I put this image in a post on my Acousticats blog to give a visual for a gig we played last summer where there were a lot of flies. This image alone brings 150 hits a month that blog. So here it is on this blog . (Can you say link bait?)
Carbon Telephone Mic experiment
I found this schematic on the Internets
Of course after visiting my neighborhood Radio shack They had none of the parts so I bought stuff that was close. I ended up with 3 resistors adding up to 21.6K a 1uf cap and the transformer is a audio output transformer (obviously the wrong one). I am still going to create another with the proper components when I get them but for now check out the link below for a sample of what this one sounds like.