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Chelmsford Amateur Radio Society

CARS Meetings July - September 2014

Award for All

17th October 2014

Added July, August and September Meetings  

July Meeting
Tuesday, 1st July 2014
At Oaklands Museum, Moulsham Street, CM2 9AQ
"Launching and Tracking of 434 MHz Balloons"
By Chris Stubbs, M6EDF

Chairman, John Yates, G1UZD opened the meeting with a schedule of CARS events during the past couple of months and into the future for a couple of months also.   He said the Skills Evenings had been a great success with a growing number attending.

John opening the meeting  July 2014 Attendees
Chairman John Yates, G1UZD opening the meeting to a capacity audience.
Photo by John Bowen G8DET

Chris Stubbs M6EDF then gave his presentation on the launching and tracking of 434 MHz equipped balloons.   He gave a run down of the types of balloons and how they were equipped - showing one made out of thin silver material.   As the weather was very favourable Chris said he proposed to launch CARS1 so for the first time in 50 years Members trouped outside to a spot Chris had selected at the rear of the Museum.

Chris StubbsTARG Meeting 2014  Chris StubbsTARG Meeting 2014
Spot chosen by Chris for the launch - the area in the Sun, plus CARS members trouping to the launch site.

Chris StubbsTARG Meeting 2014  Chris StubbsTARG Meeting 2014
 Chris preparing the launch - waiting to obtain Satellite aquisition - plus, the launch!

Members held their breath as the Balloon headed straight for a 80ft Fir Tree but the air currents swept it around with just a few feet to spare. Members then gently reassembled and listened intreged as Chris went through the details of how the various Balloon systems worked.

GPS Tracking Map
GPS Map of where it was after a few minutes - over Blackmore - to the South West of Chelmsford and steadily climbing

Chris gets his CARS Speakers Mug
Chairman John presenting Chris with a CARS Mug in gratitude for such a nicely presented evening.

Chris took the Amateur Radio Foundation training course run by CARS in January 2013.   He is keen on both electronic construction and software development and combines the two interests in High Altitude Ballooning (HAB).   Chris has built many tracker payloads for his balloon launches which usually take place from Danbury Common near Chelmsford.

In May he undertook a STEM (Science, Technology Engineering and Mathematics) event for pupils at the The Sandon School in Chelmsford, launching a balloon equipped with his 434.300 MHz tracker enabling the students to track the position of the balloon in real-time.

The trackers typically transmit 50 bps FSK RTTY in 434 MHz and can have a radio range of over 500 km.   The data transmitted comprises the GPS location of the balloon and other sensor readings such as pressure, temperature and altitude.   The signals are received by a network of listeners who upload the data to the UK High Altitude Society (UKHAS) central server enabling anyone to see the current location of the balloon on the web.

Some balloon flights aim to achieve very high altitudes, others aim to stay aloft as long as possible.   Leo Bodnar M0XER recently achieved a record breaking flight from Silverstone to Japan using a party balloon with a tiny solar powered payload.

Words by Trevor M5AKA and John G8DET.

Carl and James will run the now famous Raffle.

Charlie M0PZT and Carl G3PEM with the Raffle
Charlie and Carl at the Raffle Table

David and Myra (with help - hopefully) provided the light refreshments at the Break time.

Another excellent evening provided by CARS with visitors from London and Cambridge besides others.

August Meeting
Tuesday, 5th August 2014
At Oaklands Museum, Moulsham Street, CM2 9AQ
"Constructors Competition"
By CARS Members

It was our annual Constructors Competition this month, be it a humble Dummy Load to an all singing all dancing Transceiver - bring it in to the Competition. As long as the item has a link to Amateur Radio it is eligible, the only rule is that it must be electrically safe!   If it too large to bring in to the meeting then an entry of a multimedia presentation of the item is OK.

The emphasis is on the construction of the item, be it your own design, built from a kit or just copied from a magazine, we would like to hear about it!

CARS Constructors Competion.
CARS President opening the Meeting.
Photographs by John G8DET.

Peter, G3SUY 400W Linear
Peter, G3SUY explaining the construction of his 400 Watt Linear for portable working.

Bruce M0XBS Field Strength meter
Bruce Saunders, M0XBS explaining his Field Strength Meter and his 5 Amp PSU.

CARS Constructors Competition. CARS Constructors Competition.
Charlie, M0PZT explaining how he turned a Tablet into a Logging Computer.

Colin G0TRM, Morse Key
Colin, G0TRM explaining how he made a Morse Key from a Tea Strainer - 9th year he had constructed such a device.

CARS Constructors Competition. CARS Constructors Competition.
Clive, M0GHH explaining the details of his High Speed Fuse with a Hair Drier.
Photos by Colin, G0TRM

John G8DET - FM tuner
John, G8DET holding and explaining his FM Tuner from 1976.
Photo by Colin, G0TRM

Andy, G1GKN - 472kHz Transmitter
Andy, G1GKN explaining how he built his 470kHz 10 Watt Transmit Transverter for use with his FT817.

CARS Members voted and the results were as follows:-

  • First Prize - Peter, G3SUY - 400Watt Linear
  • Second Prize - Andy, G1GKN - 470kHz Transverter
  • Third Prize - Charlie, M0PZT - Logging Tablet
  • Special Prize - Bruce, M0XBS with his PSU & Field Strength Meter

    After the construction competition, Murray G6JYB gave a recap of the recent proposals in August RadCom regarding encouraging youngsters, construction and demonstrating Amateur Radio.   This provoked a good discussion on demonstrating radio to the public.

    RSGB Youngsters & Junior Licence Proposals
    Murray looking at his screen presentation, see below.

    Youngsters summary
    Murray's Summary Slide.

    A copy of the full RadCom article "I was young once...." is available in PDF Format here

    It suggest three options including a new basic/junior VHF licence but, as the summary says, if you have a better idea contact the RSGB via 'haveyoursay'.

    The now famous CARS Raffle was run by James, 2E1GUA.

    CARS Constructors Competion.
    James surrounded with the Raffle Prizes.

    Light refreshments were also served by David and Myra with a delicious selection of biscuits.

    A very good evening of a variation of Home Constructed items which shows Home Construction is NOT dead!
    Thanks to ebveryone who turned up and demonstrated their apparatus.
    The Certificates and Shield will be awarded at the October AGM.

    September Meeting
    Tuesday, 2nd September 2014, 7.30-10pm
    At Oaklands Museum, Moulsham Street, CM2 9AQ
    "D Star Radio Operation and Demonstration"
    By Joel, G0URK and Gary, 2E0ULA

    September's meeting saw Gary 2E0ULA with assistance from Joel G0URK enlighten us about the D-STAR mode.   It's a digital system that typically uses an Icom transceiver to communicate with other D-STAR users.   There is a network of digital gateways and repeaters which allow you to speak not just locally via RF, but to "conferences" from all parts of the World - Just as if it were a local QSO on 2m FM.

    One of the benefits of D-STAR is the size of the transmission - Just 6.25KHz of spectrum is required compared to the usual 12.5kHz of an analogue FM transmission. One of the downsides is that the radios are not cheap: Expect to pay around £400 for a 2m/70cm FM/D-STAR handheld!

    Thanks to Gary and Joel for their informative talk and demonstration of the D-STAR technology.

    The now famous CARS Raffle was run by James 2E1GUA and Carl G3PEM with refreshments courtesy of David G3SVI and Myra M0MYR.

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