Digital FM Transmitters and Digital FM Modulators: NEURAL DDS
Direct digital synthesis. Compact architecture.
Sold to commercial and community radio stations.
Frequency modulation: 88 to 108 MHz. 30 to 500 watts, 1 and 2 kilowatt.
NEURAL is a Family of Direct to Channel Digital FM Stereo DDS Exciter, Digital Transmitter and Digital FM Modulator that guarantees a superior transmission quality and top performances.
Output power ranging from 30 W to 1200W, using High Efficiency last LDMOS technology, housed into an ultra-compact cabinet only 2U high.
TX-HE is available also in JPN and OIRT frequencies.
TX-HE can be used as an ultra-compact stand alone station, as well as a driver in complex of high power transmitters and N+1 systems.
For any application, NEURAL is the ultimate solution that meets the most demanding customer requirements and guarantees professional features at an affordable price.
• High Efficiency last generation LDMOS technology up to 80%;
• Very LOW SIGNAL TO NOISE MORE THAN 90 DBv;
• Very LOW DISTORTION and HIGH STEREO SEPARATION;
• TOTAL SPECTRAL PURITY: > -100 DBC SPURIOUS, > - 84 DBC HARMONICS;
• SEVEN SELECTABLE COMPLETE SET-UP: READY FOR USE IN 7+1 SYSTEM ;
• FULL- RANGE POWER SUPPLY: 90-260 VAC MAINS VOLTAGE;
• COMPLIANT WITH ALL THE STANDARD: ETSI – CCIR - FCC;
• DIGITAL STEREO CODER: SUPERIOR STEREO QUALITY;
• UP TO 75% LDMOS HIGH EFFICIENCY AMPLIFIERS;
• EXTERNAL 10MHz and 1PPS SYNCHRONIZATION FOR USE ON SFN APPLICATIONS;
• HIGHEST RF SIGNAL QUALITY;
• PERFECT AUDIO FIDELITY;
• REMOTE CONTROL BY TCP/IP: WEB + SNMP OF ALL SIGNAL PARAMETERS;
• CLEAR CRISTAL AUDIO SOUND;
• DYNAMIC RDS ENCODER with TMC Function;
• FULL UECP Protocol to control remotelly all functions of the RDS;
• SFN-Single Frequency Networks;
• ASC-Automatic Audio Source Changove.
Analogue or DIGITAL?
At the time of selecting the kind of modulator, broadcasters are often confronted with a dilemma, when considering the standard Analogue FM in the the DDS that produces exactly the same Frequency modulation as any analogue FM Transmitter or Exciter.
The choice is between a transmitter with the standard instruments and protocol of an Analogue FM modulator, and the new generation of Direct Digital Synthesis FM Modulators.
The first thing to know is that Digital DDS doesn’t mean the broadcast signal is digital, it only means the process to generate the FM modulation is by means of a digital NCO – Numerical Controlled Oscillator – instead of the Analogue VCO Voltage Controlled Oscillator.
The process is different but the resulting FM Modulated signal is exactly the same in both cases.
It is here important to clarify that the final quality of the radio electrical signal generated is of the same comparable quality, and this result depends on the way each VCO or DDS is designed – and not on the type of technology chosen.
Even if both technologies are really comparable in quality to the FM Signal generated, they have small differences, each of them with pros and cons.
Standard Analogue VCO Voltage Controlled Oscillator FM Modulator
The analogue VCO generates an FM signal that is pure. The kind of electronic circuit being used is really simple and essential, but thanks to it the RF FM generated signal is pure, free of any kind of distortion or undesired spurious effect.
In these kinds of circuits the input base band audio signal directly drives a Varicap – a component which is intrinsically an Analogue FM radio Modulator.
Analogue VCO Voltage Controlled FM Modulator
Because of its simplicity, this circuit is cheap, very reliable and produces an RF FM radio modulation signal that is Clear, with very good Signal-to-Noise characteristics, Harmonic Distortion and Intermodulation Distortion. Moreover, it handles high levels of over-modulation compared to the DDS modulator, and even in this case its characteristics don’t degrade and are always of high quality.
Our Line of FM Transmitters using this architecture are The low power Synapse TXL and the line of Compact FM Transmitters AXON TXC.
Digital DDS Direct Digital Synthesis FM Modulator
The main advantage of the Digital modulation is the capability to have more functions included as standard – compared to an Analogue FM Transmitter. In fact, many of the functions given as standard in a DDS Modulator are optional in the Analogue Modulator.
The DDS FM Transmitter has a standard, built-in, complete, Professional, high performance Stereo Generator, a professional dynamic full optional RDS coder, functions of automatic base band audio change-over and a powerful synchronisation system – witch includes 10MHz and 1pps inputs to synchronise several transmitter sites and create a Single Frequency Network.