Chelmsford Amateur Radio Society

Past Club Meetings: April to June 2007

June Meeting - Table Top Sale - Colin Page, G0TRM

At this years Tabletop Sale approaching 100 Members and visitors enjoyed viewing, and in some cases buying a whole range of new and not so new electronic and other radio related items. As usual we had visitors from far a field, some traveling a good distance to attend. A few faces present on the night were also seen at the Hockley Emporium some days beforehand.

As usual the event was widely advertised both in the local press and on local radio. Readers of RadCom, PW and SWM and other radio magazines had all the necessary information clearly displayed. Many leaflets were produced for display in local libraries, bookshops and public notice boards.

Many thanks to the high number of Club members who came along to sell or to buy or maybe to chat, contributing to a great atmosphere. Thanks too, to those who donated for sale, some very fine items to be sold for Club funds.

Thanks to Geoff KLV for his part in raising a good sum by selling in quantity, many items given freely by Members and non-members. My thanks to Fred FXM, for donating a number of elderly valved radios, initially for the Canvey Rally. Those unsold then, have resided in my garage till now, but have now been sold and will get lots of TLC from their new owner. Our thanks to Denis FHA and Ron CAM who ran such a good Raffle with lots of interesting prizes. They were very ably assisted by Martyn EFL who did some pre meeting selling to the punters queuing to get in. Once again, the evening, both socially and financially was deemed a success

Finally, my thanks to all who played any part in helping to make it a very worthwhile event,

Thank you Colin for organising it.

May Meeting - Microwaves - Demystified
By John Wood, G4EAT

North West Europe is the centre of microwave activity around the world. The East of England and Essex in particular is well positioned to take advantage of this activity. This was the invitation to come to hear John's talk.

John's Strumech Mast & Aerials

Photograph of John Wood's 3 section, 20 metre Strumech mast & aerials.
Photograph taken by John G8DET

Antenna system from the top:

9 element 2metre yagi from Tonna
19 element 70cms yagi from Tonna
4 x 23 elements 23cms from Tonna
25 element 13cms from Tonna
60cms perforated Astra offset dish for 10GHz
John is a Holder of the Dain Evans, G3RPE Trophy for 10GHz Cumulative Contest.
60cms perforated Astra offset dish for 24GHz

John's Strumech Tower Base
Strumech Tower Base built on 8 cubic metres of concrete.
Aerial is approx 300 feet ASL on one of Essex's "mountains".
Note the winding reduction gear to lower the mast in high winds.

John was fitted with the clubs Radio Mic. and became the first user of the club’s new PC projector, recently acquired by John, G8DET after many trials and tribulations ! This produced a very bright large and sharp image to display John Wood's excellent Powerpoint Presentation – Over 80 slides in all and delivered in a very professional and timely manner. This writeup can’t do it justice and we are fortunate that John made a CD available

John's introduction slide
John introducing his presentation.

John took us on a tour through the microwave bands and gave a brief on the activity likely to be found on each, and their possible use as a DX provider. It became quite clear that the QSO distances on the mid-microwave bands were in the range of 100s of km and far beyond the usual line of sight expectations that many of us have. The distances result from low noise figures, high antenna gains and propagation mechanisms such as ducting or rainscatter. A recent UK 10GHz record was 1400km on just 2W transmit power from the middle of Surrey to Sweden! Johns own square collection all around Europe was most impressive.

Above 23cms, John said the most activity and use at present is the 10GHz band where dishes or horns are mainly used for antennas - Yagi elements getting a bit tiny by this time.

A look at your licence schedule shows that the bandwidths available are vast compared with any of the HF bands. So what can you do ?

  • Talk down the road – and far farther afield
  • Operate in contests
  • Construct your own gear using available surplus or commercial units (you do have to be able to solder!!)

    Back in the 1980s wideband Doppler Radar units were in use. Using these as a local oscillator as well as the transmit source a duplex station could be put together employing a two meter receiver as the IF with the other station spaced by 145 MHz.

    Developments by Charlie Sucking G3WDG and Sam G4DDK led to practical microstrip-based narrowband systems. Using narrow band (eg 3kHz bandwidth) can give as much as 20dB improvement to Signal to Noise over wideband. With dish gains at 10GHz around 30dB, the ERP from a modest source with a horn or dish can be very effective. (and of course 30dB at the Rx as well which helps link budgets enormously. Nowadays kits or ready-built modules are available up to 24GHz at about 500 Euros working and ready to go. Kuhne Electronics being a major source.

    John's Powerpoint slides were then used to show various set ups used by active stations around Europe and the US including his own at Danbury (on a hill of course) as well as portable setups. Propagation is mainly Tropo and the various ducts that can occur were illustrated (18 to 20km high)

    A portable microwave vehicle.

    The microwave bands have plenty of beacons installed and these will give easy checks on what ranges are available at any time, by tuning around the bands and directions

    In the UK there are regular ‘roundtable’ events for talks, test equipment sessions to assist your own gear and surplus kit sales. There are also a series of beginners workshops organised by the UK Microwave Group.

    John says Microwavers are a friendly bunch ready to welcome you.

    The CARS audience (numbering around 60 plus) was most appreciative of a great talk.

    CARS audience
    CARS audience listening to John, G4EAT

    Report by Murray, G6JYB.

    There was the now usual good Raffle as well.

    After the break, Murray, G6JYB gave a photo show of the CARS Traing Group at Edinburgh receiving the Kenwood Trophy for Training. This is writen-up in detail on the Training Pages

    April Meeting - Waters & Stanton
    By Sales Director Mark Francis, G0GBY

    The meeting started with John, G8DET reminding the audience that on 21st April Sandford Mill was having a public Open Day & CARS would be running two stations.   Members were invited to see Brian, G3CVI and put their names forward as Operators, Loggers or Hosts.
    CARS was also running a station (GX0MWT) for IMD on the 28th April from Sandford Mill and Operators etc were required for that event as well.

    John then introduced Mark Francis with the comment that the last time he came to CARS the meeting was held in Arbour Lane, that Marconi site is now a housing estate.

    Mark said that as he was setting up the tables, someone had wondered whether W&S had any stock left back at Hockley, “Yes, about one million pounds worth” was his answer.   “W&S have to hold this amount of stock as they have to buy in quantity to get a good price”.

    “I really appreciate the opportunity to come to talk to people like yourselves – that is where the real world is” - “I sit behind my desk & really do not get the opportunity to talk to ordinary Radio Amateurs during my normal working day. At Rallies I am too busy selling to stop to talk. You can stop me & ask questions as I go along or we can have some at the end”

    This set the scene for a very intimate presentation.

    He said he liked to stand behind tables (pilled with amateur radio items including aerials and boxes of tools (all for a £1)) as he was really a Salesman. Also on the tables were W & S catalogues for £2.95 “Too dear” someone shouted out. “If you cannot afford £2.95 you should not be here” was Mark’s quick retort to the amusement of the audience. “£2.95 does not cover the printing costs – however, to make a special occasion of it tonight they are available – all free – just about one for everyone here, also a pile of MFJ catalogues are available”. Murmur of approval.

    Mark Francis, Sales Director of W&S
    Mark Francis standing behind his tables loaded with Amateur Radio equipment

    He then told the story of someone at a Rally who bought a cheap box to spray it black, lock it & put it on the side in his house “It will drive my Wife wild”. Laughter.

    Responding to questions regarding possible price collusion between the major Amateur Radio suppliers and Pound/Dollar rates, Mark said that the thought of Suppliers getting together was simply a joke and that prices charged were at their lowest level for years.

    Mark was pleased to see the new influx of M3s.
    W & S had the stock, but commercial life was hard - last year was the death of Rallies and he quoted those which had now finished. W & S were going to have an Open Day on Sunday, May 27th but without the marques at the back. They were moving the Sales desks down into the shop to free-up space upstairs and to expose the wealth of knowledge to customers who come into the shop.
    Post meeting note. This has been completed with very favourable comments.

    E-Bay was a good place to sell pieces of equipment they get left with and seconds.

    The book, the Secret of Learning Morse Code was mentioned. “I wrote it” said Mark to the amazement of many present. When I was Manager of the Hornchurch shop, I wrote down all the tips I was given when I was doing my Morse – I am very proud of it as it has helped a lot of people”. It is still selling – PW sell 10 copies a month.

    Mark then turned to the aerials on the table and went through each product in turn, taking an example one for the FT817, - simply screw it on & you have a good HF rig – works better if you have a counterpoise earth hanging off it. (Tony, G4YTG approved).

    A Frequency Counter costing £49 was next picked up – he said he decided to rewrite the Instruction Leaflet to include very useful tips & hints – they were copied by the manufacturer. Mark then donated it to the CARS Raffle which was won later by Prof Les Barclay, G3HTF. (Chairman’s comment – Thank you Mark – very much appreciated).

    Watson is a brand name of Waters & Stanton to show that W & S have been involved with that product range to show that it is to a consistent known high standard. “We pay a little more for a QC Tested item & it pays off”.

    A Solder Station for under £5 next came to be examined – what wonderful value.

    Mark has been in the Hobby 23 years & he has realised that there are many sides to it. Some like to build radios, having built something they test it and then never use it again because they are on their next item. Others never build anything – they are scraping the most out of propagation conditions.

    Resulting from a comment from the floor, Mark said that the new High Definition TVs were superb. The prices are tumbling – but don’t look at it unless you want to spend money – it is that good.

    Mark made the point that now one does not have to pay for your Licence you should join the RSGB as without the RSGB there would be no Radio Hobby – they work hard to protect your frequencies, etc.

    During the Break, Mark remained at his desk answering questions and talking to the many people who came to see what was there.

    Chris, G0IPU, Murray, G6JYB, CARS Member & Mark Francis
    Chris, G0IPU, Murray, G6JYB, CARS Member & Mark Francis

    Thank you Mark for a very philosophical and interesting presentation.

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