Tag Archives: Part 97

This article appeared in the The Wood County Amateur Radio Club newsletter CQ Chatter February 2018 edition.

Read the rest of the series in the Digital Communications in Amateur Radio articles category.

Hurricane season wasn’t particularly fun in 2017. We had both extremes. Houston got hit with Hurricane Harvey which required little response from the ham community. Infrastructure stayed online. Disruption to communication systems and Internet was minimal. This left many hams wondering, ‘are we at the point where our infrastructure is stable enough to survive a category 4 hurricane?’ ‘Are hams still relevant since we were not needed for this type of event?’ We got the answer to those questions over the next month with two category 5 hurricanes. Irma impacted the state of Florida and Maria devastated the relatively poor U.S. possession of Puerto Rico. We went from wondering if ham radio was still relevant in emergency situations to rethinking training for extended deployment scenarios, all within a matter of weeks.

Ham radio news sources pointed out many communication techniques were utilized getting traffic in and out of affected areas. An ARRL press release indicated “Maxim Memorial Station W1AW at ARRL Headquarters is monitoring the HWN, 60-meter interoperability channel 2, and Winlink for any traffic.” Winlink gained prevalence in ham news media due to these disasters, gained popularity in emergency communications circles, and became an operating requirement for hams that assisted in Puerto Rico. Winlink is a very powerful and flexible system for exchanging all types of messages.

“Winlink (also known as Winlink 2000) is a worldwide radio messaging system that uses amateur-band radio frequencies to provide radio interconnection services that include email with attachments, position reporting, weather bulletins, emergency relief communications, and message relay” (Wikipedia). In other words, Winlink is a global email system via radio. The backbone uses the Internet for communication but users do not need an Internet connection. This makes the system popular in Emcomm when the Internet is not available. Winlink was first used recreationally by mariners, RV campers, and missionaries. The entire system is run by volunteers and a 501(c)(3) not-for-profit organization. Though similar in name, the “WIN System” is a popular IRLP repeater system based in California and entirely different.

https://www.winlink.org/content/getting_started_winlink_and_winmor

The Winlink system consists of multiple Common Message Servers (CMS) on multiple continents thought the world. The CMS servers form a “star” network configuration to coordinate traffic and provide services like email, webmail, telnet, bulletins, and reporting. Each CMS is a mirror image of the others for redundancy, failover, and outage situations. The Internet, by design, can work around outages. To date, there has been no global outage of the Internet – only regional. Having multiple servers, with redundant copies of the same data, means one or more could be affected by an outage and the system still functions. As of November 1, 2017, the CMS servers have been moved into the Amazon Web Services (AWS) cloud for greater redundancy.

Remote Message Servers (RMS) are scattered throughout the world and are the RF connection into the Winlink system. RMS gateways access the resources of the CMS servers via the Internet. These nodes are provided by hams familiar with the system and are setup on many ham bands (HF, VHF, UHF). On VHF/UHF, connectivity is limited to local clients. HF gateways serve a wider area but depend heavily on band conditions.

Finally, your computer runs the client software which interacts with services provided by the CMS, most often through an RMS gateway. The client software sends and receives messages. Size is limited to 120KB maximum, including attachments. Winlink uses a “store and forward” approach to messaging meaning clients are not constantly connected to an RMS or CMS gateway.

There are currently 6 client software applications available for Winlink. A feature comparison is available at: https://www.winlink.org/ClientSoftware. Winlink Express (formally RMS Express) is the preferred client because it’s developed by the system administrators and supports all features of the system. The software is well supported and frequently updated. The application looks and operates much like a stripped-down email client. Using a familiar email interface makes the application easy-to-use. Though free to download and use, Winlink Express is nagware. It will frequently prompt to purchase a key supporting development of the system. Registration of $24 is encouraged but not a requirement to use Winlink.

Winlink Express interacts with a wide selection of transceivers, provides different operating modes (PACTOR, Packet, Telnet, WINMOR Virtual TNC), and offers different connection methods (relay over mesh and D-STAR networks). It can be operated in any of four general methods:

Winlink: access messages on the CMS via an RF connection to an RMS gateway using the Internet.
Peer-to-Peer (P2P): messages exchanged directly with other users over RF, Internet, or mesh without the use of a RMS or CMS.
Radio-only: messages transferred between HF RMS gateways – without use of the Internet.
Telnet Post Office: connects to the CMS directly over the Internet.

A growing library of forms is available for ARES, RACES, SHARES, or MARS organizations including ICS, ARRL, and form types used in Ohio. The advantage of Winlink versus NBEMS is the ability to exchange messages over the public Internet. A form could be emailed directly to a government official instead of relayed via another ham. Winlink Express makes it easy to fill out or reply to forms by utilizing the local web browser. When composing a message, these forms are found under “Select Template.”

A “Query Catalog” accesses services provided by the CMS such as weather and marine forecasts, news, and propagation reports. Location coordinates can be reported through Winlink as well.

Winlink Express will work on a modern computer or Windows tablet running Windows Vista or later. The WINMOR Virtual TNC requires a 700 MHz or greater processor and 512 MB RAM or more due to the Digital Signal Processing (DSP) needed. An Apple or Linux version of Winlink Express is not available but it can be run using a virtual machine or dual-boot configuration. A Linux client is available but does not support all features.

This series primarily focuses on soundcard modes over HF and I will be discussing the WINMOR Virtual TNC. WINMOR is a low-cost interface utilizing the SignaLink USB for $120 as opposed to a PACTOR 3 dedicated hardware modem which can run $1,100 – $1,600. Low-cost hardware means tradeoffs. WINMOR is not anywhere near as fast or reliable as a PACTOR 3 modem, but it does a very good job.

To get started, first go to: ftp://autoupdate.winlink.org/User%20Programs/. Download two programs from the list of files: latest itshfbc program and Winlink_Express_install. ITS HF Propagation is prediction software to provide a rough estimate of the signal path quality between your QTH and remote RMS. Install both applications, order doesn’t matter. Click “next” through both installs, accepting defaults.

An Internet connection is required on the computer for initial setup. After starting Winlink Express, a “Winlink Express Properties” configuration will be seen. If not, click Settings, Winlink Express Setup. At a minimum the following fields must be completed: callsign, choose a password, enter a non-Winlink password recovery email, and grid square. Under Service Code, if you plan on using EMCOMM channels, make the code read: PUBLIC EMCOMM

I recommend checking Display list of pending incoming messages prior to download. This will display incoming message details prior to download allowing the user to select or reject messages based on size or sender. Click Update. An account will be setup on the Winlink system. The Winlink email address won’t become active until a message is sent through the CMS gateway. Click Remind Me Later on any Winlink Express Registration screens.

To create a message activating the Winlink email address, click the New message icon or click Message, New Message.

In the To field, enter your real email address. In the Subject field, enter something like “My first Winlink message.” In the message body, enter something like “This is my first Winlink message, whoo hoo!”

The message is ready to send, but wait! There is no “send” option. What gives?!? Since this system is store-and-forward, messages are Post to Outbox and appear in the “Outbox” System Folder. Messages in outbox can still be edited but will be sent when connected to a CMS.

Next to “Open Session,” in the drop-down select Winmor Winlink. Click Open Session.

Two more boxes will appear: “WINMOR WL2K Session” and “WINMOR Setup.” The WINMOR WL2K Session box is where an RMS gateway is selected and it displays the connection status.

You will be prompted to select the Capture and Playback soundcard devices in the WINMOR Setup box. For the SignaLink, select USB Audio CODEC. Leave all other settings at their defaults. Click Update. A third “WINMOR Sound Card TNC” box will appear. This window shows a waterfall along with transmit and receive state of the virtual TNC. Ignore this box for now.

On the SignaLink, begin with the TX and RX volume knobs set to the 12 o’clock position. Set delay (DLY) to the 2nd tick-mark (8 o’clock position).

If you have a way to control your radio through CI-V commands or equivalent, click Settings, Radio Setup, and configure the settings for the radio. Radio control makes it much easier when selecting different RMS gateway stations. Selecting a different station will automatically change the radio’s frequency and mode. With a VOX device like the SignaLink, for “PTT Port” select External. Click Update.

Back in the WINMOR Winlink Session box, click Channel Selection. An “HF Channel Selector” window will open. A message will ask to ‘update the channel list and recompute the propagation estimates now?’ Click Yes. If not asked, click Update Table Via Internet. This table will update with the current list of Winlink RMS gateway channels on HF. The list can be updated over radio in the future if desired.

Once updated, the presence of color in the “Path Reliability Estimate” and “Path Quality Estimate” columns mean the ITS HF Propagation predictor program is installed and working. Calculations are based on your grid square and solar flux index. Update the current grid square in Winlink Express setup and this table often when traveling. “Mode” is the bandwidth of the RMS node. A higher number means faster transfers are possible. “Hours” means the hours each day the node is online. “00-23” is all day, “02-13” is 02:00 – 13:00. The rest is self-explanatory.

To select a particular RMS gateway, double-click that row in the table. Gateways in green are good choices but ones at the top of the list may not always provide the best connection. Reliable gateways are found by trial and error and can be added to the “Favorites” list. If Rig Control is enabled, the radio should tune to the dial frequency of the RMS gateway and enter USB mode. If not, tune the radio’s display frequency to the “Dial Freq” (VERY important!) shown in WINMOR. Warm up the Tuner if it needs it. Remember to use no more than 30% power. Click Start.

If WINMOR thinks the channel is busy, it will prompt to verify you still want to connect because your transmissions maybe interfering with another station. Your radio will start pinging the remote RMS gateway station. In the WINMOR Sound Card TNC, above the receive indicator will be the “Measured T>R Latency” value. This measures the transmit/receive turnaround time. This should be less than 250ms and adjustable in part by the SignaLink DLY knob. Higher values will cause problems receiving from the RMS gateway. While receiving transmissions from the gateway, adjust the RX knob to a level that falls within the green portion of “Rcv Level.”

With any luck, your client will connect and your first Winlink message will be sent! There will be A LOT of back-and-forth (TX/RX switching) between your radio and remote RMS gateway. These are handshaking and acknowledgments or sending/receiving messages. When all messages are exchanged, the client will automatically disconnect from the RMS gateway. Clicking “Stop” will gracefully disconnect and ID at any time during a session. “Abort” should only be used when something is very wrong because communication is terminated immediately (without ID). Attempts will be made by the RMS to reestablish communication with the client before eventually timing-out.

Once the test message is received in your actual email, your new callsign@winlink.org email address is now active! Send a reply to the test message through your real email. To call a different RMS gateway, click Channel Selection and select a different station. Wait 5 minutes or so for the reply email to reach the Winlink CMS. Click Start in the WINMOR Winlink session box. You will see your reply downloaded to the inbox! When replying to lengthy messages, I will keep a few sentences (paragraph at most) of the original message. This keeps the transmission time down. The original sender can look at the full message in their client sent folder.

Before going crazy telling people to send messages, there is one crucial piece to this system. Winlink uses a “whitelist” (approved senders list) approach for external email addresses. This keeps abuse and spam to a minimum. As a Winlink user, you are free to send messages using your Winlink address to other Winlink users. Other Winlink users can do the same, freely contacting you.

External email addresses are handled very different. An external email is any mail system other than Winlink (Gmail, Outlook, DACOR, Buckeye Cable, BGSU, etc.). If you first send a Winlink message to someone@someprovider.com, that email address is automatically added to your Winlink whitelist. That means email from someone@someprovider.com will be delivered to your Winlink inbox.

For an external email address to send you a message unsolicited to Winlink, there are two options: add that email to your whitelist ahead of time or the sender must put “//WL2K” in the subject line. Example: “//WL2K Holiday Meeting.” Anything with //WL2K in the subject is considered a deliverable message and will not be flagged as unauthorized. By default, all outgoing messages have this inserted automatically by Winlink Express. When some individual replies to your message, which would have //WL2K in the subject, it will be accepted. Any non-whitelisted (blacklisted) addresses or messages without //WL2K in the subject, the sender will receive a bounced error message saying “Sender not authorized for any recipient.”

Whitelists can be managed by logging on to the Winlink My Account page and click My Whitelist. That page will provide details how to update the whitelist using client commands, if desired.

Another important detail to remember, there is no expectation of privacy with the Winlink system. RMS gateway owners and Winlink administrators can read messages exchanged through the system. They are looking for Part 97 violations and inappropriate usage of the system. Violators will be blocked. I’m sure they would find details of your camping trip fascinating, but they really don’t care.

Email messages through this system are considered 3rd party traffic under Part 97. The email message resides on the CMS until you (a ham) make a connection to another ham’s station (RMS) to retrieve your messages. This is similar in nature to passing messages over the National Traffic System (NTS).

The list of services available through the Winlink system is extensive. Winlink is quite flexible allowing many different ways to access the system over RF, APRS, or Internet. Feel free to send a message to my Winlink email address, K8JTK—at—winlink.org. Replace “—at—” with the appropriate email symbol. Don’t forget to include //WL2K in the subject!

Find out more information:

Winlink website: https://winlink.org/

Introduction presentation: https://www.youtube.com/watch?v=UTx9pY1Akl8

Resource for beginners: https://www.winlink.org/content/getting_started_winlink_and_winmor

System tutorials, documents, and FAQs: https://www.winlink.org/content/winlink_book_knowledge

Terminology of the system: https://www.winlink.org/glossary

Winlink over APRS: https://www.winlink.org/APRSLink

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – December 2017 edition

December 18, 2017 Jeffrey Kopcak

One of the responsibilities of the Technical Coordinator in the Ohio Section is to submit something for the Section Journal. The Section Journal covers Amateur Radio related things happening in and around the ARRL Ohio Section. It is published by the Section Manager Scott – N8SY and articles are submitted by cabinet members.

Once my article is published in the Journal, I will also make it available on my site with a link to the published edition.

You can receive the Journal and other Ohio Section news by joining the mailing list Scott has setup. You do not need to be a member of the ARRL, Ohio Section, or even a ham to join the mailing list. Please sign up!

If you are an ARRL member and reside in the Ohio Section, update your mailing preferences to receive Ohio Section news in your inbox. Those residing outside the section will need to use the mailing list link above.
Updating your ARRL profile will deliver news from the section where you reside (if the leadership chooses to use this method).
Go to www.arrl.org and logon.
Click Edit your Profile.
You will be taken to the Edit Your Profile page. On the first tab Edit Info, verify your Email address is correct.
Click the Edit Email Subscriptions tab.
Check the News and information from your Division Director and Section Manager box.
Click Save.

Now without further ado…

Read the full edition at: http://arrl-ohio.org/news/OSJ-December-17.pdf

THE TECHNICAL COORDINATOR
Jeff Kopcak – TC
k8jtk@arrl.net

Hey gang,

I’m touching on a third-rail topic of ham radio this month, licensing and education. I’ve heard any number of hams state something like this about new hams: ‘ham’s today only study the answers to pass the test.’ ‘I don’t like so-and-so’s teaching method because their students don’t know anything.’ They don’t approve of the “boot-camp” style training sessions for many of the same reasons. Certainly their thinking is one school of thought: learn the question pools, know the reasons, learn the theories and be able to provide reasonable explanations before taking the test.

I saw a presentation by Dan Romanchik – KB6NU on the Ham Radio 2.0 podcast (http://www.livefromthehamshack.tv/2017/05/25/episode-97-teach-1-day-technician-class-kb6nu-dayton-hamvention/). His presentation caught my attention because he publishes the “No Nonsense Study Guides” (http://www.kb6nu.com/study-guides/) which is a text-book approach to learning the question pools. Dan is sold on and teaches one-day Technician training classes (also called “Ham Crams” or boot-camps). He teaches the answers to the questions and teaches to the test. At the end of the class, follows up with the Technician exam. Why? To get people into the hobby. As a Volunteer Examiner, I can appreciate that. Getting people into the ranks is always important. Dan claims students will learn something from his class and retain at least enough information to pass the exam. This means students don’t have to make multi-week commitments to attend class. How often does something come up in real life during a 6-week training class? More often than you’d think. Our school systems have been teaching to standardized tests and college entrance exams for decades. Iowa Tests, SATs, and ACTs anyone? The reason for Dan’s teaching methodology is because the real learning happens on the radio.

After watching his presentation, I realized this is exactly how I learned things in ham radio. When I was studying, my dad mentored me with electronic theory because that is his area of education and he worked in the industry. Electronic theory wasn’t necessarily something I cared a whole lot about as a freshman in high school. I knew the Part 97 FCC rules from seeing him operate or explaining them to me and from generally being around the hobby. His interests didn’t cover the HF bands. Even by the time I took my General and Extra, I probably couldn’t hit 40 meters with a shotgun. When the opportunity came and I found myself interested in HF, that changed. Being around mentors and absorbing everything I could, I think, made learning the material on the General exam easier. That learning happened over the better part of a decade after taking my Novice & Technician exams and when I decided to upgrade to General & Extra.

Ham Radio isn’t the only hobby where you receive a license to learn. A roommate in college had his pilot’s license. He was always taking aviation classes and getting flight hours in between his other classes. You have to get a pilot’s license even before you can begin learning to fly an aircraft. The State of Ohio Bureau of Motor Vehicles requires an applicant for learners permit to pass a knowledge test about regulations and traffic signs. Then the real learning begins – hours of driving and education. Ham radio isn’t necessarily different. Sure, many students will get their license and may not ever become a pilot or ever get on the air, but that’s up to them. I believe the ARRL was trying to accomplish something similar by exploring an introductory license: http://www.arrl.org/news/arrl-board-explores-entry-level-license-options-ways-to-face-future-challenges

Hams will argue about skills. Skills needed to build a radio or operate CW are the usual examples. These are seen as relevant to ‘separate men from the boys.’ Yeah, OK. At this point, neither of those ‘skills’ are my interests. Can those same operators write a program from scratch or write an article on take-your-pick of an HF digital mode? Maybe yes, maybe no, but I can. Does that make anyone less of a ham because of different skill sets or interests? I don’t think so. The hobby is incredibly diverse with people from different backgrounds, levels of experience, and interests not even necessary related to being on the air. Such examples would be scholarships, enforcement, advocacy, public relations, regulations, laws, education, spectrum defense, and publications.

On the other hand, the ham community needs to help those hams who want to learn. I think many new hams give up because they don’t get the mentoring they are seeking. They may contact a club or two asking for help and get no response. It’s not fun when you have to constantly beg for help or get talked down to. We are all volunteers, have families, and other commitments too.

Club meetings may spark some interest on a topic but aren’t typically good places for extensive hands-on training. Many clubs focus on similar (related) topics for their meetings. Holding regularly scheduled classes and training is usually an issue due to time commitments, availability, or lack of regular interest. Other places for training might be evening classes at a local university or look at offerings of a local makerspace. Partnering with makerspaces could facilitate a place for demonstrations and training as well as bringing those with radio building skills into the hobby. Work ham radio into topics such as WiFi and Bluetooth transmitters. Don’t focus exclusively on operating demonstrations. Working with other clubs to form special interest groups, utilize subject matter “experts” to share their experiences for an extended hands-on session, or a “program your HT” evening are some other ideas. I would like to hear ideas that have been met with success welcoming newcomers into the hobby.

Retired ARRL CEO Dave Sumner – K1ZZ was on the QSO Today podcast. Dave talked about his 44 years with the League. He started as an intern in the 1970’s. The podcast starts out talking about how he got into ham radio, his antenna farm, and operating interests. Dave covered experiences with the IARU and other radio conferences during his tenure at the ARRL. He talked about programs and history of the ARRL including the Spectrum Defense fund and IARU intruder watch program. Check out QSO Today episode 172: https://www.qsotoday.com/podcasts/k1zz

In some unfortunate news, one of the largest electronics distributors headquartered in Ohio for 40 years and frequent vendor at Hamvention, MCM Electronics, is partnering with Newark element 14. Two plants will close and more than 90 workers will be laid off before end-of-year. MCM sold all kinds of tools, 3D printers, parts, wires, speakers, Arduino and Raspberry Pi computers. As of September 1, their website redirects to the Newark website. I knew the name element 14 from the Raspberry Pi computers I’ve purchased over the years. I had the opportunity to visit the MCM facility during a recent trip to Hamvention. The store was quite small compared to the massive warehouse. I couldn’t believe the size. Hopefully they’ll keep the warehouse open for parts distribution. ARRL News story: http://www.arrl.org/news/mcm-electronics-shutters-two-plants-announces-merger-with-newark-element-14

Finally, don’t forget the HF Santa Net running through Christmas Eve. Starts daily at 8:30 pm Eastern and can be found on 3916 kHz for the little ones to have a chance to talk with Santa! http://www.3916nets.com/santa-net.html. The Santa Watch Net will kick off at 6:00 pm Eastern on Christmas Eve as Santa delivers his presents. The Watch Net can be found on the *DoDropIn* Echolink conference node #355800.

Thanks for reading. Happy holidays, Merry Christmas, and Happy New Year!

73… de Jeff – K8JTK

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – November 2017 edition

November 20, 2017 Jeffrey Kopcak

Once my article is published in the Journal, I will also make it available on my site with a link to the published edition.

Now without further ado…

Read the full edition at: http://arrl-ohio.org/news/OSJ-November-17.pdf

THE TECHNICAL COORDINATOR
Jeff Kopcak – TC
k8jtk@arrl.net

Hey gang,
I’ve been playing around with a couple new radios. With the holidays approaching, these will make great gift ideas.

Cheap radios for new or young hams are hard to come by. Many opted for the under $30 Baeofung (or Pofung) UV-5R and for good reason. They’re cheap. Perfect options for new hams, young hams, or public service events were radios are prone to damage and misuse. Destroy it and its $30 vs a couple hundred, or 7, to replace. Cheap radios could replace older radios that maybe didn’t have PL, were lower power, or single band. You got what you paid for though. Inconsistencies in firmware versions lead to differing sets of features, programming software wasn’t easy to use, neither was installing the programming cable, complaints about the lack of support, and lack of a usable manual. I stopped using these radios because of the many tests proving they were good about transmitting everywhere at once (across the entire band). As hams we are given plenty of leeway in how we use our frequencies. It’s up to each of us to make sure our radios comply with Part 97 and do not interfere with other licensed radio services. The ARRL published their findings in a November 2015 QST article. Ohio Section Technical Specialist Dave – KD8TWG demonstrated this with a couple of radios he had purchased: https://kd8twg.net/2015/10/17/a-quick-and-unscientific-spectral-analysis-of-two-baofeng-radios/.

Ok, so don’t use these radios. What radio, that meets Part 97 requirements, is available for the price? This was a problem. There was no real option. About the cheapest dual-band radio was $150. DMR radios competed on price and features but, until recently, were only single band. I finally found a better option. Unfortunately, the company has “Baofeng” in the name which makes things even more confusing. A company called “Baofeng Tech” or BTech, is a US based company offering a similar radio called the UV-5X3 for under $60.

The radio looks and acts like a UV-5R. Baofeng Tech updates the firmware, modifies the radio installing better filtering on the transmitter, and includes an easy-to-read nicely printed 85 page manual. The UV-5X3 comes with all the same accessories including belt clip, antennas, charger, and ear piece. All original Baofeng accessories work too. To my surprise, they even squeezed in the 220 MHz (1.25m) band! Baofeng Tech assured me their radios meet spectral requirements for Part 97. I had mine tested at the Cleveland Hamfest by KD8TWG. On VHF the 3rd harmonic was a little higher than 40db down, UHF was spot-on. The CHRIP free programming software is the only programmer that currently works with this radio. RT Systems UV-5R programmer for the original Baofeng radios does not work with the UV-5X3.

Now there’s no excuse to get a very reasonably priced radio compliant with Part 97 spectral requirements. It even comes with free shipping if bought through Amazon. For someone looking to play around with 220, this is a great tri-bander radio. Check out this radio as an option, from a US company, for new or young hams: https://baofengtech.com/uv-5×3. Product images from Baofeng Tech.

I’ve wanted to install a dual-band DMR mobile radio in the shack. Yeah, all the DMR repeaters in the area are UHF. I like to have the flexibility of a dual-band. Connect Systems was one for the first, if not the first, to release a dual-band DMR mobile radio earlier this year. Talking with Jerry at Dayton (President of Connect Systems), they had just shipped the first batch of CS800D radios and were expecting to get another batch ‘in a couple months.’ I heard very good things from hams that have purchased from Jerry’s company previously. Connect Systems is accessible via email and social media for support, they worked to fully resolve product issues, fixed issues with firmware quickly, and let customers try out their new equipment while seeking feedback. I didn’t hesitate to get on the waiting list.

I finally got the radio at the beginning of August and I like it a lot. The radio itself looks like a Motorola CM300D or nearly identical in layout, including microphone, to the Kenwood TM-281A. Radio covers VHF: 136-174 @ 50W, UHF: 400-470 @ 45W. The head and microphone are removable and extendable with a cat5 Ethernet cable. It will hold 4,000 channels and 130,000 contacts with firmware updates – more contacts than the ENTIRE DMR-MARC user database! It’s got a couple quarks which I’m told are to be fixed in future firmware releases. Biggest annoyance being the display doesn’t always update after a button is pressed. The programming software is straight forward if you’ve ever programmed a DMR radio before. The Ohio Section website has a pre-built codeplug: http://arrl-ohio.org/digital/digital.html. N0GSG makes a great codeplug editor and codeplug converter that I found useful: http://n0gsg.com/contact-manager/. His editor now supports the CS800D, TYT MD2017 & MD9600.

The Connect Systems CS800D was a little pricey when I bought it ($399 + $15 for the programming cable) but has since dropped in price to $299. I feel this radio could have been more popular if the radio was not released in batches. Jerry was great about communicating and explaining the situation. Like any distributor, they were beholden to the timetables from their manufacturer. Nothing they could do about it. I think that allowed other options to enter the market sooner and resulted in lost potential sales. It’s a great radio and recommended for someone looking for a dual-band DMR mobile radio from a US based company. CS800D product page: http://www.connectsystems.com/products/top/radios%20CS800D.htm.

If you’ve picked up a CS800D, check the Software page for recent firmware updates: http://www.connectsystems.com/software/software%20CS800D.htm. Product image from Connect Systems.

Technical Specialist reports

Dave – KD8TWG has been busy as usual. In addition to testing radios at the Cleveland Hamfest, he tackled the issue of “operational security.” This has been a topic of discussion in the area as of late and on social media. He was seeing arguments that operational frequencies needed to be obscured for the purposes of “securing” an operation. Without encryption, there is no such thing. As Dave points out, any modern scanner can scan VHF and UHF bands within seconds. It’s even easier with SDR receivers that allow you to look at the entire band scope at once. Check out his post about Hiding Frequencies for “Operational Security”: https://kd8twg.net/2017/08/14/opsec/.

In October, another Section Technical Specialist, Jason – WG8B, gave a presentation to the Dayton Amateur Radio Association about his area of expertise: bike mobile operations. Jason provided feedback on his program:

The briefing focused on using bike mobile capabilities to support public service events and covered topics such as

Suitable antennas. Bikes are not good ground planes, and dual band antennas are important when supporting public service events from a bike since carrying extra antennas and swapping them out is not easy.
Speakers and microphones that work while bicycling while allowing you to safely operate a bike.
Properly mounting equipment to not only protect the equipment but also protect the bicycle and rider.
APRS operations from a bicycle

Most of the questions revolved around antennas. I won’t repeat specific questions to protect the innocent so to speak, so I’ll just clarify what I think good antenna requirements are for VHF/UHF bicycle mobile operations. First and especially when supporting public service events, omnidrectional antennas are absolutely required. On a bike, there is no practical way to steer antennas with directional patterns whether they be gain antennas or magnetic loops. You will be changing direction quite frequently, and you need to hit repeaters from any aspect. Second, high-Q antennas such as magnetic loops require precise tuning, something that’s not possible while on a bicycle. Stick to an antenna that does not require tuning. Your radio should be working for you while on a bike during public service events not the other way around. There’s already enough going on, and safety is first. Third, any antenna bigger or longer than a bicycle flag is not likely safe. There are balance issues with weight above the bike’s center-of-gravity, and just about the worst shape aerodynamically is an antenna. So how hard do you want to pedal? Also, I’ve had problems with low hanging branches with just a bicycle flag. Anything taller is going to be problematic. My recommendation is still to use a dual band J pole like Ed Fong’s DBJ-2 taped to a bike flag or a single band half wave dipole like Larson’s NMO 150B HW. While not the absolutely best antennas performance-wise, they will still hit every repeater in my local area and then some with a 5W HT. And these are very simple and small form factor antennas that just work and won’t get in the way when on a bike.

Finally, if you would like to see the briefing, I’ve made it accessible here: https://drive.google.com/open?id=0B2Yn-_hki2v0blFnNVVRbW9kc3c

Jason’s presentation has lots of tips and pictures for making a bicycle mobile installation a success. If you would like to have Jason at your meeting, drop him a note!

Thanks for reading and 73… de Jeff – K8JTK

Amateur Radio, DMR in Amateur Radio, Tutorials

DMR in Amateur Radio: Terminology

May 10, 2017 Jeffrey Kopcak

Read the rest of the series in the DMR in Amateur Radio series category.

Planning on picking up a new DMR radio at Dayton? DMR saw growth due to inexpensive offerings of quality radios at last year’s show. I suspect this year will be no different with new offerings from vendors and many more groups supporting DMR. How many of you know the terminology and could program a radio from scratch?

Passing around a code plug makes the mode seem plug-and-play and it’s a great way to get started. Relying on existing code plugs leaves most of us unable to change the configuration of our own radios. What happens if you need to change programming, add a repeater, the code plug information is old, or wrong?

Here I’ll explain DMR concepts and terminology as it relates to the Ham Radio service. Next, I’ll walk through programming an example repeater and hotspot for devices like the SharkRF OpenSpot, DVMega, and DV4Mini. This series is intended for the beginner to better understand the technology by providing practical reasons and examples. These won’t be tied to a specific radio or repeater though there will be differences between vendors, models, repeaters, networks, and configurations in practice. Consult the repeater owner with specific questions.

About DMR

Digital Mobile Radio is an open digital mode standardized by the European Telecommunications Standards Institute (ETSI). It was first published in 2005 and is used in commercial products around the world. Open means the specifications are available for anyone to use, modify, add, or remove features as one sees fit. DMR uses two-slot Time-Division Multiple Access (TDMA) allowing two channels in 12.5 kHz of bandwidth using the AMBE+2 proprietary codec (or vocoder, voice encoder). TDMA is old cellphone technology in use before LTE and GSM. “Spectrum efficiency of 6.25 kHz” is often used which is ‘blah blah’ marketing speak for ‘it really uses 12.5 kHz, half the time.’

ETSI’s objective was to have a low cost, interoperable, digital system. In reality, manufactures added their own proprietary features that make their radios non-interoperable with other manufactures. Motorola’s system is called MotoTRBO which is a DMR capable radio with their own proprietary features. Motorola did not create nor invent DMR but they help bring it to the U.S.

DMR is the first time a commercial system was adopted for ham use. Most of the terms heard in relation to DMR are carryovers from the commercial world. In comparison, D-STAR and Fusion were specifically designed for ham radio use. D-STAR, Fusion, and DMR are all open standards. This means commercial gear is setup for commercial users while ham gear is setup for the way hams use radios. All three use the proprietary AMBE codec allowing 12.5 kHz wide transmissions. DMR achieves two simultaneous transmissions in the same bandwidth. D-STAR uses the AMBE codec while DMR and Fusion use AMBE+2.

D-STAR has an Internet and networking component accessible by users built into the standard. This includes an APRS-like position reporting system called D-PRS. Fusion can transmit pictures messages, and position information to other stations. DMR data features in ham radio are underutilized. Up to this point, text messaging was the most widely used data feature. The Brandmeister network is the first network to begin taking advantage of position reporting data.

Most associate the openness of a standard with how many vendors sell equipment, which is an inaccurate assumption. There have been devices since D-STAR became popular that could turn any analog radio into a digital radio, including repeaters. Now, how much does that equipment cost is the more likely driving popularity factor.

Is it legal?

I hear this issue come up from time-to-time in the Ohio section. I’m sure many more have the same question. DMR is legal (in the U.S.) under Part 97 as of a decision issued on June 9, 2014 by the FCC in docket FCC-14-74. This decision modified Part 97 rules to allow emission types that cover DMR: FXD, FXE, and F7E into Sections 97.3(c) and 97.307(f)(8). Any further questions, please consult an ARRL legal or technical resource.

Keep in mind however, the DMR ID transmitted by the radio IS NOT a legal FCC ID. It’s analogous to kerchunking a repeater without identifying. There must be an identification using voice or something in the data stream must contain the station’s call sign. This includes identifying when linking and unlinking systems. D-STAR and Fusion transmissions contain the call sign in the data stream. Repeaters ID with CW like analog repeaters. The DMR ID in the data stream does not contain a valid FCC call sign and therefore does not constitute valid identification under Part 97. The transmitting station’s name and call sign may appear on your radio display, it still does not make for valid identification. See “Contacts” for more on displayed names and call signs.

Radios, CPS, and Code plugs

Inexpensive DMR radios are easy to come by. There are over 40 manufactures producing DMR equipment. The TYT (Tytera) MD-380 is the most popular ham friendly option for $100 at R & L and Universal Radio – remember to support your local dealers. Connect Systems radios are pricier but come with actual support and a wider selection, including mobiles. The super-cheap Baofeng DMR radios are just like all other Baofengs, crap.

Repurposed radios or new radios that appear on the market will work with the ham radio infrastructure. The radio must cover the appropriate VHF/UHF band and be “DMR Tier II” compliant. DMR Tier I is unlicensed 446 MHz in Europe, similar to FRS. Tier II, aka conventional, is licensed services needing higher power and IP Site Connectivity (IPSC) using the Internet for site linking. Tier III builds on Tier II adding trunking capability and advanced data services.

It’s estimated that 95% of all DMR repeaters in the U.S. are UHF with few VHF. Popular radios are only single band – a commercial carry over because commercial licenses usually cover a single band. Dual band DMR radios should be available by Dayton (2017). In the state of Ohio as of this writing, RepeaterBook is showing 60 DMR repeaters: 3 VHF, one 900 MHz, and the remaining are UHF… so make sure you pick up a UHF model.

To update settings and memories in all DMR radios requires a computer, programming cable, and Computer (or Customer) Programming Software referred to as “CPS.” CPS is the later version of RSS (Radio Service Software) which was used by radio programming professionals and commercial radio resellers. Front Panel Programming (FPP) is a software enabled setting allowing programming via the radio’s front panel. This method allows modification of important programmed functions but not all, so a computer is still required.

The radio utilizes a code plug which is a small program containing radio settings, repeater configurations, Talk Groups, contacts, power outputs, Color Codes, PL tones, signaling methods, and more. A code plug is similar to programming a ham radio with RT Systems or CHIRP. Settings and memories are programmed into the software then downloaded to the radio. Code plug is a Motorola term when physical jumpers were plugged into old radios enabling certain options. Later microprocessor based radios moved the settings internally but the term still stuck referring to radio settings. Today, they resemble small relational databases where settings and data are interrelated and interdependent. Making a change in one area may impact other settings that rely on that data. Next in this series will be programming a sample code plug.

In general, code plugs are radio specific. A TYT MD-380 will work on a MD-390 because the internals are almost identical. However, Connect Systems is not going to work in a Motorola or Hyterra. The newer a radio or less popular a radio is will make it harder to find preprogrammed code plugs.

DMR radios, unless specifically labeled, are not compatible with other ham radio digital systems like D-STAR and Fusion. Advancements are being made to incorporate all digital modes into a single radio by third-party developers.

Registering

Every user on any DMR network requires a CCS7 ID commonly referred to as a “DMR ID” or “radio ID.” CCS stands for “Callsign Communication System” (or Call Connection Service) and is a subscriber identification containing 7 digits. Users registered in Ohio are assigned 3139xxx, where ‘xxx’ is a 3-digit consecutive ID. Ohio used up all 3139xxx IDs and has rolled over to 1139xxx. One might note that the Ohio Statewide Talk Group has the ID 3139! This radio ID has its place on D-STAR, DMR, and Fusion networks but the reasons are beyond introductory level. The CCS7 is a universal ID that will work on any DMR network.

If you don’t already have a DMR ID, follow the instructions on the DMR-MARC registration site [Updated: registration site is now at RadioID] DO NOT REQUEST multiple IDs for a single callsign! Hotspot devices or different radios don’t need separate IDs. Obtaining an ID may take up to 3 days and the process can be started even before buying a radio. If you think you might already have an ID: on the registration page, click the “Database” link, click “User Database,” and search using your call sign (current or previous). To change the registered information for a call sign, use the “Contact Us” link.

Repeaters, c-Bridges, and Networks

In order to program a DMR repeater into a DMR radio, a couple pieces of information about the repeater are needed. To program an analog FM repeater into a ham radio, a user needs the repeater transmit frequency, offset/receive frequency, and PL/DCS tone configuration to access the repeater. Different information is required for a DMR repeater: Color Code and Talk Group configuration is needed. The functionality of a PL/DCS tone is replaced by a “Color Code” (CC) or “Colour” when in Europe. There are 16 possible Color Codes, 0-15. A DMR repeater cannot be Color Code-less. Like PL, the Color Code must match the repeater or the repeater cannot be accessed.

Configuration of the repeater depends on the c-Bridge or network it is connected to. C-Bridge is a communication device to route calls between different networks. There are many ham radio c-Bridges: DMR-MARC, DCI, NATS, CACTUS, K4USD, Crossroads – for example. Some c-Bridges explicitly define repeater configuration, including limiting available Talk Groups only to certain regions. For example, “Rocky Mountain regional” may not be available on Ohio repeaters. Other c-Bridges allow owners leeway in their configuration. User linking is done via Talk Groups or reflectors. Repeaters cannot be linked to directly by other repeaters or hotspots.

Brandmeister is a decentralized network of master servers. Master servers are different from a c-Bridge but an oversimplification is they both provide similar linking functionality. The Brandmeister name is synonymous with DMR but it cross-links with other networks and digital systems like D-STAR and APRS. Work is being done on linking Fusion and P25. All Talk Groups and reflectors on Brandmeister are available to all repeaters and hotspots connected to that network.

As with any linked repeater system, there are significant time delays in fully establishing connections. On an analog repeater system with multiple voted inputs, it will take two or three seconds for the system to fully come up. From the time the radio is keyed, the signal has to reach the inputs, the inputs reach the voter, voter decides which input is the strongest, bring up the transmitter(s), and all receiving stations pick up the repeater’s signal. Fast-keying is one of my pet-peeves where a transmitting station quickly keys their radio and starts talking. Receiving stations only hear the last letter or two of a callsign. Delays are even longer when networking and routing packets is involved over a wide area. This is true for any networked mode: D-STAR, DMR, Fusion, Echolink, AllStar, or IRLP. When first establishing connection on a repeater, first key up for 2 to 3 seconds before saying or doing anything to being up all links. Once links are established, they tend to react quicker so that delay can be dropped to 2 seconds on subsequent transmissions.

Another note when linking DMR systems, at the time a repeater or hotspot is connected, an existing transmission might be taking place on that Talk Group. Nothing would be heard by the station that linked. They think the Talk Group is free and end up disrupting an in progress QSO by calling another station. At the point the system is linked to a Talk Group with a transmission in progress, nothing will be heard until the first station unkeys. After linking, wait a minute while making sure the Talk Group is not already in use before calling.

At some point, you will be ‘bonked’ from a repeater. This is the tone a radio might emit after attempting to access a repeater. There are many reasons for being bonked: repeater didn’t respond because it is offline, wrong Color Code is programmed for the channel, out-of-range of the repeater, an incorrect Talk Group/time slot configuration is programmed, Talk Group doesn’t exist, someone could be making a private call, or there is some other error in the radio configuration. Most likely reason: another Talk Group is in use on the same time slot.

More information about repeaters and time slots is in the “Talk Group” and “Time Slot” sections.

Repeater owners: one big problem with DMR has been the lack of information on your repeater. It’s pointless going through the trouble of putting up a digital repeater and not telling people how to access it. Post the Talk Group layout, how to access them, and include any other procedures users should follow. Post this information on a website, use RepeaterBook or RFinder as both have provisions for listing Talk Groups. It can make all the difference in attracting new users.

Time slot (TS)

Time slots allow two conversations on the same repeater, on the same frequency, happening at the same time, and be completely separate from each other. This is what people refer to when they say ‘DMR is two repeaters in one.’ A time slot can be thought of as a ‘channel.’ Each repeater has two time slots or two channels. A user can only access one time slot at a time. Two Talk Groups cannot be accessed on the same time slot simultaneously.

Img: http://www.hytera.com/navigation.htm?newsId=1086&columnType=news

Each time slot occupies the signal for less than 30ms at a time. Within a 60ms window on a repeater: time slot 1 is transmitted for 27.5ms, then a gap of 2.5ms, time slot 2 is transmitted for 27.5ms, another 2.5ms gap, and then repeats with time slot 1. The human ear cannot detect that small of a gap in audio. A repeater transmits both time slots even though one channel is in use and the other idle. This cuts down on the on/off keying of the repeater. User radios, on the other hand, transmit for 27.5ms each 60ms window. This results in extended life of the handheld battery.

Talk Group (TG)

A way for groups of users to be separated on each time slot, without distracting or disrupting other users, is to use Talk Groups. A commercial example would be a baseball stadium. The ball park might have services like facilities management, guest services, security, first aid, concessions, traffic, and ushers all using the same radio system but the conversations are completely independent. Not all services would be using the frequency at the same time for the entire game. Each radio stays muted until their assigned Talk Group appears on the frequency, then it would unmute or activate for that transmission. Their radios would have the ability to switch over to another Talk Group. Security might need to alert first aid of a guest injury or guest services may need to notify facilities of an issue in one of the suites.

Ham radio Talk Groups can be created for any purpose and usually fall into the categories of wide-area (worldwide), regional (North America, Midwest), or a particular purpose (Ohio Statewide, XYZ club). There can be many Talk Groups available on a repeater time slot. Time slot 1 could have 5 while time slot 2 may have 25. Some c-Bridges organize wide-area Talk Groups on time slot 1 with regional, local, and special use on time slot 2.

Locals are unique and only heard on that repeater, not routed to the network in most cases. Special use includes Parrot and audio test. Parrot repeats received audio by the repeater. Audio test is a Talk Group linked to an online audio meter by the Northern California DMR Group (NorCal DMR). This has been deprecated because Brandmeister Hoseline has an audio meter for each Talk Group. Hoseline lets anyone listen to any Brandmeister Talk Group with a web browser: https://hose.brandmeister.network/. It is the “firehose” of Talk Group traffic.

The larger an area served by a Talk Group, the more repeaters and time slots are tied up simultaneously. Ohio Statewide keys about 60 repeaters at once. Calling and worldwide Talk Groups could be in the thousands and should be thought of as the 146.520 of DMR. Etiquette is to make contact then move to another Talk Group or a reflector. Tactical or TAC Talk Groups are used for longer QSOs and nets as they tie up the least number of repeaters and are selectively linked-up by repeater users.

Repeater configuration includes static Talk Groups – always connected, and dynamic Talk Groups – commonly referred to as PTT (push-to-talk). Dynamic are linked by a user for a period of about 15 minutes. After 15 minutes of no local activity, that Talk Group is dropped and the repeater returns to the static group on that time slot.

C-Bridges and networks tend to keep the same Talk Group numbering (ID) and allow cross-patching to others to keep things consistent. This means Ohio Statewide is the same group and ID on DMR-MARC, DCI, K4USD, Brandmeister, and others.

Brandmeister offers the flexibility for any two radios to key-up on a random Talk Group ID and essentially create their own Talk Group. This can be done using any Brandmeister connected repeater or hotspot. This Talk Group is not hidden or private because it will show up on Hoseline allowing anyone to listen in and any other stations can join in too. A list of known Brandmeister Talk Groups is provided in the links section.

Reflector

Update 2/2021: Brandmeister has dropped reflector support at the end of 2020. This information would still be applicable to other networks that use reflectors.

As described in the repeaters section, some c-Bridges severely limit the Talk Groups a repeater can access. What happens when you’re traveling to Florida and want to talk to your buddies back in Ohio? Or worse, talk to a buddy in England? Talk Group options become limited to wide-area ones which tie-up a lot of repeaters for a lengthy QSO. Reflectors are a way to solve this problem.

Similar to D-STAR or IRLP reflectors, nodes are connected in a round-table style configuration. When one station transmits, their signal is transmitted by all other connected nodes. So far, these sound like Talk Groups. The difference is reflectors are available worldwide and repeater users have to specifically link and unlink a reflector. This means only repeaters and hotspots connected to that reflector are tied up during transmissions and not thousands of repeaters on world-wide Talk Groups.

Reflectors are a 4-digit ID that begins with a 4, 4xxx. Not every c-Bridge has granted reflector connectivity. DMR-MARC and Brandmeister have this ability. Some reflectors are cross-patched to Talk Groups on Brandmeister so either the reflector or Talk Group ID can be used. Reflectors are seldom used on Brandmeister because of the availability of all Talk Groups to all repeaters and hotspots on the network. However, reflectors still serve the intended purpose if a station isn’t in range of a Brandmeister repeater.

Contacts

There are three call types in DMR: Group Call, Private Call, and All-Call. Each is a contact within the radio. A Group Call is a transmission from one radio to a group of radios. These instantly link-up dynamic Talk Groups when PTT is pressed. When you press PTT on Ohio Statewide (3139), all other radios configured for 3139 unmute. All-Call is a carryover from commercial and is programed into supervisor radios allowing the ability to make a call to all radios on the same time slot regardless of talk group. All-call is not used in ham radio.

Private Call is a call from one radio to another radio using the other radio ID (see Registering). In ham radio, that ID is associated with an individual. To return a private call, that users’ radio ID must be stored and selected in the radio. These calls are routed to a user’s last known location on the network, like D-STAR call routing. If someone keyed a DMR repeater in Dayton, then travels to Cleveland, the private call is still routed to the Dayton repeater. Private calls are generally discouraged and even disabled on some repeaters. They tie up a time slot and could clobber an existing QSO. Other users will have no idea why they cannot access the time slot. Private calls are acceptable between hotspots because they are lower profile with only a few users. The DV4Mini can receive private calls but didn’t seem to know how to handle returning a private call.

A common issue I hear on DMR all the time is ‘I don’t see your name and call sign on my display. I must be doing something wrong!’ This behavior depends on the contacts stored in the receiving radio. To see the transmitting station’s name or call sign on the radio display, that radio ID must be setup as a contact in the receiving radio. When the radio receives a radio ID in the contact list, the Contact Name is displayed in place of the radio ID. If the radio ID is not in the contact list, the radio displays what it knows which is the seven-digit radio ID that comes across as part of the data stream in the transmission.

The MD-380 for example, has room for 1,000 contacts which is a carryover from commercial. Most police departments and businesses don’t have more than 1,000 radios in their fleet. Ohio has 1,400+ registered users so the MD-380 cannot store all registered users. Modified firmware makes this possible or look for a radio with more memory for contacts.

(Digital) RX Group lists

An RX Group List is a list of Talk Groups that will unmute or activate the radio when received on the same time slot as the current channel. RX lists were created as a way to monitor activity on the repeater regardless of channel. Key thing to remember is these lists are time slot specific. A radio is set to Local9 with Ohio Statewide and Local9 (both on time slot 2) included in the same RX Group list. When a conversation starts up on Ohio Statewide, the radio would unmute even though Local9 is selected. One can turn their radio to Ohio Statewide and join in. These can cause confusion if a station was heard on Ohio Statewide but the reply transmission went out over Local9. Be careful and mindful of the selected channel before transmitting.

If the radio was set to Local9 and a conversation started on North America calling on time slot 1, nothing will happen. The radio would remain muted because the time slot is different – even if they are in the same RX Group list.

As the name implies, these lists only include contacts set to Group Call for their Call Type. Private calls are not included in these because a radio will always unmute when a private call for that radio ID comes over the time slot. RX Groups keep users from interrupting conversations on repeater Talk Groups they are not monitoring. While intended to cut down on interruptions, some will quickly realize they are hearing a lot more Talk Group traffic then they care about.

When a radio does not unmute as a signal is received, the frequency-in-use LED would illuminate or some other ‘in use’ indicator would be seen. This indicates a Talk Group is not in the RX Group list for the channel, another time slot is in use, or a private call is occurring. To scan across time slots and channels, see Scan List.

Channels

This is where it all comes together. Channels are like memory settings of a typical ham radio. These tell the radio which modulation type to use (analog or digital), frequency, time-out-timer setting, power level settings, and scan lists. It ties together DMR specific settings like Color Code, time slot, digital contacts, and RX Groups. Analog channels are programmed here too.

Zones

A Zone is a way of organizing channels. Most radios allow a maximum of 16 channels per zone because that’s how many positions are available on the channel selector knob on top. Channels not included in a zone cannot be selected on the radio. There can be one or many zones per repeater or hotspot. There is no limit to how channels are arranged within a zone.

Zones are selected through the radio’s menu. When a new zone is selected, channels assigned to that zone become positions on the channel selection knob.

An un-programmed position will result in a continuous error-sounding tone from the radio until a valid position is selected. This was probably intended as a notification for commercial users to indicate they are on a channel where no transmissions will be heard, so a continuous tone sounds.

Scan Lists

RX Group lists receive Talk Groups on the same time slot. Scan lists scan different channels. These lists are closely related to the scan functionality of a scanner. Lists can include the different time slots, different frequencies, and include analog channels. Scan lists have a limit of about 32 channels per list. These lists are not required for radio operation.

Roam Lists

Roam lists are similar to when a cell phone switches towers automatically. They are useful when mobile. Though not implemented by many manufactures, the same functionality can be accomplished by creating a Scan List. The scan list would contain a single Talk Group across many repeaters. Roam lists only work well for static Talk Groups. Otherwise, the Talk Group has to be activated on each repeater, essentially defeating the purpose.

Hotspots

Hotspots are low powered (20mW or so) transceiver devices that connect to a network over the Internet. The hotspot becomes the gateway to the network. An Internet connection is required. Some hotspots will require a computer (DV4Mini) or Raspberry Pi (DVMega, DV4Mini) while others are standalone (OpenSpot). Lastly, a transceiver capable of that mode is needed. SharkRF OpenSpot, DVMega, and DV4Mini are all capable of operating D-STAR, DMR, and Fusion. A D-STAR DVAP, for example, would not work with DMR or Fusion.

After trying out the DV4Mini in a number of configurations with different users, the device needs a lot more work. As of this writing, I would personally stay away from it. DVMega’s are good for tinkering or finding a working software image, which can be frustrating. The SharkRF OpenSpot is my recommendation for a hotspot because of stability, ease-of-use, features, and updates.

Communication Examples

Situation: Find any station to make an extended QSO.
Solutions: Call out on any Talk Group: this is K8XXX listening on ‘name of the Talk Group.’ Ie: “This is K8JTK listening on Ohio Statewide.” When on a “Calling” Talk Group and contact is made, keep the QSO relatively short, move to another Talk Group (TAC Talk Groups for example) or Reflector for the duration of the QSO.

Situation: Make a sked with a buddy on the same local repeater.
Solutions: Use Local9 when all stations are on the same local repeater. Use statewide or other Talk Group when you want to bring in other stations not on the local repeater or hotspot.

Situation: Make a sked with another station on a different repeater.
Solutions: Both stations must have both repeaters linked to the same Talk Group or Reflector. Then call the other station as one normally does. For different regions or countries: a common talk group between both repeater networks must be found. Typically, TAC or any Talk Group on Brandmeister.

Situation: Make a sked with a station on a repeater and other on a hotspot.
Solutions: Hotspot access is only available on DMR-MARC and Brandmeister networks. A common talk group between the repeater network and hotspot network needs to be used. Typically, statewide, TAC, or any Talk Group on Brandmeister. Both stations must link to the same Talk Group or Reflector. Then call the other station as one normally does.

If you’re still here, you made it through the terminology portion of this series, which is the hardest part. The next will bring it all together as I walk through creating a sample code plug for a DMR repeater and hotspot. DMR has come a long way since I jumped into it at Dayton in 2016. Likely in the next year, explanations here may change slightly and improvements in radio technology may make code plugs unnecessary.

Links

About CCS7 ID system: https://register.ham-digital.org/html/ccs7-ENG.html [DEAD LINK]
List of BrandMeister Talk Groups: http://www.dmr-utah.net/talkgroups.php, https://brandmeister.network/?page=talkgroups
Ham Radio 2.0 podcast (DMR 101 (Greater Houston Hamfest Forum)): http://www.livefromthehamshack.tv/2017/04/18/episode-90-dmr-101-greater-houston-hamfest-forum/

References used for this writeup
Ham Radio 2.0 podcast (DMR 101 (Greater Houston Hamfest Forum)): http://www.livefromthehamshack.tv/2017/04/18/episode-90-dmr-101-greater-houston-hamfest-forum/
BrandMeister Getting Started Guide: http://n8noe.us/DMR/files/BrandMeisterGettingStartedGuide.pdf
Connect Systems CS600/CS700 Programming Guidelines: http://www.connectsystems.com/products/manuals/CS600_CS700_Programming_Guidelines.pdf
Amateur Radio Guide to Digital Mobile Radio (DMR) by John S. Burningham, W2XAB: http://www.trbo.org/docs/Amateur_Radio_Guide_to_DMR.pdf

Jeffrey Kopcak, MBA – K8JTK