Antenna – M0AWS Amateur Radio

23 August 2026

Building MB7IBW 2m AllStarLink Internet Gateway

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

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

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

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

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

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

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

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

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

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

MB7IBW Internet Gateway hardware at the M0AWS QTH

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

More soon …

30 March 20269 April 2026

ISS Astronaut talks to UK students

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

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

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

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

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

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

More soon …

10 February 202620 February 2026

Sign the partition to allow UK HAMs to put up antennas

There’s a new partition that has been started in the UK to allow UK licensed radio amateurs to install antennas and masts without planning permission.

https://petition.parliament.uk/petitions/755675

Partition to allow UK Radio operators to install antennas and masts.

If you’re reading this and are a licensed UK Amateur Radio operator please click the link above/below and sign the partition so that we may highlight the subject with the UK government as the RSGB has failed to do this for us for decades now even though members keep asking them to do more on the subject.

https://petition.parliament.uk/petitions/755675

More soon …

13 January 202613 January 2026

Using Node-Red to build interactive log maps

I’ve not been on the radio much over the last few weeks as I’ve had my head down other radio related rabbit holes.

One of the rabbit holes is a Node-Red project to make my online logs a little more interactive. For sometime now my logs have been displayed on my website as nicely formatted, searchable HTML pages however, they don’t really allow the viewer (myself included) to see the global coverage of all the contacts so, I decided to write a Node-Red flow that would do just that.

The flow itself isn’t too complicated and basically consists of reading in the individual ADIF formatted log files, processing the data and then sending the data in the correct format to the map node for display.

I’ve had to write a few functions to handle the processing of the ADIF formatted data but, these aren’t particularly complex and are fairly easy to understand even if like me, you’re not a Javascript programmer.

The flow is working perfectly however, I’m in the process of reworking the format generic payload function to reduce the amount of code and make it more efficient.

M0AWS SSB / CW / FreeDV Interactive Log World Map

The flow generates two maps, one for voice / CW /Satellite contacts and the other for WSJT-X FT4/8 contacts. Every pin on the map is colour coded by band with satellite contacts being denoted by a satellite icon.

Each pin / icon on the map is clickable and reveals the data of the QSO being displayed.

In the top right-hand corner of the map there is a drop down layer menu that allows the viewer to filter by band thus reducing the number of icons on the screen at any one time.

Seeing the data presented on a map really brings my logs alive. An example of this is that I had no idea I’d worked so many stations in India on the QO-100 Satellite.

The small icons in the pins show a microphone for SSB/FM/FreeDV contacts and a downwards pointing triangle in a box for CW contacts. Sadly I couldn’t find a Morse key icon in the collection available.

M0AWS filtered view of QO-100 Satellite contacts

I only use FT4/8 for testing new antenna designs however, it’s interesting to see the global coverage accomplished with this weak signal mode.

M0AWS WSJT-X FT4/8 Interactive Log World Map

Once I’ve finished rewriting the format generic payload function I will make the flow available for download here so that others can also create an interactive view of their radio logs.

If you want to have a look at the maps and try them out for yourself, they are available under the Logs menu above.

This Node-Red instance is running in a virtual machine (VM) on a 16GB RAM RaspberryPi 5 that is also running a number of other VMs at the same time so, it’s safe to say it’s not heavy on CPU and will run on the older Pi4 as well.

More soon …

22 April 202523 April 2025

1946 Philips 170A-15 RadioBerry Receiver Project

Back in January 2025 I wrote an article about a little RadioBerry Project I’d started that was based around a very old Philips 170A-15 receiver from 1946.

The idea of the project was to build a nice shortwave receiver for the radio shack based around the RadioBerry HAT on a RaspberryPi 4 housed in a vintage receiver cabinet.

The project has taken longer than I imagined due to getting side-tracked by other projects that I already had ongoing.

1946 Philips 170A-15 Shortwave Receiver Internal View

With the original internals removed there’s plenty of room inside for the RadioBerry, RaspberryPi 4 and the small 15w audio amplifier. The audio is delivered via a pair of Celestion speakers that I had that were originally part of an old surround sound TV system.

Power distribution is achieved very simply using a multi-plug adapter that also has USB A connections in it. The whole thing is then powered via one 240v mains cable.

The screen fits over the original opening for the glass tuning display and is held in place by two mounting screws on the rear of the LCD panel.

I purchased some new speaker grill cloth from Amazon and remade the speaker grill front with cut outs for the speakers. It looks really tidy and matches the rest of the bakelite cabinet nicely.

1946 Philips 170A-15 Shortwave Receiver RadioBerry HAT on RaspberryPi 4

To finish the project off I need to purchase 3 rotary encoders so that I can have a VFO knob and two more knobs for other things (to be determined). The Volume control is already in place with the original knob fitted to it. It will be nice to complete the 4 knob line up.

1946 Philips 170A-15 Shortwave Receiver Rear Panel

I had to make a couple of fittings top and bottom to hold the original rear panel in place but, it worked out just fine and I only had to fit an SO239 antenna connector and ethernet RJ45 port so that it can be connected to my local LAN.

Receiving radio Caroline on 648Khz

The audio quality from the little RadioBerry and 15w amp is pretty good. With the speakers hidden nicely behind the refurbished speaker grill the project looks quite tidy!

It also makes a great receiver for the HAM bands with it’s coverage of 100Khz to 30Mhz.

The DL1YCF Enhanced fork of PiHPSDR works really well on the touchscreen and provides a modern control interface to the RadioBerry HAT.

Listening to the 20m HAM Band

I’ll drop a final article once I have purchased the 3 rotary encoders to fill the 3 remaining holes in the front of the cabinet.

More soon …

29 January 202529 January 2025

Breathing new life into a vintage receiver

Sometime back I purchased a RadioBerry HAT for my RaspberryPi 4 single board computer (SBC) to use as an experimental platform to test PiHPSDR software modifications and to test changes to the actual RadioBerry software. With these two projects completed I decided that the receiver on the RadioBerry was so good it would be a shame not to put it to good use.

For many decades I’ve been an avid Short Wave Listener (SWL) but, haven’t had a general coverage receiver for many years. The RadioBerry fills this gap in my radio lineup perfectly but, needs to be put into a suitable cabinet with speakers, display, control knobs and antenna connections.

Rather than just buy another bland square box I decided it would be nice to repurpose an old, vintage radio receiver from a bygone era and bring it into the 21st Century.

1950 Philips valve radio receiver — 1946 Philips valve radio receiver

After much searching on the popular auction sites online I eventually found the perfect old receiver for the project, a vintage Philips 170A-15 valve receiver from 1946.

This lovely old Art Deco looking receiver is made from Bakelite which was an early type of plastic made from phenol-formaldehyde resin, obtained from coal tar and methanol.

The full specification for the receiver can be found on the Radio Museum Website.

Sadly this is a non working example of this lovely old receiver and so I don’t feel so guilty stripping it out and replacing it’s internals with the RadioBerry.

1946 Philips receiver Serial Number plate

1946 Philips receiver Licence Plate — 1946 Philips receiver Serial Number plate

Having the original serial number and Licence plate on the radio is nice, it also makes it easy to search for information about the old receiver.

One nice thing I did discover during the disassembly of the receiver was the signature of the person that put the radio together during manufacture on the inside of the Bakelite cabinet.

Getting the internals out of the cabinet was fun, so many little screws holding the old valve electronics and tuning display in place.

1946 Philips Receiver - Internal View — 1946 Philips Receiver – Internal View

1946 Philips receiver - removing the original control knobs — 1946 Philips Receiver – Internal View

Once the electrical part of the radio was removed I gained access to the old speaker that was fitted to the front panel of the receiver. Unfortunately the speaker cone had a tear in it rendering it useless so I’ll need to get a new speaker(s) for the rebuild.

Once I got the speaker and fittings removed I set about cleaning the cabinet inside and out to remove the 79 years worth of dirt and grime that had collected within. The fascia of the receiver cabinet seems to have lost it’s shine and will need to be polished to get it back to it’s original beauty.

79 years worth of grime and dirt to be removed!

Washing the Bakelite receiver case — 79 years worth of grime and dirt to be removed!

It took 5 lots of fresh water and washing up liquid to get the cabinet clean. The first three lots of water looked like mud in no time at all such was the state of the cabinet.

With the cabinet now cleaned and put to one side to dry thoroughly I have started to search for the best type of polish to use to put the sheen back onto it.

Once I’ve got the cabinet looking good again I’ll start fitting the new internals. I also need to find a source for a new piece of material to cover the speaker hole at the front of the cabinet as the original material is looking somewhat tired.

The old Philips Emblem from 1946 on the receiver case

More soon …

24 October 202431 October 2024

Wouxun KG UV-980PL Quad Band Radio

I recently decided to look into a 2m/70cm FM radio for the shack for use on the local 2m/70cm repeaters and was considering the offerings from Yaesu and Icom however, the Wouxun KG UV-980PL caught my eye as it is a quad band, full duplex radio. Not knowing much about Wouxun radios I had to do some research to get an idea of what it’s like. Generally the radio gets very good reviews and most mention the excellent build quality.

There are two versions of the 980P radio, the 980PL that offers 6/4/2m and 70cm bands and the 980P that offers 10/6/2m and 70cm. The 4m is a band I’ve been wanting to try for some time and the 980PL with it’s 4m band coverage became even more appealing.

Wouxun KG UV-980PL Quad Band FM Duplex Transceiver

I decided to take a trip down to Martin Lynch and Sons (MLANDS), a good 2 hours or more drive for me, so that I could get hands on with the radios that I had been looking at.

I invited Alan, G1SQB along for the ride and a day out playing with radios as he lives 3 miles away and we often chat on air.

Arriving at the store we grabbed a hot brew and set about playing with the great selection of radios on display.

I initially looked at the Icom IC-2730E, a dual band full duplex transceiver that has been around for about 10 years and has good reviews. As expected the build quality is excellent and very easy to use. I found I was soon able to set up memories etc via the front panel controls. The only draw back is that it isn’t supported by the CHIRP programming software that I use. Other than that it certainly meets all the requirements for a 2m/70cm FM transceiver

Icom Ic-2730E Duplex FM Transceiver — Icom IC-2730E FM Duplex Transceiver

Next I moved on to the offerings from Yaesu including the FTM-500DE 2m/70cm transceiver. The colour screen is very nice and the menu system very easy to use however, the price is getting on for close to double that of the other radios and it doesn’t really offer anything more that interests me since I’m only looking for an analog radio.

Yaesu FTM-500DR dual band FM Transceiver

Sadly there wasn’t a Wouxun UV-980PL out on display and so I had to persuade the salesman to get one out of stock for me to play with. Unpacking the radio I was surprised at how good the build quality is, it really is comparable to the other radios that I had been looking at.

The Wouxun menu system is fairly easy to use once you’ve looked at the manual and got to grips the abbreviations used. The big plus is that this radio is CHIRP compatible with an optional programming cable (£19) and so loading the memories with repeaters etc will be extremely easy.

The Wouxun has dual receivers built in with a quad-plexer so, you can transmit on one band whilst listening to another band on the other receiver. One thing to note is that the 1st receiver covers all the bands, 6/4/2m and 70cm however, the 2nd receiver only covers 2m and 70cm so, it’s not possible to receive 4m and 6m at the same time. The radio also only has one antenna connection on the rear, would had been great if it had one connector for each receiver.

The really good thing about the Wouxun UV-980PL is that it comes with everything you will need, apart from the programming cable!

After much tinkering I decided to purchase the Wouxun KG UV-980PL, a Diamond V2000 6/2m and 70cm antenna plus 20m of Hyperflex-13 coax cable and connectors.

In the box you’ll find two mounting options for the removable head. There is a short connecting cable for use when the head is mounted directly on the radio body and a 5m long connecting cable for mounting the head remotely. This is really useful as I wanted to mount the head on a mic boom arm so that it’s easily accessible and didn’t clutter the desk space in the shack.

M0AWS Shack — Wouxun KG UV-980PL head mounted on a Mic boom arm

Since the radio also comes with the mobile mount I’ve fixed the radio body on the wall behind the PC monitor out the way. This setup has proven to be extremely good as I can see what’s happening on the display at a glance and easily grab the mic if called.

Programming the radio memories is extremely quick and easy using CHIRP. I had the local repeaters and my AllStarLink node frequencies and offsets uploaded to the radio in no time at all and was soon on air.

Programming the memories on the Wouxun UV-980PL using CHIRP

The microphone that comes with the radio is extremely good. You can operate most of the controls on the radio directly from the mic with ease and it has a good feel in the hand. Audio reports have also been very good and there’s no need to change it.

I’ve not yet got the new Diamond V2000 antenna erected but, I’ve been using the radio with my homebrew 2m/70cm end fed vertical dipole and my 4m band end fed vertical dipole and am getting excellent results. I can access all the local repeaters using the lowest power output setting and only have to use the medium/high setting for the repeaters that are further afield.

On the 4m band the radio performs well and I’ve been surprised at the distances I’ve been able to cover even though my 4m antenna is only 6-7m above the ground currently.

A few days after I got the new Wouxun radio there was an ARISS event whereby a group of Girl Guides would be talking to Astronaut Sunita Williams aboard the ISS. This was a great opportunity to test the receive capability of the radio and so I setup ready for the pass. Using just my simple 2m/70cm end fed vertical dipole I got great reception as can be heard in the video below.

Overall I’m extremely pleased with the Wouxun KG UV-980PL quad band radio and considering it’s much cheaper than the offerings from the main radio manufacturers it’s well built and performs extremely well. If you’re looking for a simple, analog FM radio for 6/4/2m/70cms then you can’t beat it!

More soon …

6 October 2024

ISS Special Event contact with Astronaut Sunita Williams

A special event organised by the RSGB and Amateur Radio on the International Space Station (ARISS), in collaboration with the UK Space Agency, Girlguiding Surrey West and Brooklands Museum’s Innovation Academy programme took place today and I was fortunate enough to actually receive the signal from the ISS as it passed over Europe.

The contact with NASA astronaut Sunita Williams was also attended by The Duchess of Edinburgh who asked the first question via radio to the NASA astronaut.

Following this a number of girl guides posed questions which were very quickly answered as the ISS passed overhead.

Using my new Wouxun UV-980PL and simple end-fed vertical dipole I got a great signal from the ISS HAM radio station and was able to receive the ISS side of the conversation as the space station approached the N/W Coast of Spain until it eventually dropped below the horizon out of site nearing East Russia.

Below is a short video clip with audio showing the clarity of reception. The ISS peaked at an S9 signal, it was a perfect pass for the special event.

I’m hoping to put up a better antenna for 2/4/6m & 70cm in the next few days so that I can start joining the local nets on these bands and perhaps get contacts through a few more of the FM Low Earth Orbit (LEO) satellites.

I’ll also be writing a full article on the Wouxun KG UV-980PL in the very near future, so if this radio is of interest to you then watch this space.

More soon …

25 March 202425 March 2024

More 868Mhz Antenna Tests

After initially finding that I couldn’t tune the 868Mhz ground plane antenna with the radials bent down at 45 degrees I decided to experiment to find out why.

Initially I had the radials connected to the 4 corners of the base of the chassis mount N Type socket. This works great if you have the radials completely horizontal and gives an SWR of 1.1:1 but, with the radials bent down at 45 degrees the best SWR is around 2:1.

M0AWS 868Mhz Ground Plane Antenna Close Up

Removing the radials from the base of the N Type chassis socket and soldering them to the outer of the N Type plug at the same level as the feed point for the radiating element I found that an almost perfect SWR can be achieved very easily.

M0AWS 686Mhz Antenna with radials soldered to the N Type Plug — M0AWS 868Mhz Antenna with radials soldered to the N Type Plug

It seemed weird to me that such a small change could have such a big effect on the obtainable SWR for the antenna but, as can be seen in the image below with the radials soldered to the N Type plug and bent downwards I immediately got an SWR of 1.07:1 and a much wider SWR curve.

M0AWS 868Mhz Antenna SWR curve with radials soldered to N Type plug.

By making my own antennas I’m learning a lot about antenna design for the 800-900Mhz frequency range. Minor changes seem to have a much bigger impact than they do at much lower frequencies.

More soon …

20 March 202420 March 2024

Difference between dBi and dBd

This is a question I get asked regularly via email and so I decided to post this article so that I can refer to it in future emails.

Callum of DXCommander fame has just published a great video explaining the difference between dBi and dBd that is well worth watching if you don’t understand the difference between the two.

More soon …