This feature is supported only on the OEM729.
For applications requiring greater precision than what is possible using the on-board Voltage Controlled, Temperature Compensated Crystal Oscillator (VCTCXO), the OEM729 can be connected to an external, high stability oscillator, at 5 MHz or 10 MHz.
Connect a cable from the external oscillator to the receiver’s external oscillator input connector. For the OEM729, a MMCX female connector (J1901) is used as shown in Figure: OEM729 Connector and Indicator Locations. The receiver does not have to be powered down during this operation. However, if handling a card directly, observe anti-static practices. The OEM729 input impedance is 50 ohms.
When the external oscillator is installed, use the EXTERNALCLOCK command to set the clock type (e.g.: cesium, rubidium or ovenized crystal) and frequency.