All posts by Tom

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.

The Arrival of the Transistor in Amateur Radio with Duncan James M0OTG

Following on from his November 2021 RADCOM article “Amateur radio and the arrival of the transistor” we recently welcomed Duncan James, M0OTG as our guest presenter.

Duncan gave an excellent talk showing the historical development of the transistor through the ages from primitive laboratory pieces through to today’s hyper-miniaturised devices.

You can watch Duncan’s talk again right here:

If you are interested in joining RADARC for our meetings either in-person or online, please check out the Membership page of our website.

CQ World-Wide WPX SSB contest this weekend

Thought I’d put up a note that ALL this weekend is the CQ World-Wide WPX SSB contest. This is one of the very busiest weekends on HF for the entire year, and is a great opportunity to get some contacts on HF, even if you’re not a contester. Large contest stations with very capable receive antennas, which would not normally be on the air, will be operating worldwide – so you will be heard by more stations and further away than normal. People will want to work you.

Don’t be daunted by the fact it’s a contest – there’s no requirement to enter formally (though it’s encouraged) and all you have to do to complete a contact in this contest is give the report (always 5/9) and a number which you increment by 1 each time. For example, “you are 5/9 001”, “you are 5/9 002” etc. If you did want to enter, a contest logger is recommended (I like N1MM+) but not required – look on cqwpx.com for setup instructions for N1MM+.

Many large stations will be sitting there calling CQ continuously on one frequency for literally hours at a time. There will be busy times with huge pile-ups and quieter times where you’ll easily make the QSO. Rich pickings to be had for these on Sunday afternoon – work your way up a whole band and make easy QSO after QSO.

The permitted bands are: 160m, 80m, 40m, 20m, 15m and 10m.
Times are 0000 UTC tonight to 2359 UTC Sunday, i.e. 48 hours.
The full set of rules is here: https://www.cqwpx.com/rules.htm

Good luck, have fun!

HF + No PTT by Dave Porter G4OYX

Recently RADARC welcomed Dave Porter, G4OYX, as our guest presenter for an evening talk.

Dave is a well known author from, among others, VMARS’ magazine Signal, and joins us for a talk entitled “HF + No PTT”. I wonder what that could be about? Here’s a clue: the transmit powers involved are somewhat higher than most of us are accustomed to.

Join Dave G4OYX as he loses 249,750 Watts, goes “professional in Europe with home-brew”, but is on the air without a PTT!

Don’t forget to check out the club Events page for upcoming talks, also announced on the RADARC mailing list as well as our Discord discussion server – click the links to join either.

Dr. Bob Heil K9EID – The Science of Audio

In January, we were delighted to welcome the one and only Dr. Bob Heil K9EID for a talk entitled “The Science of Audio”.

Bob really needed no introduction. This talk is a “must” for radio amateurs and music fans. A tech pioneer in the 60s/70s rock scene he’s worked with many of the “greats” including Joe Walsh, Peter Frampton and Jeff Beck and sets the “gold standard” in audio.

He went on to define “the state of the art” in amateur radio audio with products many of you will be familiar with though “Heil Sound” and continues to innovate in all things tech. He’s too prolific for us to even begin to scratch the surface of what he’s done.

You can watch Bob’s talk back right here:

Talk by Mike Gloistein – British Antarctic Survey

Recently RADARC was privileged to be given a talk by Mike Gloistein GM0HCQ of the British Antarctic Survey about his experiences past and present with said survey, on board the newly commissioned Research Vessel Sir David Attenborough.

Mike has worked for the British Antarctic Survey for over thirty years. Initially sailing as a Radio Officer until GMDSS came along, then as a Communications Officer and now as an Electronics Officer on board the RRS Sir David Attenborough.

In 2004 Mike was awarded the Polar Medal by Her Majesty the Queen.
During his time with the Survey Mike has operated as GM0HCQ/MM, VP8CMH/MM, VP8ROT, VP8SGK and VP8SIG.

Mike shared with us a hugely illuminating exposé of what it’s really like to live and work in this kind of environment – from technical, through practical and all the way to dealing with the local wildlife, of which there is plenty!

We are delighted to share our recording of Mike’s talk right here:

Don’t forget that RADARC have a YouTube channel where more of our talks and other content get posted when we can.

RADARC on Discord

Hope you are all keeping safe and also well hydrated in this heat!

Some members may not know that RADARC is now running a Discord server. Discord is an internet-based chat tool that runs quietly in the background, and is great for those times between meetings that you just remember something you want to discuss, either to someone specific at the club, or as an open discussion. It’s much more lightweight and quick turnaround than email is.

It’s available for Windows, Macs, iPhones and Android phones, is free, and pretty easy to use once you’re up and running. There’s been lots of interesting chat already on lots of different topics, and you can mute what you’re not interested in. The only thing missing is you!

If you’re interested, ping someone on the committee directly for an invite, or email committee @ radarc.org.

GB7PY Repeater Stolen

Some unfortunate news from our friends over at Cambridge Repeater Group:

[DMR Repeater] GB7PY has been stolen from Madingley, Cambridge, on 23rd December at approx 2115hrs.
Repeater info:
Motorola SLR5500 UHF:
Model: R10QCGANQ1AN
Tanapa : PMUE4392AA
Serial: 478IRW1189
Also stolen was a Teltonika RUT950 4G router:
IMEI on the Router ends with 6502, which has been network blocked and will therefore not work on any network now.
Any information, please pass to Cambridgeshire Police quoting crime reference number 35/92597/19.

Obviously this is a significant loss for the group. Can members please be on the lookout for this equipment through the various channels, and should anything come to light please do the right thing and pass on any details as requested, however insignificant it may seem.