> Did you use the K3's MENU:MIC SEL option to choose high gain for the > microphone input?
Good advice from Ron. After checking that, and assuming the mic is relatively old and its past quality-of-life unknown, I would consider replacing the D-104's mic element with a similar crystal element from Mouser: http://www.mouser.com/catalog/specsheets/KT-400023.pdf Price in small quantities is USD $4.77. If you use a single-transistor FET buffer, be careful of the various designs and mods seen on the web. Some utilize unnecessary components at best, and performance-degrading parts at worst. If an existing 2-stage Astatic buffer is used, one can place a resistor in series with the mic lead, > 1 megohm in value and make up the gain with the amp's level pot although it may become unstable and certainly noisier than a well-designed single-stage FET circuit. Either circuit can be powered from the K3's mic connector through a current-limiting resistor. The existing input Z of the Astatic pre-amp calculates to ~ 470K-ohm and although it may seem high, it's just not high enough for a crystal element to achieve a reasonably flat response down to 80-90 Hz -- the first fundamental of most male voices. My D-104 achieves this with the K3 in ESSB mode, although I'm not sure if all of the extended low-end can be captured in the K3's default SSB Tx setting. Paul, W9AC ______________________________________________________________ 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
