Down Memory Lane: Reboot Amateur Radio WhatsApp Group – Reboot Coffee Drink Event 20 July 2019 9 AM STARS Restaurant, Mossel Bay

The Reboot Amateur Radio WhatsApp Group as well as the Reboot Coffee Drink Event is open to all radio amateurs and prospective radio amateurs in South Africa. All our events are informal and not club related in any way!!

Saturday 20 July 2019 was a cold and wet winters day due to a strong cold front that resulted in gale force winds, rain and snow on the high mountains of the Western Cape. But as they say in the classics the show must go on. Only the “brave” attended the Coffee Drink session in Mossel Bay which was again an enjoyable and successful event despite the low attendance figure.

Those present by way of mind: = 21

Kobus ZS2BBB, Mari ZS1MEH, Hentie ZS1LH, Jacques ZS1WC, Danie ZS1DJB, Dave ZR1OAC, Ettiene ZS008, Christi ZS4CGR, John ZS1ZR, Hennie ZS1IK, Nick ZS1N, Georg ZS1GFL, Chris ZS1M, Casey ZS1AAS, Abe ZS1ZS, Jimmy ZS1RB, Willie ZS2CC, Llewellyn ZS003, Conrad ZS1KG, Andre ZR1E en Johann ZS2BVD.

Those present in the flesh: = 6

Johan ZS2I, Thys ZS1TBP, Francois ZS1Q, Beat ZS1HB, Russel ZS2AHF and Johan ZS1I.

All present were welcomed by the administrator of the Reboot Amateur Radio WhatsApp Group. Once again there was no formalities and the only business of the day was the “Rondomtalie” / “Round Robin”, Mini Lectures/Demonstrations. (Participation is not compulsory! You can just sit and enjoy your coffee and learn.) It is impossible to provide all the finer and juicy details of the event. Moral of the story is to attend each and every coffee drink event.

Rondomtalie/Round Robin:

• Beat ZS1HB Mossel Bay displayed the DIY 2 Meter J-pole Antenna he constructed. He gave and overview of the working of this large and well built antenna. He indicated that this antenna will be used as a replacement antenna for the 145.600 Mhz Danabay Repeater. The J-pole antenna was constructed from 22mm copper water pipe. The antenna is fitted with a fine tuning bolt to adjust for the lowest SWR. Beat confirmed that the SWR reflected iro the antenna is 1:1 at 145.600 Mhz. The attached photos and documentation were supplied by Beat for distribution to any radio amateur who is interested to build such an antenna. After the J-pole discussion/demonstration Beat gave an update from his previous talk on the AIS (Automatic Information System) for ships and how he monitors VHF propagation all along the southern coast of South Africa. This discussion also included aircraft tracking and aircraft scatter. Thys then explained how APRS is used in 18 wheelers to also monitor VHF propagation. Most interesting!!
• Russel ZS2AHF George told the participants that he is busy restoring a grand old Kenwood TS520S HF Radio. He is currently experiencing a problem to locate the “paddle” or “bat-handle” switches (Send Receive, Vox, Noise Blanker etc.) for this specific radio. One cannot find new replacements anymore. If anybody can help to relocate a scrapped TS520S or 3D printed “paddle” or “bat handles” Russel will be most grateful. Russel is also busy constructing a LED Stand Alone Frequency Counter for this Kenwood TS520S and will keep us updated on his progress in future. Come on guys let us try to help Russel to get this fine old “lady” radio again in a full operational state!!
• Johan ZS1I Mossel Bay displayed the Southern Cape 2 Meter Hospital Slim Jim Antenna. He explained where the name for this antenna originated from. This antenna was constructed by Johan ZS1I many years ago when Isak ZS2I (SK) was in the local hospital in Mossel Bay. He had a HT radio in hospital but was not able to get into the 145.600 Danabay Repeater from his hospital bed. This antenna was taken to the hospital on several occasions. Isak was able to communicate with his fellow radio amateurs through the repeater while in hospital. This antenna is still today available on loan to any radio amateur who would like to use it from the local hospital in Mossel Bay. One would find it strange for somebody that was sick in hospital to still speak to his fellow radio amateurs for his hospital bed. Those who knew Isak (SK) would know that nothing was to much for him in life. He lived a full “Amateur Radio” life till the end!
• Johan ZS2I Mossel Bay (Just for clarity Johan is Isak’s (SK) son and he now hold the call-sign ZS2I) If Johan tells you that the current sun cycle is near the bottom and responsible for poor HF conditions then you must know that he knows what he is talking about. Johan an avid DX Chaser gave an overview of the current HF band conditions and DXpeditions. He however stressed that there is still openings at times and that one must be patient. He encourage all radio amateurs to call CQ on the bands at any time and not just except the fact stated by so many that the bands are “dead”. CQ CQ CQ.....!!!!!!
• Francois ZS1Q George recently acquired a new 2m HT radio. He wanted to connect this radio to an external antenna but the connector on the radio required a specific adapter which is not locally available in George. This was no problem for Francois and he decided to construct a unique extension cable from parts that he salvaged from other old radios. This extension cable works far better than the advertised connector as it is far more flexible to use and easier to install to the radio. Francois you should patent your extension/adapter cable for future marketing.
• Thys ZS1TBP Mossel Bay. We were all glad to see Thys at the session as his work do not always allow for him to attend the coffee drink sessions. Thys displayed and demonstrated the working of a homebrew USB Soundcard Interface that was designed and constructed by Danie ZS1DBJ. (currently visiting Australia). Danie designed the PCB with an on/off switch, RX/ TX volume controls and a PTT force switch. Thys has been using this unit very successfully on his Kenwood TRC80 and it is working flawlessly.

Other matters discussed by the participants:

• FT8 DX and Normal Modes and Changes.
• Tracking Aircraft and Flight Radar. (ADB-S)
• Interference and rising RF noise levels. It is not going to get better just worse!
• Ship to Shore Beacons. (AIS)
• APRS and 18 wheel trucks.
• Sun Cycle and HF Bands.
• Painted antennas do not work? Is this true?
• How to make the Hospital Slim Jim directional. Wil cleaning the antenna on the one side make it directional?
• Static electricity and HF antennas on large 18 wheel trucks.
• Interference on HF coming from the ABS braking system on large 18 wheel trucks.
• Lightning, static discharge and amateur radio antennas, earthing/grounding, protection etc.
• Short amateur radio related story from the past - 2 meter repeater ragchewing in the Southern Cape (1am to 4am in the morning) by those who cannot sleep at night.

A big thank you to all the participants for sharing their knowledge with us all. Highly appreciated!

Finally: A new coffee drink record (2 hours 12 min) was set during the event. Record? NO attendees just enjoyed themselves so much that time was no factor at all.

I concluded the event by thanking everyone for attending the event. Even though the attendance figure stood at 6 it really does not matter and has no effect on those present. The topics discussed reflected this fact. A great time was enjoyed by everyone!

We look forward to the next Reboot Coffee event which will be held in George on the 17 August 2019 at 9 am. The venue in George will be announced closer to the date.

73

Johan ZS1I

Mossel Bay

21 July 2019

Photos:

J- Pole Construction info - ZS1HB

 J-Pole Radiation pattern - ZS1HB

 J-Pole Plan - ZS1HB

DIY Extension Cable - ZS1Q

 Thys ZS1TBP admiring the work of Danie ZS1DBJ

 USB Sound Card Interface - ZS1DBJ

 The large J-Pole constructed by Beat ZS1HB

 Close up USB Sound Card Interface displayed by Thys ZS1TBP

 Beat ZS1HB with the 22mm copper J-Pole antenna

 The 6 BRAVE men enjoying themselves!!

 The Southern Cape 2m Hospital Slim Jim - ZS1I

 Bottom section of the Southern Cape 2m Hospital Slim Jim

 Snow on the mountains

 Cold cold cold!!

Snow on the mountains - ZS1Q

Information about the ZS1I DMR Repeater now also available on APRS

Image:  APRS activity in the Western- and Southern Cape

Here is another upgrade to the ZS Link Network and specifically to the ZS1I DMR Repeater located in Mossel Bay.  As with many other systems the DMR Repeater is now also listed on APRS and provide information about the repeater.  Below follow more information on how to setup APRS and the DMR Repeater firmware WSPD.

Click on image for larger view.  (ZS1I-D)

APRS in WSPD Dashoard for ZS1I

WPSD (W0CHP-Radio) offers full APRSGateway support, allowing for advanced APRS data sharing with specific digital modes (DMR, YSF) and enabling Position updates to be sent directly from your hotspot/repeater to mapping systems like aprs.fi. 

For setting up your specific station (using ZS1I as the example):

1. Configuration in WPSD

• Locate APRS Settings: Navigate to the Configuration -> APRS screen in your WPSD dashboard.

• Station Setup: Enter your callsign, e.g., ZS1I, in the APRS callsign menu. Ensure you add the appropriate dash number if required (e.g., ZS1I-1 or ZS1I-10 for hotspot instances).

• Enable Position: Ensure My Position Set is set to a proper GPS source (usually "GPS" or "Radio" if your radio provides it).

• Map Settings: Input your Latitude and Longitude to ensure your position is sent to the network. 

2. Operating with Digital Modes (DMR Example)

If you are trying to transmit APRS data from your handheld to the WPSD dashboard to appear on a map:

• DMR Settings (Anytone): In your radio's Digital APRS settings, define a D-APRS channel, set the APRS report type to "Digital," and set the APRS RX to checked.

• Digital APRS Channel: Set your digital APRS channel to 1 and ensure your radio is configured to send GPS positions. 

3. Verification

• WPSD Dashboard: Monitor the "Live Caller" or "Local RF Activity" screen on your dashboard to see packets arriving.

• aprs.fi: Check your station on aprs.fi to verify that the beacon data sent via the DMR/YSF network has been parsed correctly.

Note: WPSD allows for full APRS support, including D-Star (via ircDDBGateway), YSF, and DMR.

 

Click on images for larger view.

ZS1I DMR Repeater now also connected to the APRS-ZA Server (ZS1I - Yellow Arrow)

A big thank you to Hennie van Rensburg ZS6CEY for allowing me to use the server.  As can be seen this server is rather busy.  See the images above.

 

Setting up the APRSGateway in WSPD - Go to Admin - Advanced - APRSGateway.  Enter the details as shown in the above images and add your APRS Server Password. That's it you should be up and running.

Click on images for larger view.

ZS1I DMR Repeater now also listed on Aprs.fi web-site

Click HERE to view the APRS information in near real time. Many thanks to Aprs.fi for hosting the ZS1I DMR Repeater information. (ZS1I-D)

 

Click on images for larger view.

Finally:   It is wonderful how one can nowadays integrate a wide variety of equipment and software to leverage internet-linked networking, understanding specific digital modes (DMR, D-STAR, System Fusion), using Hotspots / MMDVM Repeaters for flexible access, and optimizing software settings for clear communication. Digital radio provides high voice quality, data transmission (GPS, text), and global connectivity without high power and large band width..

Kennisgewing: Opgradering van die Stilbaai Herhaler, Saterdag 9 Mei 2026 ..... sien ons jou daar?

Foto:  Stilbaai Herhaler (Klik op foto om te vergroot.)

Daar word beplan om Saterdag, 9 Mei 2026 die Stilbaai Herhaler op te gradeer mits die weer saamspeel.  Verskeie veranderinge gaan aangebring word maar die hoof oogmerk is om 'n Internet verbinding te bewerkstellig waarna die Echolink stasie ZS1SB-L na die herhaler perseel verskuif sal word.  In 'n toekomstige artikel sal ek meer besonderhede hieroor verstrek.

Dit is egter belangrik dat ons asseblief 'n aanduiding kry van hoeveel radio amateurs beplan om Saterdag, 9 Mei 'n besoek te bring aan die Stilbaai Herhaler.  Daar is vooraf reelings wat getref moet word in die verband.

Versoek:  Indien jy wel gaan opdaag, bevestig asb jou voorneme op die 625 WhatsApp Groep voor Woensdag (6 Mei 2026) 08h00 SAST.

Kom ons maak dit maklik vir Johann ZS1AAC en sy span op Stilbaai wat die nodige reelings tref in die verband.

Administrateurs:  Suid Kaap ZS Link Netwerk Groep

 

Photo: Still Bay Repeater (Click on photo to enlarge.)

It is planned to upgrade the Still Bay Repeater on Saturday, May 9, 2026, weather permitting. Various changes will be made, but the main objective is to establish an Internet connection, after which the Echolink station ZS1SB-L will be moved to the repeater site. In a future article, we will provide more details about this.

However, it is important that we please get an indication of how many radio amateurs plan to visit the Still Bay Repeater on Saturday, May 9. There are prior arrangements that must be made in this regard.

Request: If you are going to show up, please confirm your intention on the 625 WhatsApp Group before Wednesday (May 6, 2026) 08h00 SAST.

Let's make it easy for Johann ZS1AAC and his team at Still Bay who are making the necessary arrangements in this regard.

Administrators: Southern Cape ZS Link Network Group

Your DMR Repeater will not work once the Internet goes down? (Part 1)

A while ago I overheard a conversation between two radio amateurs discussing DMR and that DMR Repeaters will not function once the Internet goes down.  They were of the opinion that these new digital repeaters are useless if the Internet is down during a disaster or emergency.  This discussion set me thinking - always dangerous but I decided there must be a way/ways to run a DMR Repeater without the Internet.  Before I explain one of the methods I found to work flawlessly when there is no Internet, lets first look into the reasons why one would run a DMR Repeater without the Internet.

The question was how to run a standalone MMDVM DMR Repeater with no access to the Internet. The first question is why? 

DMR systems must be connected to the Internet, otherwise it just does not work correctly and does not make any sense. Well, it is not entirely true and I will prove the point that DMR Repeaters can still operate locally when there is no Internet.

There are two reasons for running a standalone DMR repeater in a very remote locations with no chance of having Internet access.  You can use Talk Group 9  to communicate within direct range of the repeater.  More on how to setup your DMR Radio in this regard can be found further on in this article.

The second reason of running a standalone DMR repeater is for use during natural disasters and any other random legitimate reasons.   Make sense in this day and age to be able to use a digital repeater for emergency communications.

The first thing I found is if the repeater is connected to the Internet (through a router) using an Ethernet cable and if the cable gets unplugged, the repeater is still working locally (TG9) without any problem.

However – once the repeater restarts, and there is no access to the Internet network (even local RF transmissions) the repeater does not work anymore.

I hear you say but I told you so and that the two radio amateurs having the discussion were not wrong.  

Your DMR Repeater is useless without the Internet!!

Well there are several ways to solve this issue of no Internet to a standalone MMDVM DMR Repeater.  In part 1 we will be looking at setting up a DMR repeater on a AREDN Mesh Network without the Internet.  Let's get cracking!

Image:  AREDN ZS1I Main Node

Setting up a DMR repeater on a AREDN mesh network enables off-grid digital voice communications by replacing Internet backhaul with RF links. Use AREDN firmware on compatible nodes to establish a "tunnel" or direct RF link, mapping your node to the network. An MMDVM-based repeater connects directly via Ethernet to the AREDN node. 

Key Components & Setup Steps

• AREDN Node: Ubiquiti or Mikrotik radio flashed with AREDN firmware.
• DMR Repeater: An MMDVM-compatible repeater (e.g., using a Raspberry Pi and MMDVM modem).
• Networking: The MMDVM node connects to the LAN port of the AREDN node.
• DHCP/Routing: The AREDN node acts as the network gateway, providing an IP address to the MMDVM Repeater.

Integration Process

1. Mesh Link Establishment: Ensure your AREDN node has a strong, reliable link to the mesh network using directional antennas.
2. DMR Setup: Configure the MMDVM host (Pi-Star or WPSD) to use a static IP within the AREDN network range or DHCP.
3. Bridge Connection: Use a DMR bridge (like cBridge) to connect to a Master Server over the mesh instead of the public internet.
4. Network Testing: Check for 100% connectivity. AREDN nodes should show the MMDVM IP in their DHCP table.

I will not be going into great detail here as AREDN Main Mesh Nodes differ from one to the other depending on which equipment you are using.  My equipment is fairly old as I started playing around with mesh networking in early 2002 when it was called HSMM (High Speed Multi Media) which used Linksys WRT54GL routers.  In 2015 I moved to AREDN which at the time was mainly using Ubiquity equipment. In November 2016, I started a community organization called Mossel Bay Initiative (MBI)  a pilot program for the AREDN Mossel Bay Mesh Network. More on this in a future posting. Through the years several other products were added to use with AREDN.  Comprehensive list of equipment  available HERE.

View the video below for my setup and an overview of how I used AREDN with my DMR Repeater while there is no Internet connection.

In short crypto I setup the equipment as follows:

1.  I use a Netgear GS105E Switch that connect all the equipment together.  The switch has 5 Ethernet ports and I allocated them as below:

Port 1 = ZS1I Mesh Server (Web Pages) running on a Raspberry Pi.

Port 2 = ZS1I-2 AREDN Node running a  Ubiquity Nano Beam M5 16

Port 3 = Windows 7 Desktop PC to view dashboards etc.

Port 4 =  ZS1I DMR Repeater using a Raspberry Pi 

Port 5 =  Internet connection when available from a Router.  This port stayed open as we do not want any Internet connection.

2.  Startup AREDN Main Node, Computer, DMR Repeater if not already running.  IP addresses will be allocated by the ZS1I-2 AREDN Node. In my case 5 IP addresses were allocated. I use Advanced Port Scanner to obtain the IP addresses. For now 3 IP's are important to gain access and to view dashboards.  This would be the ZS1I-2 AREDN Main Server Node; the DMR Repeater WSPD Dashboard and the Window 7 Desktop PC Browser to access the ZS1I-2 Node and the WPSD Dashboard for ZS1I (the latter not connected to the Internet but to AREDN).

 

 

 

3.  Lets look at how to open and view AREDN node information and the WPSD dashboard.

Access the AREDN node via the Window 7 Internet Browser.  Enter the allocated IP address for the node and click enter. The ZS1I-2 Mesh Node status page will open.  Login under Setup and once logged in you can go through all the different screens and pages.

 

 (Click on image for larger view.)

 

As far as the WPSD Dashboard, open the dashboard via the Window 7 Intenet Browser.  Enter the allocated IP address for WPSD and click enter.  The WPSD Dashboard for ZS1I will  open.  The dashboard will reflect that DMR and DMR Net are active (Green) while APRS Net and DMR Master BM 6551 South Africa is not active (Red).  In other words off-line.  So there is no Internet connection but the DMR Repeater is still working locally in the Mossel Bay area.

 

I programmed all my DMR radios to use TG65522 (World Wide Repeater Talk Group with Internet) and TG9 (Southern Cape Local Talk Group without Internet).  

 

 

(Click on images for larger view.)

Setting up Talk Group 9 (TG9) on a TYT MD380 for repeater use requires creating a digital contact for TG9, establishing a new channel with specific repeater parameters, and adding that channel to a zone. TG9 is frequently used as the "Local" talk group on DMR repeaters for local traffic or to link to other talk groups.

1. Create a Digital Contact for TG9 

• Open the TYT CPS (Code plug Programming Software) and navigate to Digital Contacts.

• Click "Add" and create a new contact:

  • Contact Name: TG9 (or Local 9).

  • Call Type: Group Call.

  • Call ID: 9. 

2. Create a Channel for the Repeater

• Navigate to Channel Information and click "Add" to create a new channel.

• Configure the following settings:

  • Channel Name: Choose a name (e.g., "Local 9" or "Rep TG9").

  • RX Frequency: Set to the repeater's output frequency.

  • TX Frequency: Set to the repeater's input frequency.

  • Channel Type: Digital.

  • Color Code: Match the repeater (usually 1).

  • Time Slot: Match the repeater (often TS2 for local/TG9).

  • Contact: Select "TG9" (the contact created in step 1).

  • RX Group List: Select a group list that includes TG9.

3. Add Channel to a Zone 

• Go to Zone Information and select the desired zone (e.g., Zone 1).

• Move the newly created channel from the "Available Channels" list to the "Members" list. 

4. Finalize Programming

• Go to General Settings and ensure your personal DMR ID is entered.

• Use "Write Data to Radio" to upload the new configuration to the MD380.

Important Notes for TG9 Usage:

• Local Communication: TG9 is designed for local QSOs and is not typically transmitted over the internet to other repeaters.

• Linking: In some systems, such as FreeDMR, you can link to other talk groups by using TG9 and the "Dial-a-TG" function (using manual dial).

• Timeslot: Always confirm with the local repeater manager whether they use TS1 or TS2 for local traffic. 

• Parrot Channel: It is recommended to create a “Parrot” (Echo) channel to test that your radio’s settings work correctly.

• Repeater Access: Ensure you have the correct frequencies (Offset) for the repeater and that your colour code is correct.

• Promiscuous Mode: If using custom firmware you can turn on Promiscuous Mode to hear all talk groups regardless of the RX Group List.

 

Above: Video of the equipment setup and demonstrating the use of the DMR Repeater without the Internet.

 

The information provided in this article resolved the problem of no Internet for my DMR Repeater while it usually work with Internet access.  As already stated this is one solution.  In future topics I will be looking at other methods on how to run a DMR Repeater with no access to the Internet. Some of these solutions are quite simple but seeing that I have an AREDN Mesh Network running, I wanted to use the method described in this article.

Keeping the ZS1I DMR Repeater in Mossel Bay cool!

Image:  Fans and Fan Speed Contoller fitted to the DMR Repeater.

In the previous article I described the two PWM Fan Controllers that I purchased to install in the MMDVM Repeater to keep it cool during those hot summer days.  I setup the controllers and tested them at different temperatures on the workbench.  So far they work as expected.  I fitted the two controllers in a 3D printed project box and installed it at the back of the DMR Repeater.

I opted to mount the fans on the outside of the repeater cabinet as the spacing inside the repeater cabinet makes it rather difficult to work on the fans and installing the controllers.  By mounting the fans and fan controller box on the outside of the repeater cabinet, it is now easy to access the controllers and service/replace the fans when necessary.

The modification turned out quite well and the fans and controllers are working as it should. Herewith a few images of the repeater after installing the new fans and controllers.

Images:  Click on images for larger view.

Keep your Repeaters, Simplex Radio's and Raspberry Pi's cool

Image:  PWM Fan Contoller  (Click on image for larger view.)

Well this is a bit late to cool things down as we say good bye to summer and hello to winter.  I wrote several articles in the past providing information on building you own Thermo-Fan Controllers for use to keep radios, raspberry pi's and other electronic equipment cool during operation.  All of these controllers are still in operation on a daily basis and up to now I have not had any problem with any of them.

I recently noticed that my DMR Repeater fans are very noisy and I suspected that they are close to failure as they have been in operation for several years now.  Low and behold two days ago one of the TX fans decided that it had enough and failed as expected.

I considered to build another trusted IC741 op-amp Thermo-Fan Controller for use with the DMR Repeater.  As the years are creeping up on me and the eye-sight not being so good anymore I decided I would rather buy a ready to use simple/cheap PWM Fan Controller.   I ordered two different models.  In this article I will only provide information on the one model depicted in the images below.

The controller is designed as a model that combines manual control and automatic temperature control.

Here is more information on the specific model:

This single-channel PWM fan controller is designed for 12V DC fans, supporting both 2-wire and 3-wire fan types for precise speed regulation.

 

It enables smooth, efficient, and stable fan speed control, making it ideal for cooling systems, industrial equipment, and DIY thermal management projects.

 

Key advantages:

• Single-channel PWM speed control

• Supports 12V DC fans (2-wire / 3-wire)

• Smooth speed adjustment with low noise

• Compact module for easy installation

• Ideal for cooling systems and thermal control

 

Other detail:

Input Reverse Connection Protection: Yes
No output overload protection.
Power Interface: XH-3P Terminal Block (2.54mm Pin Spacing)
Fan current: 0.8A (not overloaded)
Fan Interface: KF2510-3P Terminal Block (Pin Spacing 2.54mm)
Temperature sensor parameters: NTC 50K B = 3950 Length = 50 cm.
Temperature Sensor Interface: XH-2P Terminal Block (Pin Spacing 2.54mm)
Temperature resistance of probe: ring probe 110℃
PWM Output Range: 5% to 100%
Operating temperature: -20°C ~ 60°C.
Dimensions: 43 x 18 x 9 mm. 

I am not going to go into detail on programming and setting up the controller as YouTube and Google is your friends here.

Finally:  I setup the controllers and tested them at different temperatures on the workbench.  So far they work as expected.  I will be fitting the two controllers in a 3D printed project box and install it at the back of the DMR Repeater to provide the necessary cooling when needed.

Images:  (Click on images for larger view.)

Videos: