Should the power button stay illuminated on my 6600M after installing a GPSDO?

Yes. The colours are explained in the SmartSDR manual, but as long as it is getting a valid GPS signal, you will have a Blue button.

• FLASHING GREEN: Radio is starting or shutting down 

• SOLID GREEN: Radio is in receive mode 

• FLASHING RED: See Error Conditions below 

• SOLID BRIGHT RED: Transmitting on PA 

• SOLID DIM RED: Transmit engaged, but transmit interlocks are not ready. Refer to the SmartSDR documentation for description of the transmit interlocks. 

• SOLID ORANGE: Transmitting on XVTR port with low power 

• SOLID PURPLE: Radio is performing a software update 

• FLASHING WHITE: Radio is performing a reset to factory defaults 

• OFF: Radio is off 

When the optional GPS Disciplined Oscillator is installed:

• SOLID AMBER: Radio is off, GPSDO is powered for stability 

• FLASHING YELLOW: GPSDO is warming up 

• SOLID YELLOW: GPSDO is “holdover” mode (has lost satellites) 

• SHORT FLASH BLUE: GPSDO is locking 

• LONG FLASH BLUE: GPSDO is in “hold phase” mode 

• SOLID BLUE: GPSDO is locked