Chelmsford Amateur Radio Society
G0MWT, GX0MWT, GB5HF, GB100MWT & GB100-2MT

CARS Meetings: April - June 2022




April Meeting
Tue 5-Apr-2022, 7.30-9pm
Online by Zoom
"Radar History - from 1895!"
Philip Benstead

Our April talk provided a fresh and fantastically well-illustrated perspective on the history of radar.

Our speaker Philip Benstead has been involved with the development & implementation of radar systems from 1964 through to 2020. His career started as a Marconi Apprentice in 1963-68, including a time with Marconi Radar at Great Baddow. His early work included NADGE, before moving to Plessey Radar on the Isle of Wight in 1976. His time there covered MESAR, 996 and Watchman radars. After attending a talk at Bletchley he realised that radar history has some earlier origins than Robert Watson Watt.

Philip outlined some early chronology:-

Prior to Daventry, the UK effort had been on acoustic detectors including unwieldy huge concrete sound mirrors. After Daventry, radar development moved in 1935 to Bawdsey Manor on the Suffolk coast prior where it developed rapidly to the deployment of the Chain Home (AMES Type-1) radar network, such as the mast now at Baddow.

One early key contrast was that whilst the Chain Home radar systems for the Battle of Britain were on ~20-30MHz, the German Freya system was up at ~220MHz (which is why the Germans did not correctly identify CH).

Another key difference was that Chain Home was one element of an integrated reporting and control system that Dowding implemented for RAF Fighter Command. In contrast the Germans did not integrate their radars to anything like the same degree.

Later on Magnetrons and other developments enabled the move to convenient microwave frequencies so that smaller antennas could form accurate directional beams; or even ground imaging for night time (H2S was at 3GHz) - the latter by Bernard Lovell (who later went onto create the Jodrell Bank radio telescope).

Our thanks to Philip for a fascinating 100-slide tour of radar history.



May Meeting
Tue 3-May-2022, 7.45-9:30pm
Danbury Village Hall
"Is Life too Short for QRP"
Steve Hartley G0FUW

Steve Hartley G0FUW, will be talking about QRP – operating with low power, the G-QRP Club and how he went from being a CBer to now being Chairman of the G-QRP Club, a Trustee of the RCF and leader of Bath Based Distance Learning – and a former RSGB Board member too!

In brief: Is life too short for QRP, and how did I get here?

Note our new meetings venue!
CARS meet on first Tuesdays at Danbury Village Hall CM3 4NQ and no longer use Oaklands Museum.

Radio Surplus to recycle? Members are welcome to bring it along and place it on a spare table!

This will be a hybrid meeting with Zoom in use as well

  • Meeting ID: 872 1544 6400
  • Passcode: 055551



    June Meeting
    Tue 7-Jun-2022, 7.35-9:30pm
    Danbury Village Hall
    "10 Different Radio Topics"
    Jim Salmon 2E0RMI

    Jim Salmon 2E0RMI, will cover a wide variety of 10 radio topics, different to Amateur Radio

    Note our new meetings venue!
    CARS meet on first Tuesdays at Danbury Village Hall CM3 4NQ and no longer use Oaklands Museum.

    This will be a hybrid meeting with Zoom in use as well
    Details to due course...


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