Category Archives: Uncategorized

Vin G4JTR publishes EFHW write-up

Our very own Vin G4JTR has written a rather excellent paper covering the advantages and the nuances of EFHW – end-fed half-wave – multi-band HF antennas.

It’s great to get some first hand experience and sensible analysis of this often over-simplified subject area.

Read the full article here:

We look forward to Vin’s next planned article – on noise, and presumably, its mitigation.

Happy 90th, RADARC!

This year, RADARC celebrates its 90th birthday. Through the year, the members plan to run some events to celebrate this special year.

To kick us off, Michael M0MPM has organised and activated the special event callsign GB0RDG for an initial one month period. Michael will be in touch with members soon with an update as to how they can participate with this callsign.

Min G0JMS has been in contact with Ofcom and hopes to bring us some exciting news shortly – watch this space.

We anticipate that the summer time will be a great time in particular for special commemorative activations and other events relevant to the big anniversary.

All members are encouraged to share their thoughts and ideas around the club and with the committee – and just to get out and have fun – after all the club is nothing without its members.

Portable Operating on Microwave and Millimetre wave by David G1EHF

This evening we gave a warm RADARC welcome to David G1EHF for a talk entitled “Portable Operating on Microwave and Millimeter Wave”. David gave a great talk about particularly the practical aspects of operating portable microwave, all the way up to 122GHz using RADAR chips from cars, and kindly brought along some kit for inspection. He is often to be found up Walbury Hill in the North Wessex Downs, picking his way among various evidence left by sheep in search of the perfect spot to place the mast.

David’s presentation was recorded and we hope to be able to bring it to members in due course.

We thank David for his talk and hope to have him back in future.

Visit to National Grid ESO

Thanks to Steve G8CSK, RADARC members recently had the opportunity to visit the National Grid ESO (Electricity System Operator) control centre near Wokingham.

We were treated to a warm welcome, a very informative presentation from two members of operational staff, and a period viewing the control room itself from the elevated viewing gallery at the rear, with great explanation given, throughout which our hosts enthusiastically answered the inevitable barrage of great questions from our members.

The visit comes at a period of change for National Grid ESO in their transition to becoming the National Energy System Operator, a new, independent, public corporation that will be responsible for planning Britain’s electricity and gas networks and operating the electricity system, and with “embedded generation” – solar and wind connected to downstream distribution networks over which the system operator have no control – increasing rapidly. We learned a great deal about the realities of the strategic and operational side of balancing the grid, both economically and technically, having a direct impact on grid frequency and ultimately safety and security. It is fantastic to see first hand how carefully and professionally this is national-scale system is managed.

Our sincere thanks go out to everyone involved in organising and hosting us, and especially to our two hosts on the day, Pat and Ceiran.

February Top Band Net

On 29 February 8pm UTC, Vin G4JTR hosted a club top band net, on 1850kHz.

Using a George Smart Wellgood active receive loop approx 1.5m diameter inside a roof space, reports at M0LTE HQ were:

Vin G4JTR 5/9+ -59dBm
Michael M0MPM 5/9 -68dBm
Brett 2E0HFW 5/8 -75dBm
Nick M0NPK 5/7 -82dBm
John G4RDC 1/6 -92dBm
Alan G3UQW 5/9 -73dBm
Simon M0ZSU 1/6 -92dBm
Jeff G4AAO 1/6 -93dBm
Ian G8NXJ 5/8 -78dBm
Loz G2DD no trace
Min G0JMS 5/6 -88dBm
Dave G4RGK 3/7 -90dBm
Robin G4IWS 5/9 -59dBm
And a late entry Steve 2E0SBH 4/6 -90dBm

This was against a noise floor here of -93dBm in 3.3kHz. Virtually no QSB.

Several participants were audible on the Hack Green web SDR. The noise floor was fairly high for some, but with few exceptions generally reports were good to very good. Some tips were exchanged on audio setups, resulting in significant improvements even during the net. There was a Zoom backchannel being used to exchange signal reports and for a post-net chat.

No doubt this fun event will remain a popular fixture in RADARC calendar.

RADARC branded clothing / accessories

Announcing the grand opening of the RADARC official tat shop!

We have today launched an online store with a wide selection of goods proudly showing off the RADARC logo.

Caps, polo and tee shirts, hoodies, coasters, mugs, water bottles, phone cases, stickers and more – we’ve got it all. Items are made on demand by the shop supplier and not handled by the club.

The store is set up as a non-profit store, that is, the club does not take a margin on sales, and nor is there any cost to the club. This is just about getting the word out there and looking your finest!

Visit the online store and make your purchases today at

Graham Bedwell G3XYX SK

With immense sadness, I must report the following from Judith Bedwell, Graham’s wife. UPDATE 27th July:

You will be pleased to hear the celebration of his life was very well
attended both in general and by RADARC members. I suspect there were many BBC folk there too. The church was full.

“It is with great sadness that I write to tell you that Graham passed away on 9th July 2022, having had a severe stroke on 6th May.

A service of thanksgiving for Graham has been arranged as follows:

Venue: Rose Street Methodist Church, Rose Street, Wokingham, Berkshire, RG40 1XS

Time: 2.30pm

Date: Wednesday 27th July 2022

Should you wish to attend, you would be most welcome to help the family celebrate Graham’s 80 years of life. As you probably know, Graham didn’t like formality, so we would encourage you to attend in bright and casual clothing.

We would ask you not to buy flowers, but would welcome any donations you might wish to make to one of two charities close to Graham’s heart; the RNLI (The Royal National Lifeboat Institution) and Action for Children.

Any donations in Graham’s memory may be made via:



Tel: 0118 978 4040

Please note that parking is limited in the car park adjacent to the church and in Rose Street itself, but there are two public car parks a short walk across town off Easthampstead Road (East Car Park, RG40 2EG and Easthampstead Road West Car Park, RG40 2EH).”

Graham G3XYX SK

Chris G0JTN writes:

Where ever you are I hope you are keeping all the PAT testing up to date and that all the PA systems are working well. I will miss our evenings about this time of year going through all your collection of excellently maintained audio gear. Inspection and test was always an important part of your maintenance regime keeping the equipment in tip top condition. The club benefited greatly from your outside broadcast skills that you learned at the BBC.

You will be greatly missed.

Chris G0JTN

Brett 2E0HFW writes:

If there was a film in the style of Oceans 11 of Radio Amateurs, Graham would be in it.  

And like the film, Graham was one of the “A listers” in the local amateur club and brought with him many specialist skills. For starters he was a technical master in broadcast audio and above all an amazing Story Teller.

Graham had lived his life to the max, travelling the world and meeting many people, which gave him the material for many stories, which he would entertain us with on club evenings and nets.

One such net runs on 80m on a Tuesday morning, which I listen to occasionally.   Once the net had finished today I popped up just to say my good bye to him, in the hope he was listening on his new fancy radio in heaven.  

RIP Graham. You will be missed.
Brett 2E0HFW

“He was involved in a few different scout events that included Amateur radio, we had the RSGB satellite Van at Wings in Windsor park a week of International Scouts visiting the station, think he also did JOTA as well as many years at three Towers checkpoints including East Isley” — Ian G6IZA

From Charles Coultas:

During the pandemic, my doorbell rang. I gingerly opened the door and there stood Graham Bedwell, portable short wave receiver in his hand squealing away. Graham lives about 150 yards, line-of-sight from me. I got to know Graham through my work at Bletchley Park computer museum.

“There’s something broadcasting a strange noise on about 3.5Megs, and it seems to be coming from here.” he said.

“Well that’s very unlikely” said I, I am not an amateur but I do have have lot of electronic gear running in the house.

He stayed outside (distancing regs of course) while I went upstairs and started turning things off. He suspected a Chinese wall-plug power supply, I have lots of these. Eventually there was a triumphant shout from the open front door:

Graham: “That’s it, what did you turn off?”

Me: “The digital class D power amplifier that was driving two long unscreened cables to two loudspeakers”

Graham: “Well don’t turn it on again please!”

Me: “Very sorry, I now realise that class D amps modulate a carrier, up towards the megahertz region”

Graham: “Hmmph, that’s all right”. He walked back to his house standing a little taller.

Graham was a passionate defender of the airwaves – He cared deeply about the hobby and in particular, that the bands should be clear of man-made noise for the benefit of other amateurs.

That was the last time i saw Graham, my love and best wishes to Judith and his friends.

Charles Coultas

Ian Alderton G6IZA:

“He was involved in a few different scout events that included Amateur radio, we had the RSGB satellite Van at Wings in Windsor park a week of International Scouts visiting the station, think he also did JOTA as well as many years at three Towers checkpoints including East Isley”

From Simon G6ZTZ:

A photo of Graham “Ace” Bedwell (as he was known).

With Keith Burton on the right and Stanley Unwin centre

Colin M0XCA writes:
“Such sad news. I have often listened to Graham on the radio and the RaDARC Nets and will miss hearing him and his BBC memories.”

Graham was always someone I aspired to. Immensely talented and well known for his love of all things audio, it may be less well known his knowledge of radio and RF generally was second to none. Always miles ahead of me, his wit was always a pleasure to experience either in person or on air. But a kindler, gentler soul you could not wish to meet.

Graham was ever generous, particularly in his support for RADARC for which we owe a huge debt of gratitude.

RIP Graham. You will be missed.

John G4RDC

Encrypted radio signals, Enigma, Lorenz, and Colossus – presentation by Charles Coultas

We were recently delighted to welcome Charles Coultas for his club presentation on “The discovery of encrypted radio signals, both Enigma and Lorenz leading to the development of Colossus” for a lecture covering:
– Why Bletchley Park was chosen, and who worked there
– Government concerns about what is going on in wartime
– Alan Turing who joined at the outbreak of WW2
– Enigma, how it works and how it was broken by Turing
– The purpose and importance of radio communications
– The mathematicians at Bletchley Park
– A light hearted dip into some aspects of cryptography
– The strange radio signals from 1941, what they were and how the code was broken, and how this shortened the war
– How the “computer” came about and Turing’s part in it

We’re pleased to say you can re-watch Charles’ whole presentation right here:

With thanks as always to our video editor Chloe 2E0JPM.

UK Radio Astronomy Association talk with Paul Hearn

Further to the January 2022 RadCom article entitled “A Collaboration of Enthusiasts”, we recently welcomed club member Paul Hearn who gave us an introduction to Radio Astronomy and the UK Radio Astronomy Association.

Paul kindly gave his presentation in person at our new venue, the Scout hut. There’s something for all wavelengths here from VLF to microwaves!

You can re-watch the full presentation right here. Don’t forget to check out all of our other videos on our YouTube channel.