rise time of pulses of a HP8133A by Tek 11403, TDS 820 and Tek 11801 - Page 1
Forum section: electronics / projects

author: Physikfan
author_rank: Regular Contributor
timestamp: September 16, 2017, 08:24:48 pm
content: Hello oscilloscope friendsI plan to show the rise times of a HP8133A by Tek 11403 (11A72, 1GHz), TDS 820 (6GHz) and Tek 11801 (with SD-20, 20GHz).Why this?The HP 8133A can provide pulses between 33 MHz and 3 GHz frequency,with up to 3.0 Vp-p amplitude and transition times of <60 ps (20% -80%).It is at least interesting to me which oscilloscope can show the form of pulses, and how close to reality.I hope that these experiments are not considered absolutely trivial and can be of interest.I am curious about your comments, tomorrow morning I will startregardsPhysikfan

author: edavid
author_rank: Super Contributor
timestamp: September 16, 2017, 09:26:38 pm
content: Don't we use 10%-90% here?How will you interconnect the HP8133A and the scopes? (I would suggest a short hardline.)

author: Physikfan
author_rank: Regular Contributor
timestamp: September 17, 2017, 07:18:16 am
content: Hi edavidHP specification for 10% up to 90% amplitude (rise time) is <100 ps.I will not use a rigid cable, because I want to use the same cable for all three oscilloscopes, for the 11402 I will use an adapter SMA to BNC.But I will try to find out a possible difference between a flexible and a semi rigid connection.

author: PartialDischarge
author_rank: Super Contributor
timestamp: September 17, 2017, 07:33:57 am
content: You should visit "show us your square wave" !!https://www.eevblog.com/forum/testgear/show-us-your-square-wave/

author: Physikfan
author_rank: Regular Contributor
timestamp: September 17, 2017, 03:21:11 pm
content: Hi mastertechThanks for giving me the hint to visit "show us your square wave".I have learned a lot.Unfortunately most of the pictures were not readable for me:"please update your account to enable 3rd party hostingfor important info, please go towww.photobucket.com/P500"RegardsPhysikfan

author: Physikfan
author_rank: Regular Contributor
timestamp: September 17, 2017, 08:29:38 pm
content: These are the first results:Square wave of the HP8133A with the Tektronix sampling oscilloscope 11801C, x-axis 50ps / div, y-axis 200mV / div, with head SD26, rise time 17.5 ps, bandwidth 20 GHz.200 ps wide pulse of the HP8133A with the Tektronix Sampling oscilloscope 11801C, x-axis 50ps / div, y-axis 200mV / div, with head SD26, rise time 17.5 ps, bandwidth 20 GHz.The displayed rise time is about 50 ps in both cases.

author: David Hess
author_rank: Super Contributor
timestamp: September 17, 2017, 11:20:47 pm
content: Quote from: edavid on September 16, 2017, 09:26:38 pmSometimes you have to use 20%-80% because 10%-90% is unrealistic when the cable suffers from dribble up.

author: Physikfan
author_rank: Regular Contributor
timestamp: September 18, 2017, 08:24:16 am
content: Here are the results measured by a TDS820, 6 GHz oscilloscope with 44 ps rise time:Square wave of the HP8133A, x-axis 50ps/div, y-axis 200mV/div:200 ps wide pulse of the HP8133A, x-axis 50ps/div, y-axis 200mV/div:The displayed rise time is about 65 ps in both cases.

author: Leo Bodnar
author_rank: Frequent Contributor
timestamp: September 19, 2017, 08:05:04 pm
content: Quote from: Physikfan on September 17, 2017, 08:29:38 pmWhy don't you use internal 11801 risetime calculation?If you select the risetime measurement then tap on "Rise" rectangle then you can adjust Proximal and Distal values to 20% and 80% using the knobs - like below.Let the machine do it for you. Tek engineers designed 11800 series 30 years ago so it's time we finally figured out how to use it.CheersLeo