Pendulum Instruments · Frequency & Time References
FTR-210R
GNSS-disciplined rubidium frequency and time reference with built-in traceable calibration
The FTR-210R is for the situations where you must be able to state what a frequency was measured against: a GNSS-disciplined rubidium oscillator whose 1 pps output stays within 10 ns rms of UTC, with traceable calibration built in. While locked, GNSS provides the long-term accuracy and the rubidium oscillator provides short-term stability and holdover after a loss of lock. Typical holdover drift is about 1 µs per 24 hours, so a temporarily blocked antenna does not invalidate a measurement session. Standard outputs are 5 x 10 MHz, 1 x 5 MHz and 1 x 1 pps, expandable to 11. The first thing to settle before installation is the antenna location: this instrument gets its accuracy from the sky, and reception decides whether it reaches its rated figures.
Overview
A frequency and time reference has two requirements that pull against each other: long-term accuracy (tracking UTC) and short-term stability (low noise). A GNSS receiver alone is accurate over the long term but noisy over seconds; a rubidium clock alone is stable over seconds but drifts slowly. The FTR-210R locks the two together so that rubidium supplies the short-term stability and GNSS applies the long-term correction, and both requirements are met at once. That decides where it is used: calibration labs run it as a working standard with traceability upward; telecom and satellite ground stations synchronize equipment from it; aerospace and defense test ranges use it as the common timebase for the whole site. The output set is flexible: the standard 5 x 10 MHz, 1 x 5 MHz and 1 x 1 pps grows to as many as 11 outputs, and options add 2 x 100 MHz plus a programmable pulse output from 0.5 Hz to 100 MHz with IRIG-B DCLS, so one unit feeds equipment with different interface needs. Because traceable calibration is built in, an audit does not require separate proof of traceability. Evencat is the authorized distributor for Pendulum Instruments in Taiwan and quotes the FTR-210R with its output and software options.
Key specifications
| Oscillator | GNSS-disciplined rubidium atomic oscillator |
|---|---|
| Standard outputs | 5×10 MHz, 1×5 MHz, 1×1 pps (expandable to 11 outputs) |
| Optional outputs | Option 211 4x 10 MHz, Option 212 at 0.1, 1, 5 and 10 MHz, Option 213 4x 1 pps, Option 214 2x 100 MHz plus 2x 10 MHz; programmable pulse 0.5 Hz to 100 MHz (with IRIG-B DCLS) |
| Time reference accuracy | < 10 ns rms (1 pps to UTC) |
| Holdover drift | Typical 1 µs / 24 hours |
| Aging | < 5×10⁻¹¹ / month (manual holdover mode) |
| Measurement input (optional) | DC to 400 MHz |
| Time resolution | 14 ps (7 ps optional) |
| Frequency resolution | 12 to 13 digits / 1 s gate time |
| Display | 5-inch color touchscreen |
| Interfaces | Gbit Ethernet, USB 2.0, built-in web server |
| Traceable calibration | Option 220 documenting frequency comparator (independent of the disciplining process) |
Features
Long term and short term both covered
GNSS keeps the unit on UTC and the rubidium oscillator supplies short-term stability; locked together, each covers the other's weakness.
Loss of lock is not a stop
Holdover drift is typically about 1 µs per 24 hours, so measurements continue while an antenna is blocked or under maintenance.
10 ns rms to UTC
The 1 pps time accuracy is enough for telecom synchronization and calibration traceability.
One reference feeds many instruments
The standard 7 outputs expand to 11, with optional 100 MHz outputs, a programmable pulse output and IRIG-B DCLS.
Traceable calibration built in
Traceability documentation is generated by the instrument, so audits and QA do not need a separate request.
Look at the antenna before the instrument
Accuracy comes from GNSS reception, so evaluating the antenna site before installation matters more than any setting.
In operation

Numeric measurement
Large digits, read at a glance
The 5-inch color touchscreen shows the frequency reading in large digits (13-digit resolution) with period, Vmin / Vmax / Vp-p alongside, and limit indicators for a quick pass/fail read.
Statistics and distribution
Live statistics and frequency distribution
The built-in histogram and statistics engine reports mean, min, max, peak-to-peak, standard deviation and Allan deviation (adev) of the sample set live, so the stability of the device under test can be judged without external software.


Long-term trend
Long-term stability at a glance
A time-axis plot of the measured value (over 1000 seconds and more) follows long-term drift and aging of the device under test, which is what calibration and verification work needs.
Options and configuration
Tick the options you need. We compile the configuration list and carry it into the quote request form so we can prepare your quotation.
Standard configuration (included)
Hardware options
Software options (SW licenses)
Downloads
- Product datasheetDatasheet · PDF
- User manualUser Manual · PDF
- Programmer's handbookProgrammer's Handbook · PDF
- Online manualOnline Manual · HTML
- Firmware downloadFirmware
The FTR-210R is the recommended replacement for the discontinued GPS-12R and GPS-88 GPS-disciplined frequency standards.
Need pricing, specifications or lead time for FTR-210R?
Also available for rent: FTR-210R is part of the Pendulum rental program, for project peaks, calibration backup and pre-purchase trials. Rental inquiry →
