FLEX-6400/FLEX-6600 Hardware Reference Manual
Page
37 of 45
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11
DIGITAL MODE SETUP (SOUND CARD INTERFACE)
There are two options for operating digital modes with the FLEX-6400/FLEX-6600 SDRs.
The
preferred
method does not use a physical sound card connection; it uses DAX (Digital
Audio eXchange) where the audio is streamed digitally between the radio and client
software over the Ethernet connection via the IP/UDP protocol. This method eliminates
unnecessary analog to digital and digital to analog conversions which degrades signal to
noise ratio (SNR) performance.
You may also operate digital modes in essentially the same manner as most analog/DSP
radios where analog audio from the speakers and to the microphone input is interfaced
with a PC sound card. The following procedure can be used for operating digital modes
with the FLEX-6400/FLEX-6600 interfaced to a sound card.
This procedure assumes that you have a working knowledge of operating digital modes
with your favorite sound card based digital mode program and will not delve into the
details of configuring specific third-party digital mode programs.
Connecting the FLEX-
6400/FLEX-6600 to a PC sound card
There are several audio inputs and outputs on the FLEX-6400/FLEX-6600 that can be used
for connecting the radio hardware to a PC sound card. Please refer to the
SmartSDR
Software
User’s Guide
for a detailed description on configuring and enabling digital
modes.
The basic audio schematic is used to connect a FLEX-6400/FLEX-6600 to a PC sound card:
•
PC Sound Card Mic / Line In <---> FLEX-6400/FLEX-6600 Audio Output
•
PC Sound Card Line Out / Speaker Out <---> FLEX-6400/FLEX-6600 Audio Input
FLEX-6400/FLEX-6600 Inputs:
•
Rear panel microphone connector [MIC] (
1/8” TRS
)
•
Rear Balanced Input [BAL] (
1/4” TRS connector
) - FLEX-6600 only
•
Rear Accessory input [ACC] (15-pin D-sub connector)
FLEX-6400/FLEX-6600 Outputs:
•
Rear panel headphone [PHONES] connector (1/8
” TRS connector)
•
Rear Powered Speaker connector [PWR SPKR] (1/8
” TRS connector)
•
Rear Accessory output (15-pin D-sub connector)
The audio input and output you choose is mostly a matter of your operating preferences.
For example, if you also operate phone modes, you may not want to constantly
disconnect your microphone and speakers to facilitate the connection to the PC sound
