If I connect the ext. ref. out of a 53132A counter to a E4407B ext. ref. input, will the frequency counter of the E4407B be the same as the 53132A frequency readout? I am using a E4438C generator as the source and seeing a 0.21 ppm difference between the two frequency readings.
The ESA marker frequency counter accuracy specification is:
+/- (marker frequency x frequency reference error + counter resolution)
The frequency reference error has many components such as aging rate, period of time since adjustment, settability and temperature stability. This term is 0 since the frequency counter reference is locked to the ESA. The only other component is counter resolution and the ESA minimum counter resolution is 1 Hz, so on a 1 MHz signal you could have up to 1ppm error.
Regards -