[HN Gopher] From Oscilloscope to Wireshark: A UDP Story (2022)
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       From Oscilloscope to Wireshark: A UDP Story (2022)
        
       Author : ofrzeta
       Score  : 61 points
       Date   : 2026-03-19 19:18 UTC (3 hours ago)
        
 (HTM) web link (www.mattkeeter.com)
 (TXT) w3m dump (www.mattkeeter.com)
        
       | Retr0id wrote:
       | > I configured the oscilloscope to collect 100M samples at 1 TSPS
       | 
       | Typo? I didn't think we had sample rates anywhere near that high!
        
         | KK7NIL wrote:
         | A Keysight UXR can do one quarter of that, 256GS/s, but a
         | Tektronix 6 series is limited to 25 GS/s iirc, so you're right.
        
           | HunterWare wrote:
           | Looks like max 50GS/s per their site. That also looks
           | reasonable with the screenshot they have in the article
           | showing 1ns / div horiz. But clarity on the data would be
           | lovely. =)
        
             | HunterWare wrote:
             | Actually I take it back: For the series 6B spec page...
             | Real-time: 50 GS/s (2 channels), 25 GS/s (4 channels), 12.5
             | GS/s (> 4 channels) Interpolated: 2.5 TS/s
        
           | Junk_Collector wrote:
           | If you are an absolute nutcase, you could characterize a set
           | of line stretchers and a multiplexer on a high end VNA then
           | offset the inputs of the 4 channels on that UXR with them,
           | take a capture and finally rebuild a 1TSamp/s signal out of
           | the 4 results.
           | 
           | You have to have the 240V model of the scope to run all four
           | channels at full rate (110GHz) though.
        
             | jacquesm wrote:
             | Hehe, take that Nyquist ;)
        
         | nativeit wrote:
         | > Random equivalent-time sampling takes advantage of the nature
         | of a repetitive signal by using samples from several trigger
         | events to digitally reconstruct the waveform. Since sampling
         | occurs on both sides of the trigger point, pretrigger
         | capability is very flexible. Because repetitive signals are
         | being sampled, the bandwidth of an equivalent-time scope can
         | far exceed its sample rate.
         | 
         | https://www.tek.com/en/documents/application-note/real-time-...
        
           | nativeit wrote:
           | Here's a more specific example: PicoScope 9400 series
           | supports just 500Msps per channel, however it's advertising
           | "70ps transition time and 1TS/s (1ps resolution) random
           | equivalent-time sampling", this sort of "equivalent sampling"
           | is presumably where that seemingly crazy spec comes from.
        
           | Retr0id wrote:
           | But you can't use equivalent-time sampling for something non-
           | repetitive like network packets.
        
             | Aurornis wrote:
             | For measurements like this the SDK will usually include
             | some utilities to send the same data over and over on a
             | port.
        
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       (page generated 2026-03-19 23:00 UTC)