I've been experimenting with electret replacements for the D-104 crystal element. I found this site with a really excellent description of what lies inside those little electret capsules. Here it is:
http://www.openmusiclabs.com/learning/sensors/electret-microphones/index.html
Re: Central Electronics 100V Opposite Sideband Supression Adjustment
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Thanks for the advice Roger. I’ve dialed it in as best I could using a
Wandell and Goltermann AT-611 selective level meter to look at and listen
to the re...
4 hours ago
You could have just opened one up, they are cheap and available. I did years go, was surprised that the FET, while in a small package, was still a recognizable device. I was expecting blob of epoxy.
ReplyDeleteI think it was 1968, Popular Electronics had an article about how electrets worked, and even had a sidebar about making your own. Used the high voltage from a color tv set to provide the charge.
Electrets are like electrostatic headphones, except no HV supply needed. While there have been construction articles about making electrostatic speakers and even headphones, I've never seen a construction article about making electret headphones or even speakers.
Michael