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AllStarLink Control Dashboard

By: M0AWS
12 September 2024 at 19:53

Ever since I built my RaspberryPi/SHARI AllStarLink node I’ve had to manage connecting/disconnecting to/from other nodes using the Allmon2 or Supermon web admin interfaces. These work fairly well albeit, a bit clunky and buggy. It’s impossible to use from a mobile device though and so I have to get my Macbook out each time I want to connect/disconnect nodes.

Being a Node-RED fanatic I decided that I should put something together that was more portable, mobile friendly and much easier to use. A simple user interface is all that is required and can be achieved very easily using the standard Node-RED dashboard nodes.

Initially I started investigating the Linux command-line interface for Asterisk, the VOIP system that underpins AllStarLink (ASL). I very quickly discovered that the ASL node can be very easily controlled directly from the command-line and that this would be an ideal interface to use to enable node management via a Node-RED dashboard.

In very little time at all I had an experimental control dashboard working with the ASL node and was able to connect/disconnect to/from a single node. All that was required now was to extend this so that I could connect to a number of nodes with nothing more than a push of a button.

AllStarLink Control Dashboard - Node-RED Flow
Completed v1.0 AllStarLink Control Dashboard – Node-RED Flow

The resultant flow consists of 3 sections, Connect/Disconnect Main Flow, Manage Node Subflow and /var/log/asterisk/connectlog Subflow.

The Connect/Disconnect Main Flow handles all the input from the buttons on the dashboard and the communication to the underlying Asterisk VOIP system.

The button status is denoted by 3 colours, green (Ready to connect), orange (Transitioning to/from connect) and red (Connected). Each button is updated automatically by the button refresh function that is triggered every 2 seconds.

The Manage Node Subflow provides a simple interface to restart the Asterisk VOIP system, reboot the RaspberryPi and shutdown the RaspberryPi. The node status is automatically updated every 45 seconds and will show when the Asterisk subsystem is being restarted or the node is being rebooted or shutdown.

Finally the var/log/asterisk/connectlog Subflow monitors the Asterisk connectlog looking for connect/disconnect messages so that it can signal to update each button status.

Node-RED AllStarLink Dashboard
Node-RED AllStarLink Dashboard

Each section of the dashboard can be collapsed/opened by touching/clicking the little blue arrows on the right of the dashboard. The dashboard works fine on Android, iOS, Windows, MacOS and Linux.

If you’re not familiar with Node-RED and haven’t yet installed it to your PC, take a look at the Node-RED Getting Started Page. The information takes you through installing Node-RED onto a multitude of devices including PC and RaspberryPi devices.

Once you have Node-RED installed all you need to do is download the AllStarLink Control Dashboard Flow and import it to your Node-RED flow editor.

Once downloaded, select Import from the burger menu icon on the right-hand side of the flow editor as shown below and import the flow file.

Node-RED Flow Editor import Menu Item
Node-RED Flow Editor import Menu Item

Once imported you will find that some of the nodes in the flow are not available. This is because you need to add them to the flow editor palette before being able to deploy the flow.

Drop down the same menu as shown above but, this time select Manage Palette. This will open another window where you will need to select the Install tab as shown below.

Node-RED Flow Editor Palette Install Tab
Node-RED Flow Editor Palette Install Tab

You need to install two node sets to complete the flow, node-red-contrib-bigssh and node-red-dashboard. Type in the name of each package one at a time in the search bar and then click the Install button.
Once the two packages are installed you then need to configure the credentials for logging into your RaspberryPi. This is simply done by double clicking the blue Send Command to ASL node at the top of the main flow and then clicking the Pencil button at the end of the Credentials field. This will open another window where you will need to type in the IP Address of your ASL RaspberryPi into the Host field, then enter 22 into the port field, add repeater into the Username field (repeater is the default username, if you have changed this then you will need to add the new username name in instead) and then the password associated with the repeater login into the Password field. (Normally allstarlink)

Once this is done, do the same on the other blue nodes, namely “Get Node Uptime“, “Command =>> RaspberryPi” and “Tail ConnectLog”.

The final thing to setup is the dashboard size. Click on the downward pointing triangle at the top right of the menu bar (under the burger menu) and select dashboard. Check that the sizes are set the same as in the image below. For some reason, these settings aren’t always imported (Possible bug?) so, if your dashboard layout isn’t like shown above it will be because these settings failed to import.

ASL Dashboard Settings
ASL Dashboard Settings

You are now ready to deploy your AllStarLink Control Dashboard!
Press the red Deploy button at the top of the flow editor window.

To access the dashboard from any device, open your favourite web browser and enter the following URL: http://IP-Address-of-Node-RED-Computer:1880/ui

Finally, if you want to change the nodes that each button connects/disconnects you will need to edit the set flow var’s function at the top of the main flow. All you will need to do is replace the existing node numbers taking care not to alter the rest of the code in any way otherwise, it could stop the flow from working.

Once you’ve edited the node numbers, double click on the associated button node and change its Label to show the new node name.

Once your changes are complete, Deploy the flow again and your changes will be live.

This is version 1 of the ASL Dashboard, I already have ideas for version 2 that will also have the ability to enter a node number into a field and connect to it without the need to program it into a button.

More soon …

Updating MagTag WX for OpenWeatherMap API 3.0

By: robert
9 September 2024 at 18:29

A couple of years ago, I put an Adafruit MagTag Weather display together.  The MagTag was a fairly inexpensive CircuitPython device with an eInk display and built-in WiFi.  It used a free (at that time) service called OpenWeatherMap API

Within the past month, OpenWeatherMap changed their policy and now requires a credit card to validate the API key, but they still don’t charge for up to 1,000 API calls per day.  Their interface allows you to set restrictions on the maximum API calls per day (it defaults to 2,000).  In my case I set it down to 500, so I never have to worry about a software bug causing me to get billed.

The code.py program that Adafruit supplies currently, is out of date, as it uses the API 2.5, which has been replaced by API 3.0.  The change needed to the source file is trivial – simply change the line that has the 2.5 reference to 3.0 and you are all done.  Like this:

URL = “https://api.openweathermap.org/data/3.0/onecall?exclude=minutely,hourly,alerts”

Note: I had edited the original bitmap background image to add my call on the top line.

Testing the Node-RED AllStarLink Dashboard

By: M0AWS
31 August 2024 at 12:27

Coding of version 1 of the AllStarLink Dashboard is now complete and in the final testing phase. Below is a short video clip showing some of the functionality.

The Node-RED flow for the web app is pretty compact and easy to alter should I add more functionality in the future.

M0AWS Node-RED flow for the AllStarLink Node Dashboard
M0AWS Node-RED flow for the AllStarLink Node Dashboard

The dashboard is designed such that it’ll display nicely on mobile phones, tablets and desktop computers so, I can easily control my AllStarLink SHARI node from any of my devices around the house.

I’ll put together a more detailed article on the web app once testing is complete and it’s ready to be released into the wild.

More soon …

No Counterpoise Speaker Wire Antenna

By: WB3GCK
10 August 2024 at 10:04

It’s been a while since I’ve done a cheap speaker wire antenna, so here’s another one for you. Back in the early to mid-2000s, an antenna commonly referred to as the “No Counterpoise Antenna” was making the rounds on the Internet. I thought I might give it another look.

The No Counterpoise Antenna is either a 25-foot or 50-foot length of two conductor wire with half of one conductor removed. Essentially, it’s a radiator fed through a balanced line feeder. The 25-foot version is said to cover 20M through 10M, while the 50-foot version is supposed to cover 40M through 10M. It was usually connected to a balanced tuner of some sort or sometimes fed through a 4:1 balun. It was typically constructed from zip cord or speaker wire. So, this is perfect for another speaker wire project. (Actually, I built the 50-foot version years ago, but I don’t recall ever putting it on the air.)

A picture is worth a thousand words, so here goes:

No Counterpoise Antenna diagram

I’ve seen this antenna sometimes referred to as a Zepp. A true Zepp is basically a half wave radiator with a quarter wave balanced line matching section. Unlike a true Zepp, the No Counterpoise Antenna is non-resonant, so I guess it’s actually “Zepp-ish.” Because it’s non-resonant, a tuner is required for this antenna. 

I did some extensive research into the origins of this antenna. (OK… I just did a few Google searches.) Jeff Imel K9ESE came up with this design. I remember Jeff used to sell a high-quality version of the antenna on eBay. The reviews were generally positive.

Pete Millis, M3KXZ, is another name often associated with this antenna. I think that’s how I first came across it. Pete once made a phased array from two 25-foot versions

In the August 2020 edition of Ozark QRP Banner, the Four State QRP Group’s newsletter, Terry Fletcher, WAØITP, had a nice write-up about it. He discusses his experience with both the 25- and 50-foot versions. 

This antenna design has been around the block a time or two. So, there’s no innovation here on my part whatsoever. 

Construction

I happened to have a 25-foot roll of #18 awg speaker wire on hand, so this time around, I opted to build…you guessed it… the 25-foot version. 

Construction was about as easy as it gets:

  • I split the speaker wire halfway and cut off one side
  • Next, I twisted a loop at the end of the single wire and secured it with some Goop® adhesive. As an alternative, you could just tie a loop at the top or crimp a ring lug over the wire’s insulation. 
  • I stripped and tinned the wires at the feedpoint and installed spade lugs. You can just strip and tin the wires, if you like.
  • To keep the speaker wire from splitting further, I put some heat shrink tubing a couple of inches up from the lugs. I also added a dab of Goop® in the middle of the antenna where one side of the wire was removed. All of this is completely optional. 

Construction probably took me all of 15 minutes or so. That doesn’t include allowing the adhesive to cure overnight. However, the antenna was certainly usable without the adhesive and heat-shrink tubing I used. I’m just prone to overkill.

On the Air

To test the No Counterpoise Antenna, I drove down to Ridley Creek State Park (US-1414, KFF-1414). Using my drive-on mount, I supported the antenna from a 28-ft Jackite pole. I used a homebrew 4:1 unun at the feedpoint and ran 15 feet of coax into the cab of my truck to my KX3 (5 watts, CW). I used the long side of the antenna as the radiator.

I used my roll-on mount to support a 28-ft Jackite pole
I used my roll-on mount to support a 28-ft Jackite pole

Before I got started, I checked to see how the tuner in the KX3 would handle the antenna. The KX3 easily found a 1:1 match on all bands from 40M through 10M. Just for the heck of it, I tried 60M and 80M. The KX3 was able to find a good match on those bands, too. (That’s not too surprising, given that I once forgot to attach my coax to an antenna, and the KX3 still found a match.) I doubt this antenna would work well on 60M and 80M—but stranger things have happened. I wasn’t able to try it, but I’m sure the KX3 would be able to match it directly connected to the radio without the 4:1 and coax. 

I used a 4:1 unun at the feedpoint
I used a 4:1 unun at the feedpoint

Band conditions weren’t very good, so this wasn’t an ideal test. Despite the mediocre band conditions, I logged 13 contacts during my short activation. Most of my contacts were on 40M. There was considerable fading on 30M and 20M, but I made a contact on each of those bands.

This was hardly a rigorous evaluation, but the 25-foot No Counterpoise Antenna got the job done. I need to give it another try, when conditions are better.

Anyway, if you have some speaker wire and a few minutes to spare, give this one a try and see what you think. 

72, Craig WB3GCK

Meshtastic BBS

By: M0AWS
6 July 2024 at 06:25

Meshtastic devices have really taken off in the UK over the last few months and there is now an established Mesh across a large portion of the UK mainland.

Looking to expand the device capability I stumbled across a really interesting little project that is still in the early stages of development but, is functional and worth trying out.

The TC²-BBS Meshtastic Version is a simple BBS system that runs on a RaspberryPi, Linux PC or virtual machine (VM) and can connect to a Meshtastic device via either serial, USB or TCP/IP. Having my M0AWS-1 Meshtastic node at home connected to Wifi I decided to use a TCP/IP connection to the device from a Linux VM running the Python based TC²-BBS Meshtastic BBS.

Following the instructions on how to deploy the BBS is pretty straight forward and it was up and running in no time at all. With a little editing of the code I soon had the Python based BBS software M0AWS branded and connected to my Meshtastic node-1.

M0AWS Meshtastic BBS Main Menu accessible on M0AWS-1 node.
M0AWS Meshtastic BBS Main Menu accessible on M0AWS-1 node.

The BBS system is very reminiscent of the old packet BBS systems of a bygone era but, it is ideal for the Meshtastic world as the simple menus and user interface are easily transmitted in seconds via the Mesh using minimal bandwidth.

The BBS is accessible by opening a Direct Message session with the M0AWS-1 node. Sending the letter H to the node will get you the initial help screen showing the menu above and then from there onwards it’s just a matter of selecting the menu item and following the BBS prompts to use the BBS.

The BBS also works across MQTT. I tested it with Dave, G4PPN and it worked perfectly via the Meshtastic MQTT server.

This simple but, effective BBS for the Meshtastic network will add a new message store/forward capability to the Mesh and could prove to be very important to the development of the Meshtastic mesh in the UK and the rest of the world.

More soon …

Deep Dive – Node-RED QO-100 Satellite Ground Station Dashboard

By: M0AWS
12 June 2024 at 19:25

Following on from my article about my QO-100 Satellite Ground Station Complete Build, this article goes into some detail on the Node-RED section of the build and how I put together my QO-100 Satellite Ground Station Dashboard web app.

The Node-RED project has grown organically as I used the QO-100 satellite over time. Initially this started out as a simple project to synchronise the transmit and receive VFO’s so that the SDR receiver always tracked the IC-705 transmitter.

Over time I added more and more functionality until the QO-100 Ground Station Dashboard became the beast it is today.

M0AWS QO-100 ground Station Control Dashboard built using Node-RED.
M0AWS QO-100 Ground Station Control Dashboard built using Node-RED.

Looking at the dashboard web app it looks relatively simple in that it reflects a lot of the functionality that the two radio devices already have in their own rights however, bringing this together is actually more complicated than it first appears.

Starting at the beginning I use FLRig to connect to the IC-705. The connection can be via USB or LAN/Wifi, it makes no difference. Node-RED gains CAT control of the IC-705 via XMLRPC on port 12345 to FLRig.

To control the SDR receiver I use GQRX SDR software and connect to it using RIGCTL on GQRX port 7356 from Node-RED. These two methods of connectivity work well and enables full control of the two radios.

M0AWS Node-RED QO-100 Ground Station Dashboard - 12/06/24
M0AWS Node-RED QO-100 Ground Station Dashboard Flow as of 12/06/24

The complete flow above looks rather daunting initially however, breaking it down into its constituent parts makes it much easier to understand.

There are two sections to the flow, the GQRX control which is the more complex of the two flows and the comparatively simple IC-705 section of the flow. These two flows could be broken down further into smaller flows and spread across multiple projects using inter-flow links however, I found it much easier from a debug point of view to have the entire flow in one Node-RED project.

Breaking down the flow further the GQRX startup section (shown below) establishes communication with the GQRX SDR software via TCP/IP and gets the initial mode and filter settings from the SDR software. This information is then used to populate the dashboard web app.

M0AWS - Node-RED QO-100 Ground Station Dashboard - GQRX Startup
M0AWS Node-RED QO-100 Ground Station Dashboard – GQRX Startup Flow

The startup triggers fire just once at initial startup of Node-RED so it’s important that the SDR device is plugged into the PC at boot time.

All the startup triggers feed information into the RIGCTL section of the GQRX flow. This section of the flow (shown below) passes all the commands onto the GQRX SDR software to control the SDR receiver.

M0AWS - QO-100 Ground Station Dashboard - GQRX RIGCTL flow
M0AWS Node-RED QO-100 Ground Station Dashboard – GQRX RIGCTL Flow

The TCP RIGCTL -> GQRX node is a standard TCP Request node that is configured to talk to the GQRX software on the defined IP Address and Port as configured in the GQRX setup. The output from this node then goes into the Filter RIGCTL Response node that processes the corresponding reply from GQRX for each message sent to it. Errors are trapped in the green Debug node and can be used for debugging.

The receive S Meter is also driven from the the output of the Filter RIGCTL Response node and passed onto the S Meter function for formatting before being passed through to the actual gauge on the dashboard.

Continuing down the left hand side of the flow we move into the section where all the GQRX controls are defined.

M0AWS - QO-100 Ground Station Dashboard - GQRX Controls
M0AWS Node-RED QO-100 Ground Station Dashboard – GQRX Controls Flow

In this section we have the VFO step buttons that move the VFO up/down in steps of 10Hz to 10Khz. Each button press generates a value that is passed onto the Set DeltaFreq change node and then on to the Calc new VFO Freq function. From here the new VFO frequency is stored and passed onto the communications channel to send the new VFO frequency to the GQRX software.

The Mode and Filter nodes are simple drop down menus with predefined values that are used to change the mode and receive filter width of the SDR receiver.

Below are the HAM band selector buttons, each of these will use a similar process as detailed above to change the VFO frequency to a preset value on each of the HAM HF Bands.

The QO-100 button puts the transmit and receive VFO’s into synchro-mode so that the receive VFO follows the transmit VFO. It also sets the correct frequency in the 739Mhz band for the downlink from the LNB in GQRX SDR software and sets the IC-705 to the correct frequency in the 2m VHF HAM band to drive the 2.4Ghz up-converter.

The Split button allows the receive VFO to be moved away from the transmit VFO for split operation when in QO-100 mode. This allows for the receive VFO to be moved away so that you can RIT into slightly off frequency stations or to work split when working DXpedition stations.

The bottom two Memory buttons allow you to store the current receive frequency into a memory for later recall.

At the top right of this section of the flow there is a Display Band Plan Info function, this displays the band plan information for the QO-100 satellite in a small display field on the Dashboard as you tune across the transponder. Currently it only displays information for the satellite, at some point in the future I will add the necessary code to display band plan information for the HF bands too.

The final section of the GQRX flow (shown below) sets the initial button colours and starts the Powermate USB VFO knob flow. I’ve already written a detailed article on how this works here but, for completeness it is triggered a few seconds after startup (to allow the USB device to be found) and then starts the BASH script that is used to communicate with the USB device. The output of this is processed and passed back into the VFO control part of the flow so that the receive VFO can be manually altered when in split mode or in non-QO-100 mode.

M0AWS - QO-100 Ground Station Dashboard - Powermate VFO section
M0AWS Node-RED QO-100 Ground Station Dashboard – Powermate VFO Flow

The bottom flows in the image above set some flow variables that are used throughout the flow and then calculates and sets the RIT value on the dashboard display.

The final section of the flow is the IC-705 control flow. This is a relatively simple flow that is used to both send and receive data to/from the IC-705, process it and pass it on to the other parts of the flow as required.

M0AWS - QO-100 Ground Station Dashboard - IC-705 control flow
M0AWS Node-RED QO-100 Ground Station Dashboard – IC-705 Control Flow

The IC-705 flow is started via the timestamp trigger at the top left. This node is nothing more than a trigger that fires every 0.5 seconds so that the dashboard display is updated in near realtime. The flow is pretty self explanatory, in that it collects the current frequency, transmit power, SWR reading, PTT on/off status and S Meter reading each time it is triggered. This information is then processed and used to keep the dashboard display up to date and to provide VFO tracking information to the GQRX receive flow.

On the left are the buttons to change band on the IC-705 along with a button to tune to the VOLEMT on the 60m band. Once again there two memory buttons to save and recall the IC-705 VFO frequency.

The Startup PTT Colour trigger node sets the PTT button to green on startup. The PTT button changes to red during transmit and is controlled via the Toggle PTT function.

At the very bottom of the flow is the set transverter IF Freq function, this sets the IC-705 to a preselected frequency in the 2m HAM band when the dashboard is switched into QO-100 mode by pressing the QO-100 button.

On the right of the flow there is a standard file write node that writes the 2.4Ghz QO-100 uplink frequency each time it changes into a file that is used by my own logging software to add the uplink frequency into my log entries automatically. (Yes I wrote my own logging software!)

The RX Audio Mute Control filter node is used to reduce the receive volume during transmit when in QO-100 full duplex mode otherwise, the operator can get tongue tied hearing their own voice 250ms after they’ve spoken coming back from the satellite. This uses the pulse audio system found on the Linux platform. The audio is reduced to a level whereby it makes it much easier to talk but, you can still hear enough of your audio to ensure that you have a good, clean signal on the satellite.

As I said at the beginning of this article, this flow has grown organically over the last 12 months and has been a fun project to put together. I’ve had many people ask me how I have created the dashboard and whether they could do the same for their ground station. The simple answer is yes, you can use this flow with any kind of radio as long as it has the ability to be controlled via CAT/USB or TCP/IP using XMLRPC or RIGCTL.

To this end I include below an export of the complete flow that can be imported into your own Node-RED flow editor. You may need to make changes to it for it to work with your radio/SDR but, it shouldn’t take too much to complete. If like me you are using an IC-705 and any kind of SDR controlled by GQRX SDR software then it’s ready to go without any changes at all.


More soon …

The Matrix HAM Radio Community continues to grow

By: M0AWS
10 June 2024 at 10:12

A couple of years ago I built a Matrix Synapse server and connected it to the decentralised global Matrix chat network that is federated world wide by enthusiasts who host their own Matrix servers. Due to the enthusiasm for a decentralised network the Matrix has grown exponentially and is now an established force in the world of Opensource global communication services.

When I built my server and configured it online my aim was to bring together an enthusiastic group of Radio Amateurs (Radio HAMs) who could build a friendly, welcoming community where people could share, learn and have fun with other liked minded individuals without all the nonsense you see on commercial social media platforms.

Overtime we’ve increased the number of rooms available in the HAM Radio space and the number of subjects covered. This has grown organically as our community has grown and we’ve ventured together into new areas of the hobby.

Global Matrix Ham Radio Space hosted on the M0AWS Matrix Server
Global Matrix Ham Radio Space hosted on the M0AWS Matrix Server

From the community a number of projects have spawned including the Opensource.radio Wiki that Mike, DK1MI is sponsoring that aims to detail all the Opensource HAM Radio software, Hardware and projects in one centralised site on the internet. This is a great project and one I am very happy to contribute to.

Thanks to Mike, DK1MI we now also have our own Matrix AllStarLink node available. This is a great resource for the community as it is often not possible for all of us to communicate via the radio waves due to geo-location, time zones, local planning regulations etc. Having this 24/7 internet based resource makes it a lot easier for the community to chat at any time even when propagation on the HF bands isn’t in our favour.

Mike, DK1MI has written an excellent article on the Matrix AllStarNode and more, I highly recommend you take a look at it.

We also have a very active satellite room with regular nets on the QO-100 satellite. With such a great range of rooms and subjects there’s plenty to read and talk about with the community.

If you fancy being part of this growing, enthusiastic group of Radio Amateurs and Short Wave Listeners (SWLs) then click on the link below and come and say hello, a warm welcome awaits!

https://m0aws.co.uk/matrix

More soon …

QO-100 Satellite Ground Station Complete Build

By: M0AWS
5 June 2024 at 14:49

I get quite a few emails from readers of my blog asking how my QO-100 satellite station is put together and so, I thought perhaps now is a good time to put together an article detailing the complete build.

My QO-100 satellite ground station is built around my little Icom IC-705 QRP transceiver, it’s a great little rig and is ideal for the purpose of driving a 2.4Ghz transverter/up-converter.

Of course all the software used for the project is Opensource and freely available on the internet.

M0AWS QO-100 Ground Station Build Visual
M0AWS QO-100 Ground Station Build Visual (Click to Enlarge)

The station comprises of the following building blocks:

  • Icom IC-705 Transceiver
  • DXPatrol 28/144/433Mhz to 2.4Ghz Up-Converter
  • DXPatrol GPSDO Reference Oscillator
  • DXPatrol 2.4Ghz 5/12w Amplifier
  • Nolle Engineering 2.2 turn 2.4Ghz IceCone Helix Antenna
  • 1.1m (110cm) Off-set Dish
  • Bullseye 10Ghz LNB
  • Bias-T to feed 12v to LNB
  • NooElec SmartSDR Receiver
  • PC Running Kubuntu Linux Operating System
  • GQRX SDR Opensource Software
  • Griffin Powermate USB VFO Knob
  • QO-100 Ground Station Dashboard developed using Node-RED
  • LMR400-UF/RG58 Coax Cable
M0AWS QO-100 1.1m off-set Dish and IceCone Helix antenna ground station
M0AWS QO-100 1.1m (110cm) off-set Dish with IceCone Helix antenna and Bullseye LNB.

To get a good clear view of the QO-100 satellite I have the dish mount 3.2m above the ground. This keeps it well clear of anyone walking past in the garden and beams the signal up at an angle of 26.2 degrees keeping well clear of neighbouring gardens.

The waterproof enclosure below the dish houses all the 2.4Ghz equipment so that the distance between the feed point and the amplifier are kept to a minimum.

The DXPatrol amplifier is spec’d to run at 28v/12w or 12v/5w, I found that running it at 28v produced too much output for the satellite and would cause the LEILA alarm on the satellite to trip constantly. Running the amp at 12v with a maximum of 5w output (average 2.5-3.5w) is more than enough for me to have a 5/9+10 signal on the transponder.

The large 1.1m dish gives me quite an advantage on receive enabling me to hear the very weak stations with ease compared to other stations.

2.4Ghz ground station enclosure ready for testing
2.4Ghz ground station enclosure ready for testing

The photo above shows the 2.4Ghz equipment mounted in the waterproof enclosure below the dish. This photo was taken during the initial build phase before I rewired it so, the amplifier is shown connected to the 28v feed. To rewire the amp to 12v was just a matter of removing the 28v converter and connecting the amp directly to the 12v feed instead. This reduced the output from a maximum of 12w down to a maximum of 5w giving a much better (considerate) level on the satellite.

It’s important to keep all interconnects as short as possible as at 2.4Ghz it is very easy to build up a lot of loss between devices.

For the connection from the IC-705 to the 2.4Ghz Up-Converter I used a 7m run of
LMR-400 coax cable. The IC-705 is set to put out just 300mW on 144Mhz up to the 2.4Ghz converter and so it’s important to use a good quality coax cable.

Once again the output from the 2.4Ghz amplifier uses 1.5m of LMR-400-UF coax cable to feed up to the 2.2 turn Icecone Helix Antenna mounted on the dish. This keeps loss to a minimum and is well worth the investment.

Bullseye 10Khz High Stability Unversal Single LNB for 10.489-12.750Ghz
Bullseye 10Khz High Stability Unversal Single LNB for 10.489-12.750Ghz

The receive path starts with a Bullseye LNB, this is a high gain LNB that is probably one of the best you could use for QO-100 operations. It’s fairly stable frequency wise but, does drift a little in the summer months with the high temperature changes but, overall it really is a very good LNB.

The 12v feed to the LNB is via the coax and is injected by the Bias-T device that is in the radio shack. This 12v feed powers the LNA and associated electronics in the LNB to provide a gain of 50-60dB.

Bias-T to inject 12v feed into the coax for the Bullseye LNB
Bias-T to inject 12v feed into the coax for the Bullseye LNB

From the Bias-T the coax comes down to the NooElec SmartSDR receiver. This is a really cheap SDR device (<£35 on Amazon) based on the RTL-SDR device but, it works incredibly well. I originally used a Funcube Dongle Pro+ for the receive side however, it really didn’t handle large signals very well and there was a lot of signal ghosting so, I swapped it out for the NooElec SDR and haven’t looked back since.

The NooElec SmartSDR is controlled via the excellent Opensource software GQRX SDR. I’ve been using GQRX SDR for some years now and it’s proven itself to be extremely stable and reliable with support for a good number of SDR devices.

To enhance the operation of the SDR device I have added a Griffin Powermate VFO knob to the build. This is an old USB device that I originally purchased to control my Flex3000 transceiver but, since I sold that many moons ago I decided to use it as a VFO knob in my QO-100 ground station. Details on how I got it working with the station are detailed in this blog article.

Having the need for full duplex operation on the satellite this complicates things when it comes to VFO tracking and general control of the two radios involved in the solution and so I set about creating a QO-100 Dashboard using the great Node-RED graphical programming environment to create a web app that simplifies the management of the entire setup.

M0AWS QO-100 ground Station Control Dashboard built using Node-RED.
M0AWS QO-100 ground Station Control Dashboard built using Node-RED.

The QO-100 Dashboard synchronises the transmit and receive VFO’s, enables split operation so that you can transmit and receive on different frequencies at the same time and a whole host of other things using very little code. Most of the functionality is created using standard Node-RED nodes. More info on Node-RED can be found on the Opensource.radio Wiki or from the menu’s above.

I’ll be publishing an article all about the QO-100 Dashboard in the very near future along with a downloadable flow file.

I’m extremely pleased with how well the ground station works and have had well in excess of 500 QSO’s on the QO-100 satellite over the last last year.

More soon …

Using AI to generate modern QSL Cards

By: M0AWS
15 May 2024 at 21:41

With the recent explosion of artificial intelligence (AI) art generators that are making the news of late for all the wrong reasons, I decided to see if I could put it to good use and design some futuristic QSL cards.

Having recently been contacted by the Special Callsigns QSL Manager and being advised that there were 18 QSL cards waiting for me, I decided it was time to create some QSL cards of my own for future use.

Having never used any form of online AI and not having any artistic abilities I was amazed how easy it was to create images using nothing more than a paragraph or so of text to describe what it was I wanted to create.

Since all the QSL cards I received were for contacts on the QO-100 satellite, I set out to create a visually futuristic QSL card that was based around a radio HAM operator and satellite communications.

M0AWS - 1st attempt to create a futuristic QSL card using AI Art
M0AWS – 1st attempt at creating a futuristic QSL card image using AI Art

To my surprise the results of my first image generation were surprisingly good. The AI generated an image that resembled the simple text that I entered, although I never requested a one legged HAM operator!

Pleased with my very first attempt I gradually improved the description of what I was looking for, adding more and more detail to the text and including things that I wanted to see in the image. Over a fairly short period of time this approach started to generate some very interesting images.

M0AWS - AI Art QSL Image attempt 2
M0AWS – AI Art QSL Image attempt 2
M0AWS - AI Art QSL Image attempt 3
M0AWS – AI Art QSL Image attempt 3
M0AWS - AI Art QSL Image attempt 4
M0AWS – AI Art QSL Image attempt 4

With each iteration I gradually got closer to what I was trying to achieve but, never quite got exactly what I wanted so, I decided to rewrite the descriptive text adding even more information than before. The text was now a full blown paragraph with quite specific things described including the angle at which the scene was being viewed from.

The other option I wanted to try out was the theme functionality that the AI offered. This allows you to set a theme for the image from things like steampunk, cartoon, manga, real world and many more. The results were quite impressive and added yet another angle to the image generation.

M0AWS - AI Art QSL Theme 1
M0AWS – AI Art QSL Theme 1
M0AWS - AI Art QSL Theme 3
M0AWS – AI Art QSL Theme 3
M0AWS - AI Art QSL Theme 2
M0AWS – AI Art QSL Theme 2

I disappeared down the theme AI Art generation rabbit hole for quite some time and generated some very interesting and fun results. The best by far though was the Thunderbirds themed image, this did put a smile on my face!

M0AWS - AI Art QSL Thunderbirds Themed
M0AWS – AI Art QSL Thunderbirds Themed

At the other end of the spectrum I tried the Salvador Dalli theme, it produced an image that was very like the work of the famous artist but, wasn’t quite what I was looking for.

M0AWS - AI Art QSL Salvador Dalli Themed
M0AWS – AI Art QSL Salvador Dalli Themed

After much fun I eventually settled on the image I was after, a futuristic scene of a radio HAM with a satellite ground station over looking a mountain range and city below.

M0AWS Satellite QSL Card generated using online AI
M0AWS Satellite QSL Card generated using online AI

I’m really pleased with the results from my ventures into AI generated art. The next challenge is to create a QSL card for HF bands Contacts.

More soon …

Radiosport 2.0 is not taking your baby (but it is giving it a new lease on contesting life)

By: N0SSC
7 June 2024 at 05:01

context: Kyle AA0Z invited me to a roundtable discussion on his youtube channel] this evening, and it stirred up some discord and stoked the ongoing controversy grinding old-school contesters’ gears since his W1DED interview, the K5ZD N6MJ KL9A contester panel followup, his reaction, and the 2024 hamvention contesting forum call-out by K1AR. I wrote this to try to help clear some murky air, and posted to the Ham Radio Crash Course discord #radiosport-contesting channel where the fun was taking place. To a regular reader, this might seem out of place, so sorry about that. I hope you can read through that, and gather some ideas and discourse on the subject of contest modernization i.e. RadioSport2.0.

also long time no see lol

***

ok i got fired up and started typing and wrote a bunch so sorry, but #offmychest…

I wasn’t a big fan of the 1984ing on the stream bc i wanna hear out and debate the hot takes. During the stream I was typing that whole time with @QROdaddy (W4IPC) because he got quieted and I wanted to hear the discord (haha pun). I really don’t like echo chambers, and I really don’t like stuff that doesn’t take holistic perspectives from all points of view, so I think we, the radiosport2.0 community need to take some better care hearing it out. Whether it’s from current youth, young and old, seasoned or noob contesters, non-contesters, or QRZ lol. With that being said, here’s my dissertation on the whole radiosport thing that’s been bouncing in my head since 2011 (https://www.arrl.org/news/youth-hamradio-fun-what-is-radiosport-and-why-do-we-do-it) and opined since 2016 (https://n0ssc.com/posts/320-contest-modernization also rip cqcontest.net but today’s is https://contestonlinescore.com)

I think we want the same thing – we contesters all want to contest, and for there to be people to contest with well into the future. I think the ideas we’re tossing around formulates an inviting, fertile ground for new contesters just coming into ham radio and contesting for the first time. Out of this, I hope we discover and create novel in-roads for normies to get into the next level. Current young contesters may think it’s great right now, because it is, but you are a lucky few who had some kind of magical unmatched personal dedication, brilliant elmering, ham family, or just ADHD hyperfocus (it me) to get hooked for life. And i’m v proud of that. But without pushing for some kind of modern, mainstream aligned ideas, environments, activities, overlays, categories, and just straight up new stuff, radiosport will stagnate as the VAST BULK of contesters pass away, out leaving behind a fraction of today’s young contesters for tomorrow. That’s facts based on statistical projections based on numerous demographic surveys and data, and you can see it plainly in Craig’s K9CT interview. So as content creators, visionaries, and rabblerousers, we’re gonna go in hot and heavy, get complainy, and poke at the hornet’s nest to bring this to the light throughout the ham community to find people interested in making it a thing, only to see if it’s a thing. Might want to work on the delivery, but the point stands.

I also think we are miscommunicating the intent of radiosport2.0 becasuse of all the “reeeeee your killing my contests get off my lawnnnn nothing is wrong why do this nooo reeee” type comments . and I don’t disagree there might be some misinformation, or really just ignorance and misremembering on our (my lol) part. There’s also the weirdness of the K9CT folks, ARRL/CAC people, and log developers keeping their radio sport 2.0 plans close to their chest (compared to us who are baring it all and at least showing somebody is out there thinking “it would be cool if…”in hopes we can garner some grassroots perturbations in the community and do something cool for the sake of the fun of it, and maybe for the sake of the hobby). But imagine things like saving the contest committee 100 hours out of their thousands to check logs by, i dunno, posting every log submission and qsordr capture carte blanche to an academic database and letting the database wizards poke at it to see how close their solutions come to the traditional methods? Or giving those connected to the internet an opt-in option to cryptographically sign their QSOs that get posted to a blockchain ledger as a smart contract for realtime, verifiable adjudication (and figure it’s vulnerabilities to nefarious players? Or let there be a new button in their log’s score reporting menu that says “send to realtime ledger” or “report [entire QSO/band-mode/freq/rotator] data to blahblahblah db/server” for beta testers and early adopters to futz with while also not ruining or even remotely changing their experience as a contester doing a contest – they’ll still be valid (depending on what they’re opting in to send they might need to change to a different category e.g. CQWW Explorer), they’ll still submit a cabrillo, they’ll get a real score in whenever time, meanwhile 99% of people probably won’t notice that button until HRCC hosts a livestream of a radiosport tournament battle royale with your hosts Kyle AA0Z and Sterling N0SSC, backed up by your experts in the field N0AX and N6MJ – all enabled by that button, only just now realizing they too can get in on that action ALL THE WHILE on the air it just sounds like regular contesters contesting; just with more of them doing this goofy livestreamed tournament thing.

And I’m not a “*real*” contester. I don’t put up high scores on 3830 because I cannot do a 24/36/48 hr contest. I go to N0AX/W0ECC/W0EEE, sit down for 2 hours, do my 200-300Q/hr rate, let the pile die, and give up for a while with a beer and a chat with the other’s on the bench, and come back at 4am when the grey line is approaching to listen to the world turn from 160m and 10m because that shit is cool. I don’t even have HF at home, and I don’t have the time to set up remote stations and be a basement dweller for a whole weekend. And I have gone a loooong time since I had my butt in a chair for more than a few hours that wasn’t at my day job. But I’ve worked at least 2 or 3 big contests every year since I was 15 years old, I’ve won plaques and paper as a sad teenage G5RV owner in nowhere Missouri, i’ve played in sweeps every year except one (not under my own callsign typically – usually under N0AX, W0ECC, and W0EEE), I drop in at random field day sites and fire through 100 QSOs in half an hour and disappear, and I had elmers like N0AX, Ed K0KL (SK), K0ZT (SK) K0ZH and the WA0FYA Zerobeaters ARC, W0EEE alumni, and K3LR and the Contest University crew who let me in free for like 3 years straight because I was the only one without gray hair. I really love contesting – it’s my favorite part of ham radio. And now as a 32 year old geezer, I do want something I can do in my tidbits of free time, that is just a bit different than a CWT or WWSAC, that isn’t just a 2 hour stint on a major contest – i want to be competitive and be ranked and scored with a pool of other contesters. I want team deathmatch, CTF, in-game perks/power-ups/items, and matchmaking lobbies. I think there’s an untapped reserve of potential new hams that would also be into that kind of radiosport. I don’t want the existing contests or methodologies to die or change, but as they stand now – as they have forever ago and forever on — are excellent grounds for trying out these new ideas unbeknownst to guys like VP5M with barely enough bandwidth for the cluster [thanks connor], the off-grid pacific islanders, africans, antarctic researchers, nordic polar bears all who make CQWW/WPX & IARUHF so much fun, or folks who just don’t do the internet and log with paper. Coexistance is a requirement, and so is the longevity of our hobby.

Tldr I want to play ham radio when I’m retired (25-30 years from now lol) so I have some ideas.

***

a few edits were made for profanity, clarification, correction to K0ZH’s call.

thanks W4IPC and KG5XR for inspo and AA0Z for sticking his neck out to get these ideas on the cutting room floor

73 🛌

All the Things

31 May 2024 at 08:00

It’s been a busy few months, and the folx who I interact with on Mastodon already know that I’ve got lots of irons in lots of fires. I figured it’s probably time for me to do a quick ‘state of the shack’ post to give a quick highlight on where all my various projects and activities stand, in case anyone has been wondering about the status of any particular item.

So, in no particular order, here we go:

Repeater

Check out the Repeater Page and posts tagged repeater for more details.

The quick summary here, is that my Motorola GR1225 died, so I currently have a machine on the air using a pair of Kenwood TK840 radios, the duplexer from the Motorola, and a new USB interface from Repeater-Builder to connect it to the computer that runs the Allstar software. After some very positive feedback on the post I wrote as I was trying to get the machine running again, I decided to start a fund-raiser to support some upgrades to the repeater, and to also help repair and get some additional repeaters on the air, which brings us to the next project…

r4e

Check out the r4e project pages for more details.

r4e is an acronym for Repeaters 4 Everybody.
As a way to support upgrades on my repeater and some additional repeaters that are operated with a purposeful mission of openness and acceptance, and to help bulk up the RF side of the Pride Radio Network, I’ve started the r4e project which some of you may have stumbled across already in the header of my site. If you’re willing to help support some repeaters financially, or with donations of equipment, or to just connect an existing repeater to the pride network, those gifts and actions can go a long way towards our roadmap!

Subversive Radio

Check out the Subversive Radio Shop for details, and to buy cool stuff!

This project is an offshoot of the r4e project, and is a way to raise additional funds for those projects by selling radio merch that (I hope) is unlike most of the stuff already out there. Buy some cool stuff to support the project!

Radio Rocket

Check out the Radio Rocket Page and the Radio-Rocket Tagged Posts for more details.

Version 3 of the rocket (Ponzu) had some body tube damage during its first flight, which is now repaired, and it’s ready to fly again. I also built a new ground station that is an all-in one unit with the single board computer, LoRa receiver, an RTL-SDR dongle for receiving APRS packets, touchscreen for launch control and data display, etc. Motors are ordered for the next launch, which will be on June 13th or 14th, as weather permits.

Club Net

Check out the Narwhal Amateur Radio Society, and our Nets Page (details coming soon, if they aren’t already there!) for more info.

A while back I joined the Narwhal Amateur Radio Society (NR7WL) - they’re a relatively new club, but have values that I dig. We had kicked around the idea of a club ‘network’ to be able to connect via digital modes, and potentially a club net. That idea sat for a little bit, but bubbled back up recently, so I took the initiative to set up an Allstar node for the club (61672) which will serve as our hub, and the location for our first club net, for which I’ll be serving as net control!

Net details as follows:

Narwhal Amateur Radio Society Club Net

Time: 1st Tuesday of Every Month at 7pm Pacific, 10pm Eastern

Location: Hosted on the NR7WL Allstar Node (61672) and the Pride Radio Network. The Pride Radio network has bridges that will allow you to connect via DMR, IRLP, System Fusion, M-17, NXDN, P-25, D-Star, Echolink, Hamps Over IP, Hamshack Hotline, plus others!

Shack

Check out posts tagged shack for more details.

I haven’t made any major updates to the shack recently, but I have moved a few things around. In the utility space behind the operating position I added a DIY rack made from lumber to move the various computer and network bits and bobs into. My next project in the shack is related to re-doing some of the audio routing - I have designs drawn up in KiCad for an interface device that will sit beside my mixer and convert all the audio to the OHIS standard. The basic reasoning behind this for me, is that by converting the audio to OHIS, I can leverage an existing standard to run a single shielded cat6 cable to each radio and device, instead of the 3 or 4 audio and PTT cables that run to each radio now. I currently have some bursting-at the seams cable management, and doing this should reduce the mess in there quite a bit. The plan is also to eventually replace my aging mixer, and build a new rack mount arrangement to the left of my operating position to house the mixer, interface, and some other related shack equipment.

ARIP

Check out the ARIP website for more info.

Diversity is something important to our hobby. If you disagree, or think this statement is somehow political, you’re part of the problem in the hobby, and I won’t engage with you on the subject. If you do feel the same way I do however, the ARIP is one of my projects that is essentially a tool that clubs, individuals, or other organizations can use as a way to show their commitment to inclusion in the hobby. The most recent update on this effort is some changes to the website and methodology to make it more of a self-serve tool. There is more information about that available on the ARIP Website

Radio League of America

Check out the Radio League of America website for more info.

Currently, the Radio League of America (RLA) is little more than an idea. That idea being that the amateur radio community is too large and diverse for everyone to have their voices heard by a single national organization. There are many amateurs who have voiced a desire for something different to be available, and the RLA is just one of many potential avenues as that movement takes life. I have committed to at some point in the near future getting together an initial presentation of what that might look like, and setting up a recurring (probably quarterly) series of meetings for people who are interested to see if it is something worth fleshing out in more detail and organizing around.

Update to my NodeRed QO-100 Dashboard

By: M0AWS
13 May 2024 at 10:59

Ever since my QO-100 ground station has been operational I’ve been using my NodeRed QO-100 Dashboard to control my IC-705 and GQRX SDR software to drive my NooElec SmartSDR receiver. This gives me a full duplex ground station with both transmit and receive VFO’s synchronised.

This solution has worked incredibly well from the outset and over time I’ve added extra functionality that I’ve found to be useful to enhance the overall setup.

The latest addition to the ground station solution is a Sennheiser Headset that I picked up for just £56 on Amazon (Much cheaper than the Heil equivalents at the HAM stores!) and have found it to be excellent. The audio quality from both the mic and the headphones is extremely good whilst being light and comfortable to wear for extended periods.

M0AWS - Sennheiser SC 165
M0AWS – Sennheiser SC 165 Headset

To incorporate this into the ground station the headset is connected to my Kubuntu PC and the audio chain to the IC-705 is sent wirelessly using the latest version of WFView. This works extremely well. The receive audio comes directly from the GQRX SDR software to the headphones so that I have a full duplex headset combination.

Audio routing is done via pulse audio on the Kubuntu PC and is very easy to setup.

Since I no longer have a mic connected to the IC-705 directly I found that I needed a way to operate the PTT wirelessly and this is where the latest addition to my NodeRed QO-100 Dashboard comes in.

Adding a little functionality to the NodeRed flow I was able to create a button that toggles the IC-705 PTT state on and off giving me the ability to easily switch between receive and transmit using a simple XMLRPC node without the need for a physical PTT button.

M0AWS - Additional NodeRed PTT Flow
M0AWS – Additional NodeRed PTT Flow

The PTT state and PTT button colour change is handled by the Toggle PTT function node shown in the above flow. The code to do this is relatively simple as shown below.

M0AWS - NodeRed Toggle PTT Function to change button colour
M0AWS – NodeRed Toggle PTT Function to change button colour

The entire QO-100 Dashboard flow has grown somewhat from it’s initial conception but, it provides all the functionality that I require to operate a full duplex station on the QO-100 satellite.

M0AWS - NodeRed QO-100 Dashboard complete flow
M0AWS – NodeRed QO-100 Dashboard complete flow

This simple but, effective PTT solution works great and leaves me hands free whilst talking on the satellite or the HF bands when using the IC-705. This also means that when using my IC-705 it only requires the coax to be connected, everything else is done via Wifi keeping things nice and tidy in the radio shack.

M0AWS - Updated NodeRed QO-100 Dashboard with PTT button
M0AWS – Updated NodeRed QO-100 Dashboard with PTT button

The image above shows the QO-100 ground station in receive cycle with the RX/TX VFO’s in split mode as the DX station was slightly off frequency to me. The PTT button goes red when in TX mode just like the split button shown above for visual reference.

As you can probably tell, I’m a huge fan of NodeRed and have put together quite a few projects using it, including my HF Bands Live Monitoring web page.

More soon …

Drive-on Antenna Mount Article

By: WB3GCK
12 May 2024 at 18:54
Drive-on Antenna Mast Mount

Back in December, Becky Schoenfeld W1BXY, Editorial Director for ARRL’s On the Air magazine, asked me if I would be interested in writing a detailed set of step-by-step instructions for my Drive-on Portable Antenna Support. Naturally, I said I would.

I submitted my manuscript, along with an all-new set of pictures. The article was published in the current issue (May/June 2024) of On the Air (pages 20-22).

If you’re interested, have a look. ARRL members have access On the Air as part of their membership.

73, Craig WB3GCK

Foray Into AREDN

17 April 2024 at 08:00

I’ve been dabbling with AREDN the last several weeks. I’m not really an emcom guy, but I did want to dabble with the mesh stuff, and in my particular use case, it seemed like it might be a fun way to send my Radio Rocket’s data ‘back home’ instead of using a cellular hot spot and paying for data. I figure AREDN is a way I can do my dabbling, but maybe be of some use to the emcom folx by at least filling in a bit of a coverage hole if they need it, since there are no nodes around me, and I do have some limited emergency power at my disposal if needed.

Even though the mesh stuff is mostly line of site, I think I should still be in good shape, because of our 4 primary launch sites, one definitely has a line of site shot back home, one of them probably should, and one of them might. The 4th is probably a no-go for direct line of site, but I do have access to a TV tower on a family member’s property to add a relay node if needed…

Anyway, I haven’t done anything terribly exciting yet to really share, other then just getting my first 2 nodes set up. My only advice is to maybe avoid the TP-Link CPE210 devices. It may have been user error, but I fought with one until I gave up :-). For the 2 nodes that I got running, the GL.iNet AR300M16-ext device I got to be the mobile node was wild easy to set up, and the Mikrotik Basebox that I set up for my home node went pretty much according to directions, after being extremely careful about making sure I had the most recent nightly build of the firmware, and followed the directions exactly. (Imagine that!)

I may share more stuff on the project in the future, but for now I threw up a new static page with info on my nodes that folx can check out if they’re curious.

Thanks for stopping by!

Meshtastic: Empowering Off-the-Grid Communication

Meshtastic is an open-source project enabling long-range, off-grid communication using inexpensive LoRa radios. It offers encrypted, decentralized messaging with excellent battery life and optional GPS. Utilizing LoRa, it supports up to 100 devices concurrently and provides resilience, privacy, and community building. Meshtastic empowers communication beyond traditional boundaries, ideal for adventurers and those seeking reliable off-grid connectivity.

868Mhz Ground Plane Vertical Antenna

By: M0AWS
18 March 2024 at 13:45

In my quest to improve my Meshtastic signal range using home-brew antennas I’ve finally put together a neat little ground plane vertical antenna for the 868Mhz ISM band.

The design follows the normal ground plane simplicity using 4 radials and a vertical radiating element albeit on a tiny scale. The radiating element is 82mm long and the radials are each 92mm long.

M0AWS 868Mhz Ground Plane Vertical Antenna
M0AWS 868Mhz Ground Plane Vertical Antenna

Initially I modelled the antenna at a height of 3m above the ground with the radials tilted downwards at 45 degrees. I took this approach as this is how I have built ground plane verticals for the 70cm band in the past and so I thought I’d try the same approach on the 868Mhz ISM band. (I later found this to be detrimental to tuning!)

The 3D far field plot for the antenna shows it has a very nice, relatively high gain lobe at just 2 degrees elevation with a number of lower gain lobes higher up.

M0AWS 868Mhz Ground Plane Vertical Antenna 3D Far Field Plot
M0AWS 868Mhz Ground Plane Vertical Antenna 3D Far Field Plot

Looking at the 2D far field plot you can get a better understanding of the radiation pattern and gain figures at various angles. At 2 degrees there is 6.7dBi gain with the next major lobe being at 8 degrees with 4.36dBi gain, far more than I imagined I’d see for such a simple antenna.

M0AWS 868Mhz Ground Plane Vertical Antenna 2D Far Field Plot
M0AWS 868Mhz Ground Plane Vertical Antenna 2D Far Field Plot

Putting the antenna together was easy enough with particular attention being paid to the measurements of both the radials and radiating element. I soldered some lugs to the ends of the 2.5mm diameter solid core wire radials to enable easy attachment to the N Type chassis socket that I decided to use as the base for the antenna. This worked out well and provided a good solid mechanical and electrical connection for the 4 radials.

For the radiating element I used an N Type plug with the vertical 2.5mm solid core wire element soldered to the inner centre pin of the male connector. I also slid a small piece of insulation down the wire to stop it from shorting against the metal outer of the plug and then pushed in a tight rubber plug to stop water ingress.

M0AWS 868Mhz Ground Plane Antenna Close Up
M0AWS 868Mhz Ground Plane Antenna Close Up

Connecting my VNA I found the antenna was mostly resonant at 790Mhz with an SWR of 2.5:1. I knew this would be the case and that the wires would need a little trimming.

Trimming the wires a couple of times in 1mm nibbles I got the point of resonance up to 868Mhz but, the antenna was still exhibiting a lot of reactance that was keeping the SWR above 2:1. Trimming the radials reduced this slightly but, I could not get an SWR much lower than 1.95:1.

Scratching my head I decided to try moving the radials back up so that they were horizontal rather than at 45 degrees downwards, this had the immediate effect of the SWR dropping to 1.1:1.

M0AWS A rather fuzzy photo of the 868Mhz SWR curve for the GP Antenna
M0AWS A rather fuzzy photo of the 868Mhz SWR curve for the GP Antenna

The SWR stays below 1.2:1 from 868Mhz to 871Mhz which is plenty wide enough for the Meshtastic devices. Why there is so much reactance when the radials are bent down at 45 degrees I am not sure, but it was easy enough to resolve.

M0AWS 868Mhz Ground Plane Antenna
M0AWS 868Mhz Ground Plane Antenna

The finished antenna is tiny but, seems to work well. Signals from my other nodes are up by 6-9dB according to the SNR reports in the Meshtastic app. I now need to make a couple more of these for my other nodes and then hope to hear some other nodes locally once they appear on air.

Remodelling the antenna in EzNEC with the radials as shown above the gain at 2 degrees is now 5.5dBi, down 1.2dBi but, the overall radiation pattern is identical to the original.

Total cost of the build is about £1 and an hour of my time tinkering with it, bargain!

M0AWS-4 Meshtastic Node 868Mhz Antenna Deployment
M0AWS-4 Meshtastic Node 868Mhz Antenna Deployment

More soon …

Finished a Goal From 6 years Ago

By: robert
31 January 2024 at 21:14

Way back in January 2018, I had a goal to “3D print an electronics project case”.  I had enrolled in a SolidWorks class at my local community college to learn 3D modeling.  Sadly I didn’t complete it, and it remained a goal of mine for several years until I decided to move on to something I might actually finish.

There were a couple of reasons for not completing the goal.  The first was a life-threatening illness that left me pretty weak and unable to complete the class I was taking.  The second was that the 3D printer I had was more of a toy than a tool, and it was rarely able to print anything successfully.

Even though I didn’t list it as a goal for 2024, I had a growing itch, and decided to replace my original toy printer with a FLASHFORGE Adventurer 5M Pro.  The big steps up were a heated platform and full enclosure that allows for better thermal management.  In addition, it is blazingly fast, by about a factor of 16, compared to what consumer printers were capable of back in 2018.  No longer a toy, this is a tool for a maker.

I’m happy to report that after six years, I have finally completed the goal, 3D printing two parts to make an enclosure  for a 3.5″ LCD display and an ESP32 processor. I guess I will count this as a “wildcard” replacing any project I don’t complete in 2024.

The two parts of the enclosure: The bottom is on the left, and the top on the right.

The enclosure with the LCD visible on the top (4″L x 3″W x 1.5″T)

 

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