This is correct, and a lot of the "pre-amped" microphones or very good and some or not. I used an old dynamic microphone case and pulled the guts out of it. It had been in a flood. Then built a preamplifier and condenser microphone on a small PC board and installed it in the old microphone case. I actually used two condenser microphone cartridges from Radio Shack. I don't remember the number but they were about dime size round and thick. I think I used three transistors but I don't remember the circuit as that was several years ago. My wife, Vickie, helped dye the new spit cloth and glued it in. See the picture at http://wa5bxo.shacknet.nu/HAMPICTURES/Pictures/Ham%20Radio/Mic.jpg The LEDs were a small optical add-on.
John, Coleman WA5BXO -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Grant Youngman Sent: Monday, March 14, 2005 2:32 PM To: 'Discussion of AM Radio' Subject: RE: [AMRadio] Xtal mike Most any HI-Z mic will do. You can use a crystal mic, you can use a dynamic mic with an impedance step-up transformer, you can use most any mic with a preamp, etc. Nothing magic about "crystal" per se. As others have said, the D-104 can be a good choice, but it is a buyer-beware situation. The elements are degraded by high heat and humidity, and eventually plain old age takes its toll, and if that has happened the mic will sound thin and "tinny". It's hard to tell what you're getting if you buy one off the 150 deg F hood of a pick'em-up truck at a 'fest (in fact, if you do that you have a high probability of getting a bad element). Astatic/Omnitronics no longer manufactures or supplies D-104 elements to resellers, but apparently they still have new ones, and will (for a price) replace them if you send them the mic. Grant/NQ5T > Excuse me...'senior moment'...I need one...anyone have one for sale? ______________________________________________________________ AMRadio mailing list Home: http://mailman.qth.net/mailman/listinfo/amradio Help: http://mailman.qth.net/mmfaq.html Post: mailto:AMRadio@mailman.qth.net
