Having received signal reports that my audio from a number of different microphones was lacking in top I did the following after modeling the appropriate circuit values on the KSB2.
As per KD2BD mod, changed C34 from 2.2uF to 0.47uF moved LF -3dB response from about 80Hz to 400Hz. Did not change C32 as it made little difference in simulation. Changed C20 from 0.33uF to 0.047uF this moved the LF -3dB from again about 80Hz to 450Hz (0.068uF would have been better, but I didn't have one). Result much brighter transmit audio with all mics, and no adverse effects on either the RF output or VOX operation. It may make the signal cleaner because of reducing any LF clipping products (sub 800Hz) the third harmonic of which may make it through the SSB filter. _______________________________________________ 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
