bradley, Disney, Michaels Arts and Crafts, JanSport, Taylor Made, Williams Sonoma, and other companies.

He is a commercial pilot and certified flight instructor with instrument and multi-engine endorsements. He is also a certified motorcycle safety coach, currently teaching motorcycle safety at Hutchinson Community College.

Minutes: April 24, 2018

There was no formal business meeting.

Shaun Halstead, KØPER, joined Chapter 79. Three members paid their Chapter 79 dues for 2018.

Attendance: 12 members and 3 guests.

Joe Pajor, KBØKFH, arranged for the very interesting program presented by Dr. Brian A. Coon, traffic engineer and Americans with Disabilities Act coordinator for the City of Wichita.

Dr. Coon’s program, “Traffic Signals: Look Who’s Talking Now,” included information about various ways traffic signals can be programmed. Some intersections even have helpful talking signals for people who have impaired vision.

Preview: April 24, 2018, meeting

Joseph Pajor, KBØKFH, has lined up a guest speaker for our next meeting. Dr. Brian A. Coon will present a program titled “Traffic Signals: Look Who’s Talking Now.” This sounds like a program you won’t want to miss.

Dr. Coon brings his experience as an engineer, attorney, and police officer to bear on transportation-related problems. After graduating the University of Iowa, Brian was youngest elected representative to the Iowa House of Representatives. Going back to engineering from politics, Brian studied at the University of Nebraska-Lincoln, where he worked with the Midwest Roadside Safety Facility, where the SAFER Barrier was developed to protect racecars during crashes. After earning his master’s degree in civil engineering, Brian was a Fulbright Scholar at Sweden’s premier transportation research institute, VTI, Statens väg- och transportforskningsinstitut.

After returning from Sweden, Brian earned his doctorate in engineering and then graduated law school with honors at the University of Nebraska and is licensed to practice law in Colorado, Kansas, and Nebraska. Brian is a licensed Civil and Mechanical Engineer in Nebraska, a licensed engineer in Kansas, a Professional Traffic Operations Engineer, and an accredited Traffic Accident Reconstructionist. Brian is the chair of the Machine Design Exam Committee with NCEES and was a reserve police officer with the City of Maize for ten years. Brian also served as the sole technical expert in a whistleblower lawsuit, where a jury found that Trinity Industries had defrauded the Federal Government, awarding a $663M verdict. Brian is currently the Traffic Engineer and the Americans with Disabilities Act Coordinator for the City of Wichita, Kansas.

Bring a friend, and if you see a former Chapter 79 member ask him or her to join us again. If you have an idea for a program, or know of someone who will present a program for one of our meetings, let Harold Childress, WBØLFH, know.