General technical description, D4t transmitter – Lectrosonics D4 System User Manual
Page 4
D4T/D4R
LECTROSONICS, INC.
4
General Technical Description
D4T Transmitter
The transmitter can accept up to four inputs from digi-
tal or analog sources. The inputs can be configured as
follows:
• Four analog inputs using all four jacks
• Two digital inputs using jack 1 and two balanced
analog inputs using jacks 3 and 4
• Four digital channels using jacks 1 and 2
The input connectors are TA3 “mini XLR” types with
the same pin numbering as standard XLR connectors
for AES/EBU and balanced line level analog signals.
Input preamp circuits use a special balanced amplifier
with very high common mode rejection to minimize
hum and noise.
Either analog or AES/EBU digital input signals are
converted to an internal 24-bit digital format which is
then encoded, organized into packets, and passed to
an RF modulator using spread spectrum techniques
and error correction for robust reception. The modu-
lated RF signal is filtered before and after amplification
to suppress out-of-band noise and spurious signals,
and a circulator/isolator guards against intermodulation
interference (IM).
A USB port is provided for firmware updates.
POWER
AMP
OSC
900 MHz
RF
MOD
DIGITAL
BASEBAND
ENCODER
24-bit D/A
(analog)
AES/EBU
OUT
(digital)
24-bit D/A
(analog)
AES/EBU
OUT
(digital)
24-bit D/A
(analog)
24-bit D/A
(analog)
TA3M
INPUTS
CIRCULATOR
ISOLATOR
FILTER
1
2
3
4