The Pendulum Frequency Distribution Amplifiers, FDA-301 and DA-36, offer an economical solution to low-jitter and long-range distribution of Frequency Reference and/or Time Synchronization Signals. 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
  • EMP-proof
  • RF-to-FO conversion and FO-to-RF conversion


The versatile and modular FDA-301 can distribute the following signal types from a central source to up to 18 remote sites (point-to-multipoint)

  • Sine reference frequency, default 10 MHz
  • Pulse signals, for example 1-pps and unmodulated IRIG (DCLS)
  • Serial Time-of-Day messages (NMEA or user defined code)
  • Telecom sync signals (E1/T1 clock/data, 2.048/1.544 MHz/Mbps)


The small and low-cost DA-36 can distribute a sine reference frequency to 1 remote site (point-to-point).


The DA-36 will interface directly to FDA-301, and FDA-301 can be a drop-in replacement in current DA-36 (or legacy DA-35) networks. A distribution system can be designed with a mix of DA-36 and FDA-301, for example distribution to only one remote site (DA-36), with several local user (FDA-301).


Differences between the DA-36 and the FDA-301:

 Model no.  FDA-301  DA-36 
Distribute sine frequency  yes  yes
Distribute pulses (1-pps, IRIG)  yes   -
Distribute Serial Time-of-Day  yes   -
Distribute E1/T1 clock/data  yes   -
Fiber/coax input 10MHz  yes/yes  yes/yes
Auto change-over 10MHz input  yes  yes
Coax outputs 10MHz*  4 / 8 / 12  4
Fiber outputs 10MHz*  6 / 12 / 18  1
DC power option  yes   -

* The number of outputs can be multiplied via cascading FDA-301 or DA-36


The lower cost DA-36 is an excellent electrical to optical converter, optical to electrical converter and point-to-point distribution amplifier for reference frequency. The versatile and modular FDA-301 offers excellent point-to-multi-point distribution of a variety of signal types.


Key specifications

FDA-301 Frequency Distribution Amplifier

  • Multiple signal type inputs, multiple modular outputs
  • Fiber and coax distribution
  • Distribute reference frequency 10 MHz
  • Distribute 1-pps and IRIG (DCLS) and more
  • Input signal redundancy with auto-change-over



DA-36 Frequency Distribution Amplifier

  • Distribute reference frequency 10 MHz
  • Fiber and coax distribution
  • Input signal redundancy with auto-change-over
  • Small, flexible, low-cost






ul. Lotnicza 37
80-297 Banino


tel:. +48 (58) 681 89 01
fax:. +48 (58) 684 86 49


global resellers list


Pico Second Resolution Test Set

NEW product PicoTime as optional front-end to CNT-91 provide 1ps@1s ADEV noise floor and 100 femtoseconds frequency resolution (1s) on CNT-91. Read more here.

Option 99/11

Service Agreement

NEW Service Agreement option provides support, yearly functional check, yearly calibration, priority repair and more. Read more here.