At 3:34 PM -0500 7/2/04, Chuck Gehring wrote:
I have an old Astatic D104 Desk Microphone that I would like to modify to use with a modern Transceiver. Does anyone have some suggestions?
The D104 works quite well with the K2. There are a couple of ways to make the D104 match the input impedance of the K2. A 600 ohm - to-10K impedance matching transformer can do the job. A better solution is to use a small amplifier with high input impedance and low output impedance. One such amplifier using a transistor is described on the Elecraft Web page. I put together a circuit using an op amp based on a circuit from the 2003 ARRL Handbook. Op amps are perfect for this situation since they naturally have high input and low output impedances.
I almost forgot - my D-104 has the original G stand without the amplifier. If you have a stand with the amp built-in, then just hook things up, everything you need is already in place...
-Jack Brindle, WA4FIB ======================================================================= MacDobs - helping to shift the paradigm for low-cost amateur astronomy. _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
