DA-36
Frequency Distribution Amplifier
- Category: Frequency Distribution Amplifier
- Manufacturer: Pendulum Instruments
- Reference frequency: 10 MHz (sine)
- Frequency range: 200 kHz – 16 MHz
- Inputs: 1 x fiber optic input + 1 x BNC coax input
- Outputs: 1 x fiber optic output + 4 x BNC coax outputs
- Data sheet: Download PDF
- External link: Official product page
Overview
The DA-36 solves the problem of distributing a reference frequency from a central frequency standard to one or several remote receiving points. It is a compact all-in-one transceiver with one fiber optic input and one BNC coax input, plus one fiber optic output and four BNC coax outputs. The distribution is completely analog and the signal is reconstructed with a narrow-band, high-Q filter that heavily suppresses noise and distortion, keeping phase purity at its best without adding any PLL jitter. Fiber transmission reaches up to 2 km, creates the galvanic isolation that eliminates ground current loops and is EMP-proof, which suits long-distance distribution between floors or buildings. Cascading several DA-36 units extends the system into a multi-point architecture. The DA-36 works with Pendulum frequency standards such as the GPS-12R, 6688/89 and FTR-210R, with Fluke 908/909 and 910/910R standards, and can equally be used on its own as an RF-to-fiber or fiber-to-RF converter.
Key features
- Fiber and coax distribution in one unit — A single DA-36 provides one fiber optic output alongside four BNC coax outputs, so remote and local users are served from the same box without a separate splitter.
- Completely analog, PLL-free distribution — Nothing in the signal path uses a phase-locked loop or any other frequency recovery circuit, so the electronics add no jitter or wander and the phase purity of the frequency standard is preserved.
- Narrow-band, high-Q filtering — The built-in narrow-band, high-Q filter heavily suppresses noise and harmonic distortion, keeping the phase noise floor of the output low even after a long distribution path.
- RF to fiber conversion, either direction — The DA-36 also works on its own as an RF-to-fiber (E/O) or fiber-to-RF (O/E) converter, and as a coax-to-coax amplifier and splitter, which makes it flexible in a rack.
- Ground loop isolation and EMP protection — Fiber transmission isolates the two ends galvanically, removing ground current loop noise, and is EMP-proof — appropriate for aerospace, defense and telecom infrastructure that is sensitive to interference.
- Cascade into multi-point distribution — Several DA-36 units cascade into a multi-point distribution network, extending one frequency standard to measurement points throughout a building or across sites.
Typical applications
- One frequency base shared by every instrument in the room — A calibration laboratory normally runs from a single rubidium clock or GPSDO as its master reference. The DA-36 distributes that 10 MHz sine reference in the analog domain to the counters, signal analyzers and phase noise measurement systems in the same room, so no PLL adds jitter and every instrument traces back to the same time and frequency base — which is what an ISO 17025 traceability regime asks for.
- Frequency synchronization across the floors of a plant — Telecom equipment manufacturers often need dozens of test stations on one site running from the same frequency. The DA-36 carries the 10 MHz reference over fiber from the central standards room to other floors or buildings up to 2 km away, removing the ground loops and EMI that long coax runs pick up, so results agree from station to station. Several of the world's leading telecom manufacturers already run their distribution this way.
- Point-to-point frequency transfer across a campus or site — Once a frequency base has to cross between buildings, differences in ground potential and the risk of an electromagnetic pulse (EMP) make conventional coax cabling impractical. The DA-36 uses fiber as the transmission medium, giving electrical isolation and EMP resistance, and several units can be chained into a multi-point network — for research campuses, defense facilities or a group of plant buildings that have to share one frequency base.
Key specifications
Key specifications for DA-36, as published by Pendulum Instruments. For the full datasheet or a customized configuration, please get in touch.
| Reference frequency | 10 MHz (sine) |
|---|---|
| Frequency range | 200 kHz – 16 MHz |
| Inputs | 1 x fiber optic input + 1 x BNC coax input |
| Outputs | 1 x fiber optic output + 4 x BNC coax outputs |
| Input amplitude range | 0.2 – 2 Vrms |
| Input impedance | 50 Ω (nominal) |
| Maximum fiber length | 2 km |
| Distribution method | Completely analog, no PLL or frequency recovery circuit |
| Dimensions (W x D x H) | 125 x 170 x 30 mm |
| Weight | 650 g |
| Operating temperature | 0°C to +50°C |
| Storage temperature | -40°C to +70°C |
| Safety and EMC | EN 60950, UL 1950, CE; EMC EN 55022 |
Frequently asked questions
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