HermesLite2 – M0AWS Amateur Radio

24 May 2026

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

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

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.

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.

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

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.

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 …

2 May 20262 May 2026

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.

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.

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.

Fitting TRS connectors into the AIOC solder jig

Fitting AIOC board into the solder jig. — Fitting TRS connectors into the AIOC solder jig

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.

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

Fitting the AIOC into the 3D printed case.

AIOC case with 2 x TRS connectors in place. — Fitting the AIOC into the 3D printed case.

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 …

13 April 202622 April 2026

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)

Xiegu XPA125b Cooler with Hermes Lite 2 cradle - side view — Designing the Xiegu XPA125b cooling system using tinkerCAD.

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.

M0AWS-Xiegu-XPA125b-Fan-Module-v11 Download

More soon …

10 March 202610 March 2026

Xiegu XPA125B Button Press

For some time now I’ve been using my Xiegu XPA125B amplifier with my Hermes Lite 2 + I/O board combo with great success. With the amp changing bands automatically it really is nice to use.

With the multitude of remote controlled smart plugs available today I’ve now got the ability to switch the station on remotely however, there’s been one issue that has plagued me until now and that’s the Xiegu amp doesn’t come on when power is applied to it, you have to press the power button on the front of the amp before it will fire up.

This of course stops me from being able to fully use the station remotely as there’s no one there to press the power button on the amp, until now.

Chatting with Steve, M0XVT he discovered that if the power button is held pressed all the time the amp will come on when power is applied. This then gave me the idea of designing a button press device that I could 3D print and clip onto the front of the amp so that the button is always pressed.

M0AWS Xiegu XPA125B Clip on Power Button Press

The Xiegu amp has a very nice flange around the front edge of the amp case that lends itself nicely to clip on a simple button press device as shown above in my 3D design software.

The button press is designed so that the top is put on first and then the bottom is just snapped into place with a gentle push. This makes it easy to get on and off without marking the amplifier.

In just a few minutes I had the button press design uploaded to my Bambu Lab A1 Combo 3D printer and in no time at all the button press was ready for use.

As you can see in the photo above it fits snugly to the front of the amp gently holding the power button in so that the amp comes on when power is applied. Simple but, effective.

I’m sure I’m not the first person to have this problem and so, I’ve made the .STL 3D print file available for download below.

Xiegu-Button-Press-v3 Download

I hope this is of use to people who want to be able to use their Xiegu amp remotely without leaving the power on all the time.

More soon …

14 December 202515 December 2025

FreeDV audio routing with PiHPSDR and Hermes Lite 2

I’ve recently been trying out the FreeDV RADEv1 digital voice mode on the HF bands with great success. The audio quality is astounding when compared to the normal analog SSB mode. Using only 20w I’ve been surprised how successful I’ve been talking to stations in the UK and Europe as can be seen in my FreeDV Log.

FreeDV has been around for quite a few years with development being funded by an ARDC grant and financial sponsorship from the Software Freedom Conservancy.

So what is FreeDV?

To quote the FreeDV website:

“FreeDV is a suite of digital voice modes for HF radio. Our flagship mode is the Radio Autoencoder (RADE). You can run RADE using a free GUI application for Windows, Linux and macOS that allows any SSB radio to be used for high quality digital voice.“

And the most important part:

“All software is open source, released under the (a) GNU Lesser Public License version 2.1 (GUI and legacy FreeDV modes) and two-clause BSD license (RADE).“

FreeDV running under KDE-Plasma on Kubuntu PC

Looking at the digital voice (DV) community in the HAM Radio world, it’s stuffed full with proprietary DV modes from small software houses and black box transceiver manufacturers with no real OpenSource alternatives, until now.

Installing FreeDV is pretty simple regardless of which operating system (O/S) you use. Being a Linux user I grabbed the AppImage from the website and set about reading up on how it works and how it is configured.

I decided to take the two sound card approach since I have 2 USB sound cards connected to my shack Kubuntu Linux PC.

Configuring the audio routing isn’t straight forward as both the receive and transmit audio to/from the radio needs to be routed via the FreeDV app. To make this even more complicated I am using my Hermes Lite 2 SDR transceiver and PiHPSDR software, a complete OpenSource/OpenHardware Amateur Radio Station.

M0AWS FreeDV and PiHPSDR Audio Routing Diagram

Trying to clearly describe the audio routing using words alone would be impossible and very confusing so, I put together the diagram above.

Using two USB sound cards I’ve configured the system such that USB Sound Card 1 (an old Griffin iMic USB sound device) handles just the audio from/to the headphones and microphone. All the audio at this point in the system is analogue.

The second USB sound card, a cheap Plug and Play (PNP) USB audio device from Amazon, handles all the digitised signals from/to FreeDV and PiHPSDR.

Taking this 2 sound card approach keeps confusion to a minimum and separates the analogue and digital components of the audio routing.

So, how does this translate to the FreeDV and PiHPSDR audio settings?

Transmit Audio Chain

FreeDV Transmit Audio Settings

Starting at the beginning of the transmit audio chain, let’s look at the transmit audio settings in FreeDV.

Looking at the FreeDV Transmit audio settings screenshot below we can see that the
Input From Microphone to Computer device is set to:

alsa_input.usb-Griffin_Technology_Inc_iMic_USB_audio_system-00.analog-stereo

This is the microphone connection on the iMic USB device (USB Sound Card 1) and is the analogue transmit audio input to FreeDV.

The Output From Computer to Radio device is set to:

alsa_output.usb-0c76_USB_PnP_Audio_Device-00.analog-stereo

This is the digitised audio output from FreeDV (via USB Sound Card 2) to PiHPSDR and is used as the transmit audio that is sent to the Hermes Lite 2 transceiver.

PiHPSDR Transmit Audio Setting

To complete the transmit audio path we next need to look at the PiHPSDR transmit audio setting.

As can be seen in the screenshot above, the Local Microphone device in PiHPSDR is set to the Monitor of USB PnP Audio Device Analogue Stereo.

This effectively routes the digitised output audio from FreeDV (Output From Computer to Radio device) to the Input audio of PiHPSDR.

The reason for using the Monitor audio feed is because FreeDV does not recognise the Mic Input in PiHPSDR as a valid output device for FreeDV to use, hence we just need to monitor the FreeDV output device and use it as our input audio device in PiHPSDR.

This completes the transmit audio chain.

Receive Audio Chain

PiHPSDR Receive Audio Setting

Starting at the beginning of the receive audio chain we first look at the PiHPSDR receive audio setting.

In the screenshot above we can see that the receive audio output from PiHPSDR is set to
USB PnP Audio Device Analogue Stereo (USB Sound Card2). This is the DX station’s digitised audio as received by the Hermes Lite 2.

FreeDV Receive Audio Settings

Next let’s look at the receive audio setting in FreeDV.

The Input To Computer from Radio device is set to the monitor of the
USB PnP Audio Output Device:

alsa_output_usb_0c76_USB_PnP_Audio_Device-00.analog-stereo.monitor

This effectively routes the digitised audio output from the PiHPSDR receiver to the digitised audio input of FreeDV.

Once again we have to use the monitor of the USB PnP Audio Output device as FreeDV does not recognise the PiHPSDR output as a valid input device.

Next, the Output From Computer To Speaker/Headphones device is set to:

alsa_output.usb-Griffin_Technology_Inc_iMic_USB_audio_system-00.analog-stereo

This is the analogue audio output on the iMic USB Sound card (Sound Card 1) that routes the analogue audio to the headphones and completes the receive audio chain.

Summary

The audio routing required by FreeDV can appear very daunting when first attempting to configure it on the Linux platform but, hopefully the diagram and screenshots above will help in understanding the complete end-to-end audio chain that is required to make this mode work.

PiHPSDR can of course be replaced by your black box radio CODEC entries that will appear in the device lists shown above if you have your radio connected via USB. The config is basically the same but, just uses a different device instead of USB sound card 2 shown in the diagram above.

I hope this article is useful to those wanting to try FreeDV on the Linux platform and I look forward to hearing you on RADEv1.

More soon …

16 July 202518 July 2025

Trialing DeskHPSDR

For sometime I’ve been using PiHPSDR software to drive my Hermes Lite 2 (HL2) SDR transceiver. It’s a great piece of OpenSource software for SDR transceivers and has the best documentation that I have ever seen from an OpenSource project.

I must admit, I’ve had to make a few changes to get the software how I like it but, that’s the great thing about OpenSource software, you get the source code and can do what you like to it.

Following in this thread I recently decided to give DeskHPSDR a try.
DeskHPSDR is a fork of the original PiHPSDR but, with some changes mainly aimed at larger display computers.

After compiling DeskHPSDR on my Kubuntu Linux PC in the radio shack, I found there were a few issues, mainly the colours were hard on the eyes and band/channel markers wrong/missing on a few of bands.

DeskHPSDR default colour scheme on Kubuntu 22.04LTS (KDE-Plasma)

I decided to dive in and take a look at the source code and try and sort out the colour issues as blue writing on dark buttons made them almost impossible to read under a KDE-Plasma desktop.

Delving through the appearance.c and css.c files I found that there were many changes required to get the end result I wanted. The biggest pain is that you have to recompile the source code after each change to see if the code change had worked, this results in many recompiles, a tedious task.

After spending many hours making changes I decided to email Heiko, DL1BZ who is the developer of DeskHPSDR. Over a number of emails we discussed getting the colour management code changed such that it was read in at start time from a separate css file rather than having to be compiled into the main program.

After a few emails back and forth, Heiko changed the code so that a separate CSS file could be read in at start up instead of the hard coded CSS in the C code files, this worked great and made it much easier to make colour changes without constant compilations of the code.

Next I needed to edit the bands.c file to change some of the band edge markers to show the UK band plan as, by default they are incorrect even though I have the region set to UK.

Editing the appearance.c file once more I was able to change the colour of the rather bright green panadapter signal display to a much more pleasing blue fading to red as the signal gets stronger.

One thing I really like about PiHPSDR was the channel markers on the 60m band. Anyone that uses the 60m band will know that the UK allocation is split into 11 different channels separated by spaces used by the primary user of the band. The channel markers make it just that bit easier to ensure you don’t stray out of the allocated channels however, this code had been removed from DeskHPSDR as Heiko didn’t consider it necessary.

Once again I pinged an email over to Heiko explaining how useful it is to UK HAMs and he very kindly put the code back into DeskHPSDR so that the 60m channels are once more clearly visible on the panadapter.

DeskHPSDR modified colour scheme on Kubuntu 22.04LTS (KDE-Plasma)

Feeling happy with the new colour configuration I decided to test it out on Linuxmint Cinnamon. Sadly the scheme that looked so nice under Kubuntu 22.04LTS didn’t look the same under Linuxmint and so I had to set about coming up with a version of the CSS file for this platform too.

After quite a few hours tinkering with CSS code I found it to be impossible to get the colour scheme on Linuxmint Cinnamon Edition identical to that I’d created under Kubuntu KDE-Plasma so, I settled for a look that was as close as possible.

DeskHPSDR on Linuxmint Cinnamon Edition with colour modifications.

Chatting with Steve, M0XVT we thought it would be a good idea to test it on his Kubuntu Linux and Linuxmint PCs. He is using a later version of Kubuntu than I am (24.04LTS) and so, it would be a good test to see if the colour scheme looked the same.

Sadly it turns out that for some bizarre reason the colours come out different in the later version of Kubuntu. This is a real nuisance as it means we’d need a separate colour scheme defining for each version of the O/S. Perhaps using CSS isn’t the best way to define a colour scheme in applications.

For some very strange reason the colours were also rendered differently on his Linuxmint PC even though he was using the same version of the O/S as I am.

DeskHPSDR running on Kubuntu 24.04LTS with colour scheme not rendering correctly

Another issue was found whilst testing on Steve’s computers which seems to be caused by the fact he uses an Anan 200D SDR.

Looking at the documentation on github in theory DeskHPSDR should support the Anan range of SDR transceivers however, we found that it’s impossible to select the sample rate as the drop down selection list is completely missing from the Radio menu with the radio defaulting to its lowest sample rate of 48k resulting in not being able to see the full spectrum of frequency ranges on the bands.

DeskHPSDR Sample Rate drop down missing when using an Anan SDR

The other thing to note is that the Remote Server functionality has also been removed from the code by Heiko as he feels it’s not necessary. This may be a deal breaker for some and so they may choose not to use DeskHPSDR and to continue using PiHPSDR instead.

I will at some point make the O/S specific CSS files and source code available for download for those that want to use DeskHPSDR with my colour scheme changes.

I’m not sure at the moment whether I will continue using DeskHPSDR or go back to PiHPSDR, time will tell.

More soon…

17 April 202517 April 2025

Updates to my install-pihpsdr.sh script

Over the last few weeks I’ve been working on my install-pihpsdr script to build a version of the DL1YCF PiHPSDR fork that will work with the Adalm Pluo, Pluto+ and LibreSDR transceivers.

Since I don’t own any of these devices, Steve M0XVT has loaned me his Adalm Pluto and LibreSDR devices to test with.

Initially neither of the devices would work with the PiHPSDR build that my script was creating. After some investigation I found this was due to the fact that the developer build script was only building the SOAPYSDR library, it wasn’t building the modules for each device type.

This was easily fixed by adding some extra code that would build the necessary SOAPYSDR modules so that the devices were discovered on the local LAN.

Since I had the devices to hand I took the opportunity to test the updated build script on a number of Linux Distro’s that I have to hand.

PiHPSDR running on Linuxmint 22.1 Cinnamon Edition using the LibreSDR transceiver

I tested the updated build script on Kubuntu 22.04LTS, Linuxmint 22.1 Cinnamon Edition and RaspberryPi 4/5 running the latest RaspberryPi OS 64bit version.

These all worked great with the transceivers and will now make a great platform for QO-100 stations that use either the Adalm Pluto, Pluto+ or LibreSDR devices.

Of course this build of PiHPSDR will also work with the Hermes Lite 2 and RadioBerry devices that I use most of the time in my own radio shack.

The updated PiHPSDR install script can be downloaded from my original blog article on the subject that is located here: https://m0aws .co.uk/?p=3686

The updated build script will most likely work on most Debian based Linux distro’s and build a working version of PiHPSDR. If you find a distro where you have problems please email me and let me know the details and I’ll happily look at the issue and try to resolve it.

Thanks to Steve for the loan of his precious SDR transceivers, I had a lot of fun with them!

More soon …

9 March 202521 June 2025

Hermes Lite 2 Audio

I often get unsolicited good audio reports whilst using my Hermes Lite 2 (HL2) on the HF bands with people asking what settings I am using so, I thought it was time I put together an article on the subject.

I use the DL1YCF enhanced fork of PiHPSDR to drive my HL2, a great OpenSource SDR software package that supports many SDR radios including some very high end, expensive models.

PiHPSDR is extremely configurable via it’s well laid out menu system. It’s possible to change the settings on almost everything which, when combined with really good hardware like the HL2 gives the operator the ability to create an extremely high spec transceiver at a fraction of the price of the typical black box commercial offerings.

Starting at the beginning of the transmit audio chain the first settings to be changed are in the Transmit (TX) menu.

Using my Sennheiser headset I found I needed to set the Radio Mic setting to Mic Boost. This increases the audio level so that it drives the radio properly. It’s important to make sure that boosting the audio doesn’t cause distortion though.

Next I set the TX Filter Low to 150Hz. This ensures I don’t have that nasty bass sound that you hear often on the HF bands today.

The TX Filter High is set to 2700Hz. This gives me a transmit filter width of 2550Hz which is well within the 2700Hz standard for the HF bands.

I also set the compression level to +10dB to increase the average talk power of the audio.

Next in the transmit audio chain is the TX Equalisation. The PiHPSDR software has a very good software defined Parametric EQ menu that provides all the audio tailoring capabilities any HAM operator will ever need.

Having watched many videos by the great Bob Heil, K9EID (SK) I understand that all the articulation in the voice is around the 2500hz range. Today on the HF bands you often hear bass heavy audio that sounds muddy and horrible. This is exactly the type of audio I don’t want to have so, to this end I have adjusted my EQ settings such that the articulation is accentuated to increase clarity and give a little pep to my rather dull sounding voice.

Since the transmit filter width is set from 150Hz to 2700Hz there’s really no point in making EQ adjustments outside of this range. As show above I have made the following changes to the transmit EQ settings in PiHPSDR:

Frequency	Gain
150hz	+6dB
500Hz	+5dB
1500Hz	+6dB
2500Hz	+6dB

The final part of the audio setup is the Mic Gain, I keep this set at 5. This keeps the audio nice and tidy with no IMD.

My HL2 TX Drive is set so that it puts out a maximum of 500mW, this is enough to drive my Xiegu XPA125B amplifier to 100W.

With these settings I find that the Sennheiser headset, PiHPSDR software and the Hermes Lite 2 combination gives me a great signal on all the HF bands.

I hope this helps all those who have asked how my audio is setup and have been so impressed by this great little radio.

More soon …

19 January 202511 August 2026

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.

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.

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

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

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

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

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.

main-uf2 Download

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 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 …

10 December 202413 May 2025

Using the DL1YCF version of PiHPSDR with the RadioBerry

(This information is also for the Hermes Lite 2, Adalm Pluto, Pluto+ and LibreSDR)

During my RadioBerry build I started out using the version of PiHPSDR that was created just for the RadioBerry. The problem with this is that it is hard coded for a very small screen making it hard to use on a big screen since the user cannot resize the window dynamically.

I decided to look for a forked version of the PiHPSDR software that had the ability to change the window size to suit all use cases. During my search I stumbled across the DL1YCF fork of the source code that has some enhancements, one of which is the ability to change the display size.

In no time at all I had the source code downloaded and compiled only to find that it didn’t work with the RadioBerry. After some investigation I found that this was due to the fact that the RadioBerry software has compiled into it code that is used to access the GPIO pins on the RaspberryPi so that it can communicate with the RadioBerry HAT. This is fine except that the DL1YCF version of PiHPSDR also has code in it to use the GPIO pins. This of course causes a conflict and the net result is that nothing works.

Reading through the source code and Makefile I found that all I needed to do was to compile a version of PiHPSDR without GPIO support. This would then remove the conflict and allow the RadioBerry software to operate correctly.

To this end I put together a download/compile/install script for the DL1YCF version of PiHPSDR that will work on a RaspberryPi with a RadioBerry HAT and give the ability to resize the window to fit any size screen.

The script also works on a Linux Desktop PC running Ubuntu/Kubuntu/Linuxmint/Debian operating systems. (It will most likely work on other distro’s too but, these are all I have to hand currently). You can of course also use this software with a Hermes Lite 2 transceiver.

DL1YCF PiHPSDR running on RaspberryPi 4 with RadioBerry HAT on a large monitor

To install this enhanced version of PiHPSDR on your RaspberryPi/Desktop PC with GPIO support disabled, download the installation script below, unzip it and run it in a terminal on your RaspberryPi/Desktop PC in your home directory. (/home/<your-username>).

The script will download the latest source code from the DL1YCF github, disable the GPIO code and then compile and install it to your computer. If installing on a RaspberryPi it will create an icon on the desktop for you to use to start the software.

If installing on a PC then you will need to create your own desktop icon as the one created only works on a RaspberryPi. You can of course just start the software from the command line in a terminal. (My preferred method).

If you have a RaspberryPi 5 then I highly recommend that you run this version of PiHPSDR on it as it has a lot more computing power and handles using dual receive with ease. It will run on a Pi4 but, you will load the CPU more as it’s not as powerful as the later model Pi5.

The script will ask if you want to compile in SOAPYSDR support so that PiHPSDR will work with RTL-SDR, Adalm-Pluto, Pluto+ and LibreSDR. Enter Y to compile in support or N if you don’t need it.

install-pihpsdr-v22-update Download

I hope this proves useful to all the RadioBerry, Hermes Lite 2 and Pluto users out there who want to use PiHPSDR on a big screen.

More soon …