Tag: digital ham radio

WARC DMR Repeater Basics

By John Lock, WARC Repeater Trustee

This is some basic info for setting up and using the Wichita Amateur Radio Club DMR repeaters.

If you are wanting to learn and understand DMR, here are some websites with good information on what DMR is and how it works:

* http://www.dmrfordummies.com

* http://www.miklor.com/ DMR/ppt/DMR-BasicTutorial.pdf

* https://www.raqu.ca/~ve2rae/dmr/Amateur_Radio_Guide_to_DMR.pdf

* http://www.ccc.ve6hams.com/Operating_DMR_Radio.pdf

* https://wiki.brandmeister.network/index.php/Main_Page

* https://www.bridgecomsystems.com

DMR setup is not simple, so expect to spend time learning about DMR in order to set up a radio and get it on the air without causing problems for other users and repeater owners.

For those wishing assistance with programming their radios, the local digital communications group meets at Spangles, Kellogg at Broadway, on the fourth Saturday of each month. Please arrive by 6:30 p.m. and purchase a meal as the meeting room is provided free of charge.

One of the first steps is to go to Radio ID at https://radioid.net/and register your call sign and get your DMR ID number. The analogy I use is that your DMR ID is like putting your address on a letter to be mailed in addition to your name.

Do your research before you buy a DMR radio to make sure you have a source for support for that model to help you get it set up and going.

Caution: Many Baofeng DMR radios are not Tier II compliant and many DMR repeater groups have completely banned the use of all Baofeng DMR radios on their repeater because of the problems caused by non-Tier II radios.

Before operating a DMR radio on WARC DMR repeaters, make certain that it is fully Tier II compliant.

Please note: Some repeater owners have also banned certain worldwide talk groups because of problems.

The WARC DMR repeaters are on the Brandmeister network. See the website listed above for more information on what talk groups are available on that network. Just like AOL and Yahoo were separate networks for instant messenger service, there are several separate amateur DMR networks. Brandmeister, DMARC and KØUSY are examples of three different ham radio DMR networks.

WARC DMR repeaters are set to color code 3. This is equivalent to setting the CTCSS tone for an analog FM repeater. If you don’t have the correct color code set, you won’t access the DMR repeater. See https://brandmesiter.network/?page=repeater&id=310169 for more info on WARC DMR.

The WARC DMR repeaters have the (31201) BYRG talk group (Back Yard Repeater Group, a Kansas City club) set as a static, meaning a continuous connection on time slot 2. BYRG is the only talk group that is allowed on TS2. This is a requirement of BYRG, which owns the DMR equipment provided to WARC. To talk with other local hams, use BYRG TG 31201 on TS2. This is also a good place to get started with DMR as there are hams around the region that monitor this talk group.

Time slot 1 is for dynamic use, which means this is the time slot you will use to temporarily connect to the various talk groups available on the Brandmeister network. While a time slot can technically be connected to more than one talk group at the same time, it is not recommended and will make using the repeater and having a QSO difficult (think of it as four people trying to hold two separate conversations at the same time on the same telephone call).

The repeater will be shared among many hams who want to use different talk groups. We ask that you practice good repeater etiquette to allow the best experience for everyone. This includes checking to make sure the time slot is not already in use before bringing up a talk group on TS1 and disconnecting the talk group when you are finished.

Many radios have what is called a promiscuous mode or digital monitor that will let you listen to all traffic on a time slot to help determine if the time slot is in use. We recommend you check your radios for that feature and how to use it.

Be cautious when using this function as you will not be able to correctly call someone or join in on a QSO unless you have that specific talk group and time slot programmed into a channel on your radio. It is very easy to try and answer someone on the wrong talk group or time slot and fail while the monitor function is on. Some radios also have an indication method to show that the time slot is in use but will not show you which talk group is active.

Due to the shared nature of DMR repeaters, the proper ham courtesy is to program your radio so that it will not transmit if the time slot is already in use. Please ensure your radio setting is correct before using the repeater. Different CPS software can call this feature by different names but Admit or Permit are two common names.

To test your radio, use the parrot function on TS1, TG9990 private call. Make a short test transmission and after a short pause, the network server will play your signal back to you. This will allow you to check your mic gain setting, audio quality and signal strength into the repeater before you try to make a QSO.

The WARC DMR committee is in a learning process, just like rest of the local ham community, and these DMR protocols and procedures are preliminary and subject to change as our knowledge and experience grows. Look for more columns in the Grounded Grid in future months. DMR repeaters take time and money to set up, especially as they need full-time high-speed Internet access to function properly.

If you are interested in DMR and are not a member, please join WARC to help support the development of DMR both financially and with your time. Even if you don’t join WARC you can still support DMR development by donating to WARC, which is a 501(c)3 public charity.

More DMR Musings

By Dale L. Puckett, KØHYD

These are exciting times in amateur radio here in the Wichita area. The VHF DMR repeater is on the air from atop Wesley Medical Center. This new machine creates many new possibilities for local hams.

Wichita Amateur Radio Club repeater trustee John Lock, KFØM, gives you the technical details. His excellent article in the March edition of the Grounded Grid, and found here on this site, also shows you the proper way to use it. I’ve worked with the repeater and had a lot of fun during the past month. Last week I spoke with John and we came up with a list of topics designed to complement his article. We both thought a quick introduction to time slots would be an excellent starting point.

Time Slots

Consider this: time slots are all about spectrum efficiency. Let’s compare them to a typical analog signal.

An analog FM signal is often 25 kHz wide. A DMR signal is only 12.5 kHz wide. The use of Time Division Multiple Access (TDMA) doubles the efficiency again. It allows the transmission of two separate conversations on this single channel. DMR using TDMA is then four times as frequency efficient as analog.

TDMA delivers this efficiency by splitting the signal. Alternating 30 millisecond slices carry the two conversations. Time Slot 1 and Time Slot 2 are the names given to these two time slices. John’s article describes how time slots work on the new W0SOE DMR repeater.

Static vs. Dynamic Talk Groups

The next topic John and I thought pertinent was the concept of talk groups. Consider this analogy: Imagine the two time slots as the two halves of a duplex home. The two sides of the house are independent and they each contain different rooms. In our analogy, these rooms are the talk groups.

The duplex may have two types of rooms, bedrooms and living rooms, for example. Our DMR talk groups also have two types: some are static and others are dynamic.

When a repeater operator creates a static talk group in a time slot that talk group is always available. Dynamic talk groups come and go.

To switch your radio to a talk group you key the radio with a channel pointing to the desired talk group. When you do this the hotspot or repeater opens a route to that talk group. Note: You may only do this when the channel is clear and no one is talking.

When you switch to a talk group the hotspot or repeater will stay connected until you disconnect, or until the end of the time out period defined by the repeater operator.

When you finish your conversation in a talk group, disconnect. Both courtesy and protocol dictate this. You do this by connecting to Talk Group 4000.

Sending a transmission to Talk Group 4000 disconnects the talk group you were using. Note: Do not do this yet on the new W0SOE DMR repeater. This functionality is being tested by the SysOps.

Pause Between Transmissions

What is the most important thing you can do in the DMR world? Pause between transmissions! The fast pace you need during HF operation makes it a hard habit to develop. But you must. Leaving a short pause gives other hams a chance to link to a talk group or disconnect from one. The connect and disconnect operations all must take place when no one is talking.

Another interesting note about DMR operation. If your radio cannot reach a repeater it will stop sending. Most of the time it will also place a message on your radio screen letting you know why it stopped sending.

Kansas vs. KS-Link Talk Groups

Someone once said that the dumbest question is the one that is never asked. Bowing to this theory I had to ask. I couldn’t for the life of me figure out what the difference was between the Kansas and the KansasLink Talk Groups. As it turns out the “Kansas” Talk Group is Brandmeister Talk Group 3120. Most repeaters in Kansas provide it, often as a static talk group. It’s where you’ll be able to hold a conversation with other hams in Kansas.

KansasLink is completely different. It is a network of repeaters in Kansas using both DMR and System Fusion. The repeaters are linked on an independent, locally provided network. While they do provide links to wide area networks to allow the use of popular talk groups, the primary focus is to provide YSF and DMR users with a high quality mobile network within Kansas.

The KansasLink repeaters provide “Kansas” on Time Slot 2, Talk Group 3120. All repeaters in the KS-DMR network carry this talk group. However, it is not the same as the Brandmeister Talk Group 3120. It includes only the repeaters on the KS-DMR network. Connection to a selection of Brandmeister network talk groups must be made on Time Slot 1. Conversations between users on repeaters throughout the state stay within Kansas and are not bounced off master servers around the nation and the world.

If you are using a DMR radio you connect to the repeaters on KansasLink by connecting to Talk Group 31203. If you are using a YSF repeater you connect to YSFReflector US-KansasLink by using the WIRES-X mode on your radio. To do this you connect to WIRES-X room 21696. It is important to note that YSF users need to avoid the use of Voice Wide (VW). Rather, they must use the DN mode. If they use VW their voices will not pass through the Brandmeister bridge.

Final Tidbits

In closing I thought I would pass along information about a new DMR network in Kansas. For information browse to http://ks-dmr.net/. This network is a partnership between the KØUSY Group, KØPRO and NV80 / N7KLR.

There is a lot of information on the KS-DMR.Net website. It includes details about a new DMR repeater in El Dorado. By the way, I can work this repeater using an antenna on my tower from west of Goddard. You’ll find it on 444.9875 MHz. The transmit frequency is +5. The Color Code is 1.

To find information about any repeater in the Brandmeister network, including W0SOE, browse to https://brandmeister.network. Click on the Repeaters tab on the left and then do a search.

Questions? Please Ask! Let me know what you want to read about here: k0hyd@arrl.net.

Code Plugs Unite Hotspots & Radios

By Dale L. Puckett, KØHYD

In the December article we introduced the concept of hotspots. These magic devices let you communicate with D-Star, DMR and YSF users worldwide. You can use them anywhere, even without a local repeater. They do this by connecting your handheld radio to the Internet, routing the signals to a gateway.

This month we’ll tackle the link between your hotspot or local repeater and your radio. You do this by programming your handheld by creating a code plug and installing it in the radio. We’ll also take a brief look at using your radio after installing the code plug.

What’s in a code plug?

You can break a code plug into two parts. The first determines the frequencies your radio is operating on. The second guides you through the DMR network.

Some of the items you program include time slot, color code, talk group, channel, and zone.

DMR gives you two time slots. The time slot setting in your code plug determines which one your radio will use.

The color code is analogous to the CTCSS code in your analog radio. Your local repeater operator determines the color code you must assign.

The talk group you pick determines where you plan to communicate. For example, you assign talk groups to states, regions and countries. Each has a network ID. You define these talk groups in your code plug and assign them to your contact list.

The channels in your code plug bring all the information together in one selection. They contain frequency, power, talk group, and color code plus information.

Finally, zones give you a place to gather channels related to each other. You can put up to 32 channels in a zone and many radios can handle as many as 256 zones. One zone might contain your local repeater channels while another holds simplex channels.

Additionally, your code plug defines your admit criteria. This tells your radio when it may transmit. Most repeater operators prefer that you use the color code to determine when to send.

How do you set up your code plug?

The first step in setting up your code plug is to decide who you want to talk to. Or worded in a different manner, which talk groups you want to operate in.

You create talk groups in the contacts section of your code plug. You define them as either private or public. A public contact is a group all.

You can start your DMR adventure with a small selection of your talk groups. For example, start with Brandmeister 3100, which is the nationwide talk group. Then add 3120, which is the Kansas talk group.

Use talk group 2 to connect to your local repeater when it becomes available. It will also connect you to other repeaters linked to your local repeater.

The other talk groups you will want to add are the TAC channels. Talk groups 310-313 are the most popular. Use these channels for longer QSOs. Many with a military background say TAC stands for tactical. Others call them Talk Around Channels.

If you need to test your radio every once in awhile you’ll want to enter private talk group 9990. This is the Brandmeister Parrot or echo test which lets you hear your radio played back to you. Talk group 9998 serves the Motorola-based systems.

How do I enter channels?

First, enter the frequency, power, color code, talk group and time slot information. It goes in the channel section of your code plug software. Give each channel a name that is easy to identify.

What about zones?

The last step is to create your zones. Place the name of any channel in a zone that you want to group with others. You may place these channels in more than one zone.

What’s next?

After you’ve used your radio’s code plug software to define these items, you load it into your radio. Follow the directions provided by the manufacturer.

Once the code plug is in your radio you can use it by selecting a contact that contains the talk group you want to use. Then, key the radio and this will connect you to that talk group. If you are using the Pi-Star hotspot software, you can confirm that the radio is talking to the correct group.

Other information!

There are many sources of information about setting up and using your DMR. If you learn by watching, search for your radio on YouTube. If you learn by reading and following step-by-step directions, search Google for your radio.

An outstanding source of information is the Bridgecom website. Check out their Anytone radio support page. You’ll find about a dozen videos there to teach you the tricks.

I hope this series of entry-level intros to digital radio has helped you begin your journey. If so, let me know what else you would like to see. I’m considering an article or two exploring the world of SDR dongles and their software. If you have any questions or comments, you may contact me at kØhyd@arrl.net.

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!