One thing Audio
Quad
ESL Projects, Yann Zeeuwe and Martijn Schmidt
YEM-1
A few months ago a very good friend of ours in the Netherlands mentioned that his teenage son was building an electrostatic panel as a school project. I assumed he meant ‘refurbishing’ a manufacturer’s panel – but no; he and his school colleague were building an electrostatic panel FROM SCRATCH. Naturally, we were more than a little curious and said, “Do let us know if we can be of any assistance”.
This got me thinking. Was I doing anything at the age of sixteen of comparable ambitiousness? Well, I’d built a box camera and a bike, but that wouldn’t count! I’d built a dozen crystal sets of varying complexity and a one-valve detector set utilising a car battery and a 90 volt HT battery given to me by my science teacher. But neither I (or my science teacher, come to think of it) would have had much idea what an electrostatic panel was. If pressed, I would have guessed that it was the latest device for stunning flies. The year, significantly, was 1957.
Fast-Forward 50 years (not TOO fast, please.. .) and here we have two youngsters in Holland building their very own electrostatic panel, with their own chosen materials. Well, better standards of education these days? The information revolution.. . but still a tall order, I would have thought for teenagers to tackle with no previous experience, and no tuition, save what you can glean from the web or a public library. What’s more, the two young scientists (Yann Zeeuwe and Martijn Schmidt) only had a limited time in which to complete the project – when I contacted them, no more than a few weeks to have a working prototype to demonstrate before an audience and point-awarding adjudicators! And as the fateful day grew nearer, I picked up on a sense of urgency in their emails – panic might be a better word for it, especially when Martijn fell ill and had time off from school. Then I learnt that the panel was only the ‘practical’ half of the project – the deadline also required a ‘thesis’ on the history and development of electrostatic panels! Some ‘cramming’ necessary here. [Does some of this sound familiar!?]The boys fell silent for a week or so, and I had visions of them slumped in a corner, suffering from exhaustion and heading for a nervous breakdown! So I wrote to Yann’s father, Hans, asking him to take a look and check there there were still signs of life. But I needn’t have worried: they had heeded my advice to forget the deadline and just proceed steadily and methodically. The work would get done much quicker this way. But there were still some frustrations, like the SOS I received one day from Martijn: “In a burst of stupidity, Yann has just burnt a whole in the diaphragm!!!!” When we’d picked ourselves up off the floor from laughing, we replied: “Tell Yann not to worry. You have to burn 10 holes in diaphragms before you’re a good panel builder. Yann still has 9 to go.”
Well, I’m delighted to report that the boys not only completed their project, they were awarded top marks for their efforts. Perhaps only those amongst us who have beavered away trying to build an electrostatic panel, and have encountered all the pitfalls, could get the full measure of what these boys have achieved – and to a deadline at that!
The following pictures were a requirement of the project – not only was it necessary to turn your private room into a sweatshop, it was essential to photograph every stage of your progress! But... what wonderful memories to carry with you into a promising future.
At the end of the picture show, we have added (with apologies for the print quality) some reprints from Wireless World in the ‘20s and ‘30s, announcing some pioneering efforts and the inception of a long tradition to which our two enterprising Dutch schoolboys belong!
Take a deep bow, Yann Zeeuwe and Martijn Schmidt.. .you’re ON.
Day 1 - Assembling the electronics
Day 2 - Testing the electronics
Day 3 - Making the second case
Day 4 - Building the frame and recieving One Thing Audio package
Day 5 - Wiring the frames
Day 6 - First day cutting Plexiglass
Day 7 - Second day cutting Plexiglass
Day 8 - Reinforcing the frames
Day 9 - Tensionig the diaphragm
Day 10 - Making the diaphragm conductive
Day 11 - The HT-grid
Day 12 - Gluing the frames together
Day 13 - Testing the panel
Day 14 - Making dustcovers
Day 15 - Done!
At the Paris Electrical Exhibition of 1881, Dolbear exhibited a complete electrostatic telephone system. What is interesting about this fact is that it pre-dates by some 30 years any attempts to convert electrical energy into sound by alternative means. In other words, it appears that elerctrostats appeared first – its now commonly accepted “moving-coil” counterpart very much the later invention.
Further development of the ES principle appeared in Germany in the 20s and 30s, and here’s how the great British public heard about those developments:
Download PDF-file of how the great British public heard about those developments
