The intent of this article is to provide insight to a limited mobile device to Brandmeister Network experience helpful for those looking for another field capable communications option. And, if you are a child of the 1980's you will easily understand the villainous image above!
Using the "Mumla" Android or iOS application, you can easily link a few talk groups via Brandmeister for access on your mobile phone from anywhere for limited DMR access.
Your DMR ID - You MUST use the newer 31xxxxx format ID. Older 11xxxxx will not work.
Your hotspot - Make sure you enter in your SSID as part of your hotspot, but I have realized your hotspot does NOT need to be on the network for this to still work.
Where does it work? This will work anywhere you have mobile device coverage
Connecting The All Seeing Eye!
Now that you have set everything up and you connect, you should see something like this on your mobile device. You can then click into the limited list of bridged talk groups and communicate globally.
Be aware that certain ranges of talk groups will not be permitted to be added after opening a ticket with Brandmeister and even then, you will have to have a server configured to hopefully allow you to get added to Mumla.
After some testing, this works rather well as an alternative communication method using my Android and iOS devices.
This will NOT replace anything for me, but its nice to have this set up "just incase" I need it. Plus, it works well with a Bluetooth headset and audio is rather good.
One last note, if you want to see what happens after hitting the PTT button on Mumla while watching your Pi-Star dashboard, make sure you add the talk group to your hotspot so you can see your traffic.
One idea this gives me is getting more SOTA or POTA people in the Hudson Valley on the TriState NY-NJ-PA talk group while doing activations if they have mobile service if something other than a local repeater is needed for spotting and you do not want to use a hotspot while at the park or in the woods.
Now, how about this as our next ham mobile inspiration!
Kraken is coming and we all need to prepare for its arrival. On Tuesday October 19th 2021, Steve K2GOG was invited to the North Star Digital Net to give a quick chat about what does it do and why its important for the future within the broader topic of "software defined radio".
A few people who could not attend the live discussion had asked Jim WA2UMP and Steve K2GOG to see if they could record the audio presentation. This is a fun problem that needed to be solved first to start this article, so read onward!
How do you record DMR audio?
Steve K2GOG planned to use his Alinco DJ-MD5XTG to talk via his hotspot which reaches the Brandmeister 31630 (STEM) talk group. A nice feature with this radio, as well as the popular Anytone AT-878 series of radio, is that it can record transmit and receive audio with timestamps and by who was speaking.
Its easy to scroll through recorded audio files one by one or play all your recordings on a loop to play them all in order. This could be helpful if you thought you may have missed some important scheduled discussion or activity on your favorite talk group.
One annoyance is that the recordings save to internal memory on the radio instead of a micro SD card, like on radios such as the D-Star focused Kenwood TH-D74 or the Fusion based Yaesu FT-5DR.
Both of those radios and even the Icom IC-705, all require the user to remove the SD card from the radio to access recorded audio but that makes it really easy to access those files on your computer and send them to someone to share interesting transmissions like during a satellite contact.
In the case with the Alinco and Anytone, you need to connect up a cable to your computer to access the recordings but you can not pull those files off which is super annoying. The manufacturers software seems to lock this function out but would otherwise clearly support this as pictured below.
If you click any of the files listed in photo above, the recording simply plays through the radio speaker but we are no closer to sharing the recordings.
The Alinco DJ-MD5 series of radio uses a simple USB micro cable to program the radio but does not output audio. The way to solve this problem is to use the headphone port on the Alinco which uses the standard 3.5mm plug found on most all consumer headphones.
Using a 3.5mm stereo to stereo cable, the other end plugs right into the microphone jack on your computer sound card. If you have a modern laptop which uses a TRRS (Tip, Ring1, Ring2, Sleeve) style connector, you may instead need to use a USB sound card as mentioned in Steve's explanation video below.
Now that we have that problem solved, you can use a program like Audacity with the sound activated record function enabled to "re-record" the audio from the radio to your computer. While this takes a little while to do, it lets you easily stitch together the audio segments you want with no gaps.
If you are over a certain age where you may remember double cassette recorders, this activity may bring back memories of less technological days when you had to get creative to make a mix tape from "borrowed" cassettes or maybe songs off the local broadcast station.
Hopefully this modern solution may give you some ideas on getting more from your DMR radio.
Getting back to Kraken
After all that, now we can finally get to the recording you might have missed!
It sounds like he missed a few parts but is otherwise complete. It looks like a time intensive operation to click on all recordings in order, so bear that in mind if you wish to do something like this yourself.
The recorder function works on any "over the air" DMR signal, so using it also to record simplex activity like what took place during the NEARFEST on US national DMR simplex of 446.075 MHz on time slot 1, color code 1 and talk group 99 is another idea.
But, if you plan to record audio from Brandmeister you can also just use the "Hoseline" function and route that audio from a talk group into Audacity just as easily using virtual audio cables.
And with that, I hope you are looking forward as much as Steve is to getting the new Kraken once its starts shipping in March 2022.
Software Defined Radio is eating the world. SDR devices have become common place in both the amateur radio and electronics hobbyist world for many years now and the good news is that hardware comes at different prices in order to appeal to different users.
On October 5th 2021 during the North Star Digital Net, Rick W1RHS, will be talking about the inexpensive RTL-SDR USB dongles and where they fit in along side other much more expensive devices aimed at the amateur radio community.
For under $30 USD, this popular RTL-SDR V3 has been covered before on HVDN and Carl Laufer who is the manufacturer of this SDR has even shared some HVDN articles on his very popular RTL-SDR.com blog
And, because HVDN and Jim WA2UMP who runs this excellent DMR weekly discussion are close friends with Rick W1RHS, here is a quick link to Rick's upcoming presentation which will be live on talk group 31630 (STEM) on Brandmeister next Tuesday.
Its also possible to listen to the discussion without a DMR radio by looking for 31630 in the talk group list at https://hose.brandmeister.network/#/
What about the software? What about the Kraken?
Rick covers some really great detail on hardware plus some ideas for software, which is really needed to get your "software" defined radio to do anything.
Between Rick's latest presentation and one that Steve K2GOG did a while back on "Sensing the world around you", you will see many of the same references to certain software, like SDR#, SDR Play, SDRangel and a few others. Since the below chart was created, another cross platform application worth a strong look is called SDR++
One area which both presentations did not talk about is something called a phase coherent software defined radio which actually combines multiple radio's together in order to provide very unique capabilities.
The RTL-SDR.com website not only offers its inexpensive SDR many just call the "V3" but also a device called the Kerberos and its upcoming really exciting update to this called the Kraken.
This topic on phase coherent SDR is best left for another time, like how to change some code to use the older Kerberos hardware with the newer software meant for the Kraken.
Please give a listen to support Rick and his October 5th SDR presentation by marking your calendar now incase you have other things in the Hudson Valley or beyond taking place the same evening.
As more and more users of digital voice amateur radio shift towards hot spot devices instead of local repeaters, it gets hard to find where people in your area are using DMR.
Since hotspots have such limited range, you would not likely be able to hear them "over the air" and there is not really any way to simply "scan the band" looking for activity like one may do on 2m or 80m. So, how do you find DMR activity?
DMR: Get Predictive
Is this suggestion cheating? Not really. There is a way you can use one of the many somewhat hidden analytic tools to find out what talk groups are most active and when. This will help you learn when and where to spend time "lurking" since there are 1,439 officially set aside talk groups according to this nice Pi-Star DMR BrandMeister Talk Grouppage.
Using talk group 31630 (STEM) as an example, the chart below is predictive in the sense that every Tuesday evening at 20:00 hours Eastern US time, is a big spike of activity for a little over an hour. This is when the Northstar Digital Net takes place.
Another example on when you may find activity if you are traveling in the state of Louisiana is shown below by looking at talk group 3122.
How about if you want to feel really special and have "Nationwide US" all to your self with fewer people constantly asking for a radio check or signal report? 06:00 AM Eastern US may just be the time for you to sit on talk group 3100.
Where do you get these charts?
Here is where to go and find some possibly interesting talk groups and times to see what sort of activity is taking place.https://brandmeister.network/?page=callstats
And now you know how to find the best of the best on DMR.
In October of 2016, Steve K2GOG made a presentation at the Overlook Mountain Amateur Radio Club of Ulster County New York at its monthly membership meeting.
At that point in time according to Repeaterbook.com, there were 45 DMR repeaters across all of New York State.
Fast forward to March of 2018, that count has increased to 61 according to the same website. What about Fusion, D-Star Repeaters in New York?
D-Star had 29 and is now up to 33
Fusion had 32 and is now up to 39
What about global growth of digital voice repeaters?
2,204 Fusion repeaters (1,431 in Oct. 2016)
2,315 D-Star repeaters (2,051 in Oct. 2016)
2,326 DMR repeaters (1,493 in Oct. 2016
330 P25 repeaters (213 in Oct. 2016)
107 NXDN repeaters (82 in Oct.2016
How much growth has there been since October 2016?
154% growth for Fusion
112% growth for D-Star
156% growth for DMR
155% growth for P25
130% growth for NXDN
With Icom's D-Star being the oldest digital voice technology at 15 years, its days of accelerated growth are unlikely due to a lack of new radio equipment being introduced. The newest radio supporting D-Star is Kenwood's tri band TH-D74 handheld at $550 USD. A dual band FT-70DR Yaesu Fusion radio can be had new for as low as $199.99. Icom's only current dual band D-Star hand held radio is the $390 ID-51.
There are multiple dual band hand held options from different vendors however for DMR ranging from $86 for the Radioddity GD-77 at the low end and no less than 4 others from vendors such as alinco, Anyone, Aiulence, Retevis and TYT for between $150 to $200.
There are also commercial radios that can be purchased new or at reduced cost for used options for DMR, P25 and NXDN. DMR is the only mode supported by non-commercial radio vendors though.
What about non-repeater use?
Hot spot devices such as the Shark RF OpenSpot, MMDVM based ZUMSpot, JumboSpot, NanoSpot devices and a few others allow users not near a repeater to talk globally. All of these devices are capable to support most all modes listed above and a few able to cross mode translate. This function allows a user to use a DMR radio to talk on D-Star or Fusion networks as an example.
According to Brandmeister Network, there are 5,498 hot spots currently connected to its network which is interesting given that there are only 7,282 digital voice repeaters accounted for globally. Combined, repeaters and hot spots make a very robust communications network for both local and global communications.
Democratized Modern Radio
Digital voice infrastructure would not be needed if there were no users looking to access it, so a rough conservative estimate is that there should be between 350,000 and 700,000 hand held digital amateur radios in somewhat frequent use globally based on repeater and hot spot deployment figures. That figure is based on the following criteria:
Number of known registered DMR users
Number of hot spots currently internet connected
Number of repeaters currently internet connected
Number of repeaters not internet connected
Number of DMR handheld radio products sold in last 12 months on E-Bay
Estimated number of D-Star and Fusion users and equipment currently in use.
