GPS-88
Frequency & Time Standards
- Category: Frequency & Time Standards
- Manufacturer: Pendulum Instruments
- Status: Discontinued (FTR-210R recommended instead)
- Local oscillator: High stability oven-controlled crystal oscillator (OCXO)
- Frequency stability (locked to GPS): 24 h average offset <2×10⁻¹² (20–26°C); ADEV <3×10⁻¹¹ (τ=100 s), <5×10⁻¹² (τ=1 s)
- Standard reference outputs: 5× 10 MHz sine (>0.6 Vrms / 50 Ω), 1× 5 MHz sine, 1× 1 PPS (jitter 20 ns rms against UTC)
- Data sheet: Download PDF
- External link: Official product page
Overview
This model is discontinued: the GPS-88/89 no longer appears in the Pendulum catalogue, and the FTR-210R is recommended instead. The GPS-88 is the cost-effective member of the Pendulum GPS-88 / GPS-89 family, the one with an OCXO local oscillator, and provides a precise frequency and time reference usable anywhere in the world for telecommunications, the electronics industry, calibration laboratories, automatic test systems and design departments. Long-term frequency stability comes from the atomic clocks on board the GPS satellites: when locked to GPS the 24-hour average frequency offset is better than 2×10⁻¹², while the local OCXO supplies excellent short-term stability. A built-in high-resolution phase measurement core compares the GPS signal against the local oscillator continuously and stores the phase and frequency deviation in non-volatile memory (24-hour frequency offset and adjustment data are kept for two years), so a traceable calibration report can be printed at any time with the supplied GPSView™ software, while the front panel shows the current 24-hour average frequency offset continuously — an unbroken traceability chain from the first day the unit is switched on. The standard configuration provides 1× 5 MHz and 5× 10 MHz sine outputs plus a 1 PPS output; a distinctive manual hold-over mode temporarily suspends automatic correction during a measurement to improve medium-term stability, which suits jitter and wander measurement on digital telecommunications networks particularly well. After being moved, the unit is ready in about 10 minutes, and an optional Ethernet interface allows remote monitoring.
Key features
- GPS-controlled OCXO — The local OCXO is continuously calibrated by the atomic clocks on the GPS satellites; when locked to GPS the 24-hour average frequency offset is better than 2×10⁻¹², giving Cesium-class long-term stability.
- Traceable self-calibration — The built-in continuous comparison and high-resolution phase measurement core lets you print a traceable calibration report with GPSView™ at any time, building an unbroken calibration history at no calibration cost.
- Front-panel frequency offset display — The front panel shows the current 24-hour average frequency offset continuously, so the operator can see the frequency accuracy directly instead of trusting a black box.
- Manual hold-over mode — Hold-over mode can be selected manually during a measurement to suspend automatic correction and improve medium-term stability, which suits jitter and wander measurement on telecommunications networks particularly well.
- Remote monitoring — With the optional Ethernet (10Base-T) interface, status can be read remotely, phase and frequency deviation data retrieved and calibration reports printed.
- Standard frequency outputs — 5× 10 MHz and 1× 5 MHz sine outputs plus 1 PPS come as standard, supplying several instruments at once for telecommunications, calibration and test system use.
Typical applications
- A traceable frequency standard for the calibration laboratory — As a traceable frequency standard in a calibration laboratory, the GPS-88's built-in continuous comparison and phase measurement core records the frequency offset without interruption, and GPSView™ prints a traceable calibration report whenever one is needed — an unbroken calibration chain from the first day the unit is switched on, at no calibration cost.
- Jitter and wander measurement on telecommunications networks — The distinctive manual hold-over mode temporarily suspends automatic correction during a measurement to improve medium-term stability, which suits jitter and wander measurement on digital telecommunications networks particularly well, while still supplying the standard frequency that telecommunications and test systems need.
- A shared frequency source for automatic test systems — The standard 5× 10 MHz and 5 MHz sine outputs (with a further 5× 10 MHz if Option 70 is fitted) supply several instruments at once, and the optional Ethernet interface allows remote monitoring — an ideal local frequency reference for automatic test systems and design departments.
Key specifications
Key specifications for GPS-88, as published by Pendulum Instruments. For the full datasheet or a customized configuration, please get in touch.
| Status | Discontinued (FTR-210R recommended instead) |
|---|---|
| Local oscillator | High stability oven-controlled crystal oscillator (OCXO) |
| Frequency stability (locked to GPS) | 24 h average offset <2×10⁻¹² (20–26°C); ADEV <3×10⁻¹¹ (τ=100 s), <5×10⁻¹² (τ=1 s) |
| Standard reference outputs | 5× 10 MHz sine (>0.6 Vrms / 50 Ω), 1× 5 MHz sine, 1× 1 PPS (jitter 20 ns rms against UTC) |
| Warm-up time (+25°C) | 20 minutes to GPS lock |
| GPS receiver | 12-channel parallel tracking, L1 / C/A code, N-type antenna connector |
| Traceable calibration / data storage | GPSView™ produces a traceable calibration report at any time; 24 h frequency offset and adjustment data held in non-volatile memory for 2 years |
| Power supply / dimensions / weight | 100–240 V, 47–63 Hz, <12 W (continuous operation); 315×86×395 mm; net weight 3.9 kg |
Frequently asked questions
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