Frequency Electronics, Inc. FEI-Zyfer, Inc.
GPS Time and Frequency Systems

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System Features:

Multiple Outputs:
1 PPS, 5 MHz, 10 MHz
    PTTI, IRIG, Have Quick
    and 2 Frequency
    Programmable Outputs

Ext. Reference Inputs
1 PPS or PTP

GPS Receiver:
    Standard Civil C/A-Code
    or SAASM MPE-S
    Force 22E MRU Military

Low Phase Noise

NTP Server / PTPv2
    Grandmaster / Slave:
Telnet, SSH, SNMP
    MIB II, IPv4 and IPv6

User Interface
Zyfer Monitor™ GUI

All units are calibrated with
    an in-house standard
    traceable to UTC

AccuSync II® Model 405

The AccuSync II from FEI-Zyfer provides an unparalleled array of standard and user configurable options for customers requiring a cost effective, versatile GPS time and frequency reference in a compact, rack-mountable chassis.

The AccuSync II incorporates the latest developments in time and frequency technology including off the shelf support for IEEE 1588-2008 Precision Time Protocol (PTPv2) and the latest civilian C/A or military
SAASM GPS receivers (GB-GRAM MPE-S or Force 22E MRU).

The AccuSync II was developed to meet the precise time and frequency reference needs for most applications. The design incorporates support for the most common output interfaces, including 5 and 10 MHz Low Phase Noise (LPN) frequency references, multiple time references (PTP, NTP, IRIG, Have Quick, TOD) and 1 PPS reference outputs. Additionally, the AccuSync II provides user configurable options such as programmable DDS Frequency Synthesizer outputs, selectable IRIG output types and multi-use 10/100 Ethernet ports. The system may also be configured as a PTPv2 Grandmaster or Slave unit.

In the event of GPS signal loss or lack of other external reference source, the AccuSync II will continue to provide accurate time and frequency (holdover) using our standard high stability crystal oscillator (OCXO). For customers requiring extended holdover, a Rubidium (Rb) atomic clock oscillator is available.

As with all FEI-Zyfer products, the AccuSync II uses the latest FEI-Zyfer proprietary learning algorithm to compensate for external and internal environmental characteristics that affect accuracy, ensuring the most accurate GPS time and frequency reference available. All FEI-Zyfer products are calibrated with an in-house standard traceable to UTC.

   Rear Panel View


1 PPS - 5 MHz - 10 MHz - PTTI - IRIG B - HAVE QUICK - TOD - DDS - ETHERNET - RS-232

AC or DC
Power Options




Antennas and Accessories

   Time, Frequency and Communication Inputs / Outputs  
Qty.  Description of Rear Panel Inputs / Outputs Conn. Type I/O
1  1 PPS External Reference BNC Input
4  1 PPS TTL into 50 Ω BNC Output
6  10 MHz Sine Wave Output, 13 2 dBm BNC Output
4  5 MHz Sine Wave Output, 13 2 dBm BNC Output
2  DDS (Freq. Synthesizer) TTL Software programmable 1 kHz to 50 MHz (in 10 Hz steps) BNC Output
1  PTTI Port: BCD, Have Quick Time, 10 VDC 1 PPS and 1 PPM DE-9S Output
1  IRIG B Output, user selectable AM or DC shifted BNC Output
1  Have Quick Output, user selectable Have Quick II, Have Quick PTTI, and  Extended
 Have Quick
BNC Output
1  TOD, Serial I/O, RS-232 with Alarm Status pins DE-9S Output
   Communication and Control I/O    
2  10/100 Ethernet (NTP, PTPv2 IEEE-1588, SNMP, MIB II, TELNET, SSH, IPv4, IPv6) RJ-45  
2  Control Ports (1 on Front Panel, 1 on Rear Panel, RS-232C) DE-9S  

 Output Specifications


1 PPS Output:

 Oscillator Type:  Rubidium  OCXO
 GPS Locked:  < 100 ns at 95 % probability to UTC
 Coasting (Holdover) (a,b):  < 3 S @ 24 hrs  < 7 S @ 24 hrs
  10 MHz Output:  
 Oscillator Type:  Rubidium  OCXO
 GPS Locked:  < 1E-12  < 1E-12
 Coasting (Holdover) (a,b):  < 1E-11  < 1E-10
  Phase Noise:  
 Oscillator Type:  Rubidium  OCXO
 1 Hz:


 -90 dBc/Hz
 10 Hz:  -100 dBc/Hz  -125 dBc/Hz
 100 Hz:  -125 dBc/Hz  -140 dBc/Hz
 1 kHz:  -135 dBc/Hz  -147 dBc/Hz
 10 kHz:  N/A  -150 dBc/Hz
  Short Term Stability (Allan Deviation):  
 Oscillator Type:  Rubidium  OCXO
 1 Sec:  < 3E-11  < 1E-11
 10 Sec:  < 1E-11  < 1E-11
 100 Sec:  < 1E-10  < 1E-10
   GPS Receiver Options  
 Standard GPS Receiver - Civil C/A-Code:
 Type:  12 channel, parallel tracking
 Frequency:  1575.42 MHz (L1)
 Code:  C/A
 Acquisition Time:  Warm Start: < 2 minutes, Cold Start: < 20 minutes.
 MPE-S GB-GRAM SAASM  GPS Receiver - Military P(Y)-Code (d):
 Type:  12 channel, continuous tracking
 Frequency:  1575.42 MHz and 1227.60 MHz (L1 & L2)
 Code:  C/A and P(Y)
 Acquisition Time:  Warm Start: ≤ 90 seconds
 Hot Start: ≤ 10 seconds
 Force 22E MRU SAASM GPS Receiver - Military P(Y)-Code (d):
 Type:  24 channel, simultaneous tracking of L1, L2 and C/A codes
 Frequency:  1575.42 MHz and 1227.60 MHz (L1 & L2)
 Code:  C/A and P(Y)
 Acquisition Time:  Warm Start: ≤ 60 seconds
 Hot Start: ≤ 10 seconds
 Key Load Interface:  
 Electrical Interface is per IS-GPS-154C and IS-GPS-164
 Communication Protocol is per DS-102
 PLGR/DAGR Interface:  
 Electrical Interface is per IS-GPS-154C and IS-GPS-164 (RS-232 & 1 PPS I/O supported)
 Serial Interface Protocol is per IS-GPS-153C
   Power Options  
 AC Power:  100 - 240 VAC, 50-60 Hz, 60 W
 DC Power:  36-72 VDC
 DC Power:  12-36 VDC
   Chassis Physical Dimensions  
 Height:  44 mm (1.75") (1U)
 Width:  438 mm (17.25) (19" EIA Rack)
 Depth:  305 mm (12.0") including connectors
 Weight:  10 lbs. (max.)
 Operating Temperature:  0 °C to 55 °C
 Rate of Change:  15 °C/Hour (30 C/Hour non-destructive)
 Storage  Temperature:  -40 °C to +85 °C
 Relative Humidity:  5 % to 95 %, non-condensing
 Altitude, Operating:  -60 m to 4000 m
 Altitude, Storage:  -60 m to 9000 m
(a) After 72 hours of GPS locked operation, fixed antenna location, antenna delays entered.
(b) Ambient temperature change 10 C per hour.
(c) 24 hour average.
(d) U.S. Government policy restricts the sale of Precise Positioning Service (PPS) equipment to those
authorized by the U.S. Department of Defense. Non-U.S. authorized users must purchase PPS equipment
through the Foreign Military Sales (FMS) process.

 Product specifications subject to change without notice.


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