How Can I Upgrade a Standard OctoClock CDA-2990 To a OctoClock-G CDA-2990

Updated May 28, 2020

Reported In


  • CDA-2990
  • OctoClock

Issue Details

How can I upgrade a standard OctoClock CDA-2990 to a OctoClock-G CDA-2990?


To upgrade a standard OctoClock CDA-2990 to a OctoClock-G CDA-2990, you just need a Board Mounted 783173-01 GPSDO (OCXO) . Just like the table shown below.


Additional Information

Both OctoClock models can input a 10MHz reference and a 1 PPS signal via the SMA connectors EXT 10MHz INPUT and EXT PPS INPUT, respectively, located on the front of the device, Additionally, the OctoClock-G contains an internal GPSDO which provides its own internal references to the device.
There is a switch on the front panel of the device with two positions INTERNAL and EXTERNAL that specifies which reference will be used when appicable.
The switch is used to tell the onboard software which reference source is preffered. For the OctoClock, there is no internal timing or clocking sources, so the Octoclock will always use external 10MHz and 1 PPS sources. Switching to internal when there is no internal source will fail (there is actice detection of the reference signal) and the OctoClock will default back to external. Once you have a GPSDO plugged into the internal socket you will able to switch to internal.