The HP 5370B's timebase specs are stated on page 1-4 of the Operating and Service Manual, available for download at: http://www.home.agilent.com/agilent/techSupport.jspx?pid=1000001408%3Aepsg%3Apro&pageMode=OV&cc=US&lc=eng&pselect=SR.PM-Find%20by%20Product%20Model%20Number%20-%20Specifications.Technical%20Support Greg