Audio Switching Tab - microHAM microKEYER II User Manual

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User manual (49 pages)

Table Of Contents

Table of Contents

microKEYER II uses an advanced, custom USB audio subsystem which allows Router to handle all of the

audio routing. Microphone and receive audio are always connected to microHAM CODEC (the

microKEYER II "sound card").

On transmit, the selected microphone or sound card output will automatically be connected to the

transmitter's microphone or line (rear panel) input based on the mode, and optionally frequency, reported by

the transceiver in response to polling by the application (logger) and/or Router. If Router is not able to read

the operating mode from your radio (radio does not have computer control port or does not report usable

mode information), you can select one of four fixed "no radio" modes or one "no radio" mode with manual

(keyboard/keypad) mode selection.

Many radios fail to provide a separate mode for digital operation or the serial control protocol

implemented by the radio does not report the digital mode when operating AFSK, PSK or other

audio based digital modes. This is true for all Kenwood transceivers, most Ten-Tec transceivers,

most older Icom transceivers and the Elecraft K2. With those radios, digital operation (except for

FSK) must done using voice modes (USB or LSB).

The traditional method – feed the microphone jack from the sound card output through a

transformer – is not optimum for many reasons: you need to remember to turn off any speech

compressor and EDSP or other signal processing when using digital modulation operating using in

digital modes. In addition, the microphone amplifier in the radio can cause distortion because it is

optimized for voice and its frequency response is often not as flat as necessary for digital

modulating signals.

The proper method is to feed sound card audio to the microphone jack only for voice modes (SSB,

AM, FM) and to the jack designed for digital modes - generally on the transceiver's rear panel –

when using sound card based digital modes.

Even though the radio may not report a unique

DIGITAL mode, Router can make an intelligent choice

and apply the DIGITAL or VOICE configuration for

Audio and PTT based on the operating frequency from

the radio.

The VOICE/DIGITAL settings selector is used to control automatic switching when the

operating frequency is in the "Digital Band" as defined in the Digital Band Map and the transceiver is in

USB, LSB or FM mode.

Select by frequency: Router will select DIGITAL settings when detecting a frequency inside the "Digital

Mode" boundaries. These boundaries can be fully customized in the Band Map by clicking the

Digital Band Map button or selecting Router | Options | Digital Band Map.

NOTE: Use "Select by frequency" only if your radio does not have a dedicated mode (PKT, DIG,

DATA, or USB-D/LSB-D etc.) for audio based digital modes like PSK31, MFSK, OLIVIA, AFSK-

RTTY etc. and you must use USB/LSB/FM for digital operation.

Use VOICE settings: VOICE settings will be used regardless of frequency and mode (USB/LSB or FM).

This should be used with most Yaesu transceivers, late model Icom transceivers that support USB-D

and LSB-D and the Elecraft K3. Router will select "DIGITAL" when it detects the special digital

modes and use the "VOICE" settings for USB/LSB and FM.

Use DIGITAL settings: DIGITAL settings will be used regardless of frequency for USB/LSB or FM.