The non-amplified D-104 microphone is a great one for frequency response *if* it is working into a very high impedance (50k to 2 megohms). Unfortunately, the input impedance of the K3 and most other modern transceivers is in the vicinityof 600 ohms, so the D-104 will sound very bad when used directly with those transceivers.
You could use a single FET stage behind the D-104 (it will easily fit into the base) to match the impedances and it will sound good. Otherwise, it is a 'museum piece'. Others have suggested a simple series resistor (something on the order of 100k should do) to allow the stock D-104 to drive low impedance transceivers - the crystal (or later ceramic) mic element produces lots of voltage. I have not tried this technique, I am just passing along information received. 73, Don W3FPR -.-. --.-N3TU -.-. --.- wrote: > I tried a non amplified D104 and it was not good at all. The audio was real > low when the mike was at 60. It had a slight "fan noise" and I had no fans > running. The mic was wired up right because when I put it back on my ADI > radio it worked well. My ADI radio hand mic works on my K3. ADI and Kennwood > wiring is the same. Now the non amplified D104 is a museum piece in the > shack. > > > > > George & Jan wrote: > >> I presently use a D104 that I modified using a rubber mounted Radio Shack >> electret element. With bias on it works well. Reports on air are good. >> >> Reports using the crystal element were poor. >> >> George >> AI4VZ >> >> Anyone ever use the non amplified D104 mic? If you have, how does it >> perform >> and what's it look like on the scope? Does it sound good and natural >> without sounding like you are talking in a trash can? How do you compare >> it >> to other mics. >> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[email protected] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> >> >> > > > ------------------------------------------------------------------------ > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.409 / Virus Database: 270.13.109/2384 - Release Date: 09/20/09 > 06:22:00 > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
