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 …

Hermes Lite 2 and Xiegu XPA125B Auto Band Switching

Since I’ve had my Hermes Lite 2 (HL2) and Xiegu XPA125B amplifier combo I’ve had to manually change the band setting on the amp as I never purchased the HL2 I/O board when I initially purchased the kit.

At the time I didn’t think I would need it but, changing band manually on the amp (and sometimes forgetting causing tuning issues) is a nuisance and so I put my hand in my pocket once again and ordered the I/O board for the HL2.

Hermes Lite 2 I/O Board
Hermes Lite 2 I/O Board

The HL2 I/O board is a small RaspberryPi Pico controlled device that can be used for a multitude of functions depending on the software loaded. Many people are writing their own software for the Pico to do things like control transverters, remote antenna switches, amplifiers and just about anything else you can think of. It’s a really versatile little add on board for the HL2.

The I/O board arrived after about 10 days from Makerfabs, all nicely packaged as always. Unfortunately due to Christmas, New year and other priorities it’s sat in the box since it arrived.

A couple of days ago I finally got round to getting it out of the box and set about configuring it to control the Xiegu amp.

The Xiegu amp needs three connections from the I/O board. They are PTT, Band Switching Voltage and Ground. These are easily accessed from the I/O board via 3 jumper wires to connect to the DB9 connector on the rear of the board.

The other thing that is required is some software for the RaspberryPi Pico to control the whole process. Steve, M0XVT has kindly supplied me with a copy of the software.

Soldering the jumpers from the relevant points on the circuit board to the DB9 connector was pretty straight forward. You can use any of the pins on the DB9 connector that you like as from the factory the DB9 connector isn’t connected to anything. I decided to use pins 2, 6 and 8 and so will refer to those pins from this point forward.

HL2 I/O Board Jumpers
HL2 I/O Board Jumpers

I used a different colour for each of the jumpers so that I knew which jumper was for which connection. The colours used also match the colours of the wire in the old RS232 serial lead that I cannibalized to make the connection between the I/O board and the amp thus making it easy to ensure continuity.

The colours are as follows:

Black Jumper - Ground - Pin 2 on DB9 Connector
White Jumper - PTT - Pin 6 on DB9 Connector
Red Jumper   - Band Control - Pin 8 on DB9 Connector

The I/O board gets its power feed directly from the HL2 main board however, the 3 pins it needs to connect to don’t have any headers in place and so, it’s necessary to solder a short row of 3 header pins onto the HL2 main board.

I found the easiest way to do this was to put the 3 header pins into the correct position and then use the HL2 to N2ADR filter board connector to hold them in place whilst soldering. This worked perfectly and I soon had the header pins soldered onto the main board.

Extra 3 header pins soldered to the main HL2 board
Extra 3 header pins soldered to the main HL2 board

It’s important to note that the 3 extra header pins need to be placed 2 holes away from existing header pins as shown above. Take care to get these pins in the right position so as not to cause any damage to the 3 circuit boards once all are connected and powered up.

Note: The HL2 main board must be removed from the case to solder the extra 3 header pins in place. Take care to ensure the correct fitting of the PA heatsink when when refitting the HL2 main board into the case.

At this point I refitted the N2ADR Filter board back into the HL2 case so that the two sets of header pins aligned correctly ready for the placement of the new I/O board that would connect all 3 circuit boards together.

Preparing the N2ADR Filter board for reconnection
Preparing the N2ADR Filter board for reconnection

Once the filter board was in place I fitted the new I/O board taking care to ensure all pins aligned with the socket and then gently pushed it home.

Close up of the HL2 I/O board fitted to the main HL2 board and N2ADR Filter board
Close up of the HL2 I/O board fitted to the main HL2 board and N2ADR Filter board

The close up of the I/O board connector above shows how the extra 3 header pins connect to the last 3 sockets in the I/O board connector. It’s a snug fit with the N2ADR filter board below it.

View of the fitted HL2 I/O board from above
View of the fitted HL2 I/O board from above

Before the HL2 case can be put back together it’s necessary to load the software onto the RaspberryPi Pico (top left in photo above) that controls the I/O board.

This is accomplished by pressing the tiny button on the Pico whilst connecting a USB lead to the USB socket on the board that had already been plugged into my PC. Once connected the Pico appeared as a USB drive on my Kubuntu Linux desktop. All I then had to do was to copy the software file onto the drive. Once the software file is on the drive the Pico will reboot automatically and the little LED on the board will start to flash to show it has booted successfully. At this point I could safely unplug the USB cable.

The software for the RaspberryPi Pico is available for download below.


The I/O board comes with a new back panel for the HL2 to accommodate the extra connectors on the rear. Refit the top of the HL2 case and then attach the new rear panel using the original 4 counter sunk screws.

Supplied HL2 I/O board replacement rear panel fitted to the HL2 case
Supplied HL2 I/O board replacement rear panel fitted to the case

The final part of this project is to make the lead that will go from the HL2 rear DB9 ACC connector to the Xiegu XPA125B mini din ACC socket.

For this you will need a 6 pin mini din plug (AKA PS2 plug), (these are readily available on Amazon) and an old fashioned DB9 female connector from the days of RS232 serial leads..

The connections are as follows:

DB9 Pin 2 (BLACK) to Mini Din Pin 6 (GND)
DB9 Pin 6 (WHITE) to mini Din Pin 2 (PTT)
DB9 Pin 8 (RED) to Mini Din Pin 3 (Band Switching Voltage)

Below are a couple of screenshots from the Xiegu XPA125B user manual showing the Mini Din pin layout and the data interface connections for the amplifier.

Xiegu XPA125B Amplifier ACC Interface Connections
Xiegu XPA125B Amplifier ACC Interface Connections
Xiegu XPA125B Amplifier ACC Connector Pin Information
Xiegu XPA125B Amplifier ACC Connector Pin Information

Before I connected the lead to the two devices, I tested the end-to-end continuity of the lead to ensure all pins were correctly connected and that there were no shorts between any of the pins.

It’s important that the wires are connected to the correct pins on each end of the lead. Failure to ensure correct connection could cause damage to your HL2 and/or amplifier.

Once the lead had been tested, I connected it to both the Hermes Lite 2 and the Xiegu XPA125B amplifier. I also had to switch the amplifier band switching to AUTO.

Now when I change band on my HL2 in the PiHPSDR software the amplifier also changes band at the same time keeping the two devices in sync. No more manual band changing for me!

I hope this article is of use to other Hermes Lite 2 users who have purchased the Xiegu XPA125B but, have yet to setup auto band switching between the two devices.

Thanks to Steve, M0XVT for all the jumper information and the RaspberryPi Pico Software to get this all working.

UPDATE:
The RaspberryPi Pico software originally came from Ramon, KP4RX. More information can found in this Google Groups article where he released the binary into the wild.

A full table of I/O resources available on the HL2 I/O board can be found on the KP4RX Guthub page.

The source code for the main.uf2 file above can be found at KP4RX.com

More soon …