Tag: WARC

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.