Why doesn't my YBGPS1 GPS Timing Reference Unit improve the frequency accuracy of my YBT250? I've connected it to the Frequency Reference input.

Why doesn't my YBGPS1 GPS Timing Reference Unit improve the frequency accuracy of my YBT250? I've connected it to the Frequency Reference input.

The YBGPS1 output should be connected to the Timing Input on the YBT250. The reason is that the GPS receiver is putting out one second clock pulses, not a 10 MHz reference signal. The YBT250 takes this information and uses it to improve the frequency accuracy to .015 PPM, or 30 Hz at 2 GHz.