10MHz Rubidium Frequency Reference

Description

For sale is a frequency reference based on an SA.22c Rubidium oscillator from Symmetricom (later acquired first by Microsemi and then by Microchip). Rubidium oscillators are generally very stable and drift only extremely slightly over time, unlike e.g. OCXO and TCXO oscillators. According to the manufacturer, the SA.22c drifts by no more than 0.0005 ppm (0.5 ppb) per year (continuous use). It is a really good and simple solution if you want high precision without periodic calibration. The frequency was measured on 23/10 2026 using an Agilent 53220A counter with an external high-end GNSS reference. The deviation immediately after PLL lock is below 0.1 ppm (100 ppb) and after full warm-up is currently around 0.0001 ppm (0.1 ppb) at an ambient temperature of 23°C. This is a fully functioning instrument built as part of an experimental project. It contains all the necessary circuitry to make the SA.22c usable in practice. Used SA.22c units are almost impossible to buy online today; they are only sold as ready-built references, like this one. However, on sites such as ebay.com these cost over 5500 kr. plus shipping, VAT, customs duties, etc. !!! Connections: 3 x SMA 10MHz provide a 10.000000 MHz sine-wave output (2.4Vpp unloaded or +5.5dBm into 50 ohm). 1 x SMA 1PPS a 1.000000 Hz square-wave output (400ns pulse width, 5V CMOS, can drive a 50 ohm input). Indicators: Status LED (red/green) lights up red until the SA.22c has achieved PLL lock (typically within 5-10 minutes), then turns green. Service LED (red/off) is normally off, only turns red if the SA.22c needs servicing ** **) The total operating time was recently read out as 17602 hours (approximately 2 years), but the SA.22c has an expected lifespan of 10 years (continuous operation), so there are many good hours left before it wears out. Accessories: External 12V power supply included. Shipping: The additional charge for shipping to Denmark is 60 DKK (PostNord to the nearest collection point). See my other ads too, and save with combined shipping. PS: This is a private sale by default, but if desired, an invoice can instead be issued to a CVR-registered business so that the VAT can be reclaimed.