The Brandywine Communications Model FDU-240 offers the user the most requested and reliable frequency distribution features in one time and frequency distribution unit.  The base unit is a dual input, 24 output frequency distribution amplifier suited for 5MHz or 10MHz.  Each output is monitored and will set the alarm if an output fault is detected.

For enhanced phase noise performance an optional clean up oscillator is installed between the rear panel inputs and the inputs of the transfer switch. A clean up oscillator may be installed between both Input A and Input B inputs or only on Input A.

When fitted with the optional clean up oscillators, the stability of the outputs are the same as that of the input(s). This is accomplished by disciplining the clean up oscillator(s) to the reference input(s).


The FDU-240 is one of Brandywine's low phase noise distribution units that has a three-position front panel switch chooses automatic operation or may be used to manually select one of the two input sources. When the AUTO mode is selected the AUTO indicator will be illuminated and Input A will be used if it is available. Should Input A fail Input B will be chosen automatically. Indicators show the status of the inputs and which input has been selected.


Product Specifications
Product Data Sheet
User Manuals

Reference Frequency Inputs:  
Connector Two rear panel BNC's
Amplitude 0.5 Vrms - 1 Vrms
Input Impedance 50 Ohms
Frequency 10 MHz
Fault Discrete Input:  
Number of Inputs 2
Connector DB9
Level TTL
Active Level Link selectable, high or low
Sine Wave Outputs:  
Number of Outputs 24
Connector BNC
Frequency (MHz) Same as input
Level +13, +/- 2 dBm into 50 Ohms
SSB Phase Noise (with clean-up osc. Option)
Offset (Hz) dBc/Hz
1 -60
10 -110
100 -140
1,000 -150
10,000 -155
Harmonics 30 dBc
Spurious -80 dBc
Without clean-up option Same as input
With clean-up option +/- 3x10-9, 0
Operating 0 to + 50°C
Storage -40 to +85°C
Humidity To 95% non-condensing
Dimensions 19 inch Rack Mount, 1.73 inches high (1U)
14.5 inches deep
Weight 7.5 lb typical

alt FDU-240 Data Sheet



About Brandywine Communications

Brandywine Communications Inc. offers superior products to the time and frequency marketplace. Our mission is to provide the finest equipment coupled with excellent before and after sale service.

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Brandywine Communications
Ultra-Precision Time & Frequency

1153 Warner Ave
Tustin, CA 92780
Phone: +1 (714) 755-1050