Kubuntu – Page 2 – M0AWS Amateur Radio

14 December 202428 February 2025

Building a new Desktop Environment for the RaspberryPi 5

Regular readers of my blog will already know that I am a huge fan of the Linux operating system, it’s clearly evident in most of the content on this website.

I am also a very enthusiastic user of one of the first credit card sized computers that came to be, namely the RaspberryPi. I own all the iterations of this wonderful little computer from the very first version to the latest and greatest, RaspberryPi 5.

This little computer has done more for computing in education than Microsoft and Apple will ever achieve and it’s done it at an incredibly low price making it more accessible to schools, colleges and students than any other platform.

The RaspberryPi has what most consider to be the best support on the planet when it comes to single board computers (SBCs). From the dedicated team that build Raspberry Pi OS, to all the amazing projects and forums that are available, for free on the internet today.

The RaspberryPi computer really has revolutionised computing for the masses.

My RaspberryPi 5 that I am writing this article on — My RaspberryPi 5 that I am using to write this article.

Raspberry Pi OS really is very good. It’s based on the great Debian distro’ that many of us seasoned Linux users dearly love. It’s light weight, fast and meets the needs of everyone that is venturing into the exciting world of Linux and SBCs for the first time.

Overtime as we all become more experienced with Linux on the RaspberryPi we become more demanding and start to find the Raspberry Pi OS desktop environment lacking. Sure it can be enhanced by adding more and more to it however, it never quite reaches the point of satisfaction and we are always wishing for something more.

With the Pi-5, the latest iteration of this great credit card sized computer, users are now able to seriously think about building a more powerful desktop environment for their little berry flavoured computers.

On my desktop PCs dotted around the house I have used Kubuntu for decades. It’s a slick and powerful desktop environment that has met my needs for many years and I love it more than any other Linux desktop. Sadly Kubuntu isn’t easily available out the box for the RaspberryPi and so I decided that it was time to replicate it as closely as possible on my new, super powerful RaspberryPi 5.

When I ordered my RaspberryPi 5 from Pimoroni I added the NVMe base and 250GB M.2 SSD drive to the order. Up until now I’d always used SD cards however, they are slow and unreliable and so I decided that since the Pi-5 has PCIe it was time to take the step away from SD cards and start using SSD technology.

Getting the OS onto the SSD is a two stage affair. First you have to create a bootable SD card to boot the Pi-5 from and then use it via the RaspberryPi Imager to install the OS onto the SSD. It’s a bit long winded but, easy enough.

Since I’m a huge Kubuntu fan I decided my desktop of choice for my new Pi-5 was going to be KDE-Plasma. I had tried to install this desktop before on older model Pi’s however, it ran so slow that it was unusable. With the new Pi-5’s increased computing power and the speed of the SSD I was confident that this was now possible.

I started out installing the Lite version of Raspberry Pi OS on the SSD. This is a command line only version of Linux that doesn’t include any desktop environment, a nice clean slate to start from.

RaspberryPi Imager showing Pi OS Liite (64bit) — RaspberryPi Imager showing Pi OS Lite (64bit)

Once the Lite version of the OS was installed on the SSD I shutdown the Pi-5 and removed the SD card and then powered the Pi-5 back up again so that it booted from the SSD.

Upon booting I was presented with the simple Linux Login prompt. After entering my username and password as setup during OS install I landed at the Linux command prompt.

sudo su -

I used sudo to become root user as shown above and then set about building my new KDE based super computer. First I needed to update the operating system with all the latest patches and security fixes.

apt update && apt dist-upgrade

The update and upgrade process ran for a while but, it was soon complete.

reboot

I issued the reboot command and then logged back in again, I was now ready to start building the KDE desktop environment.

sudo su -
apt install kde-plasma-desktop gldriver-test

Becoming root again I type the command to install the KDE-Plasma desktop and the graphics-related config services. There’s a lot of packages to download and install so, I left it to do its thing.

A little while later all the packages were installed and ready to go. I now needed to tell the system to boot into the new graphical user interface instead of the command prompt using systemctl.

systemctl set-default graphical.target

Once this was done I needed to make a change to the display settings using the raspi-config program.

raspi-config

Selecting No.2 on the menu, Display Options and then D2 Screen Blanking, I disabled screen blanking so that I got the full 4K support for my KDE Desktop.

Once the system had been configured for a graphical user interface there was only one thing left to do and that was to shutdown the RaspberryPi.

shutdown -h now

The beautiful KDE-Plasma Desktop on RaspberryPi 5

Powering the Pi-5 back up again I was greeted by the standard KDE Plasma login screen and then, after logging in I was transported to the beautiful KDE desktop. I was now smiling like a Cheshire cat!

The KDE desktop is incredibly snappy on the Pi-5 with an SSD, app’s open instantly and run with minimum CPU exertion. It was now time to load the rest of the KDE application suite to complete the build. Popping open a terminal I hit the command line once more.

sudo su -
apt install kde-full vim yakuake vlc firefox rsyslog

This loads the full set of KDE applications adding just about everything you’ll ever need to the desktop environment. It’s about 1GB of packages and so depending on your internet speed it could take a while but, it’s well worth the wait.

Once complete you are ready to go with a fully functional, snappy, powerful desktop.

I’m extremely pleased with the performance of the Pi-5. KDE is super fast, snappy and responsive. With 8GB of RAM on tap the RaspberryPi has no problem with performance. The Pi-5 and KDE-Plasma really do make a great desktop computer at an incredible cheap price.

Looking for a new computer?

Add a cheap USB sound card and a pair of speakers and this little setup will meet the needs of 90% of the population with ease and go on to satisfy the more seasoned, demanding Linux user or programmer without breaking the bank.

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 …

19 November 202429 November 2024

Another new radio!

Many years ago when I lived in France I had a Flex-3000 transceiver, one of the first fully SDR transceivers on the market. It was paired with a proprietary Windows XP application called PowerSDR (now Opensource and called Thetis) and connected via a firewire connection.

17 years later I am once again venturing into the world of SDR transceivers in the form of a Hermes Lite 2. (HL2)

The HL2 hardware is available via the Makerfabs website in kit form. I ordered the HL2 motherboard, the N2ADR Filter Board to ensure a clean signal from the transceiver and the enclosure. Total cost for all the parts and shipping was £288.00 including all taxes.

The kit took about 10 or so days to arrive and was very easy to put together making sure to fit the PA transistor heat sink the right way round so that it doesn’t short out the main board. (There are many videos about this on YouTube)

Once the hardware was put together I needed to install some software to control/drive the HL2. Being a heavy weight Linux user my software choice had to come from the Opensource world.

M0AWS Hermes Lite 2 SDR Trasnceiver and Xiegu XPA125B Amplifier

After much research and chatting with other HAMs on the Matrix who have the HL2 I found that most people use the closed source SDR Console software to control the transceiver. Since this software is for Windows it’s not something I can use as I don’t have any Windows PCs, they’re all Linux only.

To this end I started researching Linux SDR software for the HL2 and decided that PiHPSDR was the one I was going to try first.

PiHPSDR was originally written for the RaspberryPi 3/4/5 single board computers (SBCs) but, I wanted to have a go at compiling it on my Kubunu Linux desktop PC. I found it straight forward to follow the instructions in the pihpsdr-install.pdf file and in no time at all I had the software compiled and running.

PiHPSDT running on Kubuntu Linux 22.04LTS — PiHPSDR running on Kubuntu Linux 22.04LTS

PiHPSDR is infinitely configurable and thus it feels like it has an infinite number of menus and options. Since the HL2 has two separate receivers, it’s possible to listen to two bands at the same time. This is the one feature I really missed more than anything with my FTDX10 so, I’m glad to have dual receive capability back once more!

Going through all the settings I realised that the A and B VFOs have individual settings. Initially I setup the software using just VFO A but, when I switched over to VFO B none of my settings were there. I then had the realisation that the settings apply only to the active VFO. I quickly went through all the settings again for VFO B and all was well.

In no time at all I was on the air with just 5w as my Xiegu amp hadn’t arrived. Not being perturbed I tuned up on the 15m band and started searching for stations. Interestingly it was CQWW SSB weekend and the band was full of contest stations. Working my way along the spectrum I found I was able to work quite a few stations with ease using my vertical and inverted-L antennas.

Contacts of note were VE3KG at 3406 Miles, VE3JM at 3382 Miles, RW9DX at 2380 Miles, KC1XX at 3331 Miles and N1DE at 3600 Miles. I also worked a bunch of European stations and had a great time giving away points with my little QRP rig.

Contests are a good time to try out new radios as all the big stations with good ears are on the bands and make the effort to get us QRP guys in their logs.

I have been extremely impressed with the receivers in the HL2 radio. It handles both strong and weak stations exceptionally well. PiHPSDR really does have brick-wall filtering and I was able to work the weaker stations right next to large contest stations with ease. At no time did the front-end of the receiver get overloaded.

Below is a short video clip of a conversation on the 80m band. The band was quite noisy however, with a reduction of the AGC gain and the 2700Hz filter it’s possible to remove almost all the noise.

Hermes Lite 2 SSB reception on the 80m Band

On CW the radio is a real delight. With the filtering and AGC gain control I am able to use extremely narrow receive filters without any ringing whatsoever. I would say that on CW the HL2 is as good as my FTDX10 when it comes to receiving even the weakest of stations.

I’m sure on paper the FTDX10 receiver has better numbers however, to the ear there really is no discernible difference.

Below is a short video clip of D4DX on CW on the 80m band. The band was noisy but, with the 100Hz filter enabled and clever use of the AGC Gain I was able to remove almost all the noise completely, reducing fatigue on the ears and making reception very easy even though there was some fairly deep QSB at times.

Receiving D4DX on CW on the 80m band using 100Hz filter and reduced AGC gain

A few days later my Xiegu XPA125B amplifier arrived. Unfortunately the amp didn’t come with the normal PTT lead that comes from the factory and is detailed in the user manual. For some bizarre reason this is a chargeable option when you buy the amp from Martin Lynch and Sons even though it is included from the factory.

This meant I had to make a lead which was a problem as I didn’t have one of the mini DIN plugs required for the connection to the amplifier. Jumping onto Amazon I ordered a packet of two and sat back and waited for their arrival.

A couple of days later the DIN plugs arrived and I quickly made up the necessary phono/RCA to mini DIN lead and got the amp operational.

The Xiegu XPA125B isn’t cheap but, it’s a really nice bit of kit. The neat little LCD display keeps you informed of power O/P, I/P and O/P SWR, voltage, current draw, temperature and band selected.

With just 0.7w of input from the HL2 I’m able to get a full 100w O/P from the amp. On the lower bands I have to reduce the O/P from the Hermes Lite 2 even further so that I don’t over drive the amp.

Being an avid Short Wave Listener (SWL) I wanted to see how the HL2 performed when listening to the big AM broadcast stations. To my surprise it makes an excellent SWL receiver with better AM demodulation than many of the more expensive radios. Having the option to select receive filters up to 16Khz wide I found I was able to get the best audio possible from many of the broadcast stations including Radio Caroline on 648Khz. It’s quite an improvement over the 12Khz maximum on the FTDX10.

Listening to AM Broadcast stations

What makes this project even more exciting is that both the hardware and software are from the OpenHardware/OpenSource world. The complete circuit diagram, PCB layout and information is available for all to download, something you don’t often see these days!

PiHPSDR is one of the nicest SDR applications I’ve seen in the Linux world and even comes with a 200 page downloadable user manual. Something you don’t see in many Opensource projects. The source code for the application is downloadable and you are able to make your own changes to it without restriction.

Overall I am really pleased with the Hermes Lite 2 SDR transceiver.
It has two excellent receivers, is infinitely configurable via the PiHPSDR software and performs extremely well under all conditions. Since getting the radio I haven’t even switched on the FTDX10.

More soon …

12 September 202418 October 2024

AllStarLink Control Dashboard

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

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

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

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

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

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

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

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

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

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

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

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

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

AllStarLink-Dashboard-v1-2 Download

Note: The link above is now for v1.2 of the flow which includes some critical bug fixes. You can read about the bug fixes in the v1.2 release article.

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

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

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

Node-RED Flow Editor Palette Install Tab

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

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

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

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

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

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

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

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

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

More soon …

13 May 202413 May 2024

Update to my NodeRed QO-100 Dashboard

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

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

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

M0AWS - Sennheiser SC 165 — M0AWS – Sennheiser SC 165 Headset

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

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

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

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

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

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

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

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

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

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

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

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

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

More soon …

3 February 202420 February 2024

Taking the Hiss out of QO-100

I’ve been on the QO-100 satellite for about 7 months now and I have to admit I love it!

Having a “Repeater In The Sky” that covers a third of the world really is a wonderful facility to have access to however, there is one thing that I find tiring and that is the high level of background noise that is always present.

Even though the signals are mostly 59-59+15dB the background “hiss” is very pronounced and gets very tiring after a while, especially if like me you have tinnitus.

Currently I’m using a NooElec Smart SDR for the receiver and GQRX SDR software on my Kubuntu Linux PC. This works great but, there is one short fall, there is no DSP Noise Reduction (NR) in the software or hardware.

To fix this I recently invested in a BHI Dual In -Line Noise Eliminating Module. The unit itself is nicely put together and has a good combination of inputs and outputs making it easy to connect up to my MacBook Pro to record QSOs and connect my headphones at the same time.

M0AWS BHI Dual In-Line Noise Eliminating Module

At £189.95 plus postage from BHI direct it’s not cheap but, it is nicely put together and comes complete with a power lead and a couple of cheap audio cables. The quality of the knobs and mechanisms is good apart from the little grey DSP Filter Level knob that feels cheap and is very wobbly on the switch below. I’m not sure how long this is going to last with prolonged use and will most likely need replacing with something a little sturdier at some point in the future.

Overall noise reduction is good but, the audio amplifiers on the Audio Input Level and Line Out Level distort very early on in their range and you cannot get them much above level 5 before distortion starts to appear on the received signal. This is disappointing as my headphones are of reasonable quality and are let down by the distortion creeping in from the audio amplifier in the BHI unit.

I’ve tried altering the levels on the input from the IC-705 and no matter what I cannot get a good audio signal in my headphones without some distortion on the higher frequency ranges.

Overall the device does do what I want, it reduces the background “hash” considerably reducing the fatigue whilst chatting on the satellite. Below is a recording from a conversation on the satellite showing the noise reduction performance of the BHI module.

M0AWS Example BHI DSP NR Recording

The recording starts with the BHI DSP NR off, at 00:07 the DSP NR is switched on, you can clearly hear the difference. At 00:23 the DSP NR is turned off again and at 00:36 the DSP NR is turned on again. The BHI DSP NR Module is set with the DSP Filter Level set at 3 out of 8 which appears to be the best level to use. Switching to level 4 starts to introduce digital artefacts to the audio which only gets worse the higher the DSP Filter Level goes.

With a setting above level 3 there really isn’t much improvement in noise reduction and the audio becomes progressively more affected by the digital artefacts than it does from the background noise.

M0AWS BHI Dual In-Line Noise Eliminating Module with Icom IC-705 QO-100 Ground Station

The only other problem I have with the BHI Dual In-Line Noise Eliminating Module is that is comes in a plastic case. The case itself is solid and of good quality however, it offers no RF shielding whatsoever and the unit is extremely susceptible to RF getting into the audio chain and then being heard during transmit in the headphones and via the line out connections. For the money I would had expected the unit to come in a metal case that provides proper RF shielding. This is a real shame as it lets the unit down considerably.

As setup in the photo above I am using 300mW O/P on 144Mhz from the IC-705 into a perfect 1:1 SWR presented by the DX Patrol 2.4Ghz Upconverter via some very high quality LMR-400 Coaxial cable from Barenco but, I get terrible RF interference via the BHI unit during the transmit cycle. Considering I am only using 300mW I dread to think what it may be like if I was using a 100w HF radio. This is something I need to investigate further as it really is very annoying.

Moving the unit to a different location in the radio room does help a bit but, doesn’t solve the problem completely. At 300mW RF O/P I really didn’t expect there to be a problem with RF getting into the BHI unit.

Having a proper line-out facility on the BHI unit really is nice as it makes it very easy to connect to my MacBook Pro to obtain good quality recordings of signals on the QO-100 satellite as can be listened to above.

Overall I am happy with the BHI Dual In-Line Noise Eliminating Module but, do wish that more care had been taken over using a metal case instead of a plastic case to protect the unit from RF ingress and better audio amplifiers within the unit that don’t distort/clip so early on in their O/P levels.

Is this the perfect noise reduction unit?

No but, overall it is better than nothing and does help to reduce the background noise to a more acceptable level reducing the overall fatigue during prolonged conversations on the QO-100 satellite.

UPDATE: I tried the BHI unit with my FTDX10 on the HF bands and the RF interference is horrendous, even when using QRP power levels! This device clearly hasn’t been designed to work in an RF environment and the total lack of shielding or isolation lets it down terribly. If you are an SWL then this unit is fine but, if like me you like to monitor your transmitted audio whilst on air through headphones then this isn’t the unit for you. To prove the problem isn’t in the radio shack I put the BHI unit in the house some 30m away powered by 12v battery with nothing connected but a pair of headphones and still the unit suffered from RF interference even at QRP levels.

More soon …

8 June 20238 June 2023

Replacement for the Funcube Dongle Pro+

For some time now I’ve been using my Funcube Dongle Pro+ (FCD) as my QO-100 downlink receiver. It’s worked fairly well and has given me the ability to listen to stations on the satellite over the last few months.

During this time I have noticed a couple of things about the FCD that has lead me to the final decision to change to a new SDR device.

The first of these ‘things’ is the fact that the FCD gets seriously overloaded when there are multiple large SSB signals within the receive pass band. The only way to manage this is to constantly keep changing the software based AGC, mix and LNA settings to reduce the levels of the incoming signals so that the overloading stops. This is great except when you tune to a quiet part of the satellite transponder you have to turn all the settings back up again to be able to hear the weaker signals. After a while this becomes tiresome.

The fact that there isn’t a hardware AGC in the FCD is a major drawback when being used for satellite reception especially when it’s on the end of a very high gain LNB and dish antenna.

The second of these ‘things’ is the fact that I can’t see the whole transponder bandwidth at one time with the FCD as it has a very small receive bandwidth capability. This means that I am constantly tuning up and down the transponder to see if there are any stations further up or down in frequency.

Talking to more experienced satellite operators in the Matrix Amateur Radio Satellites room they recommended replacing the FCD with a NooElec NESDR SMArt v5 that has hardware AGC and is capable of receiving and displaying a much wider bandwidth.

Looking on Amazon the NooElec NESDR SMArt v5 is only £33 so I decided to place an order for one and give it try.

In typical Amazon style the SDR receiver arrived the next day and I wasted no time getting it plugged in and connected to the QO-100 ground station.

The NESDR SMArt v5 is based on the well known RTL-SDR that came onto the market some time back but, has a number of improvements in it that take it to the next level.

The first thing that I was happy with was the fact that the GQRX SDR software I use recognised it immediately on startup, no configuration or drivers were required it just worked, straight out of the box. Since I use Kubuntu Linux on my radio room PC I did wonder if I would need to get into installing extra libraries etc but, thankfully none of that was required.

Looking at the signals from the QO-100 satellite initially they appeared to be nowhere near as strong as they were on with the FCD. Looking at the settings in GQRX I noticed that the hardware AGC was off and the LNA setting was back to it’s default very low level.

I switched on the AGC and then increased the LNA setting to 38.4dB and found that the signals were now plenty strong enough on the display but, not overloading the receiver.

I then went on to adjust the display so that I could see the whole satellite transponder bandwidth on the screen. This is great as it enables me to see the low, middle and high beacons that mark out the narrow band section of the transponder and at a glance see all the stations using the satellite. This was a massive improvement in itself and one that I am very pleased with.

Using the NooElec NESDR SMArt v5 SDR it very soon became clear that it copes with multiple large signals in the pass band so much better than the FCD did. There’s no more overloading of the receiver, no more ghost signals appearing on the waterfall due to the front end not being able to cope and no more having to constantly keep playing with the settings to get things under control. The hardware AGC built into the SDR device does a great job at keeping it all under control whilst receiving a much wider bandwidth than the FCD ever could.

The satellite beacons are now received at S9+15dB without the receiver being overloaded, the first time I have seen this since starting out on my QO-100 venture.

The other thing that became obvious very quickly is that frequency stability is much better than it was with the FCD, it doesn’t drift up and down the transponder now and stays tuned exactly where I put it. It’s also on frequency whereas, the FCD was always 1.7Khz off frequency.

The NooElec NESDR SMArt v5 is very well put together, it has an aluminium case that acts as a heatsink (it does get warm!) and overall the build quality is much better than the plastic cased FCD. When I think that I paid close to £100 for the FCD and the NooElec NESDR SMArt v5 only cost £33, I am amazed at the build quality.

Overall I’m extremely pleased with the purchase of the new SDR, it slotted in perfectly as a replacement for the FCD, works great with GQRX, my QO-100 Node Red Dashboard and performs considerably better than the FCD. Overall money well spent!

You can find the NooElec NESDR SMArt v5 spec sheet here.

More soon …

7 June 202324 July 2023

UPDATE: QO-100 Node Red Dashboard

I’ve been making a few improvements to my QO-100 Node Red Dashboard whilst waiting for the 2.4Ghz hardware to arrive. I’ve added the ability to split the RX and TX VFOs so that I can tune away from the TX frequency for working split stations or for tuning to slightly off frequency stations. I also added a series of tuning buttons to the top of the GQRX side of the dashboard to enable easy tuning using the trackball connected to my Kubuntu PC. This worked well but, I really missed having a real VFO knob like a conventional radio.

As I had a Griffin Powewrmate USB VFO from a previous SDR radio I added it to the flow as well so that I had a physical VFO knob for the SDR receiver. Details on how I got it working using evtest and a simple BASH script are in the Griffin Powermate article.

The Node Red flow is looking a little busier with the addition of split mode and the Griffin Powermate USB VFO which has really enhanced the useability of the solution. It’s very impressive what can be achieved with Node Red with a little imagination. You really don’t need to be a heavy weight programmer to make things work.

M0AWS QO-100 Node Red Dashboard as of 07/06/23

I also put together some code to calculate the S Meter reading from the dBFS data the GQRX SDR software generates. It’s not 100% accurate but, it’s close enough to be useful.

On the IC-705 side of the Dashboard I also now display the 2.4Ghz uplink frequency so that it’s available for logging.

So with the QO-100 Dashboard ready to go live I have now started putting together the 2.4Ghz transmit path of the ground station. I have the 2.4Ghz transverter and matching 12w amplifier from DXPatrol, the IceCone Helix 2.4Ghz antenna from Nolle Engineering, some LMR-400-UF and connectors from Barenco and an appropriate water proof enclosure from Screwfix to fit all the kit into however, I’m now being held up by one simple little SMA male to SMA male connector that I need to connect the transverter and amp together.

M0AWS Waterproof enclosure from Screwfix

M0AWS Laying out the 2.4Ghz TX kit in the enclosure — M0AWS Waterproof enclosure from Screwfix

The SMA connector has been ordered but, is taking a month of Sundays to arrive! Hopefully it’ll arrive soon and I’ll finally get on the QO-100 satellite and start enjoying the fun.

More soon …

4 June 20237 June 2023

Use a Griffin Powermate with SDR via Node Red

I’ve been gradually building my QO-100 ground station over the last few months and have had the receive path working for some time now. One of the things I really miss with the Funcube Dongle Pro+ (FCD) SDR is a real VFO knob for changing frequency.

My QO-100 Node Red dashboard is configured so that I can have the FCD track the uplink frequency from the IC-705 but, sometimes I use the FCD without the IC-705 in the shack and so a physical VFO would be handy.

Many years ago when I lived in France (F5VKM) I had a Flexradio Flex-3000 SDR, a great radio in it’s time and one that gave me many hours of enjoyment. One addition I bought for that station was a Griffin Technology Powermate VFO knob. It worked extremely well with the PowerSDR software for the Flex-3000 and I used it for many years.

Many years later I’m back in the UK and much of my equipment is packed away in the attic, including the Griffin Technology Powermate VFO.

I decided to dig it out and see if I could get it working with GQRX SDR software. Sadly I couldn’t get it working with GQRX however, I did find a way of getting it working with Node Red and thus could add it to my QO-100 Node Red Dashboard and then control GQRX with it via a simple Node Red flow.

Plugging the Powermate VFO into my Kubuntu PC it wasn’t immediately recognised by the Linux O/S. After a little searching I found the driver on Github. I added the PPA to my aptitude sources and installed the driver using apt.

_{https://launchpad.net/~stefansundin/+archive/ubuntu/powermate}

Once installed the default config for the Powermate device is to control the default audio device volume. To make the device available for use as a VFO knob you need to change the configuration so that the default setting is disabled. To do this is relatively easy, just edit the config file using your favourite command line editor (Vi/Vim in my case) and add the following entry.

vi /etc/powermate.toml

# Entry to control HDMI volume with Powermate
#sink_name = "alsa_output.pci-0000_01_00.1.hdmi-stereo"

# Set powermate not to work with volume control
sink_name = ""

As shown above, comment out the default “sink_name” entry (Yours may be different depending on audio device in your PC) and add in the Powermate “sink_name” entry that effectively assigns it to nothing.

Once this is done, save the file and exit your editor and then reboot the PC.

Next you’ll need to install a small program called evtest.

sudo apt install evtest

To check the evtest program has installed correctly, plugin your Powermate VFO to any available USB port and run the following command in a terminal.

evtest /dev/input/powermate

Turning the Powermate knob you should see output on the screen showing the input from the device. You should also see BTN events for each press of the Powermate device.

_{Input driver version is 1.0.1
Input device ID: bus 0x3 vendor 0x77d product 0x410 version 0x400
Input device name: "Griffin PowerMate"
Supported events:
  Event type 0 (EV_SYN)
  Event type 1 (EV_KEY)
    Event code 256 (BTN_0)
  Event type 2 (EV_REL)
    Event code 7 (REL_DIAL)
  Event type 4 (EV_MSC)
    Event code 1 (MSC_PULSELED)
Properties:
Testing ... (interrupt to exit)
Event: time 1685816662.086666, type 2 (EV_REL), code 7 (REL_DIAL), value -1
Event: time 1685816662.086666, -------------- SYN_REPORT ------------
Event: time 1685816662.318638, type 2 (EV_REL), code 7 (REL_DIAL), value -1
Event: time 1685816662.318638, -------------- SYN_REPORT ------------
Event: time 1685816662.574615, type 2 (EV_REL), code 7 (REL_DIAL), value -1
Event: time 1685816662.574615, -------------- SYN_REPORT ------------
Event: time 1685816663.670461, type 2 (EV_REL), code 7 (REL_DIAL), value 1
Event: time 1685816663.670461, -------------- SYN_REPORT ------------
Event: time 1685816664.030421, type 2 (EV_REL), code 7 (REL_DIAL), value 1
Event: time 1685816664.030421, -------------- SYN_REPORT ------------
Event: time 1685816664.334389, type 2 (EV_REL), code 7 (REL_DIAL), value 1
Event: time 1685816664.334389, -------------- SYN_REPORT ------------
Event: time 1685816665.334255, type 1 (EV_KEY), code 256 (BTN_0), value 1
Event: time 1685816665.334255, -------------- SYN_REPORT ------------
Event: time 1685816665.558230, type 1 (EV_KEY), code 256 (BTN_0), value 0
Event: time 1685816665.558230, -------------- SYN_REPORT ------------
Event: time 1685816666.030161, type 1 (EV_KEY), code 256 (BTN_0), value 1
Event: time 1685816666.030161, -------------- SYN_REPORT ------------
Event: time 1685816666.182151, type 1 (EV_KEY), code 256 (BTN_0), value 0
Event: time 1685816666.182151, -------------- SYN_REPORT ------------}

At this point you’re ready to stop evtest (CTRL-C) and then create the following little BASH shell script that Node Red will run to collect the O/P from the Powermate USB device.

#!/bin/bash

###############################################
# Griffin Technology Powermate control script #
# for Node Red.                               #
#                                             #
# 04/06/23 - M0AWS - v0.1                     #
#                                             #
###############################################

VAL="1"
echo "STEP-1Hz"

/usr/bin/evtest /dev/input/powermate | while read LINE 
do
   case $LINE in

      *"(REL_DIAL), value 1") echo "$VAL"
           ;;

      *"(REL_DIAL), value -1") echo "-$VAL"
           ;;

      *"(BTN_0), value 1") case $VAL in

                              "1") VAL="10"
                                   echo "STEP-10Hz"
                                      ;;

                             "10") VAL="100"
                                   echo "STEP-100Hz"
                                      ;;

                             "100") VAL="1000"
                                    echo "STEP-1Khz"
                                       ;;

                             "1000") VAL="10000"
                                     echo "STEP-10Khz"
                                         ;;

                             "10000") VAL="1"
                                       echo "STEP-1Hz"
                                          ;;
                              esac
                                 ;;
        esac
done

Once the BASH script is copied and pasted into a file called powermate.sh you need to make it executable by using the following command.

chmod 700 ./powermate.sh

If you now run the shell script in a terminal you’ll see a similar output to that shown below from the device when used.

./powermate.sh 
STEP-1Hz
-1
-1
-1
1
1
1
STEP-10Hz
10
10
10
-10
-10
-10
STEP-100Hz
100
-100
-100
STEP-1Khz
1000
STEP-10Khz
STEP-1Hz
1
1
STEP-10Hz

As you can see above the shell script outputs a positive or negative number for VFO tuning and changes the VFO step size each time the Powermate is depressed.

Getting this output from the BASH shell script into Node Red is really simple to achieve using just 3 or 4 nodes.

In the Node Red development UI create the following nodes.

The first node in the flow is a simple inject node, here I called it trigger. This sends a timestamp into the next node in the flow at startup to set the flow running.

The Griffin Powermate node is a simple exec node that runs the script we created above.

Configure the node as shown above and connect it to the inject node that’s used as a trigger. Note: Change “user” in the Command field shown above to that of your username on your Linux PC)

Once done create the third node in the flow, a simple switch node and configure as shown below.

The switch node has two outputs, the top one is a text output that is fed into a text field to show the current step size of the Powermate device and the lower output is the numeric output that must be fed into your VFO control flow so that the VFO value is incremented/decremented by the amount output by the Powermate device.

I’ve found the Griffin Technology Powermate USB device works extremely well with Node Red and GQRX that I use for controlling the FCD SDR radio and it’s now part of my QO-100 ground station build.

M0AWS QO-100 Dashboard with Powermate Step Display at bottom

As shown above you can see the Powermate Step size at the bottom of the dashboard, this text changes each time the Powermate device is depressed and will set a step size of 1Hz, 10Hz, 100Hz, 1Khz, 10Khz in a round-robin fashion.

The next stage of the build is the 2.4Ghz transmit path. I now have all the necessary hardware and so this part of the build can finally commence.

More soon …

3 April 2023

QO-100 Satellite Node Red Dashboard

Whilst I’ve been waiting for the weather to improve so that I can get my QO-100 dish antenna up I’ve been working on my QO-100 Node Red dashboard.

The idea of the dash board is to bring together the operating of the receiver and transmitter into one control centre so that the two separate devices are able to communicate and behave as if they were actually one device, like a transceiver rather than being individual components.

Ideally I would like to have the transmitter and receiver talking to each other such that when the VFO on the transmitter is incremented/decremented the receiver VFO also moves by the same amount.

By doing this the receiver VFO should always be in the right place on the 10Ghz band to hear my 2.4Ghz uplink signal and of course, any station coming back to my CQ calls.

So far I’ve only been working on the receive part of the Node Red flow, it’s certainly been a lot of fun getting it put together.

I control my Funcube Dongle Pro+ (FCD) using GQRX SDR on my Kubuntu PC. This software is working extremely well with the FCD and I’m happy with the level of functionality it offers.

GQRX SDR has the ability built in to control the SDR via remote TCP connection using RIGCTL protocol. Currently there isn’t a RIGCTL node available for Node Red so I have written a number of Javascript function nodes that provide the appropriate functionality in conjunction with a standard Node Red TCP node. This is working extremely well on the local LAN in the radio room and is proving to be very stable and responsive.

M0AWS QO-100 Node Red Flow – Receive Section

The flow for the receive section of the dashboard looks fairly complicated but, in reality it’s really not too difficult to get to grips with. The receive flow provides the facility to switch bands, switch modes, change receiver filter band width, display a realtime signal strength meter, receive +/- clarifier in 10/100/1000Hz increments and put the receiver into QO-100 mode where the SDR VFO is tuned to 739.550Mhz whilst the dashboard VFO shows the QO-100 downlink frequency in the 10Ghz band. This is all working very well and I’m happy with the initial result.

M0AWS QO-100 Receive Dashboard in QO-100 mode

I now need to start work on the transmit side of the QO-100 dashboard and get communications between my IC-705 transceiver and the FCD SDR working via Node Red. This could be a little more challenging as it will involve communicating with the IC-705 via WFView over wifi.

More soon …