Audio Switching Tab - microHAM MK2R Manual

MK2R provides extensive and unique flexibility in routing audio among the computer sound card, transceiver,
and the station microphone. To understand the way MK2R handles the sound cards, transceiver audio inputs
and microphone you must understand how the sound card works. The following description is valid for both
MK2R and MK2R+, the only difference is that the sound cards are integrated with MK2R+, where MK2R requires
externally connected (in the computer) sound cards.
Understanding Sound Card operation in Amateur Radio programs
Note: the following discussion and tests apply to external sound cards used with MK2R and
microKEYER. It is not applicable to MK2R+ due to the unique dual codec sound system.
Each sound card has two sets of controls - PLAYBACK and RECORDING. For most cards these settings
are independent and can be controlled by the application software, the user (from Windows VOLUME
CONTROL application), or both. To understand the operation of these controls, it is recommended that
you conduct the following tests:
Connect headphones to the sound card output and connect a microphone to the sound card microphone
•
jack.
Open the VOLUME CONTROL application (click Start | Run and type SNDVOL32 if you do not see a
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speaker icon in the System Tray area of the Task Bar).
If your system has more than one sound card installed (as it should with MK2R or MK2R+), click Options
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| Properties and select the sound card you are using. Then select "Playback" and enable ALL controls to
be displayed.
Leave the PLAYBACK VOLUME CONTROL running and open second instance of VOLUME CONTROL.
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Arrange them on the desktop so both are visible at the same time (later you can run your logging
software and watch for interactions). In the second instance of VOLUME CONTROL, click Options |
Properties, choose the same sound card as you chose for the PLAYBACK VOLUME CONTROL, select
"Recording" and enable ALL controls.
Now you have both PLAYBACK VOLUME CONTROL and RECORDING VOLUME CONTROL on your
•
desktop.
• Confirm that you have a "Microphone" channel in the PLAYBACK window. If not, your sound card will not
support "live mic" mode. You will need to upgrade your sound card to make use of those functions.
• Now UNMUTE all controls in the PLAYBACK window. If you speak to the microphone, you should hear
your own voice in headphones. You can control level with the microphone slider or master volume slider.
This is because sound card has INTERNAL LOOPBACK from the microphone input to the sound card
output ENABLED. If you MUTE microphone control in the PLAYBACK window, loopback will be disabled
and you will hear nothing.
This function is used by software to mute the microphone during message (F1-Fn) PLAYBACK and avoid
•
mixing noise from the microphone with message. During playback, the microphone is muted; after the
message is completed the microphone is unmuted allowing VOX operation.
NOTE: manipulating the microphone controls (slider or select/mute box) in the RECORDING window has
NO effect because you are NOT recording. The recording controls are used only used when the logging
software is recording (Ctrl-Shift-Fn or Control-Fn) a message as a WAV file. To record, the
RECORDING mic control MUST be selected. The logging program usually handles this function
automatically.
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AUDIO SWITCHING TAB

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