GPS-12R
Frequency & Time Standards
- Category: Frequency & Time Standards
- Manufacturer: Pendulum Instruments
- Status: Discontinued (manufacturer’s named replacements: FTR-210R, 6688/6689, CNT-104R)
- Local oscillator: GPS-locked low-noise rubidium clock
- Frequency stability (locked to GPS, ADEV): <2×10⁻¹² (τ=24 h), <5×10⁻¹² (τ=100 s), <3×10⁻¹¹ (τ=1 s)
- Standard front-panel outputs: 2× switchable 1.544 MHz (T1) / 2.048 MHz (E1) square wave; 1× switchable 1 PPS / 10 MHz
- Data sheet: Download PDF
- External link: Official product page
Overview
This model is discontinued: on 12 March 2026 Pendulum announced the immediate discontinuation of the GPS-12R/HS GPS-controlled frequency standards owing to component obsolescence, with service support continuing for up to five years subject to spare-part availability. The replacements Pendulum names are the FTR-210R, the 6688/6689 and the CNT-104R. The GPS-12R belongs to the Pendulum GPS-12 family of high-accuracy GPS-controlled rubidium reference clocks, designed for telecommunications and metrology applications of every kind. Its long-term frequency stability comes from the Cesium clocks on the GPS satellites, so the frequency reference does not age at all; short-term stability comes from the built-in low-noise rubidium clock, and when locked to GPS the 24-hour ADEV is better than 2×10⁻¹². The two standard front-panel outputs switch between 1.544 MHz (T1) and 2.048 MHz (E1) for calibrating or synchronising test instruments and network elements; the front-panel 1 PPS output provides an ultra-stable timing reference with excellent hold-over behaviour, suited to demanding timing applications such as DAB, DVB and WCDMA transmitter synchronisation or the synchronisation of radar antenna array systems. The unit is light and portable, and with the optional built-in NiMH battery it can be used in the field with no mains supply. It also serves as an internal ultra-stable frequency reference for R&D, test systems and production lines, and is well suited to calibrating the time base of SDH/SONET network analyzers, jitter meters and general test equipment.
Key features
- GPS-locked rubidium clock — Long-term stability is taken from the Cesium clocks on the GPS satellites and short-term stability from the local rubidium clock, giving near-Cesium accuracy with no frequency aging.
- Telecom standard outputs — The front panel switches between 1.544 MHz (T1) and 2.048 MHz (E1) outputs (G.703) to calibrate or synchronise test instruments and network elements directly.
- Ultra-stable 1 PPS timing — 1 PPS / 10 MHz timing outputs with excellent hold-over behaviour, for synchronisation applications with demanding timing requirements such as transmitters and radar arrays.
- Portable, with a built-in battery — The optional built-in NiMH battery needs no warm-up and allows use in the field with no mains supply, taking atomic frequency stability anywhere.
- Reliable operation in hold-over — If GPS lock is lost the unit enters hold-over mode with a timing drift of <1 μs over 24 hours, so it can serve as a resident reference clock meeting PRC requirements in a telecommunications network.
- Flexible output options — Low-noise 5/10 MHz sine outputs (Option 70B), multi-frequency outputs (71B) or G.703 telecom outputs can be fitted to suit metrology and test system requirements.
Typical applications
- A PRC reference clock for telecommunications networks — The GPS-12R can serve as a resident reference clock meeting PRC requirements in a telecommunications network, supplying standard 1.544 MHz (T1) / 2.048 MHz (E1) clocks to synchronise test instruments and network elements. If GPS lock is lost it continues in hold-over mode for 24 hours, so network synchronisation is not interrupted.
- A laboratory frequency reference standard — With the low-noise 5/10 MHz sine outputs, the GPS-12R becomes a portable near-Cesium frequency reference for calibration laboratories and test systems, providing traceable calibration of the time base of jitter meters, SDH/SONET network analyzers and test equipment of every kind.
- Transmitter and radar array synchronisation — The ultra-stable 1 PPS timing output together with the built-in battery provides atomic-level timing in the field with no mains supply, for DAB / DVB / WCDMA transmitter synchronisation or the precise synchronisation of radar antenna array systems.
Key specifications
Key specifications for GPS-12R, as published by Pendulum Instruments. For the full datasheet or a customized configuration, please get in touch.
| Status | Discontinued (manufacturer’s named replacements: FTR-210R, 6688/6689, CNT-104R) |
|---|---|
| Local oscillator | GPS-locked low-noise rubidium clock |
| Frequency stability (locked to GPS, ADEV) | <2×10⁻¹² (τ=24 h), <5×10⁻¹² (τ=100 s), <3×10⁻¹¹ (τ=1 s) |
| Standard front-panel outputs | 2× switchable 1.544 MHz (T1) / 2.048 MHz (E1) square wave; 1× switchable 1 PPS / 10 MHz |
| 1 PPS timing accuracy (against UTC after 72 h continuous operation) | ±120 ns, jitter <1 ns rms |
| Warm-up time (+25°C) | 12 minutes to 1×10⁻⁹ |
| Power supply / dimensions / weight | 100–240 Vrms, 50–400 Hz, <35 W (normal operation); 210×108×395 mm; net weight 3.1 kg (without battery) |
Frequently asked questions
Need GPS-12R/12RG pricing, rental or calibration?