Introduction

Chelmsford Science & Industry Museum has a Science & Discovery Day each year to encourage involvement with everyday science.

This year it was Sunday 25th September. In the morning, 10am was the early opening time and the local Camera Club took advantage of good lighting and plenty of equipment & items to capture on film (or digital).

Science Day 2005

CARS was invited to provide an Amateur Radio Station in the Marconi Hut.

Denis M0FHA (logging) and Malcolm G4KGL relaxing between QSOs.
Photograph by John, G8DET

The usual 80 Metre Doublet Aerial over the water course which surrounds the contributed to G0MWT putting a strong signal into the Americas where the Amateurs were just waking up.

Logging has now passed to Jeremy M0DUT but Malcolm is still on the microphone, many station calling in as they know Chelmsford or in a few cases as they are also in Chelmsford (Massachusetts, USA).

Another view of Jeremy & Malcolm working the Club FT748 with members of the public listening to the QSOs. At the end of the day over 60 QSOs were made. These were long QSOs, not the "5 by 9 QSL?"

Looking around the room a couple of new exhibits were spotted including one made by Geoff, G7KLV. It was of a demonstration of the rectifier effect produced by a Diode - the unusual point being that Geoff has used a large "Bright Emitter" diode (see right below) of a pattern produced before 1920!

The public are invited to press a knob to see the AC full wave voltage from the mains and the rectified waveform with the old valve and compare it with the waveform using a Silicon Diode. The old valve has a 5 volt filament and is really bright - something few people would ever see.

Diode demostration made by Geoff G7KLV

Teas were provided by Friends of the Museum in the old Battery Room.

The afternoon was busy with over 550 persons in total passing through the gates by the time they closed at 5pm.