[Elecraft] Audio mute while sending from sound card

[Richard Ferch]

The K3 has three external audio inputs: the front panel microphone jack, 
the rear panel microphone jack, and the rear panel Line In jack. You can 
use configuration settings to select among microphone input only (line 
input muted), line input only (microphone inputs muted), or both 
microphone and line inputs live at all times. Since the desired settings 
are likely to be different between voice modes and data modes, the K3 
remembers these settings separately in voice modes (SSB, AM, FM) vs. 
audio-based data modes (DATA A, AFSK A).

In data modes, you would normally set MAIN:MIC SEL to LINE IN. When you 
do this MAIN:MIC+LIN is automatically turned off (the display shows NOT 
APPL). The microphone input is not live, i.e. you don't have to worry 
about it when LINE IN is selected. You connect the sound card or other 
interface to the rear panel Line In jack.

In voice modes, you would normally set MAIN:MIC SEL to fP or rP 
depending on where your microphone is connected. If you are not using an 
external voice keyer, you would set MAIN:MIC+LIN to OFF. If you are 
using an external voice keyer connected to Line In, you would set 
MAIN:MIC+LIN to ON, in which case the microphone and line inputs are 
both live. This allows you to switch back and forth at will between the 
voice keyer and microphone input, which is OK for voice modes using a 
voice keyer to supplement live voice input, but not OK for digital 
modes. If you insist on putting the radio in USB mode to operate digital 
modes, you will be faced with a requirement for muting the microphone 
during data transmissions.

This is just one among several reasons why it is recommended to use DATA 
A mode in preference to USB mode when you are operating in digital modes.

73,
Rich VE3KI