Christmas Lunch

There were 17 of us the CARA Christmas Lunch on 18th December, and a good time was had.  We enjoyed a three course meal accompanied but much lively chat.  Here are a few photos.

                                                   l-r Barry M0HFY   Tony G3YYH   Peter G4ENA   Ken G3LVP
                                      Some of the ladies.  l-r G3LVP/2   G3TEV/”   G4ENA/2   G3NKS/2

Annual General Meeting

The CARA’s 42nd AGM took place on Thursday 13th December 2018 with 32 members present.

Members at the AGM

Tony G3YYH, Chair, reported a successful year highlighting many notable events including two enjoyable Fun Field Days, Foundation and Intermediate courses with high pass rates, a fascinating visit to Ben Nock’s Military Wireless Museum and a good display of home-built equipment at our annual Constructors’ Exhibition. 

The Bernard King Memorial Cup awarded for noteworthy and praiseworthy on-the-air activities was presented to Tony G3SNN for his superb DXCC scores achieved over many years of sustained effort.  The John Holt G3GWW Award for exceptional work for the club went to Smurf M0URF for his outstanding contributions to Fun Field Days.

The Treasurer, given the healthy state of the Association’s finance, proposed that the annual subscription remain at £13.  Approved unanimously.

The Committee for the year 2019 was elected.  Chair – Tony G3YYH, Secretary – Derek G3NKS, Treasurer – Peter G3YJE, ordinary committee members – Andrew M0MVA, Alan M0NRO, Christopher M0YNG.  Accounts Examiner – Tony G3SNN.

Any Other Business.  Tim G8PZD queried whether a decision had been made regarding the move to a better venue for our monthly meetings.    Two venues were contenders, one tried in November and one suggested at the meeting.  The Chair asked that, following further investigations, the Committee be allowed to make the final decision regarding the move – this was agreed.   Tony G3SNN proposed a vote of thanks to the 2018 Committee for their good work and to  the Editor, Christopher M0YNG, for producing such excellent newsletters every month.

Following closure of the formal meeting members enjoyed a light finger buffet and lots of chat.

November Meeting

Two short talks.  Different venue.

Ken G3LVP will describe ADSB – if you don’t know what this means, come along and find out!  Hint – it’s nothing to do with Digital Voice or Network Radio!  But it does involve real radio.

Tony G3SNN will ask “Is QSLing Dead?”  With “Logbook Of The World” (LOTW), eQSL, Club Log etc perhaps the desire to exchange physical cards has disappeared.  Tony will discuss – perhaps with your help!

The meeting will be held on Thursday 15th November at the Cheltenham, Football Club in the Robin’s Nest – doors will open at 7.30pm for an 8pm start.

 

October Meeting Report

The “Skills Evening” held on 18 October proved to be very popular, with one of the highest attendances so far this year. Six members manned tables around the room to demonstrate, explain and talk about an aspect of amateur radio – usually one which was a particular interest of theirs. Ken G3LVP explained how make properly make-off coaxial connectors such as BNC and N-type, with examples and supporting diagrams. Peter G3YJE demonstrated a “Tuna-Tin” QRP transmitter, showing the output waveform on a ‘scope. He was also promoting the American Radio History website to which he has been contributing for several years. Paul 2E0IFV had a display of DMR radios, including hand-helds, and demonstrated their use. Tony G3SNN showed his fine collection of exotic QSL cards for his 160m and 6m activities. Barry M0HFY had a live demonstration of FT8 (one of the latest data-modes which is currently very popular), making several contacts during the course of the evening. Mike G4GUG was extolling the virtues of Linux, and telling how well this Operating System would run on older machines. Each of the tables attracted a gathering of members for much of the evening, and much general and lively chat took place as well. Very many thanks to the six members who kindly “volunteered” to man the tables and indeed to everyone else who made an appearance; you all contributed to the undoubted success of the meeting. We were pleased to enrol Chris M6NZC as a new member and John 2E0GCR who re-joined after an absence of a year or two. Thanks once again go to Alan M0NRO for kindly manning the kitchen. Thanks also to the several members who, without being asked, helped clear away the tables and chairs at the end of the evening – your efforts are much appreciated.

October Meeting

The next CARA meeting will be held on Thursday 18th October at Brizen. Doors open at 7pm for an 8pm formal start.

A Skills Evening – tables will be set up around the room with the following demonstrations: DX QSLing – Tony G3SNN American Radio History website – Peter G3YJE.  Looking at the output of a Tuna-Tin QRP tx – Peter G3YJE.  Making off BNC and N type connectors – Ken G3LVP and Giles G0NXA.  FT8 – Barry M0HFY.  Linux and some apps – Mike G4GUG.  Come along and learn about something new and enjoy a good chat to fellow members. Tea, coffee and biscuits will be available as usual.

September Meeting

We are very please that Tim G4VXE has kindly agreed to return to the club to present another of his talks, this one entitled “UnRealRadio”. He’ll be telling us about Network Radio, how it works, what equipment is needed and how it’s used. He may, if time permits, also talk about Digital Voice radio. Tim used to live in Cheltenham and was a very active member of CARA before leaving the area. He writes regularly for Practical Wireless and will soon also be writing regularly for Radio User. Network Radio is a somewhat controversial subject among radio amateurs, some feeling that it’s not true amateur radio and it “shouldn’t be allowed”, others that it’s something new and exciting and may well be a useful facility for encouraging new recruits into our hobby. Whatever your views, please respect what Tim has to say and listen without over reacting. Thursday 20th September, 7.30 for 8pm at the Brizen Centre, Up Hatherley Way. Visitors and prospective members will be made welcome.

August Meeting

The UK military Wireless Set No 19 (WS19) was manufactured in great numbers for WW2 and used extensively during the war and in the years after. It appeared on the surplus market in the 1950s and 1960s and was used, often after modification, by radio amateurs to get on the air – in those days there were no “black boxes” from the Far East and what commercial gear there was, mainly from the USA, was very expensive. These days the set is sought after for restoration.

At our August meeting Tony G3YYH will tell us more about the WS19 set and how in recent years he has restored one to working use. He will have his set on display and, hopefully, working. This will be an interesting meeting whether or not you are a military wireless buff!

Visitors and prospective members will be welcomed, as always.

Thursday 16th August at the Brizen Centre, Up Hatherley Way. Doors open by 7.30 for an 8pm start.

The Brizen Young Peoples’ Centre is located between Morrisons Superstore and the Shurdington Road. Beware of the height barrier when entering the car park.

July Meeting Report

Last month we were pleased to welcome back Peter G3RZP, a well known speaker at amateur radio functions – at local, national and international levels.

The title of his talk was “Clean Signals” and he proceeded to tell us why transmitters, and SSB transmitters in particular, emit signals which are much wider than they should be – and so cause interference to stations on adjacent frequencies. SSB transmitters are essentially “linear” amplifiers, amplifying a signal generated at low-level up to the desired power required for transmitting a signal to wherever. However, the amplification process is not actually truly linear because of the inherent characteristics of the active devices, be they thermionic valves or solid-state devices. In an SSB transmitter the non-linearity gives rise to what are known as “intermodulation products” which spread out either side of the main signal. Intermodulation products are, in the simplest case, caused by two discrete signals being amplified mixing together, because of the non-linearity, to produce low-level signals spaced from each other by the difference in the frequency of the two signals. The further away from the main signal the weaker these products become. But even low-level “spurii” can cause QRM to near by stations.

So the way to minimise such interference – sometimes called splatter – is to make the transmitter/amplifier operate as linearly as possible. This can be done by making sure that the equipment is not over-driven – ie by not turning the mic gain up too far, by using minimal amounts of ALC and by making sure that the transmitter sees the correct load impedance. In the design stage negative feedback can be introduced to improve linearity, but this can cause other problems if not done carefully. One way to check that the transmitter is being operated corrected is to inject two audio tines into the mic socket and look at the RF output with a suitable ‘scope, the tops and bottoms of the waveform seen should be nicely rounded. Peter’s view was that in general valve amplifiers are inherently more linear than solid-state ones.

The talk was well received to judge by the number of questions asked. Many thanks to Peter for travelling from Swindon to see us once again.

JULY MEETING

How clean is your transmitted signal? What is meant by a “dirty” signal? What causes a dirty signal to be transmitted? What are “inter-modulation products”? Do you know how to adjust your transmitter so that the PA is not over-driven? For the answers to these and no doubt many other relevant questions come along to our July meeting to hear Peter Chadwick G3RZP talk on the subject of “Clean Signals”. Peter is a well known and highly qualified engineer who has given many talks to clubs over the years – including CARA. He has served as a technical advisor on national and international committees, eg IARU and ITU, so knows his stuff! We are pleased to welcome him back again for another of his thought provoking and informative presentations. Please attend and make his trip from Swindon worthwhile.

7.30 for 8pm on Thursday 19th July at the Brizen Young Peoples Centre, Up Hatherley Way – located between Morrisons and the Shurdington Road.

Beware of the height barrier when entering the car-park.

Coffee, tea and biscuits should be available as usual.

Visitors and prospective members will be welcomed, as always.