The FLEX-6000 Signature Series is the first amateur radio product family to offer an optional built-in GPS Disciplined Oscillator (GPSDO). The GPSDO plug in module provides a precision 10 MHz reference for the 983.04 MHz master oscillator and to a rear panel 10 MHz SMA output connector for external precision frequency control. Frequency stability is 1 x 10-8 within 5 minutes at 25° C and 5 x 10-12 over 24 hours with GPS lock. Rear panel SMA connections are provided for the GPS antenna input and 10MHz reference output.
When the GPSDO option is not installed, the FLEX-6700 and FLEX- 6700R come standard with a ±0.02ppm Oven Controlled Crystal Oscillator (OCXO) and the FLEX-6500 comes with at ±0.5ppm Temperature Controlled Crystal Oscillator (TCXO).