Agilent Technologies 6000 Series manual Using the 10 MHz reference clock

8 Reference

Using the 10 MHz reference clock

The 10 MHz REF BNC connector on the rear panel is provided so you can:

•Supply a more accurate sample clock signal to the oscilloscope, or

•Synchronize the timebase of two or more instruments.

Sample clock and frequency counter accuracy

The oscilloscope’s timebase uses a built-in reference that has an accuracy of 15 ppm. This is sufficient for most uses. However, if you are looking at a window that is very narrow compared to the selected delay (for example, looking at a 15 ns pulse with the delay set to 1 ms), significant error can be introduced.

Using the built-in sample clock, the oscilloscope’s hardware frequency counter is a 5-digit counter.

Supplying an external timebase reference

When you supply an external timebase reference, the hardware frequency counter is automatically changed to an 8-digit counter. In this case, the frequency counter (Quick Meas&Select&Counter) is as accurate as the external clock.

For more information on the hardware frequency counter, see “Counter” on page 244.

To supply a sample clock to the oscilloscope

1Connect a 10 MHz square or sine wave to the BNC connector labeled 10 MHz REF. The amplitude must be between 180 mV and 1 V, with an offset of between 0 V and 2 V.

C A U T I O N	Do not apply more than ±15 V at the 10 MHz REF BNC connector on
	the rear panel or damage to the instrument may occur.

336 6000 Series Oscilloscope User’s Guide