The D 104 mic (unamplified version) needs to look into a very high impedance (50k ohms or greater). That mic was developed in the days of vacuum tubes with mic amplifier input inpedances in the 50k to 1 megohm range.
Modern transceivers present an impedance of something close ot 600 ohms at the mic input jack, so to properly use a D 104 with modern transceivers, you will need an amplifier stage - the gain can be low, but the input impedance must be very high and the design output impedance should be in the vicinity of 600 ohms. A few circuits to do that have been published in QST over the past 2 or 3 years. Sorry, but I don't have a specific issue reference. I took a different route with my D 104, I put a Heil HC-5 element in the D 104 head - it works FB, but the Heil elements need about 3 to 6 dB of gain to properly drive the K2, so a preamp stage is still needed (or the KI6WX increased gain mod of the KSB2 - which is what I use). 73, Don W3FPR > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Behalf Of [EMAIL PROTECTED] > Sent: Tuesday, September 27, 2005 7:39 PM > To: [email protected] > Subject: [Elecraft] D 104 mic with K2 > > > I would like to try the D 104 Mic. (crystal element ) in the K2 . I > remember a circuit posted on the reflector on this , can anyone help ? > > > > > > > > > > > > > > Thanks ,72, 73, > Jerry Uhte K9UT K2 # 1273 > _______________________________________________ > Elecraft mailing list > Post to: [email protected] > 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 > -- > No virus found in this incoming message. > Checked by AVG Anti-Virus. > Version: 7.0.344 / Virus Database: 267.11.6/111 - Release Date: 9/23/2005 > -- No virus found in this outgoing message. Checked by AVG Anti-Virus. Version: 7.0.344 / Virus Database: 267.11.6/111 - Release Date: 9/23/2005 _______________________________________________ Elecraft mailing list Post to: [email protected] 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
