The 910 and 910R GPS frequency references are fully traceable and extremely accurate GPS frequency standards and are ideally suited for use in many applications, including telecommunications, calibration and automatic test systems.
Both the 910 and 910R deliver a precision frequency and pulse-per-second time reference which, with its many connectivity options, can be installed, monitored and managed from virtually any location.
Both models receive their long-term frequency stability from the built-in cesium standards in the GPS-satellite array, yet can also provide a very high short-term stability from the built-in oven-controlled crystal oscillator (OCXO) or rubidium oscillator (Rb).
Specifications: 910/910R GPS Frequency Standards
| Disciplined Mode: |
The frequency deviation between the internal timebase oscillator and the received GPS-signal is used to continuously adjust the oscillator (disciplining). The resulting frequency offset and adjustment data is stored in non-volatile memory every 24h, to enable printout of the traceability record. The actual frequency offset (24h mean value) is calculated and displayed on the front panel. |
| Hold-over Mode: |
The internal oscillator is not adjusted. This mode is normally automatically entered when there is no usable received GPS-signal. This mode can also be selected manually be activating the Manual hold-over key. If Manual hold-over is set together with a valid received GPS signal, the actual frequency offset is calculated and displayed plus stored in non-volatile memory every 24h. |
Frequency stability - locked to GPS 910R (GPS-Rb)
| Frequency offset (24h mean): |
<1x10-12* |
| Short term (Allan dev.): |
<1 x 10-12 (t = 100s) |
| |
<3 x 10-12 (t = 100s) |
| |
<1 x 10-11(t = 10s) |
| |
<3 x 10-11 (t = 1s) |
| Warm up (+25°C): |
20 mins to lock |
| *At temperatures 23°C + 3°C |
Frequency stability - locked to GPS 910 (GPS-OCXO)
| Frequency offset (24h mean): |
<1x10-12* |
| Short term (Allan dev.): |
<1 x 10-12 (t = 100s) |
| |
<3 x 10-12 (t = 100s) |
| |
<1 x 10-11(t = 10s) |
| |
<3 x 10-11(t = 1s) |
| Warm up (+25°C): |
20 mins to lock |
| *At temperatures 23°C + 3°C |
Frequency stability – Hold-over 910R
(GPS-Rb)
| Aging/24h: |
<2 x 10-12 (typ.) |
| Aging/month: |
<5 x 10-11 |
| Temp. (0°C…+50°C): |
<3 x 10-10 |
| Temp. (23°C ± 3°C): |
<2 x 10-11 (typ.) |
| Short term (Allan dev.): |
<3 x 10-12 (t = 100s) |
Frequency stability – Hold-over 910
(GPS-OCXO)
| Aging/24h: |
<3 x 10-10 |
| Aging/month: |
<3 x 10-9 |
| Temp. (0°C…+50°C): |
<2.5 x 10-9 |
| Temp. (23°C ± 3°C): |
<4 x 10-10 (typ.) |
| Short term (Allan dev.): |
<1 x 10-11 (t = 100s) |
| |
<5 x 10-12 ( t = 10s) |
| |
<5 x 10-12 (t = 1s) |
| Warm up (+ 25°C): |
10 minutes to 5 x 10-9 |
Phase Noise - 910R
| Offset |
Phase Noise |
| 1 Hz: |
-80 dBc/Hz (typ.) |
| 10 Hz: |
-90 dBc/Hz (typ.) |
| 100 Hz: |
-130 dBc/Hz (typ.) |
| 1 KHz: |
-140 dBc/Hz (typ.) |
| 10 KHz: |
-140 dBc/Hz (typ.) |
| 100 KHz: |
-145 dBc/Hz (typ.) |
Phase Noise - 910
| Offset |
Phase Noise |
| 1 Hz |
-100 dBc/Hz (typ.) |
| 10 Hz |
-120 dBc/Hz (typ.) |
| 100 Hz |
-130 dBc/Hz (typ.) |
| 1 KHz |
-135 dBc/Hz (typ.) |
| 10 KHz |
-135 dBc/Hz (typ.) |
| 100 KHz |
-135 dBc/Hz (typ.) |
Reference outputs (BNC)
| 10 MHz: |
sine wave, 0.5V rms in 50O |
| 5 MHz: |
Sine wave, 0.5V rms in 50O |
| 2.048 MHz (opt. 75): |
+/-1.2V +/-10% in 75 ohms (G.703:10) |
| 1 pps: |
TTL-levels; low < 0.4V, high > 2V in 50O load |
| Pulse output (opt. 75): |
TTL-levels; low < 0.4V, high > 2V in 50O load |
5 additional 10 MHz outputs (option 70)
| See specification for 10 MHz above |
Multiple Reference outputs (option 71)
| Sine wave outputs: |
10, 5, 1 and 0.1 MHz >1 Vrms into 50 Ω |
| Pulse output: |
0.1 MHz; >3 Vp-p into 50 Ω. 0 V =LO <0.8 V, 3 V |
10 MHz and 5 MHz & 2.048 MHz (opt 72) outputs
| Freq. Stability: |
See frequency stability specs for 910 and 910R |
5 additional 13 MHz outputs (option 73)
| Impedance: |
50 Ω |
| Output signal: |
TTL (symmetrical) |
| Typical levels into 50ƒn Ω |
High voltage: 2.35 V |
| |
Low voltage: 0 V |
| Risetime: |
10 % - 90 %: 2 ns |
| Jitter: |
< 0.01 UI |
| Long term stability: |
Same as main reference |
1-pps output (locked to GPS)
| Duty Cycle: |
Approx. 20% |
| Jitter: |
<60 ns rms relative to UTC or GPS (position hold, SA on) |
Pulse output
(option 75)
| The frequency is set via the included PC-program |
| Selectable frequency: |
1/(N x 10-7) Hz, N is an integer |
| Factory default setting: |
1 Hz |
| Duty cycle: |
50% |
| Jitter: |
<500 ps rms |
| Freq. Stability: |
See frequency stability specs for 910 and 910R |
Ethernet interface
(option 76)
| Communication Port: |
Connector: RJ45 |
| |
Protocol: 10Base-T |
| |
Buffer RAM: 1 kbit |
| Configuration Port: |
Connector: Dsub9, RS232 |
Internal data storage
| 24h-freq. Offset: |
2 years data, non-volatile memory |
| Adjustment data: |
2 years data, non-volatile memory |
Controls
Manual
Hold-over: |
Inhibits automatic GPS-adjustment and forces hold-over operation. This increases the short-term stability, when the internal Rubidium- or OCXO-reference is free running without any correction from the GPS-monitoring system. |
LED Indicators -
Locked to GPS
| ON: |
Disciplined mode |
| OFF: |
Hold-over mode |
LED Indicators -
Alarm
| ON: |
Alarm condition reported by instrument hardware. Explanatory text in 7-segment display area advises. |
| OFF: |
Normal operation |
LED Indicators - Manual Hold-over
| ON: |
Forced hold-over mode. If GPS signal is valid, the 24h frequency offset is displayed. Otherwise "-----" is shown. |
| OFF: |
Automatic choice of disciplined or hold-over mode depending on "Locked to GPS" status. |
GPS-receiver
| Antenna connector: |
Type N |
| Channels: |
8, parallel tracking |
| Carrier, code: |
L1, C/A |
Antenna (option 01)
| Type: |
active L1 |
| Operating temp.: |
-40°C to +70°C |
| Height: |
81 mm (3.2") (excl. connector) |
| Weight: |
>30 dB |
| Gain: |
TNC |
Antenna cable
(option 02)
| Type: |
RG213 |
| Length: |
20 m |
| Connectors: |
N-type and TNC (male) |
| Cable delay: |
101 ns. |
| Attenuation: |
Approx. 8 dB at 1.6 GHz |
PC-connection
| Interface: |
RS-232, DTE |
| Connector: |
9-pin male DB9, Rx on pin 2, Tx on pin 3, GND on pin 5 |
| Baud rate: |
9600 bps |
| Data structure: |
8 data bits 1 stop bit, no parity |
Fan
Environmental
| Temperature: |
0°C...+50°C (operating) |
| |
-40°C...+70°C (storage) |
| Safety: |
Compliant to CE: EN 61010-1 + A1 (1992) + A2 (1995) |
| EMI: |
Compliant to CE: EN 1326-1 (1997) |
Power consumption
| Line voltage: |
100...240 V (±10%) |
| Line frequency: |
47..63 Hz |
| Power 910R: |
<75 W at warm-up <35 W continuous operation |
| Power 910: |
<25 W at warm-up <12 W continuous operation |
Calibration DocumentationStatement of calibration practicesSize
| WxHxD: |
315 x 86 x 395 mm |
| |
12.4" x 3.4" x 15.6" |
Weight
| 910R |
4.4 kg net, 7.4 kg shipping (9.7 lb net, 16.3 lb shipping) |
| 910 |
3.9 kg net, 6.9 kg shipping (8.6 lb net, 15.2 lb shipping) |
