amateur radio, electronics, and IT


13 posts

DMR-MARC partners with DMRPlus! Dongle access is here!

dv4mini dongle from wireless holdings

dv4mini dongle from wireless holdings

The HCCA Repeater N8OUZ in Traverse City, MI (442.2875) is a MotoTrbo repeater on the DMR-MARC network.

As such, this announcement applies to users of the system, which serves to announce access to new talkgroups accessible to dv4mini users, as well as users of other similar technologies. Here is the text from the official announcement”


DMR-MARC is pleased to announce a partnership with the DMRPlus network that will enable DV4mini USB dongles from Wireless Holding, to access the DMR-MARC network.

Today, we are launching three new DMR-MARC talkgroups: talkgroup 133 (DMRPlus USA), talkgroup 143 (DMRPlus UK), and talkgroup 153 (DMRPlus South Pacific), which will allow interconnection between the DMR-MARC and DMRPlus networks using timeslot 1. In the coming months, we are also planning to launch additional interconnected talkgroups, including three German language talkgroups, a French language talkgroup, and a Spanish language talkgroup as well.

These new talkgroups are currently set up as ‚Äúon-demand‚ÄĚ, which can be enabled using the PTT and have a 10-minute inactivity timeout on our eight core DMR-MARC bridges. We will begin rolling out these talkgroups to our core DMR-MARC repeaters while we evaluate the loading on our gateway that connects the DMR-MARC and DMRPlus networks. If we determine the loading is acceptable, we will then roll these new talkgroups out to all of our other bridges for wider distribution. Please note that there is no plan at this time to roll out these new talkgroups to other DMR networks outside of the core DMR-MARC bridges.

We believe our partnership with DMRPlus network provides us with better options for experimentation using the DMR-MARC network, while at the same time, maintain the high degree of reliability that the DMR-MARC has become known for, allowing us to serve our communities during times of emergency when our network is needed the most.

Stay tuned for more announcements related to these talkgroups as they are made available to DMR-MARC repeaters in your local area.


The DMR-MARC Leadership Team

Additional information on this partnership is available via these links:

DMR-MARC announces deal with the DMRPlus network for DV4mini support


Callsign Update: N8OUZ

As of 6/14/2016, the new Callsign for the Houghton County Communications Authority club has been changed from KC8PBX to N8OUZ.

The DMR-MARC MotoTrbo repeater in Traverse City has been updated accordingly.

KC8PBX DMR-MARC repeater update

There’s good news and bad news.

First, the bad news:
Effective May 18, 2016, TS2 TG8052 (the Link from DMR-MARC to Mi5-StateWide2) has been terminated.

The Mi5 have decided to port their Mi5 talkgroup to Brandmeister (which is a competitor to the C-bridge used by DMR-MARC).

DMR-MARC desires to have NOTHING to do with Brandmeister due to the illicit development of BM by stealing code from other people without permission or reverse engineering protocols which can have a detrimental effect on the reliability of the network.

In addition, the BM folks have a policy of any talkgroup they syndicate can be used anywhere.

Also, there are several flaky DV4mini dongles on there that burp every couple of minutes with garbage packets.  We did not want to have to listen to that.

Lastly, we have ZERO control over accidental packet loopings (patching talkgroups with 2 origins) and that could mean failed hardware or at the very least annoying audio loops.  The BM system is basically decentralized, and as such, no one is responsible for making sure the system operates without issue. Think of it as Echolink, Allstar, D-Star, and DMR all thrown into one pot with little or no rules.

Due to the actions of the Mi-5 team, as of May 18, 2016, the DMR-MARC team have severed the connection to Mi-5, and the Mi5-SW2 group (TG52 on Mi5, TG8045 on DMR-MARC) will no longer reach the Mi-5 networks.

The issue was discovered late in the day on May 17 and we discussed a communicated and scheduled disconnection, but by early May 18, had discovered some serious security issues with the Link to Mi-5 being subject to passing data associated to the BM networks.



Now, the good news:

DMR-MARC is taking steps to clarify its administration, standards, mission and goals. At a meeting on 5/19, members of DMR-MARC discussed options related to Brandmeister, DMRPlus, and other topics. The short and vague version is that within the next few months, we expect to see some progressive and impressive changes to the network offerings among DMR-MARC systems. As I type this, plans are being made to design a sane and scalable Talkgroup topology and distribution system which will allow linking to the DMRPlus networks. Those with DV4mini (and similar) products will be able to be reachable from DMR-MARC networks.


Some review:

TimeSlot TalkGroup Name Type Purpose
1 3  N.America PTT-activated North America
1 13 WW English permanent World-Wide English-Speaking
1 100 Tech-Talk permanent Technical Discussions
1 3169 Midwest permanent MI-IL-WI-OH area
2 2 N. Michigan permanent Northern Michigan
2 8052 CMEN-MI-SW permanent Link to CMEN TS2/TG52

You’ll notice TS2 is pretty “light” and that is troublesome.
Depending on the anticipated wait time for the new DMRPlus TGs and some talk group reorganization at the C-bridge levels, the above might need to be adjusted somewhat as well..

sooooooo…. don’t go reprogramming your radios just yet. Hang on for a bit and I’ll publish a new list of TGs that will for sure be an upgrade ūüôā


73- Joe N8CN


KC8PBX 442.2875 and N8CN 444.400 repeater update

Two items:


1 – KC8PBX DMR-MARC repeater

Well, a couple weeks ago, the PA unit fried in the XPR-8400 due to a bug in the latest firmware which causes the repeater to constantly transmit garbage if beaconing is not enabled for at least 2s every 2m.

I’ve replaced the TX PA unit twice, but serial number mismatch issues have prevented the repeater from coming online.


TL;DR version: repeater is a brick.

I’ve recently removed it from service for repair, and replaced it with a Yaesu DR-1X SystemFusion repeater.

More updates as progress is made.



2 РN8CN 444.400+ (PL 114.8 optional) is online and functional. It is experimental and has a remote base link to 146.860- (PL 114.8) and is also available as echolink node ID 288970.

The range is about 5 miles from the area of Barlow and South Airport in Traverse City. Not much, but enough for me and my experiments, which is its purpose. But, all are free to play.






OpenRepeater Project goes Beta!

This afternoon I received an email from the OpenRepeater project.


They have their first PUBLIC BETA ready for RaspberryPi B+, BeagleBone Black, and Odroid C-1.

I’ve yet to try anything out yet, but am VERY anxious, as I’ve been eyeing this project for a while, hoping it still had a pulse. As it turns out, it’s VERY MUCH alive!

Even the write-up and setup instructions are well-laid-out, thorough, and simple. You can see them as well as download an image of your flavor of choice at: http://openrepeater.com/getting-started.

I’m super excited and as I’m typing this, I’m signing up for the forums section on the site.


More to come, I am very sure!



KC8PBX Traverse City MotoTrbo Repeater – 442.2875

We’ve updated the Talk Groups that are in each TimeSlot for the repeater here in TVC.
Here are the updated settings:

TimeSlot TalkGroup Name Type Purpose
1 3  N.America PTT-activated North America
1 13 WW English permanent World-Wide English-Speaking
1 100 Tech-Talk permanent Technical Discussions
1 3169 Midwest permanent MI-IL-WI-OH area
2 2 N. Michigan permanent Northern Michigan
2 8052 CMEN-MI-SW permanent Link to CMEN TS2/TG52


1) Added “Tech Talk” TG 100 on TS 1.¬† This is for discussing technical projects. There is a web blog that goes hand and hand with this talkgroup to promote sharing of technical ideas and networking with great people:¬† dmrtechtalk.org.¬† This TG uses open source DMRlink (not the C-bridge).¬† There are about a dozen repeaters on this TG currenetly with plans to double that number as a maximum.

2) Midwest 3169 has moved to slot 1 also.

3) MI statewide is TS2 TG8052 which is connected to the CMEN (not DCI) network of 15 or so repeaters.  This maps to their TG52 on slot 2. (reasoning: CMEN used a slightly unorthodox talk group ID system, so DMR-MARC TG 8052 (coordinated) maps to their TG 52.


Also, here is an updated coverage map!

KC8PBX Coverage Map

Predictive coverage of the KC8PBX MotoTrbo repeater – Courtesy Radio Mobile Online – www.cplus.org

Joe N8CN

syncing mp3 files to the cloud!

So, one of the disappointments I have found with broadcastify / radioreference streaming is the lack of being able to listen to the archives of the stream.¬† (of course, by¬†“disappointment” I mean “darn, I wish it was free.” I completely understand the need for the company to make money, and the need to offer “premium services” to achieve that. I digress.)

Since I’m generating mp3 dump files locally, and I’m trimming silence, why not pump these to the cloud into a shared folder?

Enter Copy by Barracuda to solve my issues. There’s a Linux version of the end-user client program.


Setting it up was trivial, I downloaded Copy.tgz and expanded it into a folder.

I made my synchronized folder “~/Copy” for simplicity.

For further simplicity, I moved the x86 binary folder to ~/.copy/ where config is kept (also a good thing to note)

Once it’s set up, invocation is simple. I’m running it live currently, under a screen session, and will probably daemonize it soon. For now, on a screen session, I invoke with:

~/.copy/CopyConsole -root=~/Copy -username=blah@blah.com


So, now after midnight, I changed the “dump path” of the finished file from the previous day¬†to go to ~/Copy/Scans/2015/ where it is then detected, and synchronized to “the great big cloud in the sky.”


check it out here: http://tinyurl.com/W8TCM

You’ll find a 2014 and a 2015 directory. There’s also a Misc directory (empty as of now) because I had some files I didn’t datestamp.


Sure, this isn’t as elegant as whatever time-stamped version of the “scanner wayback machine” that broadcastify uses, but it works and it didn’t cost me anything, and I own the archives. Always handy incentives. ūüôā



Joe N8CN



Using sox to trim silence out of the middle of a long .mp3

So, one of the things I’ve done lately is to set up two scanners at my Mom’s house. Each scanner listens to one of the CARC Repeaters in Traverse City, MI. Each scanner feeds one side of a stereo input on a machine running Linux.

You can listen to the live-stream result over at www.radioreference.org or www.broadcastify.com if you search for the W8TCM callsign. Or use these links:

Left Channel is fed from the scanner listening to 146.860MHz.
Right Channel is fed from the scanner listening to 442.500MHz.

There are also apps in the IOS Apple App store and Android Google Play store, which are free, that can play these streams for W8TCM (just install the app and search for W8TCM)

Ok, now that we’re done advertising, here’s the techie part.

Here’s how this is configured:

    • Ubuntu 13.10 “Saucy Salamander”
    • darkice is installed, config here:
duration        = 0        # duration of encoding, in seconds. 0 means forever
bufferSecs      = 5         # size of internal slip buffer, in seconds
reconnect       = yes       # reconnect to the server(s) if disconnected

device          = plughw:0,0
sampleRate      = 22050     # sample rate in Hz. try 11025, 22050 or 44100
bitsPerSample   = 16        # bits per sample. try 16
channel         = 2         # channels. 1 = mono, 2 = stereo

bitrateMode     = cbr
bitrate         = 32
format          = mp3
quality         = .2            #1.0 is max.
lowpass         = 6500          #cuts frequencies above 5000 Hz
highpass        = 120           #cust freq below 120 Hz
server          = [redacted]
port            = 80
password        = [redacted]
mountPoint      = [redacted]
name            = W8TCM
description     = W8TCM Repeaters, Traverse City MI
url             = http://www.CherrylandARC.com
genre           = Scanner
public          = yes
localDumpFile   = /tmp/scanners.mp3
fileAddDate     = yes
fileDateFormat  = -%Y%m%d_%H%M%S
    • crontab:¬†0 0 * * * /etc/darkice/rotate-audio.sh¬†
service darkice stop
sleep 1
touch /tmp/yo
sleep 1
service darkice start
sleep 1

    • [edit: there is more to this script, which moves the file to a location other than /tmp]

This is kinda where I left it, which was fine, I was busy. I checked a month later, and there was an issue..:

330M -rw——- ¬†1 nobody nogroup 330M Feb ¬†3 00:00 scanners-20150202_000007.mp3
330M -rw——- ¬†1 nobody nogroup 330M Feb ¬†4 00:00 scanners-20150203_000005.mp3
330M -rw——- ¬†1 nobody nogroup 330M Feb ¬†5 00:00 scanners-20150204_000005.mp3
So, there were files and files, 330 meg each. Each mp3 a 24hour dump of audio.
Now, I get how it would be cool to try to timestamp these with subaudio somehow, so that when I do the next step, I could preserve the timestamp for when things happen.
In fact, I really would love suggestions on how to do this.
For now, however, my disk is disappearing fast. I’d like to be able to archive each year on a DVD-DL at least. so, here’s what I came up with.
  • add another entry to crontab to invoke another script for this process, as we don’t want it to interfere with the restarting darkice part. Besides, it can really be done at any time.
  • Generate a noise profile from the dump file. This is important, as there is AC Hum in varying degrees on each channel, probably due to the age and quality of the scanning receivers. Here is how I generated the noise profile that will be used by our sox command:
    • Open one of the capture files with Audacity. Yes, it takes about 20 minutes to open up a 24-hr .mp3 in Audacity whether you make a copy or not. plan accordingly.
    • Find any chunk of 4-8 minute “silence” in the file, highlight, export, as mp3.Let’s call it “NOISE.mp3” to remind ourselves with all-caps that this could be an improved process.
    • sox NOISE.mp3 -n noiseprof noise.prof
  • TO-DO: Since it’s possible that the noise profile will vary somewhat over time, and generating it is a manual process, what I’d really like to do is make a part of this script that tells sox to find a 5-minute chunk of audio in each file that has no amplitude above a threshold, export it as noise-(datestamp).mp3 and then run this noise profile routine on that silence chunk for each file processed. The result will be a higher quality de-noise process. But I digress, off to saving disk space.
  • sox¬†scanners-20150204_000005.mp3¬†scanners-20150204_cut.mp3¬†noisered noise.prof 0.21 silence -l 1 0.1 0.2% -1 1.5 0.2% pad 1.0
    • Let’s break this down.
    • From the sox man page:¬†
    • silence [-l] above-periods [duration threshold[d|%]
    • ¬† ¬† ¬† ¬† ¬† ¬† ¬† [below-periods duration threshold[d|%]]
    • sox¬†
      • (source file name)¬†
      • (target file name)¬†
      • (command “noisered” for noise reduction)¬†
      • (noise profile file)¬†
      • (reduction amount is 0.21)¬†
      • (command “silence” to use the silence function)¬†
      • (-l option means to keep the below-periods amount of time intact for each silence period, otherwise known as breaks between chunks of audio separated by silence)¬†
      • (above-preiods 1 meaning that we trim silence from the beginning until we find non-silence)¬†
      • (0.1 is our duration, meaning we need 0.1 seconds of non-silence before trimming the previous silence)¬†
      • (0.2% is our threshold from our noise floor to trigger that there is something other than silence (aka: a signal) present to preserve (not trim).)¬†
      • (-1 is our below-periods, which when negative means to restart the processing of the silence function, and use the absolute value of -1 (which is 1) as the new above-periods from the restart point. This is the magic sauce making removal of silence in the middle of the file, over and over, possible without using the more-confusion “reverse” function of sox)¬†
      • (1.5, according to the sox manpage, should be our duration for below-periods, but remember, we restarted the process with -1 which became our new above-periods value of “1”. no matter, the duration here still means that while trimming silence from the middle of the file following a restart of the silence function, we’re going to leave 1.5 sec of what we consider “silence” before we trim again.)¬†
      • (Threshold is still 0.2%)¬†
      • (by the way, we want to add a second of silence at the beginning just to make it less jarring when played back. do this with the “pad” command and 1.0 is for 1 second.)
  • On the above, things highlighted with light blue are probably going to need a LOT of tuning. Things like your noise floor, audio quality, static, squelch, interference, sound card, cable quality– all that stuff will affect what you set for these values. The ones in light orange are related to timing of the cutting and what to leave as silence padding. The rest are file-operation specific.
  • Anyway, now with this scripted, I have darkice feeding the broadcastify servers AND making a local mp3 dump. Each night this file is split using crontab, and a new one started. Another set of scripts takes over and “compacts” the file down from a 24-hour mp3 which seem to be over 300MB each to varying-length mp3 files which, so far, depending on how much the systems are used, seem to range from about 9MB to 120MB.
  • Not bad, and saving disk. average is about 25meg per file. Using the 25meg per day average, we’re at about 9.125Gig per year of audio. Is it small enough to fit on a dual-layer DVD? No, not quite. But it’s close. I think I can just schedule offloading to a normal DVD each quarter. Every 3 months. So I didn’t meet my original goal of a DVD of audio per year, but this is still much more manageable.
I need to cite some very handy references for completing the above, as the sox man page alone was great, but just didn’t quite get me there¬†if you know what I mean:
  1. https://gist.github.com/devoncrouse/5534261
  2. http://digitalcardboard.com/blog/2009/08/25/the-sox-of-silence/
  3. http://activearchives.org/wiki/Padding_an_audio_file_with_silence_using_sox
  4. https://www.learnosity.com/blog/2009/11/removing-silence-from-audio-using-sox/
  5. http://comments.gmane.org/gmane.comp.audio.sox/2739
So, the above were extremely helpful in getting me there. I just didn’t find a good, concise, logical breakdown of what was doing what along my journey, and a google search for “using sox to trim silence out of the middle of a long mp3” just didn’t make the mark either. So there you go, for what it’s worth. ūüôā
73, Joe N8CN

DMR-Marc MotoTrbo Traverse City repeater status report

DMR-MARC – Traverse City MI
KC8PBX 442.2875 +5 MHz Color Code 1

Time Slot #1 РGroup Call 1 = Worldwide All Languages 
                (PTT activated with 5 min inactivity timeout)
Time Slot #1 – Group Call 3 = North America
Time Slot #1 – Group Call 13= Worldwide English
Time Slot #1 – Group Call 310= TAC 310 (PTT Activated with 5 min inactivity timeout)

Time Slot #2 – Group Call 2 = Northern Michigan Local
Time Slot #2 – Group Call 8052 = MI Statewide (Mi5)
Time Slot #2 – Group Call 3169 = Midwest Regional

You Must Have [ARS] Disabled Within Your Radio
Contact Name: Joe Erlewein, N8OUZ Email: n8ouz@arrl.net
The repeater is on a 40ft tower South and West of downtown Traverse City. It has reportedly good HT coverage of the downtown and surrounding areas. We have received reports of good coverage in all directions by mobile users with mobile radios and magnetic/permanent vehicle antennas.

Program your radios: 442.2875+

Time Slot #1 – Group Call 1 = World Wide

Time Slot #1 – Group Call 3 = U.S. / English Speaking Countries
Time Slot #2 РGroup Call 2 =  Chicagoland Repeaters Only
Time Slot #2 РGroup Call 3169 =  Midwest Repeaters Only

Antenna is ~30ft near Barlow and South Airport in Traverse City, MI and covers downtown fairly well on mobile or HT on high power.
The repeater will be moving to a tower just South and West of downtown when the snow is gone. Power will be increased, HAAT will increase, and performance should be much better.
FYI the repeater callsign is currently KC8PBX as it is operated by the Houghton County Communications Authority which has a club callsign.