Tag Archives: P25

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – November 2023 edition

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 Tom – WB8LCD 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 Tom 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 Ohio 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 click the Login button.
  • Login
  • When logged in successfully, it will say “Hello <Name>” in place of the Login button where <Name> is your name.  Click your Name.  This will take you to the “My Account” page.
  • On the left hand side, under the “Communication” heading (second from the bottom), click Opt In/Out
  • To the right of the “Opt In/Out” heading, click Edit
  • Check the box next to “Division and Section News.”  If it is already checked, you are already receiving the Ohio Section Journal.
  • Click Save
  • There should now be a green check mark next to “Division and Section News.”  You’re all set!

Now without further ado…

Read the full edition at:

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

Hey gang,

Pi-Star was great. It solved big problems for hams wanting to use VHF and UHF digital modes around 2016-2017. Personal hotspots were becoming popular. Consisting of a digital interface (modem) board capable of transmitting and receiving digital modes such as DMR, D-STAR, and System Fusion. These transceiver options are low power at about 10mW. The modem interfaced with software to manage network connections. Many devices were created for the popular Raspberry Pi or Arduino single-board computers using the GPIO headers. Others were USB-based devices that could be used with a desktop computer running any operating system or plugged into a Raspberry Pi.

The hardware was pretty solid. Software, not so much. Nearly each group attempted to make their own software distribution. In general, this failed as users couldn’t get the software to work consistently and settings didn’t work as expected – even across users with similar setups. Many didn’t have monitors connected. VNC, a remote desktop sharing application, was used. VNC generally works well desktop-to-desktop, but not desktop-to-mobile. These problems weren’t helping promote digital modes and personal hotspots.

Then along came Pi-Star. Created and maintained by Andy – MW0MWZ, it solved nearly all those problems. On the hardware site, Pi-Star supported every digital modem in a single platform. MMDVM is the software capable of “speaking” different digital mode protocols and managing network connections. It came with a web front-end that did everything needed to configure and manage devices, update network settings, update device firmware, and have a nice usable dashboard. Ultimately, the Pi-Star platform superseded all previous attempts at a viable interface for digital ham radio hotspots.

On the Pi-Star site, version 4.1.5 dated October 2021 is the latest image available for Raspberry Pi. However, 4.1.6 is available through the update sequence pistar-update then pistar-upgrade at the command line, both prefixed with sudo. Pi-Star 4.1.5/6 release is based on Raspbian 10 (buster) which has reached end-of-life. Raspbian, the standard Raspberry Pi operating system, follows the Debian release schedule. Debian 10 is out of standard security updates and into LTS (long term support). Raspbian does not offer LTS.

If you’ve read my column long enough, you know the majority of vulnerability issues can be avoided by keeping systems updated and patched. I’m also reminded of the time when I went searching and found there are Pi-Star’s accessible directly from the Internet, with the default password. What could possibly go wrong?

By all accounts, and as of this writing, Andy is no longer maintaining Pi-Star. Looking at his post count in the forums: zero in 2023 and ten in 2022. There are very few updates to GitHub repositories in the last two years, which are used to update Pi-Star devices. I’ve seen references to lack of updates due to lack of interest. Pi-Star is also lacking the latest additions to MMDVM including M17 and FM for boards that support those modes (usually through firmware updates).

The next iteration of Pi-Star (or fork) comes to us via W0CHP, called “W0CHP-PiStar-Dash (WPSD).” I learned about WPSD when AmateurLogic ran a segment in January on this new offering. I started using it shortly after. Though it was early on in the project, WPSD was labeled “not for the faint of heart” by the author.

It was really rough around the edges. I had to debug scripts in order for updates to run successfully. The dashboard would show the modem in “TX D-STAR” when only P25 was enabled. There were issues with the configuration file manual editor too.

Regardless, development is very active. WPSD has become much more stable and now considered the Pi-Star replacement. Alot has changed in the time I’ve been using WPSD and presume things will continue to evolve.

One such change, there was an option for installing WPSD on top of an existing Pi-Star installation. That option is no longer available or supported. The distribution must be flashed directly to an SD card (flash memory), exactly like Pi-Star.

I always recommend using a new card or different SD card from the current, existing installation until everything is working as the user expects. Having the old (original) card available allows switching back easily in case of problems or need to reference something from the previous installation.

Pi-Star with Nextion display (ailunce.com)

A recent blog post by the author called out people who claim WPSD is an “overlay.” At one point, it could have been installed on top of an existing Pi-Star installation. WPSD is not an overlay. It is its own software distribution.

WPSD works with most Raspberry Pi offerings (Zero, Zero 2, 2, 3, 4, …) including the Orange Pi and Nano Pi Neo variants. The Raspberry Pi Zero W 1.1 is not really recommended for use but it will work. The Zero W 2 is recommended instead. A Zero W 1.1 needs extra configuration steps after flashing the SD card. These include: creating a wpa_supplicant.conf and placing it in the /boot partition. Waiting at least 30 minutes for the image to boot and configure itself before accessing the dashboard. Steps are detailed in the link above.

While using WPSD with my Pi Zero W 1.1 it is quite a bit quicker, taking about a minute to save changes on the configuration page of the dashboard. Compared to the Pi-Star which took two to three minutes to save changes. Pi Zero W 2s are still very hard to find. If you can find one, a male header strip still needs to be soldered to the GPIO. Pre-soldered ones are nonexistent.

Not only is WPSD on a supported operating system (bullseye, Debian 11) but there are a TON of enhancements and updates over Pi-Star. Though the visual layout has changed, it’s intuitive enough for any existing Pi-Star user. Changes I noted right away were the addition of M17 support (though I don’t have any capable devices) and Nextion support built-in. Nextions are displays and/or touchscreens that can be attached to the modem or added through a TTL serial converter, such as those based on the CP2102 chipset. Adding Nextion support to the original Pi-Star was a terrible experience using hacky scripts that had to be run a couple times before the drivers and software could be usable.

WPSD Live Caller mode

Non-exhaustive list of enhancements: full APRSGateway support. DGId support. DMR Roaming Beacon Support for repeaters. Caller details include name and location. Talkgroup names are populated. On the fly changes of talkgroups/rooms/reflectors/networks including ability to pause networks for attending nets or quieting a busy mode. Live Caller mode which is a browser based (virtual) version of a Nextion display. Ability to disable cron (scheduled) updates. Updated dashboard including wider, bigger, updated fonts, user configurable options including CSS styling and fonts. Full dashboard display or Simple View with only RF and gateway activity. Configurable number of last heard stations. Configuration/Profile Manager, similar to OpenSpot, where the user can save multiple versions of a setup and restore them based on use.

A Profile Manager feature was added to WPSD, which did not exist in Pi-Star but exists in the OpenSpot devices. This allows the user to save device settings into a profile to be recalled later. These could be travelling profiles, or ones specific to a mode, network, or configuration for a net. Initial implementation of this feature did not backup saved profiles when using the Backup/Restore feature. Only the current active profile would be backed up or restored. Now, within the last two months, Backup/Restore saves ALL device profiles in the backup archive.

That is an example of the constantly evolving nature of this new WPSD distribution. Updates happen quite frequently. WPSD was updated nearly daily for a long time. Updates still happen quite frequently but at the pace of about once a week, maybe more.

Speaking of backups, it’s not recommended to use migrated configuration files or backups from Pi-Star, due to differences. If Pi-Star files are used with WPSD and there are issues, the user will be required to begin configuration from scratch.

One change I do not particularly care for is the requirement to use DMRGateway. In Pi-Star, I used Direct Mode which is the selection of a single DMR Master. For example: select BM_3104_United_States for Brandmeister and TGIF_Network for TGIF as the DMR Master. I liked this for two reasons: this functionality is similar to how a repeater would operate and it simplifies codeplug programming for talkgroups with the same TG ID across different networks. Ohio Statewide is 3139 on multiple networks meaning I only had to setup Ohio Statewide once. Though it seemed most users did use DMRGateway in Pi-Star.

DMRGateway supports simultaneous connections to six networks. With all those network connections there must be a way to differentiate which network is to receive a transmission. That way is through “prefixes,” a single number prepended to the talkgroup number. DMRGateway doesn’t appear to use a prefix for Brandmeister, 3139 would remain 3139. TGIF talkgroups are prefixed with a 5. 3139 would become 53139. HBLink prefix is 8. My HBLink would be 831983 instead of 31983.

WPSD Dashboard

If you’ve programmed a codeplug for a DMR radio, it’s not as easy as just making a new contact with the prefix. Adding the contact to an RX group, creating new channels, and reorganizing or creating new zones are all needed. Maybe I’ll purge the ‘nice to haves’ in my codeplug as I typically only use a handful of talkgroups or just make a new simplified codeplug for use with WPSD.

Changes have been made to the scripts and tools. Commands rpi-rw and rpi-ro have been removed. These were used to switch between a read/write file system and a read-only file system. There has been debate whether a read only file system corrupts any less or shortens the lifespan of the SD card when left in read/write mode. Pi-Star was constantly changing from read only to read/write during settings changes, updates, and hostfile update cycles. Mine seemed as though it could never successfully change from read/write back to read only after an update. Eliminating those scripts just ‘fixed’ those resource busy messages.

Pi-Star scripts that began with pistar- have all been removed and replaced with a smaller set of wpsd- scripts. It was great because all WPSD updates were taken care of by going to Admin -> Update. Though, a recent change has removed operating system updates from that feature. Admin Update only updates WPSD currently (probably due to those lengthy Raspbian kernel updates). To update the operating system, SSH to WPSD or go Admin -> Advanced -> Tools -> SSH Access. After logging in (same credentials used to login to the Admin or Configuration dashboards), at the command line, enter (capitalization is important):

sudo UP_OS=1 wpsd-update

As with Pi-Star, if an update fails or installation becomes borked, re-flashing the SD card with the latest available image will bring the device to a known working state. Remember to save a new backup before updating! WPSD images are updated more frequently than Pi-Star. Updates released since the image was published won’t take quite as long to apply.

There is a lot to read, including some edge features that have been removed, on the WPSD page (linked above). Comparing WPSD to Pi-Star (‘this used to work on Pi-Star,’ ‘when I revert back to Pi-Star this thing works,’ etc.) is verboten when asking for support. The main page on W0CHP’s site is a blog detailing direction and state of the project as well as reasons for changes. I recommend Pi-Star users update to W0CHP-PiStar-Dash – if nothing else, for the supported operating system and OS package updates though there are many improvements and welcome features.

Thanks for reading and 73… de Jeff – K8JTK

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – May 2023 edition

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 Tom – WB8LCD 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 Tom 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 Ohio 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 click the Login button.
  • Login
  • When logged in successfully, it will say “Hello <Name>” in place of the Login button where <Name> is your name.  Click your Name.  This will take you to the “My Account” page.
  • On the left hand side, under the “Communication” heading (second from the bottom), click Opt In/Out
  • To the right of the “Opt In/Out” heading, click Edit
  • Check the box next to “Division and Section News.”  If it is already checked, you are already receiving the Ohio Section Journal.
  • Click Save
  • There should now be a green check mark next to “Division and Section News.”  You’re all set!

Now without further ado…

Read the full edition at:

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

Hey gang,

Another Hamvention has come and gone. Unfortunately, my dad, N8ETP, didn’t make it as he is recovering from a medical procedure from earlier this year. I was flying solo again. As most of the OSJ readers are in Ohio, Dayton is a few-hour drive for most of us. It’s almost exactly 3 hours from my QTH to the hotel.

After dinner Thursday night, I went searching for digital repeaters – NXDN and P25 in particular. RepeaterBook didn’t have NXDN repeaters in the Dayton area. Guess I didn’t need to bring that radio. There was a P25 repeater I found last year and could hit from my hotel. Listening to conversations, there was mention of a P25 repeater at the Xenia site but I wasn’t able to find the details for it last year. This year, I found the Miami Valley P25 Ham Radio Network website. Their site lists repeaters on the network, including the information I needed for the Xenia site.

P25 is another digital standard used mostly by public safety agencies. It’s similar to DMR in that there are 7-digit IDs, talkgroups, and zones. Instead of a color code, P25 has NAC or network access code. Like DMR, P25 was also developed for commercial use and then adopted to ham radio. The statewide MARCS system, Greater Cleveland Radio Communications Network (GCRCN), and Northwest Ohio Regional Public Safety System are all P25 systems. There aren’t many “ham friendly” P25 radio options. Most are repurposed/used commercial radios from Motorola, Harris, or EF Johnson.

Crystal set

According to their programming guide, Miami Valley P25 sites have been upgraded to “version 2” programming of their repeaters. This may be why the talkgroups I had from last year were completely different for the Dayton repeater.

With tower sites in Shelby, Miami, Champaign, Montgomery, Greene, and Warren counties, the “MVP25” is an interconnected network of UHF (440) P25 repeaters. Each site has backup power and each repeater can operate independently when a network link failure occurs. Sites are linked with direct network connections that presumably don’t use the internet. No cloud services of any kind are utilized. The network can only be accessed via RF. No hotspot and no MMDVM connections are possible.

Reading and programming my Motorola XTS radio for the MVP25 network, I learned more about options in the software. One example is “selective squelch” which will only unmute the radio for transmissions on the selected talkgroup. Their programming template and examples helped me understand their objective and made programming easy.

Each repeater has an “MVL” (Miami Valley Link) talkgroup which is heard on all MVP25 linked repeaters and a “STE” (site) talkgroup for conversations on the local repeater. MVL is the primary talkgroup on the repeater. Users wanting to carry on a conversation locally can override the MV talkgroup by using the STE talkgroup.

Crystal set designer and builder (Vietnam veteran hat)

They recommended using the bank switch (A-B-C switch) for switching talkgroups on a single repeater site. In the context of my radio, Bank A = Zone 1, Bank B = Zone 2, Bank C = Zone 3. This was a neat idea because, for example, channel 5 in zone A & B would be the Xenia Hamvention repeater site. Zone A would be the programming for linked communication using the MVL talkgroup. Zone B would be the local site talkgroup for each repeater. Selecting channel 5 (Xenia) using the channel knob, then selecting bank A would be Xenia MVL talkgroup configuration, Bank B would be Xenia STE talkgroup configuration. Channel 8 would be the Dayton site. Switching to A would be the MVL talkgroup and B would be STE Dayton local.

Since my radio is front panel programming capable, Zone A was the FPP (I didn’t see a way to change this). In their programming guide, bank A became B. Bank B became bank C. Their template had the same exact “UCOM1” (UHF P25 simplex frequency) frequency for every channel in bank C. I took this to mean it’s a ‘flex’ bank in cases of radios that have a reserved bank. I didn’t lose anything because “UCOM1” was also channel 1 in the MVL and STE banks.

Previously, I had only used my P25 radio with my MMDVM hotspots. Programming multiple sites on the same network was a new experience. I learned about copying the current selected entry and export/import to make copies of zones. Kudos to the admins, designers, and those whom wrote the programming guide. It is well thought out and the guide made a lot of sense.

Friday, I hit the flea market. I wasn’t looking for too much this year – either new or used. I was in the market for a second set of Motorola CDM radios. I am using a UHF CDM for an AllStar node and I have a VHF model too. I would like to pick up a second set for spare radios. Also was looking for a second UHF XTS and a new to me VHF. No one was giving them away.

George – W5JDX and Mike – VE3MIC from AmateurLogic.tv along with Chip – K9MIT

In the “coolest thing I’ve ever seen at a hamfest” category was the life-sized crystal set someone built and had on display in the flea market. There were no plans, no diagrams, no anything. It was all in his head. Nothing written up. Nothing diagrammed. The only thing powered was a solar powered amplifier for received audio. If you didn’t see this thing in the flea market, you missed out. The builder didn’t have a name or call displayed unfortunately.

I wanted to hit the inside stuff on Saturday, but instead ran into George – W5JDX and Mike – VE3MIC from AmateurLogic in front of the ICOM booth. Helped them do some recording for their latest episode (which should be out by the time this is published, episode 181). Then we all hung out with Chip – K9MIT of “Chip Stick” fame from Ham Nation and Mike’s cousin (forget the call). A good time was had by all.

Didn’t spend a lot of money this year at Hamvention. Emile would approve (joke for ALTV viewers). Talking with groups and vendors got the wheels turning on some ideas – such as devices to use with my MESH node. On my way home, I stopped by the secondary hamfest called MicroCenter and spent some money there on some deals they had.

Thanks for reading and 73… de Jeff – K8JTK

Amateur Radio, ARRL Ohio Section, Presentations

Ham radio VoIP and K8JTK Hub DVMIS Presentations

Presentation on Ham radio VoIP (Voice over IP) modes and the K8JTK Hub Digital VoIP Multimode Interlink System which integrates many Ham radio modes, both analog and digital.

Framework

The framework I chose to use for the presentation slides is called reveal.js. It is an HTML framework meaning it will run in any HTML 5 capable browser. Looks a little better than a PowerPoint presentation.

Navigation

Useful navigation keys in the presentation. In addition to navigating with the keys below, you can swipe (tables/smartphones) or use the navigation arrows on screen in the lower right.

Toggle full screen: press [F11].

Advance to the next slide: press [n] or [SPACEBAR].

Go back to the previous slide: press [p] or press and hold the [SHIFT] key while pressing the [SPACEBAR].

Display presentation overview: [ESC] then use the arrow keys or mouse to select a slide. [ESC] again will exit overview mode.

Links

Clickable links are colored in brown text.

Presentations

Three variations are available: presentation version is viewable in a browser. Printable version for printing or saving in a different format (Chrome, Chromium, and variants compatible only). Finally a PDF version.

They may take some time to load because I left original images untouched and some were a couple MB in file size.

Slides

The presentation is around 60 minutes in length.

Version 3

Presentation version
Printable version
PDF version

This presentation was given at the following meetings:
West Chester Amateur Radio Association on 7/6/2023 & 11/7/2024

Version 2

Presentation version
Printable version
PDF version

This presentation was given at the following meetings:
West Chester Amateur Radio Association on 5/6/2021.

Version 1

Presentation version
Printable version
PDF version

This presentation was given at the following meetings:
Portage County Amateur Radio Service on 3/8/2021.

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – December 2020 edition

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:

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

DSCF5081 K8JTKHey gang,

One of the things I’ve been working on during my time at home is the Digital VoIP Multimode Interlink System (DVMIS), also called the K8JTK Hub. About a year-and-a-half ago, I came up with this bright idea to setup a system that would interlink many different ham radio VoIP (Voice over IP) modes for interoperability and experimentation. Through trials and tribulations, it’s experiencing some success, caught the interest of some nets, and a podcast.

Many digital modes sit on their own island and are restricted from crossing over to the analog world or to other digital networks. Some may say this is for quality-of-service but does nothing for interoperability or the ability to link and communicate across different systems. Original D-STAR DPLUS reflectors banned analog connections. My Hub supports ham radio experimentation by allowing hams to discover ways of utilizing a system that can link different modes. Utilization of ham radio spectrum is a priority through the use of hot spots and repeaters. Connections without RF are not a priority. Hamshack Hotline was provisioned because of use in Emergency Operation Centers. Many times, I’ve been asked about stations that don’t have access to RF hotspots or radios. They still have options including the Echolink app on Android and iOS devices, Hamshack Hotline phone which can be purchased for $30 (I’ve heard deals as low as $5 for a compatible phone), or the DudeStar app. The servers are hosted in a Chicago data center to provide resiliency against hardware, power, weather, and Internet outages, but still be fairly inexpensive.

All this is possible through integration of open-sourced packages including: AllStarLink which is a world wide network of Amateur Radio repeaters, remote base stations and hot spots accessible to each other via the Internet and/or private IP networks. Built on an open-sourced PBX system called Asterisk, Jim Dixon – WB6NIL (SK) built the apt_rpt module emulating functionality of a repeater controller. Jonathan – G4KLX authored programs that support D-Star, DMR, System Fusion, P25, and NXDN which are utilized in MMDVM devices like most hotspots. DVSwitch is a suite of applications for provisioning and operating Amateur Radio digital voice networks maintained by Steve – N4IRS and Mike – N4IRR. The DVSwitch Mobile app was designed to operate analog and digital modes utilizing an Android phone in conjunction with server applications running on a Linux server or Raspberry Pi. The ASL to DMR documentation (groups.io account required) got me started experimenting with these applications and ultimately lead to the build out of the system. XLXD is a multiprotocol reflector server for D-STAR by Jean-Luc – LX3JL & Luc – LX1IQ. Skip – WB6YMH & others maintain thebridge, an Echolink compatible conference bridge.

Originally, hosted on 2 servers, after troubleshooting some issues, it was more reliable to host everything across 3 VPSes (Virtual Private Servers) running Debian Linux. Parts of the system can go down and individual parts will continue to function. Aside from the VPSes, a Raspberry Pi with a Northwest Digital Radio DV3000 provides D-STAR audio transcoding to the system. Wires-X is available through the use of additional remote hardware. Wires-X is proprietary to Yaesu radios and repeaters. Wires-X is not available through open-source implementations such as YSFReflector or MMDVM without additional devices. I’d like to get the DV3000s in a reliable data center but doing so is prohibitively expensive. AllStar Link is the “Hub” that provides connectivity and linking control between all networks.

Putting all of this together provides a system with access to ten different networks and eight different modes! Any user on one network can communicate with users on other networks. Access is available through these nodes and connections:

  • AllStar Link: 50394
  • DMR: Brandmeister Talk Group 3172783
  • DMR: TGIF TG 31983
  • D-STAR: XLX983A (A = Analog Bridge. Pi-STAR = DCS983A, OpenSpot = XLX983A)
  • Echolink: *DVMIS* conference 600008
  • Hamshack Hotline: 94026 (*99 – TX, # – RX)
  • NXDN: TG 31983
  • P25: TG 31983
  • YSF: K8JTK-Hub 31983
  • Wires-X: K8JTK-ROOM 40680 (available upon request)

Dashboards:

Amateur Logic episode 149

Building this system has not been without problems. Luckily, I’m able to work around known issues. In order from least frustrating to most frustrating: all programs use IP addresses and ports to communicate, keeping all of that straight was a challenge initially. Using IPs allows for great flexibility utilizing network links such as private networks and VPNs. Dependency hell as a result of additions and changes to programs made a constant deployment from one day to the next an issue. XLXD changed its implementation to include YSF which then conflicted with the port used for the YSFReflector. Changing the YSFReflector port required propagation to Pi-STAR host files and OpenSpot DNS. DVSwitch has been rewritten two times since I’ve implemented it and they’ve released another round of changes. Data center provider choices resulted in issues with packet loss. Moving the servers to another provider yielded much better results. The previous provider finally acknowledged and supposedly resolved the issue a year after it was reported, and after I moved.

Use of physical hardware for D-STAR. OP25 software codec can transcode D-STAR but “you won’t be happy” to quote a post in the forums. D-STAR looooves IP addresses. DNS is great for switching IP addresses easily (like when moving data centers or spinning up different servers). However, D-STAR relies only on IP addresses. As a result, reflector IP changes take about a day to propagate to online hotspots/repeaters. Using AMBEServer with the DV3000 on a remote device resulted in very choppy audio. After some time, had the idea to move Audio Bridge to the same device as the DV3000 then use IP routing to send audio to and from AB. Worked great.

In order to compile AllStar Link from source takes a lot of time to get right and includes A LOT of dependencies. Finally, one that drove me crazy was the chan_echolink module for AllStar which provides Echolink connectivity natively to AllStar. When load testing with many connections, something was making stations sound as though they were transmitting underwater. After observing patterns, determined it was audio originating on the Hub being sent out to Echolink connections. Incoming audio from Echolink stations was OK and audio sent to all other nodes was also good. The problem seemed intermittent until I consulted groups.io and further determined chan_echolink has audio quality problems when more than three EL stations are connected simultaneously. Not ideal for a hub. Best workaround was to implement an Echolink Conference server. Then only allow chan_echolink connection to that conference server. Echolink users would then connect to the same conference server. This issue took a lot of time and a lot of hair pulling but implemented a workable solution that offers a quality system. Root cause is still unknown as an AllStar developer hadn’t chimed-in with any suggestions or possible reasons.

K8JTK Hub/DVMIS connections

The DVMIS hub hosts a couple nets. Tuesday nights at 9pm eastern, since about the first-time stay-at-home orders were put in place, is the Amateur Logic Sound Check net. The net encourages checkins to utilize as many modes as possible during the net to test equipment. If you haven’t seen the Amateur Logic podcast, it has been going for over 15 years and they release two shows monthly. The regular podcast has segments about technology and Ham Radio. “Ham College” is an educational show for those wanting to get licensed or upgrade. The guys asked me to put together a segment for the show. My segment can be found in episode 149. A huge thanks goes out to the ALTV crew and everyone checking into the net which helped me identify and resolve system issues. They’ve also been great in keeping up with all the changes over the last 9 months. At the end of December, I’ve been testing with the West Chester Amateur Radio Association – WC8VOA to add digital modes to their net on Monday evenings at 8pm.

Around the time my segment was airing on ALTV, Brandmeister did not approve of the linking method and linking to other networks. Brandmeister uses the MCC standard and they manage talkgroup IDs consisting of 3, 4, or 5 digits. 6- or 7-digit IDs are repeater IDs and user IDs respectively, and can be used however the assigned owner would like. The BM TG in the ALTV episode is now 3172783 and is correct in the listing above.

The Hub is open for all to use in testing equipment, software, or linking up with friends. I keep status updates listed on the page linked at the beginning of this article. For this and any linked system, please remember a couple practices. When keying your radio, pause a second or two to allow all links to rise, otherwise the first couple words maybe lost. Pause a minimum 3-5 seconds between transmissions to give time for links to reset and other stations to break in. Do not “tailgate.” Enjoy and join the nets to get a feel for the Interlink System’s capabilities.

Slow Scan TV has become big over the last couple years due to ARISS (Amateur Radio on the International Space Station) events. One of the longer events will have begun before OSJ publication: starting December 24 at 16:40 UTC and continue through December 31 ending at 18:15 UTC. Dates are subject to change due to ISS operational adjustments. Images will be downlinked at 145.800 MHz +/- 3 KHz for Doppler shift and the expected SSTV mode of operation is PD 120. Radio enthusiasts participating in the event can post images they receive at the ARISS SSTV Gallery at https://www.spaceflightsoftware.com/ARISS_SSTV/. After your image is posted at the gallery, you can acquire a special award by linking to https://ariss.pzk.org.pl/sstv/ and follow directions for submitting a digital copy of your received image. Even an HT can receive images from the space station. If you would like to receive images using MMSSTV on Windows, head over to my tutorial.

Congratulations to Scott Yonally – N8SY who won his election as Great Lakes Division Vice Director! Since he cannot hold more than one elected position at a time, he will be stepping down from his current Section Manager position when he assumes the Vice Director position on Jan 1. I wish him nothing but the best in his new role as he has done a lot for the Ohio Section during his tenure. We will then welcome Tom Sly – WB8LCD who will be appointed the new Section Manager for Ohio!

Thanks for reading. Happy holidays, Merry Christmas, and Happy New Year!
73… de Jeff – K8JTK

Amateur Radio, Presentations

K8JTK Hub DVMIS Presentations

Presentation on the K8JTK Hub Digital VoIP Multimode Interlink System which integrates many Ham radio modes, both analog and digital.

Framework

The framework I chose to use for the presentation slides is called reveal.js. It is an HTML framework meaning it will run in any HTML 5 capable browser. Looks a little better than a PowerPoint presentation.

Navigation

Useful navigation keys in the presentation. In addition to navigating with the keys below, you can swipe (tables/smartphones) or use the navigation arrows on screen in the lower right.

Toggle full screen: press [F11].

Advance to the next slide: press [n] or [SPACEBAR].

Go back to the previous slide: press [p] or press and hold the [SHIFT] key while pressing the [SPACEBAR].

Display presentation overview: [ESC] then use the arrow keys or mouse to select a slide. [ESC] again will exit overview mode.

Links

Clickable links are colored in brown text.

Presentations

Three variations are available: presentation version is viewable in a browser. Printable version for printing or saving in a different format (Chrome, Chromium, and variants compatible only). Finally a PDF version.

They may take some time to load because I left original images untouched and some were a couple MB in file size.

Slides

The presentation is about 10 minutes in length which aired on the AmateurLogic.TV podcast on 11/13/2020 for episode 149.  It includes additional slides referenced in the video segment.

Presentation version
Printable version
PDF version

Segment:

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – October 2019 edition

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:

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

DSCF5081 K8JTKHey gang,

I received a question last month from Andy – KD8SCV on setting up a digital hotspot transmit frequency compliant with “Line A.” I’ll address these as two separate issues. If the hotspot or simplex node is within the correct ranges of the band plan, Line A doesn’t matter. You’re going to need your copy of Part 97.

What is Line A? It is an approximate border between the U.S. and Canada that varies in exact location but is most often 75 miles (about 121 km) from the border. According to Part 97.3(a):

(30) Line A. Begins at Aberdeen, WA, running by great circle arc to the intersection of 48° N, 120° W, thence along parallel 48° N, to the intersection of 95° W, thence by great circle arc through the southernmost point of Duluth, MN, thence by great circle arc to 45° N, 85° W, thence southward along meridian 85° W, to its intersection with parallel 41° N, thence along parallel 41° N, to its intersection with meridian 82° W, thence by great circle arc through the southernmost point of Bangor, ME, thence by great circle arc through the southernmost point of Searsport, ME, at which point it terminates.

This is the same wording as Title 47 of the Code of Federal Regulations (CFR), Section 90.7. Doesn’t tell you much, like why does it exist? This information is a little sparse. Possibly to protect land mobile stations in Canada. Land Mobile Service (or LMS) is defined by the ITU as communications between base stations and mobile stations or between mobile stations. Think public service agencies and even private companies to coordinate people, resources, safety, or security. Amateur Radio is allocated secondary status on most U.S. allocations above 1.25m or the 220 MHz band. 420-450 MHz is shared with federal agencies and military for radar applications such as PARCS located in North Dakota near the Canadian border. As it pertains to the Amateur Radio service:

(1) No amateur station shall transmit from north of Line A in the 420-430 MHz segment. See §97.3(a) for the definition of Line A (Part 97.303(m)).
Line A (maroon) overlay. (FCC)

For stations in the western part of the state north of 41° N, no transmissions between 420-430 MHz can be made. This includes the cities of Ottawa, Findlay, Tiffin, Willard, New London, and Lodi. Close to the intersection of State Route 83 and Interstate 71, near the cities of Lodi in Medina county and Burbank in Wayne county, is where 41° N and 82° W intersect. From that location, Line A takes a northeast trajectory to Bangor, ME. North of Line A constitutes Medina, much of the Cuyahoga Valley, Hudson, bisects Streetsboro and Mantua, Hiram, West Farmington, North Bloomfield, and Andover.

For those wondering, there is a Line B, Line C, and Line D. In Canada, Line B is opposite to Line A while Line C and D divide the Alaskan border with Canada. There is no mention of Line C in Part 97. Land mobile stations licensed north of Line A or east of Line C requires additional coordination with Canadian authorities.

PARCS Radar station (Wikipedia)

The FCC has provided a couple resources that depict Line A and check Line A coordinates. The checking site won’t accept Google Maps coordinate format. It requires NAD83. I found a converter that worked well. On a Google Map, left-click until a small gray marker appears on the map. Coordinates will appear in a pop-up in the lower-center of the map. 41.460459, -81.911875 for example. Copy them. Go to the West Virginia coordinate conversion website. Paste them under “Input Coordinates.” “Lat/Lon WGS 1984” should already be selected. Under “Output Coordinates,” select “Lat/Lon NAD83.” Click Covert. Copy the output coordinates (removing the negative symbol and spaces) into the FCC Line A check site. Example Lat: 412737.6, Lon: 815442.7. The site will return “North of Line A” or “South of Line A” for the relative location.

As a general rule, don’t transmit 420-430 MHz within 80 miles from the Canadian border and you’ll be golden.

For everyone, the following applies in Part 97.303(m):

(2) Amateur stations transmitting in the 420-430 MHz segment must not cause harmful interference to, and must accept interference from, stations authorized by the FCC in the land mobile service within 80.5 km of Buffalo, Cleveland, and Detroit. See §2.106, footnote US230 for specific frequencies and coordinates.

(3) Amateur stations transmitting in the 420-430 MHz segment or the 440-450 MHz segment must not cause harmful interference to, and must accept interference from, stations authorized by other nations in the fixed and mobile except aeronautical mobile services.

80.5 km is a little more than 50 mi. Check the FCC or Radio Reference sites for issued licenses between 420 and 430 MHz in Ohio. Many licenses are assigned in the Cleveland and Toledo areas.

My OSJ article last year, though pertaining to hotspots and satellites, addressed the hotspot frequency question nicely. I’ll reiterate because this is important. Under Part 97, hotspot devices are considered an auxiliary station. In general, advice would be to ‘check with the local frequency coordinator’ but experience with the coordinating group indicates they won’t be of any help. Where should you operate a digital hotspot or digital simplex node? I do like the ARRL’s Band Plan because it spells out many details not included in graphical representations. Note: this advice only applies to the U.S. band plan. The band plan has allowances in the following frequency ranges for simplex, auxiliary stations and control links:

  • 146.400 – 146.580. Usable (at 12.5 KHz spacing): 146.4125 – 146.5675
  • 433.000 – 435.000. Usable (at 12.5 KHz spacing): 433.0125 – 434.9875
  • 445.000 – 447.000. Usable (at 12.5 KHz spacing): 445.0125 – 446.9875
Raspberry Pi Zero ZUMspot

“Usable” indicates the lower and upper frequency limits that can be used and programmed into a digital hotspot. Don’t forget to stay away from the national calling frequencies of 146.520 and 446.000. Some of these ranges are shared with repeater links so remember: it is your responsibility to ensure correct operation of your equipment and find a frequency not already in use before using it! There is NO excuse for not adjusting frequency to eliminate interference with other operators and equipment! Listen to the desired frequency by setting up a radio or scanner with the volume turned up. If you hear any kind of obvious traffic, data bursts, or digital screeching, pick another frequency then rinse and repeat. Notice none of these allowances include frequency restrictions imposed by Line A.

Every hotspot user and repeater owner reading this needs to verify your operating frequencies and take corrective action, if required. Auxiliary stations cannot operate within the satellite sub bands. Many hotspots are operating there illegally. Satellite sub bands for 2 & 440 are:

  • 2 m: 145.800 – 146.000
  • 70 cm: 435.000 – 438.000

If your hotspot is operating near edges where deviation would fall into an unauthorized band segment, operating “out-of-band” (ie: weak-signal, satellite), or operating 420-430 MHz and located “North of Line A”, you need to take corrective action now! Your cooperation is greatly appreciated!

Yahoo! Groups is going away! Since 2001, the service allowed users to “build relationships, stay in touch, share ideas, and discuss interests through the convenience of popular e-mail and Web-based tools.” Many ham radio groups over the years have used or are using Yahoo! Groups to coordinate and collaborate.

An SSTV Net in Cleveland used Yahoo! Groups to share received pictures and offer support for stations having trouble with their setup. It was the first time I used the service. Special interest groups formed on a wide variety of topics including scanner information, D-STAR, DMR, and System Fusion.

A note sent to users laid out the time line of the impending shutdown:

Beginning October 28 you won't be able to upload any more content to the site, and as of December 14 all previously posted content on the site will be permanently removed. You'll have until that date to save anything you've uploaded.

Moving or saving data needs to happen relatively quickly should you or group members want to keep the information. Read this knowledge base article to understand the changes and information on how to save content from your groups. Steps don’t seem quick or easy.

An ARS Technica article provides more details on the shutdown. Citing a successful service with 110 million users in 2010, Yahoo failed to adequately compete in other areas after being acquired by Verizon. Verizon responded by cutting budgets and staff.

I mentioned Groups.io in July as a service I joined earlier this year to keep updated on different ham radio projects. Feedback has been positive and many are recommending it as a place to transition before the shutdown. Groups.io doesn’t serve ads, track users, and has a better reputation than Facebook, which I neither use nor trust. Featuring a modern platform for communities to connect through messaging, calendar, chat, polls, databases, photos, wiki, and integration with a list of other platforms. Great place for projects to post documentation and offer support or as a platform to keep in-touch with club members. Some indicated greater engagement with club members and more attendance.

A wiki article posted contains instructions for moving content to Groups.io. It indicates transfers need to be initiated before December 1, 2019 to guarantee the transfer of content from Yahoo! Groups to Groups.io – though Yahoo was having issues with Photos.

Last month, I was invited to give a presentation at the meeting of the Lake County Amateur Radio Association (LCARA). The presentation was about, well, me. I talk about my biography including schooling, how I got involved with groups, jobs, and other presentations I’ve put together. Most importantly, talk about the duties and responsibilities of the Ohio Section Technical Coordinator and technical resources available to hams in the Ohio Section. I had a great time as I don’t get out to Lake county often and it was a fantastic day for a drive. The club was very welcoming. LCARA has many members passionate about different aspects of the hobby and they report on each during their meeting. A good time was had by all.

If you would like to know more about the TC position within the Ohio Section or want to know more about the technical resources available in our section, contact myself or a Technical Specialist.

Thanks for reading and 73… de Jeff – K8JTK

Amateur Radio, ARRL Ohio Section, Ohio Section Journal

Ohio Section Journal – The Technical Coordinator – October 2018 edition

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/2018/OSJ-Oct-18.pdf

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

DSCF5081 K8JTKHey gang,

Digital mode access points, often called hotspots, have been in the news lately. Those are the 10mW personal devices used by digital operators to cover a relatively small area like a house, car, or hotel room. Instead of tying up a gateway repeater, which largely connects local users to the Internet, many have opted for these low-powered devices to provide similar functionality. Advantages over a repeater are the hotspot owner has complete control over which reflector, repeater, or talkgroup their hotspot is connected to. They are not beholden to the preferences of the repeater owner and have the flexibility to use their hotspot however they’d like. Many use them mobile in the car or take them on a trip allowing them to enjoy their favorite digital modes where there may not be repeater coverage.

Hotspot devices in general are about the size of a deck or two of cards and require an Internet connection, computer to run the software, application or web browser for configuration, and a radio capable of operating each mode. An Internet connection can be your home WiFi or cellphone hotspot (as in WiFi-hotspot). The original OpenSpot was the only device that required a wired Ethernet connection. A PC computer may serve as the Internet connection for USB access points. The computer could be a Raspberry Pi in many cases or might be completely self-contained. A web browser or application is needed to make configuration changes and adjustments such as call sign, transmit frequency, mode, or network. These hotspots are the RF gateway to the internet which means a radio capable of transmitting and receiving that mode is also required. Few hotspots today are single mode like the D-STAR DVAP. Nearly all on the market are capable of operating multi-mode and connecting to associated networks. To operate DMR the user would need a capable DMR radio, a capable Fusion radio for the Fusion networks, and so-on.

Hotspots can utilize the many available modes & networks:

  • DMR: BrandMeister, DMRplus, XLX
  • D-STAR: DCS, DPlus, XRF, XLX
  • Fusion: FCS, YSFReflector
  • NXDN: NXDNReflector
  • P25: P25Reflector

A keen eye might ask about Wires-X, P25net, or DMR-MARC. Those networks cater to a specific manufacturer of equipment and are often closed to other vendors. You might be able to reach resources on those networks because someone has cross-linked a closed network with an open network, usually at the point where digital signals turn into analog audio. This is how a user can be on Wires-X America Link and talk with a DMR user.

Hotspots and satellites

Not the Dave Matthews Band song Satellite either. A major issue for other hams has been caused by hotspot users. Every hotspot user and repeater owner reading this needs to verify your operating frequencies and take corrective action, if required. Under Part 97, hotspot devices are considered an auxiliary station. Auxiliary stations cannot operate within the satellite sub bands. Many hotspots are operating there illegally. Satellite sub bands for 2 & 440 are:

  • 2 m: 145.800 – 146.000
  • 70 cm: 435.000 – 438.000

If your hotspot is operating within those frequencies or near the edges, within the weak-signal sub bands, or any other sub band likely to cause issues, you need to take corrective action now!

In general, advice would be to ‘check with the local frequency coordinator’ but experience with the coordinating group indicates they won’t be of any help. What should you do? Note: this advice only applies to the U.S. band plan. Every band plan I’ve seen has the satellite sub bands defined. I do like the ARRL’s Band Plan because it spells out many details not included in graphical representations. The band plan has allowances in the following frequency ranges for simplex, auxiliary stations and control links:

  • 146.400 – 146.580. Usable (at 12.5 KHz spacing): 146.4125 – 146.5675
  • 433.000 – 435.000. Usable (at 12.5 KHz spacing): 433.0125 – 434.9875
  • 445.000 – 447.000. Usable (at 12.5 KHz spacing): 445.0125 – 446.9875

“Usable” indicates the lower and upper frequency limits that can be used with a digital hotspot. Don’t forget to stay away from the national calling frequencies of 146.520 and 446.000. Some of these ranges are shared with repeater links so remember: it is your responsibility to ensure correct operation of your equipment and find a frequency not already in use before using it! There is NO excuse for not adjusting frequency to eliminate interference with other operators and equipment! Listen to the desired frequency by setting up a radio or scanner with the volume turned up. If you hear any kind of obvious traffic, data bursts, or digital screeching, pick another frequency then rinse and repeat. Your cooperation is greatly appreciated!

OpenSPOT2

Right after Dayton I started hearing rumors that the OpenSPOT was discontinued. Not the news you want to hear if you just purchased one at Dayton. The website eventually confirmed the rumors and that another device was to be announced “soon,” which turned into months. Finally, the SharkRF OpenSPOT2 was announced. This replacement addresses many issues of the now legacy device including the need for a wired Ethernet connection, limited portability, and lack of newer digital modes.

Feature-wise it is nearly the same but includes a much-needed internal WiFi antenna and support for NXDN and P25 (two up-and-coming digital modes in ham radio). It includes POCSAG which I’m not familiar but told is a paging standard. Those under 35 have no idea what a pager is. The device operates off a USB-C cable (included) and looks to be about the size of a computer mouse. It will still have cross-mode support for DMR and Fusion radios and networks. As with the previous, you will not be able to use your D-STAR, NXDN, or P25 radio in cross-mode. Release date is expected before the end of 2018. Stay tuned to their website and social media portals for exact date.

ZUMspot review

At Dayton I added to my hotspot collection. On my shopping list was a ZUMspot or something I could use with the Pi-Star software. I picked up a ZUMspot kit and case from HRO. The kit lists for $130, $110 without the Pi board. The case adds $15. The kit came with the amazingly small Raspberry Pi Zero W (W for Wireless) and the ZUMspot modem board from KI6ZUM. You’ll need to provide a Micro-USB cable which powers both devices. I’ve seen demos and received feedback saying Pi-Star was a great application to use – and is stable. Many had issues with the DVMEGA (in particular) getting a good distribution that worked reliably with that device. Pi-Star is software written by Andy – MW0MWZ. It is distributed as a Raspberry Pi image for use with Digital Voice modems.

All configurable options are available through the web interface. It’s convenient and you don’t have to mess around with multiple interfaces or carrying around a screen for the device. Services like SSH are available but generally not needed.

Before I tried to use the image, I knew I had an issue. Since this was my first Pi device without a wired connection, I couldn’t edit the WiFi settings by wiring it to my network. Instead I mounted the SD on a Linux system and edited the /etc/wpa_supplicant/wpa_supplicant.conf to include my WiFi information. Booted the ZUMspot and it connected to my wireless auto-magically. The Pi-Star site has a utility to help create the wpa_supplicant.conf file.

I’ve primarily used the ZUMspot on D-STAR and DMR but it supports all modes and networks mentioned earlier in the article. It doesn’t do as well as the OpenSPOT when D-STAR stations are marginal into their gateway. There’s more “R2D2” on the ZUMspot in that respect but it’s a minor issue. Pi-Star can enable multiple digital modes at one time. This is a great selling point and works great if conversations happen at different times on different networks. It is a “first wins” scenario. If a D-STAR transmission ends and one on the DMR network starts, nothing will be heard on the D-STAR radio until the DMR transmission ends. In other words, parts of an otherwise interesting conversation maybe missed. The case is a bit of a jigsaw puzzle but it’s fairly easy to figure out from the picture that was provided. The ZUMspot is an excellent little device and I’m happy with it.

Technical Specialists report

Dave – KD8TWG has been very busy recently. He was again in charge of the communications and networking for the Great Geauga County Fair where they run APRS tracking of their golf carts, setup a phone system and IP cameras to cover the fair. At the Cleveland Hamfest he gave his presentation on Digital Modes. He compared and contrasted modes available to ham radio operators, including quality and radio options. Updated for this year was information on digital scanners and receiving the MARCS statewide digital system. Coming up on October 30, he and a few buddies will be putting on a “Test and tune” night for LEARA. It’s a great opportunity to check operation of radio equipment and make sure it is not transmitting spurs and harmonics (*cough* *cough* Baofengs *cough* *cough*). Contact Dave if you’re in the Cleveland area, or myself for the rest of the section, to have a similar program at a club meeting or hamfest.

If you were involved with the State Emergency Test, Black Swan exercise the weekend of October 6 & 7, you likely received bulletins from The Ohio Digital Emergency Network (OHDEN). Eldon – W5UHQ and crew gave up a good portion of their weekend to help with this event. They did a fine job of handling bulletins from the EOC and those stations that came through on the wrong communication channels. Join them for the OHDEN net on 3584.500 USB using Olivia 8-500 set to 1500 Hz on the waterfall each Tuesday at 7:45 PM eastern.

WB8APD, SK

Cleveland Hamfest – 1999, hac.org

I received word that Trustee Emeritus and past long-time Treasurer for LEARA, Dave Foran – WB8APD became a Silent Key on October 10, 2018. I knew Dave for about 10 years as a member of the LEARA board and mentor but knew the impact he made on the Ham Radio community long before I was a ham. In the time I knew him, Dave was always a behind the scenes guy – rarely getting on the radio. He was instrumental in getting repeater sites and maintaining equipment for LEARA including having an input for one of the repeaters at his house. Stories have been told that his basement was the print shop for the club’s newsletter when the club had 400+ members no-less. Dave was incredibly smart with technology and the Internet before most of us knew what it was. He worked for the phone company and the joke was “Dave had half of Ma Bell in his basement.” Internet linking was something he was into early on with his own IRLP node. He owned a server that, for a long time, served resources for the Cleveland area – not only ham radio clubs but community organizations too.

HamNet BBS before closing

Maybe you even dialed into the old HamNet BBS system located in Dave’s basement (yet another reference those under 35 won’t understand). Dave was my mentor with technologies LEARA was using as I was going to be helping or taking them over. He is the reason I’m into digital modes. Cleveland’s first D-STAR repeater was in-part Dave’s doing. Of course I had problems at first and he was my go-to for questions. The little space here covers only a fraction of his involvement and lives he impacted through his countless contributions. Goodbye and 73, Dave.

Thanks for reading and 73… de Jeff – K8JTK

Computing, Tutorials

P25 Trunked Tracking and Decoding with RTL-SDR, Unitrunker, and DSDPlus

The project that got me really into experimenting with the RTL-SDR dongles is using them to decode P25 digital trunked public service radio systems.  I have been a casual scanner listener for years and like to listen to emergency calls nearby.  In college it was great to listen in on a party weekend hearing fights, disturbances, or why my street suddenly filled with cars at 3 AM.

Narrowbanding

That was when most agencies were analog.  To get more use out of the radio spectrum, the FCC decreed a narrowbanding mandate requiring a “maximum of 12.5 kHz bandwidth across the private land mobile bands between 150-174 and 421-512 MHz.”  This means going digital for much of that radio spectrum because traditional FM transmissions are 15 KHz.  Ironically they will “go digital” but move to 700/800 MHz.

As a casual listener, I wasn’t exactly thrilled with spending at least $500 for a scanner capable of digital (P25 mostly) and trunked system tracking (also Radio Reference wiki).

$40 RTL-SDR trunked scanner

Lurking around the Radio Reference forums, I saw references to being able to use the RTL-SDR dongles for trunked digital decoding.  I had to try it.  I had played around with these dongles and read about the many projects people were doing with them.  In actuality this project cost me $65.

About the project

You will need at least two RTL-SDR dongles ($20/each) and a copy of Virtual Audio Cable ($26).  I already had a premium Radio Reference account.  You can do the project with one dongle but you loose many features in Unitrunker like talkgroup priority.  Theoretically, the single dongle listens to the system control channel and then tunes to voice calls, then back to the control channel.  You will miss calls because that notification comes across the control channel while the dongle was tuned to a voice transmission.  I will cover a two dongle setup and do not plan to cover a single dongle setup.

This project is still very complicated but it is MUCH easier than it used to be.  This manly thanks to Rick, the developer of Unitrunker who implemented support for the RTL-SDR chipset in his program.  Previously, there needed to be a plug-in for both Unitrunker and SDRSharp, there were all kinds of “moving parts.”  In one respect, being able to see the signal waveform on a spectrum analyzer made it much easier to fine tune the PPM correction on-the-fly as opposed to guessing on a modulation scope.  This setup is much cleaner and the Unitrunker developer has implemented advanced features like drift correction.  It will take some time and patience to understand, research, and know the types of systems and system specifics.

There are some advantages like cost and being software based.  Changing modulation types is often as easy as changing programs.  As an example, DSDPlus will decode MotoTrbo as opposed to no standalone scanner being able to do so currently.  However, portability of this setup is limited as you have to have many pieces of equipment with you.  You’ll need an Internet connection to find sites to program and a PC to tweak settings.

Two very specific and key things to note about trunked radio systems in general:

  • You cannot tell the tower your’re listening to which talkgroup you want to monitor.  Doing so would require the ability to transmit and IS ILLEGAL because you are not authorized to do so.  If the talkgroup is not transmitted by the tower, you’re out of luck.  You can’t be in Dayton and tell the system you want to listen to a talkgroup originating from Cleveland.
  • Nothing here (and no program I know of) will defeat encryption, even if you own the keys.  Decoding encrypted transmissions is not implemented in any of these programs.  On the flip side, be aware that using this tutorial and feeding the audio to Radio Reference and Broadcastify may not make agencies happy.  You could get a take-down notice or even worse, it is trivial to turn on encryption at the system level and you just blocked reception for all scanner listeners.

Thanks to those whose tutorials I first used getting this setup working: $20 trunking police scanner and RTL-SDR Tutorial: Following Trunked Radio With Unitrunker.

Program versions

I used a Windows 7 64 bit PC. Applications and versions used in this writeup:

  • SDRSharp: 1.0.0.1330
  • Virtual Audio Cable: 4.14
  • DSDPlus: 1.51
  • UniTrunker: 1.0.30.10

Parts list

Listed below are all the parts needed to get this project working.

  • Computer with some processing and memory horse power.  It is recommended to have a computer with a recent Intel Core i5 processor and 8GB of RAM, or better.
  • Receive antenna that covers 700 & 800 MHz where P25 trunked usually resides. For an external antenna, splitters and coax runs maybe needed.  The stock RTL-SDR dongle antennas worked fine for me.
  • Two RTL-SDR Dongles.  To decode more than one voice transmission, increase the number of dongles needed.
  • Virtual Audio Cable.  Not free but trial version available.
  • Radio Reference account.  Premium account.  If you don’t want to fork over the money, become an audio feed provider.
  • Recommend a USB hub.  Couple years ago I picked up a Rosewill RHUB-300 USB 2.0 Hub 7-Port HUB.  I recommend this hub because when the dongle is plugged in, the antenna connector is pointed up.  This makes it easier to connect an adapter and a Pryme RD-98.  If available, connect the hub to an Intel USB chipset on your motherboard.  I’ve had far less issues using Intel based hardware.
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