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

CW National Field Day 2023

NFD 2023 Report by David Honey M0DHO

Setup started at 10:00 Saturday in sunny conditions on a different field from our usual one. Setup went well, and we seemed to be operational by about 13:00. Initial testing of Jim’s automatic switched dipole showed it was working as expected on all bands. So it seemed like we we’re going to be gremlin free. Spoiler alert – that wasn’t to last!

Conditions seemed good on 15m and 20m, but with 5W QRP, it seemed to be a struggle to work on 15m. A few hours later, on trying to open the multipliers window on the 1st laptop, Win-Test crashed, and any attempt to open the contest file resulted in Win-Test crashing. Panic! Fortunately the 2nd laptop had its own replicated copy of the contest, and I was able to export Cabrillo, share it across the network, create a new contest file on the 1st laptop and import. However, about an hour later Win-Test crashed again. I decided to switch to DXLog which fortunately was installed on both laptops. Exported the log again from 2nd laptop, and imported into DXlog on 1st laptop. The Win-Test crashes lost us about 30 minutes operating. DXLog was mostly trouble free.

Late in the evening, we tried 160m, but this time, the antenna would not tune as it had done earlier. Investigation showed that the switch box at the end of one of the 80m ends was not working – it must have failed in some way. We found that if we bypassed it, the auto ATU at the feedpoint would tune OK for 80m and 160m, so we had a workable solution. That probably lost us about 15 minutes operating time. So in total, these various gremlins cost us 45 minutes.

Conditions were variable. 20m was a solid band for us. During the day, 40m seemed more of a struggle, but was better in the early morning and late evening. Conditions on 80m and 160m seemed OK – it was nice not to have heavy static crashes on those bands that sometimes plague NFD.

But there seemed to be fewer German portables, and less activity on both lower bands than I remember from previous years. Perhaps we were a little late switching to the low bands. There had been good signals on 15m when we started, but it seemed to be struggle to be heard with 5W. The only significant opening on 10m was on Sunday. There was Es around, but not often to southern UK.

Operators rotated mostly around Jim G0LHZ, Michael M0MPM, Geoff G4AAO, and David M0DHO,  taking turns operating and spotting. It was cold overnight – I could see my breath in the tent in the small hours of Sunday. I was glad when Nick M0NPK relieved me around 4am on Sunday – by then my hands were getting cold and I was glad to climb into my sleeping bag to warm up!

There was the usual Saturday evening BBQ, and the Sunday morning cooked breakfast, both courtesy of Simon. Chris bought down his recycled washing machine drum for a camp fire along with firewood. Tear down was in sunny conditions but not too hot, and went smoothly.

Many thanks to all who operated, helped with set-up and tear-down, or just visited us.

Thanks to Ace G0ACE for the photos!


We are excited to announce that RADARC’s experimental web SDR has received some TLC including upgrades by member Ian G5IPX which seems to have markedly improved its performance and reliability.

Therefore it seems the right time to take the “experimental” label off the service and officially launch this hopefully valuable service.

RADARC’s WebSDR covers 6m, 4m, 2m and most of 70cm and is located at RRFC in Sonning. It utilises the club V2000 colinear antenna and the site has fairly low noise, easily picking up GB3VHF. There is even decoding of various digital modes including digital voice, as well as the usual FM, SSB etc.

You can access the club SDR at the following address:

Please feel free to share the link beyond RADARC members, and please report any issues or feedback to Tom M0LTE / Ian G5IPX via the club mailing list.

Website for the Reading And District Amateur Radio Club