The RD4/16, digital coder is a revolutional and a step forward in the aural STL. Using the CDB™ digital codification system, it permits the simultaneous trasmission of more high quality audio and auxiliary channels through the traditional narrow band STL already used for analog signals.

CD audio quality isn't degraded by the number of hops of STL. In fact a numerical recovery system permits the unlimited signal re-transmission without quality loss.

Stereo separation, crosstalk, S/N ratio, distortion are practically the same as a typical CD player in all the STL hops.

More channels: The system simultaneously accepts 2 x 15 KHz high quality audio channels plus up to 4800 bps data channel and one RDS channel.

RDS. The optional RDS interface is compatible with all Radio Data System coders and permits studio transmission without adding equipments.

SCA. In the 4 channels version it is possible to choose two 15 KHz high quality audio channels configuration plus SCA1, SCA2.

AES/EBU. The optional AES/EBU interface accepts direct connections with any digital audio equipments.

Instant Installation on traditional analog STL, without modifications.

Tolerance to interference. The CDB™ digital transmission is co-channel interferences free.

More than 20 dB of total gain permit a lower investment for antennas and transmitting equipments.


Analog audio input 4 XLR female, 600 W balanced
Analog audio level -10 to +16 dBm adj
Digitally coded output signal 0.8 to 5 Vpp into 600kW load
RCS, regenerated coded signal output (for multi hops STL) BNC, 1 Vpp
Digital audio output 48 ksps (32 or 44.1 on request)
Standard AES/EBU
Digital audio output sample rate 48 ksps (32 or 44.1 on request)
MPX + RDS output BNC, unbalanced
Data output 4800 bps, RS 232, 9-pin female
Indicators analog audio input peaks, ES/EBU status, system fault, RDS & Data
Temperature range 0 to 45 °C

STL receiver requirements:
Receiver output impedance 600 W bal./unbal
Bridge signal-to-noise ratio > 54 dB
Audio bandwidth, +/- 1 dB 10 Hz to 110 kHz
Total group delay variation < 0.5 µs
Minimum channel bandwidth 180 kHz

System specifications:
High quality audio channels 2 or 4 according to the model
Channel crosstalk -85 dB
Audio channels frequency response 15 Hz to 15 kHz, ± 0.25 dB
Distortion at 1 kHz 0.01 %
Distortion at 10 kHz 0.015%
Dynamic range 93 dB typ
Signal-to-noise ratio >= 80 dB
Sensitivity at 10-4 BER - 85 dBm tip
Max BER for no loss in audio quality <= 10-4
Audio coding method APT-x (others on request)
Audio delay <=3.8 ms

Power requirements:
Operating voltage 115/230 Vac ± 10 %, 50/60 Hz
Power requirements 34 W

Weight and size:
Weight 4.6 kg
W x H x D (see options) 483 x 45 x 357 mm


ITEL S.r.l.
Via Friuli, 6 - 33074 Fontanafredda (PN) - ITALY
Tel. +39 0434 997667 - Fax. +39 0434 997687