FLEX-6400/FLEX-6600 Hardware Reference Manual
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27 of 45
Copyright 2018 FlexRadio Systems. All Rights Reserved.
Δ –
The TX Relay outputs are designed to handle signaling levels of up to +40 VDC @ 140
mA maximum. Some amplifiers do not have circuits to prevent keying voltage
transients and older amplifiers may exceed the maximum voltage level resulting in
damage to the radio if directly connected. Verify the voltage/current on your external
device before connecting to TX Relay 1-3. FlexRadio highly recommends the use of a
use a buffer/isolator box between the radio and the external device as a best operating
practice regardless of the keying voltage.
7.18
RX-B RF INPUT (FLEX-6600 ONLY)
This female BNC connector is a direct feed to the input of the second Spectral Capture
Unit (SCU-B) in the radio. This port is for use as a RECEIVE ONLY input to the RXB SCU.
Refer to the SmartSDR documentation for information describing how to select this input,
and how it can be used.
7.19
XVTR-B TRANSVERTER PORT (FLEX-6600 ONLY)
This female BNC connector is a receiver input and low-level exciter output for use with
Transverters. Refer to the SmartSDR documentation for information regarding using the
FLEX-6400/FLEX-6600 with external transverters. The FLEX-6400 has one transverter port
and the FLEX-6600 includes two transverter ports.
I - The XVTR port can also be used as an auxiliary receive antenna connection when not
being used for transverter operation.
7.20
MICROPHONE JACK
The
MIC
connector accepts a 1/8-inch (3.5mm) stereo (TRS) plug and provides a pseudo-balanced
microphone input. Pseudo-balanced means that the mic (+) and mic (-) lines are balanced all the
way to the input of the A/D converter, where the mic (-) line is DC grounded. The connector may be
used with dynamic or electret microphone elements. A software enabled 3V bias voltage through a
2.1k Ohm source impedance may be applied to the Mic (+) line for electret microphones.
Note: The PTT signal is not accepted by this connector.
