Pendulum Instruments, the global provider of time & frequency measurement, analysis, and calibration solutions, has introduced frequency distribution amplifiers, the FDA-301A and DA-36, to offer an economical solution to low-jitter and long-range distribution of frequency reference and/or time synchronization signals. These amplifiers can deliver sufficient power to one or more sites with high strength over coaxial and/or optical fiber cables, providing high timing accuracy to various systems requiring sharp time synchronization with multiple devices.
Key Features of the FDA-301A
The versatile and modular FDA-301A can distribute sine reference frequencies and time synchronization signals (1-pps and unmodulated IRIG) from a central source to up to 18 remote sites (point-to-multipoint). Additionally it can distribute serial Time-of-Day messages (NMEA or user defined code) and telecom sync signals (E1/T1 clock/data).
It offers narrowband sine reference frequency distribution via optical fiber, or coax cable, with minimal jitter and is designed for reference signals between 100 kHz and 60 MHz. The default frequency is 10 MHz. The sine distribution is completely analog, without the use of PLLs or other types of frequency recovery circuits that may introduce jitter or wander. The signal is filtered in a narrow-band, high-Q filter, which heavily suppresses noise and distortion.
FDA-301A also offers distribution of Time Synchronization signals via the Pulse inputs/outputs of for example 1-pps and unmodulated IRIG time code (DCLS). The pulse distribution is broadband, allowing any pulse input signal up to 20 MHz.
Furthermore, the FDA-301A has separate inputs for distributing serial (RS232) Time-of-Day messages (NMEA or user defined), which together with 1-pps pulse distribution will distribute a precise time scale. All inputs are dual, in a master-slave configuration, with automatic change-over if the master fails, providing fail-safe input source redundancy.
The FDA-301A has 3 output slots for various optional output modules. All coaxial and Time-of-Day output modules have 4 connectors. All fiber output modules have 6 connectors. There is also an option for external DC power, to provide power redundancy.
The below example is a situation where FDA-301A is used for synchronization
Using one FDA-301A close to the frequency reference (the transmitter unit), you can distribute the 10 MHz reference, plus the 1-pps signal, to 6 remote sites via fiber. Each remote site has its own FDA-301A receiver and can distribute 10 MHz to 8 local users, plus 1-pps to 4 local users. Thus, with just 7 units of FDA-301A, you can provide 48 local users with 10 MHz reference, plus another 24 users with 1-pps.
The maximum number of users with just one transmitting FDA-301A can be extended to up to 218 local users using 18 remote FDA-301A receivers.
Key Features of DA-36
The Distribution Amplifier DA-36 solves the problem of distributing a reference frequency from a central frequency standard to one or several receiving points.
It offers frequency distribution via optical fiber, or coax cable, with minimal jitter and is designed for reference signals of 10 MHz (sine). The distribution is completely analog, without the use of PLLs or other types of frequency recovery circuits that may introduce jitter or wander. The signal is filtered in a narrow-band, high-Q filter, which heavily suppresses noise and distortion.
DA-36 is a compact all-in-one transceiver module with 1 coax and 1 fiber input, plus1 fiber and 4 coax outputs.
The DA-36 is designed to work with any Pendulum Frequency Standard (GPS-12R, 6688/89, GPS-88/89), any Fluke Frequency standard (908/909, 910, 910R) and with any reference clock from Orolia/Spectracom. It will also work with all other brands that produce a sine wave reference with amplitude between 0.2 and 2 V (RMS).
Key Benefits of FDA-301A and DA-36
Both models use coax cables for local distribution and optical fibers for remote distribution, giving the following benefits for fiber:
- Distribution of reference frequencies up to 2 km
- Galvanic isolation, eliminate ground current loop problems
- Low-loss distribution
- No crosstalk, no electromagnetic noise and interference pick-up
- Easy to install – flexible, lightweight and small-diameter optical fiber
Click here to learn more about FDA-301A point-to-multipoint distribution amplifier.
Click here to learn more about DA-36 point-to-point distribution amplifier.
