This is very useful test instrument that every radio amateur should have in the shack and can be built for next to nothing. Let's look at this very handy instrument and its uses.
A passive RF field strength meter is a simple, un-powered device used to detect and compare relative radio frequency signal levels. It uses an antenna to capture RF energy, germanium diodes to rectify the AC signal into DC, and a sensitive analog micro ammeter to display the relative output level without requiring a battery.
Core Components
Antenna: A telescopic whip or tuned dipole to pick up local RF radiation.
Germanium Diodes: Low forward-voltage components (like 1N60 or OA47) used for RF rectification.
Analog Meter Movement: A highly sensitive zero-center or standard 50µA / 100µA panel meter.
Capacitor & Potentiometer: Optional bypass capacitors to filter RF and a variable resistor/potentiometer to attenuate strong signals.
Common Uses
Checking transmitter output and relative power.
Adjusting and comparing directional antenna radiation patterns.
Testing the efficiency of baluns, tuners, and antenna setups.
I decided to build two of these instruments. In this issue we will be looking at the passive RF Field Strength Meter version.
Diagram
Bill of Materials
2 x Germanium Doides (IN34, OA70, OA90, IN60, BAT43 or 85)
1 x 470 pF (471) Cap
1 x 10 K Potentiometer
1 x 50 uA Meter
2 x DC Power Posts (Red + Black)
1 x Piece of Veroboard (PCB)
1 x 500 mm Stiff Copper Wire (Antenna) or old FM Radio Antenna
1 x Instrument Cabinet
1 x Potentiometer Knob
Construction
I am not going to go into detail as the diagram provides more than enough information to construct the meter successfully.
1. Reminder: Do tune into the DMR-ZA Net this evening at 19h30 SAST
Herewith a list of different equipment / apps and images that cross transmit / receive the DMR-ZA Net on a Tuesday evening. (Click on images for larger view.)
1. ZS1I 49355 AllStar Hub Network which incorporates Echolink. (ZS1I-R)
2. DMR / DVSwitch /AllStar Bridge (TG 65522)
3. ZS1I MMDVM Digital Repeater (TG 65522) 1. Reminder: Do tune into the DMR-ZA Net this evening at 19h30 SAST 4. 145.550 Mhz Analogue Simplex RF Link Mossel Bay area.
5. DroidStar / VoxDMR Applications for DMR TG655
6. ASL3 to Mumble Bridge PC (Mumble Client) as well as Mobile Phone (Plumble Client)
7. BrandMeister - Hoseline Application (PC or Mobile Phone - Receive only.)
8. DVSwitch Mobile Application (PC or Mobile Phone)
9. Many Analog-Repeaters and Links are connected to the ZS1I Hub Network on a daily basis. Some of these analogue repeaters will be connected to the ZS1I Hub Network on a Tuesday evening and they might also be linked to other repeaters country- and world wide. So why not link up with your local analogue repeater. You might just be able to connect to the DMR-ZA Net on a Tuesday evening at 19h30 SAST.
Finally: There are an abundance of means illustrated above to connect to the DMR-ZA Net on a Tuesday evening at 19h30 SAST. The DMR-ZA Net is an open net and all radio amateurs are welcome to join / connect to the net. Brian ZS5BR is the net controller and I would like to thank him for professionally conducting the net each Tuesday evening. Highly appreciated!!
2. Would WSPR work on DMR?
No, WSPR (Weak Signal Propagation Reporter) will not work over a DMR (Digital Mobile Radio) voice/data channel. They use completely incompatible modulation schemes, bandwidths, and timing structures.
Why WSPR and DMR are Incompatible
Modulation Type: WSPR uses continuous phase 4-tone Frequency Shift Keying (FSK) at an ultra-slow 1.46 baud, designed for analog SSB audio passbands. DMR uses 4-level and 2-slot TDMA Time-Division Multiple Access with 4FSK phase modulation at 9600 baud, processed by proprietary voice codecs.
Bandwidth: A WSPR signal occupies a tiny 6 Hz slice of spectrum (inside a ~200 Hz to 2.5 kHz audio window). A DMR channel requires a strict 12.5 kHz channel spacing.
Transmission Length: WSPR transmissions are precisely timed and take nearly two full minutes (110.6 seconds) of uninterrupted carrier shifting per burst. DMR cuts transmissions into rigid 30-millisecond frames and timeslot bursts.
Decoding: Standard WSPR decoders (like WSJT-X) look for specific FSK tone sequences and timing relative to UTC seconds. Passing a WSPR audio tone through a DMR digital voice codec will completely distort and destroy the weak signals, turning them into noise or data errors.
3. Ham Radio Etiquette: Do's And Don'ts On Digital Modes [2026]
Amateur radio, minding the gap refers to the crucial practice of leaving a short, deliberate pause (typically 3 to 4 seconds) between transmissions (Overs). This is essential for digital voice and data networks to properly reset, synchronize, and pass traffic without causing system-wide dropouts.
Here is exactly why we mind the gap:
Network Synchronization: For digital voice modes like DMR and C4FM/Wires-X, data travels via servers, nodes, and internet gateways. The gap gives the network’s VoIP protocol time to release the digital stream, clear buffers, and allow other stations to key up.
Preventing "Clipping": If you press your Push-to-Talk (PTT) button and immediately start speaking, the first syllable or two of your transmission is often swallowed by the digital handshaking process. Waiting a second prevents your voice from being clipped.
Allowing Break-Ins: Leaving a pause between your overs gives other operators a chance to break in. This is especially vital in emergencies when another user needs to pass priority traffic.
Avoiding "Time-Out" Timers: Many digital repeaters and network nodes have strict time-out timers (e.g., 3 minutes). Taking a breather resets these timers, preventing the repeater from dropping your transmission mid-sentence.
Thanks to Chris M9UCW For The Thumbnail Image.
Thumbnail Image For Illustration Purposes Only
73 de Mark 2E1CEQ Ham Radio Gadgets YouTube Channel Please Like And Subscribe
4. The Internet Re-Invented - - - - Internet Killer?
In this video, I build a Reticulum RNode and prove that completely different radios — LoRa and Wi-Fi — can communicate through a hardware-agnostic networking stack. Reticulum routes traffic above the radio layer, automatically bridging dissimilar frequencies, interfaces, and modulation types. I then run it over Wi-Fi HaLow Haven nodes to create a long-range, encrypted IP mesh with no traditional infrastructure. Finally, I push it further by running ATAK across the network, demonstrating a fully open-source, decentralized communication stack in action.
"Ham" started as an insult — and the frequencies amateurs were handed were dismissed as useless. So how did they end up crossing oceans, building their own satellite, and talking to astronauts?
This is the strange — and completely true — history of ham (amateur) radio, told as one story: from an invisible prediction on paper to a hobbyist satellite in orbit.
You'll meet James Clerk Maxwell and Heinrich Hertz (who thought his own discovery was useless), follow Marconi's first signal across the Atlantic, and finally find out where the nickname "ham" really comes from — and why the famous "three friends" story is a myth. You'll see how the "useless" short waves turned out to bend around the world off the ionosphere, how amateurs made the first two-way transatlantic contact in 1923, built OSCAR 1 — the world's first non-governmental satellite — and went on to talk with astronauts in space. Plus India's own proud amateur-radio story: Gooptu, Bose, the Amateur Radio Society of India, and a Prime Minister with the callsign VU2RG
00:00 Ham was an insult? 00:35 The invisible waves (Maxwell & Hertz) 01:22 Marconi crosses the Atlantic 01:47 The first home radio builders 02:30 Radio's first traffic jam 02:50 Why they're called "hams" 03:30 The band the experts called useless 03:53 The ionosphere changes everything 04:15 Relay: the birth of the ARRL 04:36 First two-way Atlantic contact (1923) 05:23 Hobbyists build a satellite (OSCAR 1) 05:48 Ham radio reaches space 06:16 India's amateur radio story 07:06 The real pattern of the story
This guy (ZS1I) is getting like the YouTube video posters with his
"What's in the Box?" I received several requests to please continue
with the series "What's in the Box?" From all accounts these postings
were of great interest to some of the readers of the previous Blog. I will oblige in this regard and will from time to time post
images and information of what is in the boxes I receive. I am also
looking at providing a review of equipment, components, modules etc. I
have not yet decided in which format to publish these reviews. It will
either be done on this blog or via a YouTube channel. Now I must say I
do not regularly buy items via the Internet. So do not expect many
posts in this regard. Some of the equipment in the boxes is not new so
do not expect the latest amateur radio state of the art equipment to be
unboxed.
Lets get cracking in unboxing this item: (Click on images for larger view.)
Image: ASL3 Diagnostic Check Command (Click on image for larger view.)
I recently experienced some issues where my 49355 ASL3 HUB node went offline for some rime or reason. The following issues were diagnosed:
Configuration Conflict: The node was simultaneously running legacy IAX registration syntax and newer AllStarLink 3 (ASL3) HTTP API configuration blocks. This structural overlap threw a fatal error, preventing authentication.
Systemd Startup Crash Loop: A system update introduced an incompatible high-priority flag (-p) into the systemd configuration wrapper. The underlying version of Asterisk rejected this flag, resulting in an immediate initialization failure (status=2/INVALIDARGUMENT), forcing the Asterisk process to repeatedly crash.
HTTP Module Bypass: While ASL3 defaults to HTTP registrations, local software variables caused the Asterisk package on this specific machine to bypass the modern res_rpt_http_registrations.so engine entirely.
How was the above issues diagnosed? Looking at the three issues the task to get the node up and running look like a daunting one where I will have to write a complete new SD Card. Writing a complete new card and setting it up would have taken me several hours. No I did not make a backup - naughty, naughty me!
In my search around on how to find out what was the actual issues I found the following command to diagnose the node. I tried using Diagnostics Reports in the Cockpit but that returned - No System Reports. Well I found the following command: sudo asl-node-auth-check
What is the purpose of this command (sudo asl-node-auth-check) when using it to diagnose your AllStarLink3 Node?
The sudo asl-node-auth-check diagnostic script was introduced in AllStarLink 3 (ASL3) to address complex network environments. It automates the verification of your node's local configuration, registration, and end-to-end network path. Here is a breakdown of what the tool evaluates when executed:
1. Holistic Configuration Audit
• Node Detection: Scans the active Asterisk environment to identify every node provisioned on the local machine. • Conflict Resolution: Cross-references file parameters to detect mismatches or syntactic syntax conflicts between config files.
2. Deep Network Profile (IP & NAT Diagnostics)
• Multi-Location Testing: Performs concurrent tests over both HTTP and Inter-Asterisk eXchange (IAX) protocols against three geographically separate AllStarLink server locations. • CGNAT Identification: By verifying network reach-ability from multiple external points, it definitively establishes if your node is trapped behind a Carrier-Grade NAT (CGNAT) or a restrictive mobile hotspot firewall. • IP History Tracker: Displays information on the last time your node’s perceived public IP address changed.
3. Individual Node Authentication & Registration
• Syntax Validation: Checks that the local registration strings match the valid format mandated by the network. • Port Verification: Confirms that the local port defined in your configuration exactly matches the database port assigned to you in the central registry database. • Server Handshake: Tests actual routing and reach-ability directly to register.allstarlink.org. • Staleness Tracking: Verifies if your node registration is active and current (checking that a valid database check-in has succeeded within the last 10 minutes).
4. Inbound IAX Reachability Test
• Parrot Routing System: Uses the newer central "Parrot/Reach-ability" system to simulate an incoming connection attempt to your node. • Port Forwarding Proof: This tests if inbound traffic on your designated port can actually pierce your local router firewall and reach the node. If your node has a green status on the AllStarLink Node List but cannot accept incoming connections, this utility isolates the fault.
As can be seen from the above this command is a very convenient way to diagnose issues your node might experience. Please note that is is a very powerful diagnostic command tool and one should use it with caution.
Checking configuration: Info: Skipping evaluation of private node 1961 Info: rpt.conf has configuration for: 49355 Info: /etc/asterisk/iax.conf contains 1 registration line(s) Info: /etc/asterisk/rpt_http_registrations.conf contains no registration lines. Info: Registrations present for configured node(s): 49355 Info: IP from https://conntest-east1.allstarlink.org/ip reports: xx.xxx.xxx.xxx Info: IP from https://conntest-west1.allstarlink.org/ip reports: xx.xxx.xxx.xxx Info: IP from https://conntest-west2.allstarlink.org/ip reports: xx.xxx.xxx.xxx Info: IP from udp://conntest-east1.allstarlink.org:4570 reports: xx.xxx.xxx.xxx Info: IP from udp://conntest-west1.allstarlink.org:4569 reports: xx.xxx.xxx.xxx Info: IP from udp://conntest-west2.allstarlink.org:4569 reports: xx.xxx.xxx.xxx OK: HTTP IP probes have consensus on the same perceived IP OK: IAX IP probes have consensus on the same perceived IP
Testing node 49355: OK: Node registration config is well-formed OK: Node registration type is IAX OK: register.allstarlink.org is reachable (via HTTP) OK: IAX registration state is Registered OK: Perceived IAX IP:PORT for this node is: xx.xxx.xxx.xxx:4569 OK: Registered to aws-east1a-register1.allstarlink.org - xx.xx.xxx.xxx OK: Server-set UDP port matches bindport in iax.conf OK: Node registration within 10 minutes: 2026-07-31 14:11:50 UTC Info: Last time IP changed was 2026-07-29 09:48:32 UTC OK: Incoming connections to IAX from other nodes is successful Info: IAX ping test has a roundtrip time of 238ms OK: No problems detected with node 49355
ZS1I@49355:~ $
xx.xxx.xxx.xxx - IP Addresses removed for obvious reasons.
Errors / Warnings will be reflected in the output of the command. From thereon you can fix the errors / omissions etc. As can be seen I experience three issues which was solved and the node is now running as it should. I also ensured that I made a paper format back-up of the current 49355 node setup as well as the back-up tool in sudo asl-menu.
I trust that this article might be of use to fellow radio amateurs that experience issues with an ASL3 node. This tool really "saved my bacon"!!
In Part 1 available HERE I gave a short overview of the Next Generation Amateur Radio Beacon (s) for the Southern Cape. You can read more HERE about theZS1I 6 Meter Magic Band Project in the Southern Cape Area of South Africa.
This past few weeks I have been working on the 6m CW Beacon.
As I said before this is not an elaborate beacon but more of a modular /
practical beacon.
Update: ZS1I 6 Meter CW Beacon Project (Part 2) available HERE
This past few weeks I have been working on the 6m CW Beacon building it into a project box. As I said before this is not an elaborate beacon but more of a modular / practical beacon.
The beacon is now built into the project box and ready to be installed to the antenna and power supply.
Site: ZS1I Station Shack, Heiderand, Mossel Bay License: ZS1I Amateur Radio License Note: This beacon is NOT located on a remote site which requires a separate license. The current location allows the owner to monitor and control the beacon while it is on the air.
I still need a solar power supply for the beacon upon final installation. The Delta Loop antenna needs to be lifted higher in the air. It appears that we are now on the home run to get this beacon on the air and ready for the "magic band" season in South Africa. An update article will follow once the final installation has been done and the beacon is up and running.
Images: (Click on images for larger view.)
Videos:
Notes:
1. The broken face-plate was replaced with 2 x PVC Pipe plates that I made out of 80 mm PVC gutter down pipe. It works great and I will in a future article explain how I turned the round gutter pipe into a flat piece of PVC. I used a very old pipe that needed to be sprayed with either white or black spray paint. Personally I think it did not turn out that bad.
2. The angle at which the second video was taken did not show the complete message on the OLED. If I lifted the project box then you would be able to see the full message. Apology for the bad photography.
The ZS1I 49355 HUB Node experience a few "glitches" in the past two days. Apart from very erratic internet connections the node would not register to the AllStar Servers and therefor not allow in and outbound connections. I enlisted the services of AI as I did not feel like re-writing ASL3 to an SD Card and go through all the settings to get the node to behave as it should. NO I did not make a back-up as I await an order for SD Cards. Locally cards are way to expensive.
Well between me and AI several issues were solved and the node is now running as it should.
I apologize for any inconvenience but if you want to stay on the forefront of new technology and developments these things do happen from time to time.
1. Reminder: Do tune into the DMR-ZA Net this evening at 19h30 SAST
Herewith
a list of different equipment / apps and images that cross transmit /
receive the DMR-ZA Net on a Tuesday evening. (Click on images for larger
view.)
1. ZS1I 49355 AllStar Hub Network which incorporates Echolink. (ZS1I-R)
2. DMR / DVSwitch /AllStar Bridge (TG 65522)
3. ZS1I MMDVM Digital Repeater (TG 65522)
4. 145.550 Mhz Analogue Simplex RF Link Mossel Bay area.
5. DroidStar / VoxDMR Applications for DMR TG655
6. ASL3 to Mumble Bridge PC (Mumble Client) as well as Mobile Phone (Plumble Client)
7. BrandMeister - Hoseline Application (PC or Mobile Phone - Receive only.)
8. DVSwitch Mobile Application (PC or Mobile Phone)
9.
Many Analog-Repeaters and Links are connected to the ZS1I Hub Network
on a daily basis. Some of these analogue repeaters will be connected to
the ZS1I Hub Network on a Tuesday evening and they might also be linked
to other repeaters country- and world wide. So why not link up with
your local analogue repeater. You might just be able to connect to the
DMR-ZA Net on a Tuesday evening at 19h30 SAST.
Finally: There
are an abundance of means illustrated above to connect to the DMR-ZA Net
on a Tuesday evening at 19h30 SAST. The DMR-ZA Net is an open net and
all radio amateurs are welcome to join / connect to the net. Brian
ZS5BR is the net controller and I would like to thank him for
professionally conducting the net each Tuesday evening. Highly
appreciated!!
2. Linux Mint isn't the best Windows replacement anymore
And the replacement is ........ ?
ZorinOS is more modern and polished, making it easier for Windows/macOS users to switch.
Built-in Windows app support
installs .exe/.msi with a click; Mint requires manual WINE setup.
Ships Wayland by default:
crisper text, smooth animations, better scaling, NVIDIA and phone
integration.
ZorinOS has been getting a lot of hype ever since Microsoft dropped support for Windows 10. Turns out the hype is justified. Linux Mint has been my go-to recommendation.
3. 16-Year-Old ARRL Member Wins 2026 Student Coding Competition
ARRL The National Association for Amateur Radio® is pleased to announce that member Ben Leovy, KC3ZPQ, of Ellicott City, Maryland, has been named the winner of the 2026 ARRL Student Coding Competition. Leovy, 16, recently completed his sophomore year at Howard High School. He designed a mobile application to help users prepare for their amateur radio license examinations.
Leovy will receive a $5,000 prize awarded by ARRL. His project was selected by a panel of judges based on usability, clarity, stability, and code quality. The judges also recognized his enthusiasm for software development and creativity by awarding him a new MacBook Neo to encourage his continued exploration of programming and technology.
“The ARRL Student Coding Competition was created to encourage young radio amateurs to apply their skills to a real-world opportunity that will benefit the amateur radio community and future entrants,” said ARRL Senior Director of Marketing and Innovation Bob Inderbitzen, NQ1R. “Ben’s project demonstrated the kind of problem-solving skills and creativity that will help shape the future of amateur radio.”
The judges were also impressed with the strength of Leovy’s technical approach and the potential value of continuing its development. ARRL has offered him a consulting project this summer, to further refine and improve the application in collaboration with ARRL employees – an opportunity to gain professional experience. Upon successful completion of the project, Leovy will earn an additional $5,000. He will also be eligible for a $5,000 ARRL scholarship when he enrolls in college after high school.
“I’m excited about the opportunity to continue improving the application and working with ARRL,” said Leovy. “I hope it helps more people, particularly students my age, to get involved in amateur radio and to join ARRL.”
Leovy became interested in amateur radio through his grandfather and through friends involved with the scouts who shared an interest in the hobby. In addition to amateur radio and programming, Leovy participates in his school’s robotics club and enjoys exploring technology through hands-on projects.
The ARRL Student Coding Competition was launched in January 2026 as part of ARRL’s ongoing commitment to developing the next generation of radio amateurs. The competition encouraged ARRL Student members ages 21 and younger, who already have ham radio licenses, to combine their interests in amateur radio and software development.
“Programs like this help young people discover that amateur radio is more than a hobby — it is a pathway that inspires hands-on, practical, and technical experiences,” said ARRL CEO David Minster, NA2AA. “By investing in students and their ideas, ARRL is investing in the future of amateur radio.”
The competition is another ARRL program intended to develop student interest in future education and careers in STEM/STEAM fields. Other ongoing initiatives include the ARRL Teachers Institute on Wireless Technology, the ARRL Collegiate Amateur Radio Program, and the ARRL Foundation Scholarship Program.
The competition judges were ARRL First Vice President Kristen McIntyre, K6WX; Hudson Division Director Ed Wilson, N2XDD; previous Director of Education and Learning Steve Goodgame, K5ATA; ARRL VEC Manager Maria Somma, AB1FM; and Education & Learning Support Specialist Max Freedman, N4ML. Additional support was provided by past Pacific Division Director Anthony Marcin, W7XM.
Since 2024, ARRL Student Membership has been free for full-time students ages 21 and younger. This no-cost membership opportunity makes it easier for students to become involved in amateur radio and access ARRL resources while they explore radio, technology, and STEM-related learning opportunities.
For more information about ARRL Student Membership, visit www.arrl.org/student.
- ARRL
4. Paper Logging
As an amateur radio operator, logging and QSLing are topics that keep me busy all the time. While I recently stopped confirming my radio contacts (QSLing), it’s still very important to me to log my QSOs. I’ve tried many different options for this and most recently used Wavelog, with which I was generally satisfied. However, I’m currently trying (not just in amateur radio) to simplify things and return to the original ways. That’s why I’ve decided to switch to paper logging, even though the drawbacks are obvious: no automatic generation of statistics, no search options, and no quick way to tell if I’ve had a QSO with a station before. However, I like having the maximum freedom to enter whatever I want into the logbook, however I want. It also feels somehow more personal to log the QSOs by hand.
After testing this out for a while with an existing paper logbook, it turned out that while I like this approach, existing logbooks don’t suit my needs. I make contacts both on shortwave and via satellites. For the latter, I need fields such as the locator or the name of the satellite. That’s why I first designed my own logbook template in OpenOffice Calc, exported it as a PDF, and then had it bound into a ring binder by a professional printing service.
The following image shows the finished logbook with 100 pages, a transparent plastic cover page, and a black plastic page as the last page for less than 10 Euro:
Now all that's left is to see how long paper logging will keep me happy...
- DK1MI
5. The Technology We Killed in the 1960s Is Now Worth $3.3 Billion
In 1904, a British engineer built the first vacuum tube in a London laboratory. Within decades, it became the foundation of modern electronics. Radio, television, military radar, and the first computers all ran on vacuum tubes. Then in 1947, Bell Labs demonstrated the transistor, and by the 1960s the entire industry had moved on. Factories closed permanently, and the vacuum tube was declared dead.
But it never actually disappeared. It survived in places most people would never think to look, and in 2022 a geopolitical crisis exposed just how dependent the modern world still is on a technology it supposedly abandoned sixty years ago.
This is the full story of the vacuum tube, from the invention that started it all to the billion-dollar market nobody sees.
6. Listen to FreeSTAR SystemX Live No App Required [2026]
Stream the conversation. Anywhere. Anytime.
FreeSTAR SystemX Live Activity Feature Directly From Your Browser, No App is Required
Listen To Any FreeSTAR SystemX Talk Group Or Set Up A TG To Listen Once It becomes Active.
Z3DMR is a free, mobile push-to-talk application designed for licensed amateur radio operators to communicate over Digital Mobile Radio (DMR) networks directly from their smartphones.
Developed by the Radioamateur Club Z37CPR, it eliminates the need for physical DMR hardware, a hotspot, or an HT (handheld transceiver) to access digital ham radio networks
Key Features:
Network Support: Connects directly to major DMR networks, including BrandMeister and Homebrew
Talkgroup Management: Features network-specific talkgroup lists, alongside manual configuration options for master servers, contacts, and custom talkgroups.
Call Types: Supports both group calls and private calls.
Advanced Automation: Automatically activates Auto-Static talkgroups and allows multiple user profiles with Extended Service Set Identifier (ESSID) support.
Built-in APRS: Includes integrated Automatic Packet Reporting System (APRS) functionality for location data transmission
Accessibility: Available in 24 languages with a modern, clean, user-friendly interface.
Platform Availability:
Android: The app is fully released and can be downloaded from the Google Play Store.
iOS: An Apple iOS version is actively under development
Official Resources:
For the latest updates, configuration guides, and community support, you can visit the Official Z3DMR Website or join their support community via the Z3DMR Telegram Group.
The Boland Amateur Radio Club (BARC) invited me to do this talk on 23 July 2026. HAMNET Emergency Communications provided the Zoom platform. The audience consisted of radio amateurs, citizens, and disaster management.
MeshCore is a newer type of license-free decentralised radio network that allows citizens, government agencies including nature reserves, disaster management agencies, and amateur radio operators to all talk together, whether in public channels, directly to each other, or even in private encrypted channels. This is WhatsApp/Telegram/Signal without the Internet.
The network is not only useful to make new friends across the city and stay in communication with neighbours, but more importantly it is a resilient network that will stay operation long after the Internet has ceased to work due to a disaster or lengthy power outages. This is achievable through solar-powered repeater nodes at high sites, and the fact that this network is not dependent on any central server or presence, and of course there is no approval or registration to use it.
My talk highlights the similarities and differences between MeshCore and Meshtastic networks, and the reasons why such a network is so important to have in place across cities and towns. I highlight two recent outages we've had in the Western Cape where towns lost their electricity supply due to adverse weather conditions, and had their normal communications cut off for up to a week. In this time HAMNET does assist with communications but only from key points. Having a broader MeshCore network available, allows citizens and disaster management agencies to stay in contact with each other for essential services and assistance.
The City of Cape Town and Western Cape Provincial Government, recognise the value of having fallback communications, and HAMNET already has emergency radio rooms at both sites, which are kept in operational readiness. We are aiming to have something like MeshCore also officially endorsed by the City and Province, so that citizens can equip themselves with these radios ahead of any potential disasters in the future.
We also have some wilderness areas in and around Cape Town which have no cellular phone coverage, such as the top of Table Mountain. These areas are also ideal to have such radio networks operational, as they are easy to deploy, and radio nodes cost around R500 each (whether bought by citizens/tourist, or even available to rent for the day).
The talk concludes with a comprehensive Q&A around various topics relating to MeshCore radio.
Chapters:
Intro 00:00 What Is HAMNET 01:49 Context Intro 03:40 What is MeshCore/Meshtastic 09:50 What It Looks Like 12:44 Diagnostic Comparison 14:20 Path Routing 19:31 Noise Floor 12:12 Bandwidth and Battery Life 22:23 Strengths of Each Platform 23:39 Use Case Scenarios 27:31 MeshCore SAR App 31:57 Default MeshCore Radio Settings 33:10 Way Forward 37:08 Danie's Website Page 38:20 MeshMapper Wardriving 38:54 Flashing Firmware 41:42 SF and CR 43:15 Local Hardware 44:04 Importance for Amateur Radio Clubs 45:30 Discord Server 46:58 Meet Your Fellow Citizens 48:40 How Close Can Antennas Be 49:33 Reticulum Radio Network 51:55 Proximity To Other Antennas 44:59 Roof Nodes 58:54 Yagi Antennas 59:29 Why 868 MHz and not 433 MHz 01:00:37 Getting Out Of Repeater Shadows 01:03:52 Repeaters on Buildings 01:05:38 Disaster Management Endorsement 01:06:23 Permission To Put Repeaters Up 01:08:40 Motivation To Put Repeaters Up 01:10:10 HAMNET Emergency Comms Trailer 01:11:48 Cape Town Moving Forward 01:12:52
Why all the hype about Meshtastic and Meshcore nowadays in Amateur Radio? Is there really a hype in this regard? To answer the hype question I must honestly answer yes, if you look around you will literally find hundreds of videos and articles in this regard. I have been watching and reading quite a bit regarding these two entirely different open-source software projects since Meshtastic started a few years ago and Meshcore joined in later. A few local radio amateurs in the George area setup a few nodes and some information were exchanged amongst radio amateurs in the area. I looked into the feasibility of setting up such a mesh network at the time but came to the conclusion that it will be of no benefit to me or the general public as I was already running a AREDN ( Amateur Radio Emergency Data Network) Network on 2.4 Ghz and 5.8 Ghz in the Mossel Bay area. The benefits of an AREDN Mesh Network clearly over shadowed Meshtastic and Meshcore. But you are talking a lot of rubbish now! What about emergency communications? Surely Meshtastic and Meshcore can be used during a disaster to assist in emergency communications?
Let me explain a few reasons why I decided not to go the Meshtastic or Meshcore route and let me make it very clear that I an not against any of these open source projects. I might in future consider to join both these open source projects depending on further development of the software, hardware and a substantial price drop etc.
Here is a few reasons why I rather use AREDN: (I will only provide a cryptic explanation.)
An AREDN (Amateur Radio Emergency Data Network) system is a high-speed, self-discovering wireless mesh network built specifically by and for amateur radio operators using commercial off-the-shelf radio hardware. It is fully open source. Its source code, custom Linux-based firmware, and build tools are publicly available on GitHub under the GPL-3.0 license. This allows amateur radio operators to inspect, modify, and contribute to the network's software development.
I already have all the equipment setup for the AREDN Mesh Network including a fully functional web-site and server. It can connect to the ZS1I AllStar Hub Network and DMR Repeater and Bridge Network even when the Internet goes down. I can connect AREDN to any repeater, radio link, digital radio link etc for emergency communication use.
The AREDN Mesh Network has already been successfully used during the Knysna Fire Storm in 2017 and proved that it is up to the task of providing voice, video, image, text, email and data communications. (forwarding and storage)
The AREDN Mesh Network can be split into several mesh networks. For example the 2.4 Ghz network can be opened for public use and a person only needs his cellphone (without a cellular network connection) to communicate to the AREDN 2.4 Ghz Network or a node in his/her vicinity. This will allow the public important direct access communications during a disaster. Same as Meshtastic and Meshcore but with more power and directional gain antennas for AREDN.
Video / Images / Email and Data Communications are vital during a disaster. AREDN can provide these with ease having great bandwidth etc. One can even "tap" into existing CCTV Cameras that might be offline or install portable cameras on tripods if there is a need for it.
Now let's look at the cost. For what I am getting from a Meshtastic or Meshcore node / repeater I might just as well use commercial off-the-shelf radio hardware for AREDN which is found in abundance secondhand or sometimes as give-a ways. On several occasions I received freebee's which I used as AREDN Mesh Nodes. Older and redundant antennas for 2.4 Ghz and 5.8 Ghz can be obtained free from many Internet Service Providers and the general public. All the antennas I currently use was free of charge.
I hear you say but the Meshtastic and Meshcore nodes are small and compact and can be used with solar battery power. Yes the form factor is small and compact but have a look at the AREDN web-site to see how small and compact some of the AREDN nodes are and they can also use solar battery power.
RF Power Output - As radio amateurs we are permitted to use higher power than any of the Meshtastic or Meshcore nodes can provide. Higher power is not always the answer but it is available if needed. Always just use enough power that is needed to make a reliable connection / contact. I am not a QRO operator by any means but it is good to know that one can use higher power if needed.
Interconnection of AREDN to other amateur radio equipment and networks. This is were AREDN is shining and I have touched on this earlier. Bridging / interconnection / linking call it what you want has become very important in this day and age. On many occasions in the past I have talked about the disparity in radio communications among emergency responders—often called a lack of interoperability—occurs due to incompatible hardware frequencies, differing agency protocols, and decentralized funding. Police, fire, and medical teams often use completely separate networks that cannot talk to each other directly during a crisis.
In my opinion AREDN is a far better and trustworthy mesh network system. Agree there are also some areas that need to be upgraded but the AREDN Team is working tirelessly to release software and hardware updates to keep AREDN in the loop and relevant today.
Finally: I am not against Meshtastic or Meshcore. Each one has it's own rightful, place and uses and I think that it is wonderful technology that needs to be developed even further. So before I jump on the "hype wagon" several changes and new features need to be released to make it an attractive option for me to use as an emergency communications tool. By all means feel free to follow the Meshtastic, Meshcore or AREDN "route". Let's see what the future will bring in this regard.
Some time ago I wrote and article on how to easily and automatically connect and disconnect an AllstarLink 3 (ASL 3) node on a schedule. In that article you needed to leverage the ASL3 asterisk CLI tool (asterisk -rx) inside two basic bash scripts. Then, you map those scripts to system execution times using Linux's built-in crontab utility.
Note: I know there are more than one way to effect these connections but here I concentrate on the newcomer to Linux and ASL3.
In this article I will provide an even simpler method to automatically connect and disconnect one node to another node. We going to setup a cron job in ASL3 to automatically connect to other nodes. Just a word of caution - you still need to monitor your dashboard as "murphy" can cause havoc at any time. Please do monitor your dashboard or your radio for any connection issues.
To set up an automatic connect and disconnect schedule on AllStarLink
3 (ASL3),
you can execute Asterisk CLI commands directly inside the system's
crontab.
This method bypasses the older built-in Asterisk scheduler, making it
highly reliable and easy to modify.
Follow
this step-by-step guide to configure your scheduled connections.
Step
1: Open the System Crontab
Log
into your ASL3 node via SSH. Open the root user's cron scheduler
using your preferred text editor (like nano) by running:
bash
sudo export EDITOR=nanosudo crontab -e
Step
2: Add Your Connect and Disconnect Cron Jobs
Scroll
to the bottom of the crontab file and add your scheduling strings.
Use the following format template:
(Note:
*1
is the specific link disconnect command).
Step
3: Save and Verify
Save
the file
in nano by pressing Ctrl
+ O,
then Enter.
Exit
the editor
by pressing Ctrl
+ X.
Verify
your entries
are correctly loaded into the scheduler by running:
bash
sudo crontab -l
Quick
Syntax Reference
Time
Format:
Crontab requires 24-hour military time.
Days
of the Week:0
or 7
= Sunday, 1
= Monday, 2
= Tuesday, 3
= Wednesday, 4
= Thursday, 5
= Friday, 6
= Saturday.
Asterisk
Path:
Ensure you specify the full path /usr/sbin/asterisk
so the cron daemon can find the execution file without environment
paths.
Do
I need a script file for this to work or will the above suffice?
The
crontab lines provided above will
work perfectly fine on their own
without any external script files. For your goal of a simple
but effective method,
putting the commands directly into the crontab is the absolute best
approach. It keeps your system clean because you do not have to
manage, execute-protect, or worry about the file paths of separate
script files.
Why
this direct method is highly effective:
Fewer
moving parts:
The system reads the time, triggers the Asterisk command directly,
and connects.
Easy
to modify:
If a net time changes, you just run sudo
crontab -e
and change the numbers in one single file.
No
permission bugs:
Running scripts sometimes fails if you forget to make the file
executable (chmod
+x).
Direct cron commands avoid this completely.
The
only rule to keep it working:
Just
ensure that your node number and DTMF steering prefixes match your rpt.conf file. (For example, if your system uses something other than *3
for connect and *1
or *76
for disconnect, change those prefixes in the crontab strings to match
your setup).
Here
is an extract, optimized text block for your information.
This is added to the bottom of your
crontab using
sudo
crontab -e:
text
# ====================================================================# AUTO CONNECT & DISCONNECT SCHEDULE FOR NODE 49355# ====================================================================
# SARL BULLETIN (Sunday Morning)# Connect at 08:00 SAST, Disconnect at 08:30 SAST00 08 * * 0 /usr/sbin/asterisk -rx "rpt fun 49355 *33373742"30 08 * * 0 /usr/sbin/asterisk -rx "rpt fun 49355 *13373742"# AMATEUR RADIO TODAY (Sunday Morning)# Connect at 09:55 SAST, Disconnect at 11:05 SAST55 09 * * 0 /usr/sbin/asterisk -rx "rpt fun 49355 *33373742"05 11 * * 0 /usr/sbin/asterisk -rx "rpt fun 49355 *13373742"
Pro-Tips for Your Setup:
• Time Zone Check: Ensure your underlying Linux operating system is set to South African Standard Time (SAST) by typing date in the command line. Cron follows the system clock.
• The Asterisk *3 and *1 commands: These lines assume your system uses standard Transmit/Receive (permanent or normal) linking prefixes. If you prefer to use Monitor Only (receive only) mode for the Sunday news bulletins so local transmissions don't interrupt the broadcast, change the connection prefix from *3 to *2 (e.g., *23373742).
Verification
Reminder:
After
saving the changes, remember to type date into your SSH terminal to make sure your Linux system clock is
actually synchronized to local South African time, as cron relies
strictly on the system time to execute.
Finally:
That's it you now have an automated connect and disconnect schedule that will assist you in connecting to other nodes. Just a reminder to monitor you dashboard to ensure that the setup runs smoothly.
