5 YEARS LIMITED WARRANTY MORE INFORMATION

• DDS REFERENCED PLL
• LOW NOISE BETTER THAN -80dBu
• FLAT 20Hz-76KHz MPX INPUT FOR AGGRESSIVE AUDIO PROCESSORS
• EXCEEDS CE/FCC TECHNICAL SPECIFICATION
• HIGH VSWR PROTECTED
• BUILT-IN 50 OHM DUMMY LOAD
• DYNAMIC RDS OPTION

DDS Referenced PLL

Direct Digital Synthesis (DDS) offers extreme precision, but at VHF frequencies, pure DDS often generates high levels of phase noise and spurs as it approaches the Nyquist limit.

The Veronica® exciter solves this by using a hybrid approach: generating a mathematically perfect signal at a low frequency, then multiplying it into the FM band using an ultra-low-noise Phase-Locked Loop (PLL). This proprietary architecture achieves a noise floor better than -80dBu, combining digital accuracy with the spectral purity of high-end analog hardware.

Ultra-Low Noise: Better Than -80dBFS

To guarantee uncompromising audio clarity, the Voltage Controlled Oscillator (VCO) is engineered with a specialized three-varicap design. By separating these critical functions, we ensure absolute maximum audio linearity:

This architecture achieves an unweighted noise floor better than -80dBFS. When factoring in standard broadcast de-emphasis, performance exceeds 90dBFS—surpassing the dynamic range of pristine 16-bit CD audio.

Integrated 50-Ohm Dummy Load for Safe Bench Testing

Engineered for immediate, out-of-the-box deployment, the Veronica® exciter board is fully 'plug-and-play'. We integrated a premium 50-ohm dummy load directly onto the PCB, providing broadcast engineers with a risk-free method to test the unit before final chassis installation.

• Safe Power-Up: Securely power the board on your workbench without needing to attach an external antenna or a third-party RF load.
• Thermal Dissipation: The onboard load safely absorbs the full 1-watt RF output, efficiently converting 99% of the broadcast energy into heat.
• Localized Audio Monitoring: A microscopic 1% of residual trace radiation safely escapes the board. This allows you to tune a standard FM receiver within a 3-meter (10-foot) radius to instantly verify frequency lock and audio modulation.

Ultra-Low Noise Modulator

Our Hartley loosely coupled Push-Pull Voltage Controlled Oscillator (VCO) delivers industry-leading stability, remaining within 10kHz of its target frequency even when the DSS and PLL are disabled. This inherent precision means the PLL requires only minimal correction to maintain an accuracy of less than 300Hz.

This advanced architecture provides two critical advantages: 1. Ultra-Low Phase Noise: Superior audio transparency as a result of reduced PLL intervention. 2. Precision Low-End Response: By utilizing a super-low frequency loop filter, the system does not mistake 30Hz bass signals for frequency drift. This allows deep low-frequency audio to pass to the varicap completely unaffected—a requirement for broadcasters using high-performance audio processors.

Professional-Grade Raw MPX Input

This version is specifically available for experienced users who require a straight, raw MPX input for external signal processing.

1. Zero Tilt for Multiband Processors

• The absolute requirement for professional processing is a flat low-frequency response. As proven by our 160Hz Square Wave Test, our input delivers a perfectly square wave with zero tilting. This allows your external processor to maintain absolute control over the modulation, ensuring maximum loudness and a legal signal without low-end artifacts.

2. Ultra-Stable Hartley VCO & Slow-PLL Architecture

Superior performance starts with a stable foundation. Our Hartley-based, lightly coupled push-pull VCO is so stable it stays within 10kHz of its frequency even with the PLL turned off. This inherent stability leads to two critical performance benefits:

• Ultra-Low Noise: Because the VCO is naturally stable, the PLL only needs to make microscopic corrections (less than 300Hz), resulting in an exceptionally clean and transparent noise floor.

• Preserved Low-End: By heavily low-pass filtering the PLL control voltage to just a few Hz, we ensure 30Hz bass notes pass through the varicap completely unaltered. This preserves the essential low-frequency response demanded by high-performance audio processors.

Result: This preserves the essential low-end audio response demanded by high-performance audio processors.

Optional Dynamic RDS Integration

Enhance your station's digital presence with our programmable RDS sub-board. This compact module plugs directly into the main exciter's SIL socket, instantly enabling advanced digital data broadcasting.

• Comprehensive Data Control: Fully customize your station's PI, PTY, static PS (Program Service) name, and scrolling Radio Text.
• Live Metadata Automation: Maintain a USB connection to your studio PC to broadcast real-time song titles, artist names, and presenter info directly to listener dashboard receivers.
• Pristine MPX Mixing: The onboard 57kHz subcarrier overlays perfectly onto your incoming multiplex (MPX) signal from an external processor or STL, ensuring flawless, low-noise integration.

Intuitive USB PC Control & Telemetry

Take full command with our custom-engineered PC control software. Interfacing directly with the PLL DDS microprocessor via USB, this lightweight app provides real-time telemetry and configuration on your desktop.

• Plug-and-Play: Native Windows 10/11 compatibility with no third-party drivers required. Auto-detects the exciter for an instant, secure connection.
• Real-Time Monitoring: Instantly view frequency lock status. Adjust frequency, RF output power, and internal parameters directly from the UI.
• RDS Management: Full control of the optional RDS board. Program PI codes, PTY, and live scrolling Radio Text from a single unified dashboard.

PCB ASSEMBLED

MPX IN - 10K ohm 775mV Nom. 30Hz-76KHz

VR1 - MPX Deviation. 10K ohm 775mV Nom.

VR2 - RF Power Lev. 10mW to 1000mW.

RDS LEV. - RDS Deviation. 0 to 5KHz

USB/PC - USB cable connection to PC

FREQ UP/DN - Freq. Adj. in steps of 100KHz

15V DC - 15V DC power input 600mA max.

1W RF - 50 OHM RF Output

50 OHM LOAD - Dummy Load Jumper

Normal state when the device is connected: the PLL is LOCKED with an output power of 0.85W and a PLL phase of 2.33V

This shows what happens if the device loses its lock. We simulated a failure by placing our fingers on the oscillator coils.

This shows the return to normal with the user command FREQ:106.7 typed in the input box below. A value between 87.5 and 108.0 MHz can be set.

After pressing 'Send:' the display returns UPDATED FREQ 106.7 along with other technical information. This causes the transmitter to change frequency.

This shows another command, RDS-PI:ABCD typed for devices with the RDS card.

After pressing 'Send': the display returns UPDATED RDS-PI:ABCD instantly updating the RDS PI code.

This shows two additional examples of RDS commands:
RDS-TEXT:[write your message here]
RDS-PTY:[number from 0 to 31]
Text is plain ASCII up to 60 chars and valid PTY Codes shown below.

Shown below are the current commands available for USB PC Control and also the PTY codes for program type. We will be making further developments, improvements and more useful commands to this app in the near future. Keep checking this page for details.

◼ DEVICE-ID
◼ STATUS
◼ FREQ:[87.5 to 108.0]
◼ DDS-ADJ:[-1,0 or 1]
◼ PWR:[0 to 1]
◼ RDS-PTY: [0 to 31 list of PTY codes]
◼ RDS-PI: [0000 to FFFF]
◼ RDS-TEXT:[any string up to 60 chars.]
◼ RDS-ON
◼ RDS-OFF

AAREFF TRANSMISSION SYSTEMS SL
AVDA ANDALUCIA 1
LA ALFOQUIA-ZURGENA
04661
ALMERIA
ESPANA.

Paul Hollings