Building a new Pi Rack

I’m a big fan of the RaspberryPi single board computers (SBCs) and have been using them since the very first model was released. (I still have the first model even now!)

Over the years I have used RaspberryPi computers for all sorts of things. These days I use them for running services on the local LANs here at home along with a number of virtual machines providing services both locally and publicly on the internet. (Yes, you can run virtual machines (VMs) on RaspberryPi computers)

I currently have 4 x RaspberryPi 5 SBCs running 24/7 and have had them stored in a simple rack that I designed when I first got into 3D printing. The rack worked ok but, it was difficult to get access to the Pi’s without removing those around the one I wanted to access. This is a real nuisance when you have services running on them all.

I’ve now had my 3D printer for a while and decided it was time to design a better solution. Before I set about diving into the CAD software I decided to have a look on Makerworld to see if anyone else had already come up with something more suitable.

Trawling through the many offerings from hundreds of 3D designers on the Makerworld website, I found a very nice RaspberryPi Modular Racking System that looked ideal for the job.

Modular RaspberryPi Rack from Makerworld
Modular RaspberryPi Rack from Makerworld

The nice thing about this design is that each Pi module connects to the other using a simple sliding, locking pin system. This means that over time you can add more and more modules to the rack as your RaspberryPi collection grows. The other nice thing is that each Pi SBC is held on its own removable sled making it possible to remove each Pi with ease and without disturbing any of the others.

I downloaded the design into BambuStudio and went through all the component parts. I was really pleased to see that there were two sizes of module available, a single board Pi only module and a tall module for housing a RaspberryPi with a HAT installed.

Since the 4 x Pi5’s that I am using have either an NVME + 2nd Gigabit Ethernet HAT or a NVME SSD Baseboard installed I will need the taller module for each unit.

To make it easy to identify each SBC in the rack I printed each module in the same colour as the hostname of the Pi, bluepi, redpi, greenpi, orangepi and a spare slot for purplepi when I get it.

My RaspberryPi rack with 4 x Pi5's in place and operational
My RaspberryPi rack with 4 x Pi5’s in place and operational

These 4 little Pi’s work hard and CPU temperatures can exceed 50 degrees Celsius very easily. They all have the Official Pi Cooler with fan installed however, this doesn’t come on until the CPU reaches 50c and so I decided to added some extra cooling in the form of a small USB fan onto the back of each module. This reduces the operating temperature of each Pi down to around 25c under full load.

The purple slot on the end is a spare ready to house another Pi SBC. I’d love another Pi5 16GB model but, at the current ridiculous prices it makes no sense to invest in another and so I will fit my spare Pi4 into the slot for now and find something for it to do.

This has been a fun little project to print and put together and will provide the perfect solution to my Pi management woes.

More soon …

Building MB7IBW 2m AllStarLink Internet Gateway

I’ve recently built another AllStarLink node to compliment my personal 70cm band SHARI node as I thought since I have a full duplex dual band handheld it would be great to have another node that I could connect to FreeStar or HUBNet at the same time as monitoring the Matrix node.

Rather than build another personal node I decided this time I would build a public node, obtain a callsign from the RSGB and make it available to the HAM’s locally on the 2m band.

This would make it possible for me to monitor both nodes at the same time using my Wouxun KG-UV9K full duplex dual band handheld whilst providing the local HAM community with access to the AllStarLink network.

Initially I thought I may be able to use my old Retevis RT85 handheld and AIOC board for the 2m node but, after a little testing it soon became apparent that it overheats during long overs (which are common on AllStarLink) and so, I needed to find another solution.

AIOC connected to the Retevis RT85.
AIOC connected to the Retevis RT85.

Chatting about this in the main Matrix HAM Radio room Steve, M0XVT sent me a message saying he had an old Key KM-4000 converted PMR radio that had been reprogrammed for the 2m band that he was looking to sell and that it might be ideal for the new node. Wasting no time, we came to an agreement and I was soon the proud owner of a converted PMR transceiver.

Key KM4000 2m Band PMR Radio
Key KM4000 2m Band PMR Radio

The KM4000 transceiver has a standard output of 15w, 10w more than I needed for the gateway and so I had to reduce the output. A quick search on the internet and I found the Thames Valley Repeater Group website that had all the information required to turn down the output.

I also had to reprogramme channel 1 to the frequency and CTCSS tone allocated to me by the RSGB so that in the event of a power outage when the radio came back on it automatically jumps to channel 1 which would be correctly setup for operation.

Unfortunately the software for programming the radio is only available for windows and so I had to build a virtual machine running windows 10 to be able to reprogramme the radio.

Once this was done I rewired the AIOC USB audio device to work with the KM4000 radio and built the AllStarLink node on a spare RaspberryPi 4.

For an antenna I made a simple end fed vertical dipole from some RG58 coax and mounted it 8m up on one of my Spiderpoles in the garden. Running a coax feed out to the antenna I did some tests into the Parrot to get the audio levels setup and checked that the DTMF codes were interpreted correctly and that the node switched connections without error.

MB7IBW Internet Gateway hardware at the M0AWS QTH
MB7IBW Internet Gateway hardware at the M0AWS QTH

Once this was done I had a few test conversations with stations on the Matrix node and FreeStar to ensure all was fine and then set the gateway status to “Operational” on the RSGB website.

This worked fine for a while with myself and some local stations using the node regularly but, then the hot weather arrived and things started to overheat. The transceiver was getting incredibly hot in the 30c+ summer temperatures and the power supply was also running extremely hot and so I decided to add some cooling.

Cooling the PSU was simple, it has a perforated top panel to which I strapped a cooling fan. This worked great and brought the temperature of the PSU down considerably.

The radio wasn’t so easy to cool. It has a solid case cover top and bottom and so cooling wasn’t going to be a simple affair.

I decided to remove the covers and drill some holes into them to allow airflow through the unit and strapped a fan to the top cover to pull the hot air out. This worked well however, on both transmit and receive I now had a warbling sound on the audio that was caused by the motor of the fan when powered up.

I found that lifting the fan up away from the case of the radio the warbling audio disappeared and things were back to normal and so, I decided to design a cooling tube to fit to the top of the radio to allow full airflow from the fan but, with the fan raised up away from the radio to resolve the audio problem.

Jumping into my CAD software I quickly designed a cooling tower to fit on the top of the radio that would allow the fan to sit far enough away from the radio so as to not affect the audio whilst at the same time pulling the hot air out of the radio and drawing cooler air in through the bottom of the case.

I sent the design through to my Bambu Lab A1 Combo 3D printer and set the print job running.

Key KM4000 Cooler
Key KM4000 Cooler

The cooler worked great with the radio staying cool to the touch and no longer overheating and reducing O/P power.

It’s amazing how much dust and dirt is in the air from all the farming activities going on at the end of our garden and how much of it is sucked in by the cooling fan. Regular cleaning is a must!

The MB7IBW Internet Gateway has been on air since mid June 2026 and has worked well. It spends most of its time connected to either FreeStar or HUBNet with connections to the Matrix Node when we have our nets.

Details on Frequency, CTCSS etc can be found under the MB7IBW menu above.

Sadly the initial interest from local HAMs has now wained and I am mostly the only user of the gateway. I was hoping more people would use it and bring some life to the 2m band, I guess time will tell.

It’s been a fun project and was interesting to go through the callsign allocation process with the RSGB representative. It was much easier than I thought it would be.

I now have all the parts to build another Internet Gateway for the 4m band. Hopefully that may attract some more interest. It’s certainly worth a try!

More soon …

Node-Red Control Dashboard for AllStarLink 3

I’ve recently built a new AllStarLink (ASL) node for my MB7IBW gateway that I have recently brought up on air on the 2m band.

AllStarLink 3 has a lot of changes in it when compared to the previous version and this of course impacts my Node-Red Control Dashboard that I’ve been using to manage my first ASL node for well over a year now.

To build the node I used the RaspberryPi imager and added the AllStarlink 3 image as detailed on the allstarlink.org website.

Installing the system this way makes it pretty easy compared to previous installs but, it comes with some quirks which cause issues with Node-Red.

From the outset the plan has always been to have AllStartLink 3 and Node-Red running on the same Pi4 to keep it totally self contained. This was easy enough to achieve and works without issue.

Node-Red Control Dashboard for AllStarLink 3
Node-Red Control Dashboard for AllStarLink 3

Installing Node-Red onto a Pi4 is really easy and is fully documented on the Node-Red Website.

Once the AllStarLink 3 operating system was installed on my SD card, booted and operational I installed Node-Red. I soon realised that there were a few things I had to do before loading the Node-Red flow.

AllStarLink 3 no longer logs connect and disconnect messages in the connectlog like it did in AllStarLink 2. To get logging working again I had to create two new BASH scripts as detailed below and put them into /etc/asterisk/myscripts.

For the connect information I created the BASH script as detailed below.

#!/bin/bash

# /etc/asterisk/myscripts/connectlog.sh

echo $1 Connected $2  on $(date +"%T") - $(date +"%m-%d-%Y")  >> /var/log/asterisk/connectlog

For the disconnect information I created the 2nd script detailed below.

#!/bin/bash

# /etc/asterisk/myscripts/disconnectlog.sh

echo $1 Disconnected $2  on $(date +"%T") - $(date +"%m-%d-%Y")  >> /var/log/asterisk/connectlog

Once these scripts were created I had to change the ownership and privileges as detailed below.

cd /etc/asterisk/myscripts
chown asterisk:asterisk ./*
chmod 750 ./*

I also had to change ownership/privileges of /etc/asterisk/myscripts.

cd /etc/asterisk
chown asterisk:asterisk ./myscripts
chmod 755 ./myscripts

Once the two scripts were in place I had to alter the asterisk config so that it called the scripts as part of the connect/disconnect process.

I found the connpgm and discpgm entries in /etc/asterisk/rpt.conf and changed them as shown below.

connpgm = /etc/asterisk/myscripts/connectlog.sh

discpgm = /etc/asterisk/myscripts/disconnectlog.sh

Next I disabled the temporary filesystems that are used by default for the apache and asterisk logging as it’s useful to keep the apache logs for debugging and I needed the asterisk logs for the Node-Red dashboard.

Disabling the temporary file system is very easy to do, just edit the /etc/fstab and comment out the two lines as shown below.

# Comment out the next line for persistent Apache logs
#tmpfs  /var/log/apache2        tmpfs   defaults,noatime,nosuid,nodev,noexec,mode=0775,size=32M 0 0

# Comment out the next line for persistent Asterisk logs
#tmpfs  /var/log/asterisk       tmpfs   defaults,noatime,nosuid,nodev,noexec,mode=0775,size=32M,uid=102,gid=106 0 0 

# Note: These lines are wrapped, should be on 1 line in the /etc/fstab

Once the entries in the /etc/fstab were commented out I rebooted the Pi4 to get persistent filesystems.

The final thing that had to be done was to allow user repeater to use sudo without a password so that it could be used to perform reboot/shutdown/process restart as user root from within the dashboard.

# /etc/sudoers

# Allow repeater sudo without password
repeater ALL=(ALL) NOPASSWD: ALL

Once this was all done I imported the Node-Red flow, configured the SSH nodes with login credentials for the Pi4 (important to use the user repeater for SSH), clicked deploy and the dashboard was ready for use.

Node Red AllStarLink3 Control Dashboard Flow
Node Red AllStarLink3 Control Dashboard Flow

I’ve been using the dashboard for a few weeks now and it’s running perfectly, without error.

If you want to build your own Node-Red Control Dashboard for your AllStarLink 3 node then, just download the flow using the button below and import it into your flow editor.


More soon …

Short skip on 20m

Yesterday morning I ventured up onto the 20m band and to my surprise, found that the band was open to inter-G, unusually short skip for the 20m band.

Wanting to take advantage of the conditions I kicked off with a QSO with David, MI0AIH in Cookstown Northern Ireland. With 59+ signals both ways, it was like being on 40/60/80m with a crystal clear path between us.

Next was GB0BBF operating POTA GB-0619, again 59 both ways and a really easy contact.

My third contact was with Aled, MW0UPH who was parked up in his car on a hill in North Wales. The path between us was incredibly good. With 59 signals both ways and an FM like arm chair copy, we chatted for a few minutes making the most of the short skip.

Aled very kindly made a quick video of our conversation and sent a copy over to me to watch. It’s always nice to hear what you sound like on the other end.

M0AWS as heard by MW0UPH on the 20m Band

Unfortunately I didn’t think to make a video of the conversation at my end but, it was exactly the same, crystal clear arm chair copy, just like a 2m FM contact.

It was great fun working UK stations on a band that I would normally only ever hear EU and DX stations. It was interesting to note that Inter-G on 40m was really poor at the same time.

Thanks to Aled for the video.

More soon …

Node-Red Dashboard for AllStarLink 3 Nodes

I’ve spent some time this afternoon modifying my Node-Red Dashboard for controlling AllStarLink nodes to work with the new AllStarLink version 3.

My original AllStarLink Control Dashboard was designed to work with AllStarLink 2 which I have running on an old RaspberryPi 3b on the 70cm band. The dashboard has worked reliably ever since deployment and is in use daily.

With the release of AllStarLink 3 and all the changes that it entails I’ve had to make a few changes to the dashboard flows in order to make it compatible with AllStarLink 3 nodes.

This entails not only flow changes but also the addition of two new bash scripts that are called by Asterisk to log connect and disconnect messages as they are not logged by default any more. (Seems a bit of a step backwards)

Node-Red AllStarLink Control Dashboard v3.0 for ASL3
Node-Red AllStarLink Control Dashboard v3.0 for ASL3

The changes also entail disabling the temporary filesystems used by default in the new ASL3 build so that log files etc become persistent.

I’ll spend some time using the new dashboard to ensure it’s working correctly and then will release it into the wild for all those that are brave enough to move over to AllStarLink 3.

More soon …

The 5 things that have revolutionised my Radio Shack

The articles I write for the blog are mostly technical but, I thought it was about time that I wrote this article as it’s been buzzing around inside my head for some time now.

So, what are the 5 things that I have found revolutionary in my shack that have brought new, exciting ideas and projects to life making amateur radio more enjoyable.

1: A RaspberryPi Single Board Computer

RaspberryPi 5 Single Board Computer
RaspberryPi 5 Single Board Computer

Ever since the first RaspberryPi Single Board Computer (SBC) was released I’ve been a huge fan. This little credit card sized number cruncher has been the base for so many projects, it has to be the first on my list.

The RaspberryPi SBC has been through a few iterations since its initial conception and is now powerful enough to take on most tasks that any radio HAM is going to throw at it.

So, what have I done with them?

Well I’ve used them to run Node-Red services for my many web app dashboards that control things like my QO-100 Satellite Ground Station, UPS power monitoring, Internet speed graphs, server and virtual machine monitoring, AllStarLink nodes, hosting websites, building an SDR shortwave receiver, running HAM Clock / Open HAM Clock, developing my own software, hosting virtual machines and a whole host of other fun and interesting things. I’m even writing this article using my RaspberryPi 500+ computer that is my daily desktop PC.

There are an endless number of things you can do with a RaspberryPi to bring new life and functionality to your radio hobby.

Want to get into Amateur TV?
Want to decode digital modes real time?
Want to track aircraft in the sky real time on a virtual radar screen?
Want to search the shortwave bands for stations of interest?
Want to host your own blog and website?

All these things and a lot more are easily within reach with a RaspberryPi.

The RaspberryPi is only limited by your imagination, the more imaginative you are the more your number crunching little friend will do.

2: A 3D Printer

Bambu Lab A1 Combo 3D Printer
Bambu Lab A1 Combo 3D Printer

Every HAM should have a 3D printer. These manufacturing marvels bring a new level of quality, design and simplicity to your HAM radio projects. I’ve found it incredibly useful since venturing into the rabbit hole that is 3D printing. When I think back to the weeks and months of my life I’ve spent making cabinets and boxes out of sheet metal, aluminium or wood for the numerous projects I’ve built over the years, a 3D printer would had made my life so much easier. 3D printing has revolutionised the making of things for the Amateur Radio home brewer.

There’s a multitude of useful things on websites like Printables, Thingiverse , Makerworld and others where you can just download the files and print high quality designs for all those things you’ve wanted to do but, don’t have the time or inclination to craft by hand.

The real satisfaction with 3D printing comes from designing your own things and making them. My first project was to design and print a fan cooling system for my Xiegu XPA125B amplifier.

From the factory the amp is passively cooled and doesn’t take long for the heat-sink to become saturated resulting in a high operating temperature. I was never happy with this and so was determined to resolve the problem.

Getting to grips with TinkerCAD was a bit of a vertical learning curve but, after a few mistakes and design mishaps I soon had it under my belt and pressed on with designing the cooler unit.

Designing the Xiegu XPA125b cooling system using tinkerCAD.
Designing the Xiegu XPA125b cooling system using tinkerCAD.

It’s not until you start designing and manufacturing things that you suddenly realise how much effort goes into them but, I persevered and over the period of about a week or so I had a perfectly fitting, operational cooling system that kept the amp super cool regardless of how long I waffled on for on the HF bands.

Once you’ve got your first design made you suddenly find yourself wanting to improve it and add things. In my case this was adding a Hermes Lite 2 holder to the top of the amp cooler and then a top shelf to hold my cross needle SWR and power meter.

Since then I’ve progressed massively with my designs and have even designed and printed things for other HAMs and family members, it’s totally addictive!

I can highly recommend the Bambu Lab A1 Combo (As shown above). It’s a quality piece of equipment that has operated faultlessly since purchase. Right now it’s printing a case for my RaspberryPi 4, just one of the many projects I’ve used it for since becoming a happy owner.

RaspberryPi 4 case from printables.com
RaspberryPi 4 case from printables.com

Go on, release your inner creativity and treat yourself to a 3D printer, you won’t regret it and it’ll help you bring to life all of those radio projects you’ve dreamt of doing but, never got round to starting.

3: An AllStarLink Node

M0AW AllStarLink Node 61928 sitting on the equipment rack
M0AW AllStarLink Node 61928 sitting on the equipment rack

Many people say that using VOIP over the internet isn’t real radio, I know because I used to be one of those people however, it has become an invaluable resource for keeping in touch with people all over the world.

Being part of an online HAM Radio Community it’s important that as a group we are able to talk to each other regardless of where we live, what bands we have access to and whether there is any propagation.

The AllStarLink (ASL) network gives global FM quality audio no matter where you are in the world. We use it daily for our breakfast net, general chatter throughout the day and even hold a weekly Matrix ASL Net on a Thursday evening.

Using our VHF/UHF handhelds (Real Radios!) and an easy to make AllStarLink Node we’re able to join in with the conversation regardless of propagation, licence type or distance, it really is great for bringing people together.

With devices like the SHARI and AIOC board now being readily available for minimal cost it really is very easy to get onto the AllStarLink network and talk to people even if you live in an antenna restricted location.

Why be alone when you can use the Matrix ASL node ( 642332 ) and join in the conversation.

4: Node-Red

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

Node-Red is a low-code programming tool for event-driven applications.

Node-RED’s goal is to enable anyone to build applications that collect, transform and visualise their data; building flows that can automate their world. Its low-code nature makes it accessible to users of any background, whether for home automation, industrial control systems or anything in between.

I’ve been using Node-Red for a number of years now and have developed a suite of web app’s that control and monitor just about every aspect of my Amateur Radio hobby and IT infrastructure.

Node-Red forms an integral part of my QO-100 Satellite Ground Station providing control of both the uplink and down link radios whilst synchronising the VFO’s, controlling filter selection and more, all from one simple to use interface using nothing more than a web browser.

It doesn’t stop there, my AllStarLink (ASL) nodes are also managed through a user friendly Node-Red Dashboard that removes all the need for technical know how and makes ASL node management as simple as clicking on a button to connect or disconnect to the many global networks.

Much of this functionality is achieved without writing a single line of code. If you can use a mouse, drag and drop objects on the screen you can develop Node-Red web app’s, it really is that easy.

M0AWS Interactive Log Flow
M0AWS Interactive Log Flow

It doesn’t end there, Node-Red is great for presenting data in easy to digest formats.

Whether it be HAM Radio Log data presented on an interactive world map or monitoring of your server, RaspberryPi, virtual machine or UPS using gauges and graphs, this can all be achieved easily with nothing more than a mouse. There’s no need to spend hours writing thousands of lines of code, just drag and drop a few nodes onto the screen and join them up. You’ll be amazed how easy it is.

I believe every Amateur Radio enthusiast should have Node-Red available in their radio shack. It’s easy to install on your RaspberryPi 4 or 5, Linux or Windows PC and Apple Mac with the same great functionality available on all platforms.

Once you’ve developed your first web app you’ll suddenly find a million more ideas will come into your head and before you know it, you’ll be where I am today with Node-Red at the centre of your radio hobby.

5: A Hermes Lite 2 HF SDR Transceiver

For years I used black box HF radios from the big 3 manufacturers along with the odd radio from the smaller enterprises like TenTec but, they all had their foibles and there was often nothing I could do about it.

My last acquisition from the big 3 was a Yaesu FTDX10, a competent hybrid SDR radio with a good receiver however, the menu system is terrible, the button layout not much better and the user experience not as good as it could be. Of course the software is closed source so there is nothing you can do about it. The radio did its job but, it wasn’t fun to use, it wasn’t what I really wanted and it didn’t put a smile on my face.

I looked at moving to software defined radios (SDR) but, with prices in the many thousands of pounds bracket and the software being closed source I came to the conclusion that they wouldn’t give me what I really wanted either.

So what was it that I was searching for?

Thinking long and hard about it I came to the conclusion that what I really wanted was a radio that gave me the same satisfaction that OpenSource software has given me for decades, namely an HF radio that I have complete control over, from the hardware through to the software and everything in between.

I wanted something that I could tailor to my exact needs. Something that was built using open hardware and open software, something where if I wasn’t happy with it I could change it, improve it and do the things I wanted with it.

At this point my search for the ideal radio headed in a completely different direction.

Xiegu XPA125b Cooler with Hermes Lite 2 cradle - front view
Xiegu XPA125b Cooler with Hermes Lite 2 cradle – front view

The Hermes Lite 2 SDR HF Transceiver (HL2) has been around for a number of years. I was first introduced to it by Michael, DK1MI and then Roger, G8VLR via the Matrix. Both Michael and Roger use the HL2 on a regular basis and have often waxed lyrical about how good it is.

Being designed by radio amateurs for radio amateurs it’s based on an open architecture from the ground up. Being an OpenSource junky this really appealed to me and as I looked deeper into it from both a hardware and software point of view I soon realised that it had the potential to be exactly what I was looking for.

It wasn’t long before I found myself on the Makerfabs website placing an order for the HL2 mainboard, filter board, I/O board and case. A couple of weeks later it arrived and I dived head first into the SDR rabbit hole.

2 years later and the HL2 has become my main HF radio in the shack. Partnered with a Xiegu XPA125B amplifier and PiHPSDR software running on my Kubuntu Linux PC it is everything I have been looking for in an HF radio.

I’ve made modifications to the software to suit my operating style and needs with the user interface being exactly how I want it, no unnecessary buttons or knobs, just the controls that I use on a daily basis cleanly placed in a logical, easy to use layout, the way I want it.

My understanding of software defined radio and how it works has improved a hundred fold. Having access to the software and being able to go through the code and understand the architecture has been an interesting journey and one that has enhanced my radio enjoyment considerably. I now have a smile on my face every time I go on air.

Do I miss the FTDX10?

No, not in the slightest!

So, those are the 5 things that I feel have revolutionised my radio amateur hobby and made it a more enjoyable experience. I’m sure over time I will add to this list as I venture down future rabbit holes in our wonderful radio hobby.

More soon …

Bring your old handheld to life with an AIOC

I’m sure there are many radio amateurs around the world today who have an old handheld radio sat on the shelf that works perfectly but, has been replaced by a new, shiny, all singing, all dancing model that gets used on a daily basis. I for one have fallen into this trap with the recent purchase of a very nice Wouxun KG-UV9K full duplex 2m and 70cm handheld.

On my shelf there is a cheap Retevis RT85 that gave sterling service for a number of years and even today is ready to continue that service, if only I had a need?

Well now I do!

Currently I have an AllStarLink node running on a RaspberryPi 3b connected to a SHARI device that operates on the 70cm band. This node works great and gives me the ability to chat with people all over the world from my trusty handheld. It does of course also give me access to the weekly Matrix AllStarLink Net that happens on our Matrix node ( 642332 ) every Thursday evening at 20:00 UK time, a great way of bringing the Matrix HAM Radio community together regardless of propagation.

For some time I’ve been wanting to bring another AllStarLink node online so that I can have a connection to HUBNET/FreeNet whilst keeping my current node connected to the Matrix node for our regular daily chats. Since my new Wouxun handheld is a full duplex unit it makes sense to bring a new node up on the 2m band as I can then monitor both at the same time easily. I do have a spare SHARI node however, it’s a UHF only unit and I don’t want another node on the 70cm band. This is where the old Retevis RT85 comes in to play.

The All In One Cable ( AIOC ) board is a very neat little CM108 compatible sound card and serial interface that is sold by Steve, KM9G of YouTube fame ( Temporarily Offline ) that plugs into any handheld radio that has the now pretty much standard Kenwood ‘K’ type mic connector.

AIOC board from Steve, KM9G.
AIOC board from Steve, KM9G.

The AIOC board really is tiny but, beautifully put together. The four large solder pads on the top and more on the underside are positioned such that the TRS plug solder lugs line up perfectly for soldering. Attempting to do this by hand would be impossible as it’s critical that the spacing between the two connectors matches that of the spacing of the sockets on the radio.

AIOC Solder Jig.
AIOC Solder Jig.

Searching online I found a very handy soldering jig on Github that enables you to hold both the TRS connectors and AIOC board in the perfect position for soldering.

Downloading the .STL file I quickly printed off a solder jig on my Bambu Lab A1 Combo 3D printer and fitted the components into place ready for soldering.

Everything fitted rather snugly into the jig and I soon had the board and connectors soldered together. Test fitting to my Retevis RT85 I found the TRS plugs lined up perfectly and it slid into the sockets with ease.

I then thought about designing a case for the AIOC board so that the bare circuit was nicely protected but, quickly searched online and found that NA6D has already designed a case and made the .STL available publicly for download on Printable.com. I quickly grabbed a copy of the file and punted it off to my 3D printer to get to work on.

3D print NA6D AIOC case.
3D print NA6D AIOC case.

Once the print was complete I fitted the AIOC board and snapped it together ready for testing.

Now that the AIOC was production ready I moved on to getting the latest version of AllStarLink onto my RaspberryPi 4 that I had taken out of my RadioBerry based shortwave receiver that I am going to upgrade to a Hermes Lite 2 in a later project. The RaspberryPi 4 is perfect for AllStarLink 3, a 64bit app and operating system.

Using the RaspberryPi Imager I pulled the image down onto an SD card and slipped it into my Pi4. ( Instructions on how to do this are on the AllStarLink website here )

Booting the Pi4 for the first time I found that it went through a number of reboot and configuration cycles before it was ready for use.

Once ready I went through all the normal configuration of the Pi4 namely, static IP assignment, timezone config, security, port forwarding etc etc.

Having configured an AllStarLink node for myself and only just a few days ago for another HAM I was pretty familiar with the setup. Wanting to make sure there were no “gotcha’s” I also watched a couple of KM9G’s videos on Youtube to make sure I wasn’t missing anything.

Using the asl-menu command line app as user root I set about configuring Asterisk to work with the AIOC board. Much to my frustration I could not get Asterisk to recognise the AIOC board as an available sound device. I checked and double checked all the settings ensuring that I had selected “AIOC” in the available devices menu but found that Asterisk constantly errored saying it could not find the selected audio device. This went on for a whole day without success and so, I decided to put it to one side and come back to it later, a method I found that often worked.

A couple of days later I revisited the problem and had decided to take a different approach. Rather than continue going through the asl-menu app I decided to drop down to a lower level and go through the asterisk config files in the /etc/asterisk directory.

It wasn’t long before I found a file called res_usbradio.conf. Inside this file was the config for the AIOC board however, it was all commented out which meant it was disabled.

I’m guessing here but, I imagine this is what should get enabled when selecting AIOC in the available devices menu in the asl-menu command line app but, for some reason it doesn’t happen.

[general]
;usb_devices = 1209:7388    ;comma delimited list of usb
                            ;descriptors to allow.
                            ;format vvvv:pppp in hexadecimal
                            ;vvvv=vendor id, pppp=product id
                            ;
                            ;1209:7388 = AIOC (all in one cable)

Above is the disabled configuration which is easily edited to enable the AIOC device as shown below.

[general]
usb_devices = 1209:7388    ;comma delimited list of usb
                            ;descriptors to allow.
                            ;format vvvv:pppp in hexadecimal
                            ;vvvv=vendor id, pppp=product id
                            ;
                            1209:7388 = AIOC (all in one cable)

Once the updated file had been saved and I restarted Asterisk using systemctl the AIOC burst into life and Asterisk recognised it immediately. The Retevis RT85 switched between TX and RX and I was ready to check out the audio.

Setting the volume levels for both RX and TX via the command line tuning app I connected the node to my already existing node. Sure enough the two nodes connected without error and I was able to send and receive audio between them via the AllStarLink net.

Connecting the new node to the parrot I checked the audio levels to ensure it sounded ok and then connected it to the Matrix node where I had a brief chat with Ben, M8TKK.

All that is left to do now is to 3D print a case for the Pi4 so that it isn’t left naked and at risk of being shorted out on conductive surfaces and it’ll be ready for service.

I also plan to build another AllStarLink node using a 4m band handheld and another AIOC board and then will apply for MB7Ixx callsigns for the two new nodes. This will hopefully help to bring some life to the 2m/4m bands locally and introduce HAM’s both to the weekly Matrix Net and HUBNet/FreeStar via AllStarLink.

More soon …

There’s always someone listening!

I had a fun day on the radio yesterday. It started with the Matrix QO-100 Satellite Impromptu Net at 16:00 BST on 10489.873Mhz. A net that started off as an impromptu event that over the last couple of years has become a weekly staple. Hardly impromptu at all but, we liked the name and so stuck with it.

During the Impromptu net I noticed that my 2m radio was burbling away in the background and that a lot of European repeaters were coming through so, as soon as the net had finished I quickly switched over to my trusty Wouxun KG-UV980PL and started tuning around the 2m band.

2m was alive with repeaters from France, Belgium, The Netherlands and the UK, often beating against each other on the same frequency.

Being near the East Coast and closer to Belgium than I am to many parts of the UK I jumped onto the ON0WV repeater in Bruges. Being S9+ with me I called a few times but, no one came back to me so, I moved on.

Tuning across my Norwich Repeater memory slot I heard two French stations chatting, it was obvious they weren’t on GB3NB as the bell between overs was not the normal chime.

I quickly opened RepeaterBook on my iPhone and searched for repeaters on the same frequency, there are many!

Eventually I worked out that it was ON0HT so I quickly set about loading the repeater settings into the next available radio memory channel. I loaded a few others from The Netherlands at the same time as I was hearing more than normal from that part of the world.

2 French Operators on the ON0HT repeater in Belgium close to the French border.

Having the correct settings in place for the repeater I was now able to call in and have chat with the two stations.

Jean-Claude F5JOX and Didier F6DKO were surprised to hear an English station call in but, were most welcoming. We had a chat for a few minutes exchanging details and commenting on the great conditions. Sadly the conversation was eventually brought to an end as there were so many repeaters on the same frequency it became impossible for me to hear them clearly so, I gave them 73 and went tuning around.

The 2m band was absolutely full of UK and EU repeaters with many beating against each other on the same frequency. Wouldn’t it be nice if there was more of a split between the UK repeater frequencies and the EU allocation. Would certainly make it easier to use the EU repeaters in lift conditions.

Later in the evening Roger G8VLR, Steve M0XVT and I were having one of our Impromptu Nets on the 60m band. Often there are others from the Matrix that join in too but, on this occasion there were just the 3 of us.

I’m acutely aware that we often have listeners to our on air chats as I quite often get emails from SWL’s and licenced HAMs commenting on how much they enjoy our conversations. Yesterday evening was no exception as it turns out that we were once again attracting listeners albeit, unbeknown to us at the time.

Later in the evening Alan, G1SQB sent me a message via the Matrix with a YouTube link to a recording of us on the 60m band from that very same evening made by @KevinOReillyswl.

Yes, that’s yours truly waffling on about satellites as normal.

Kevin O’Reilly is clearly a very active SWL as he has many interesting videos on his Youtube Channel that are worth a look.

I must confess that I’ve never heard of the MLITE-880 receiver before but, after running a search I found it to be quite a popular radio in the SWL community.

There’s a very good review on swling.com that’s worth a read.

The short video above shows it to be a surprisingly good shortwave receiver in a very compact, portable package that’s ideal for listening whilst out and about on camping trips or other outdoor activities.

A big thanks to Kevin O’Reilly for posting the video and letting us see how we sound on the other end.

More soon …

Xiegu XPA125B Amplifier Cooler 3D Print File

Some time back I designed and 3D printed a 3 fan cooler for my Xiegu XPA125B HF amplifier that stops the heat-sink from becoming heat saturated.

Having printed this for Steve, M0XVT and myself we’ve thoroughly tested it and found that it greatly reduces the temperature of the amp during operation.

I’ve now decided to make the .STL file available for download so that those who have their own 3D printer can print their own cooler for the amp.

The 40x40x10mm 12v fans that fit onto the mounts on the cooler module can be obtained from Amazon. (Note: Originally they came in packs of 4)

I’m happy to print this for people who don’t have a 3D printer of their own, please contact me via email for a price.

For those who have their own 3D printer, the .STL file is available below for download.

Please note that I am releasing this STL file into the public domain for non-commercial, personal use only.


More soon …

ISS Astronaut talks to UK students

Students at the Simon Langton Grammar School for Boys in Canterbury, Kent UK, today had the opportunity to talk to astronaut Jack Hathaway, KJ5NIV, aboard the International Space Station (ISS).

Checking the ISS pass data I could see it was going to be a good pass for me to listen and so I setup my Wouxun KG-UV980P quad bander on 145.800Mhz to see if I could hear Jack.

Having only a Diamond V2000 vertical antenna, I don’t have the best station for satellite communications however, it has worked well in the past.

Sure enough, as the ISS approached the UK from the South West and reached 2deg above the horizon the signal started coming through. Below is the video I took of the pass.

I ended the video at 6min and 35sec as I thought I’d lost the satellite as it was out to the East over Russia and blocked by farm buildings near my QTH however, once I stopped videoing I remembered to move the VFO down 5Khz and sure enough I was able to hear the ISS right up until the point that Jack signed and ended the QSO.

I really should try to see if I can get some QSO’s via the ISS FM Repeater as the received signal really is very good. Whether the transmitted signal would be as good remains to be seen.

More soon …