10 responses to “EEVblog #430 – Fluke 91 Scopemeter Teardown”

• Tom February 27th, 2013 at 09:56

  Unfortunately PCB wave soldering video is private.

  Reply

  • fred February 27th, 2013 at 12:06

    Why is the wave soldering video is private?

    Reply

    • Tom February 28th, 2013 at 10:16

      I think I was trying to watch it while it was still uploading…

      Reply

• fred February 27th, 2013 at 12:08

  Why is the wave soldering video is private?
  If this get published twice it’s my computers fault it stutters sometimes

  Reply

• Fredrik February 28th, 2013 at 05:06

  Isn’t the Fluke scopemeter orginally from Philips? Then made in Holland seems logical.

  Reply

• Njay February 28th, 2013 at 11:24

  Good work!

  Did you noticed the dual footprint on the memory chips?

  The ADC’s datasheet says 40MHz *minimum*. Maybe Fluke was hand picking and overclocking their chips. If you have the time, scope the clock inputs (pins 16 and 17 of the TDA).

  Cheers!

  Reply

• Nasos February 28th, 2013 at 19:38

  The 50MHz of the spec is the bandwidth and TDA8703 has less than 20mhz bandwidth, and bandwidth is something that you cant overclock… is like an rc filter on the input of the ADC… So i think to posibilities
  1) they colect ADC from the production line with better characteristics…. (and also they overclocked them)
  2) i think the most possible…. The unknown custom chip is an analog sampling memory chip that it has 50MHz ΒW and high sample rate maybe 100MSPS or even more and afte the sampling the TDA8703 reads the samples… Also thats the reason why there is not a fast memory chip ( and counter or asic) or fifo near the tda8703.
  That is not something unusual… I think most low end tektronix oscilloscope use this technique… (and thats why they have small sampling memory like 1K) i dont remember the model that has a sampling rate of several 100MSPS or even 1GSPS using analog sampling memory (asic) and then reads the samples with an mc10319 (25msps adc)

  Reply

  • f4eru March 1st, 2013 at 09:31

    you can also compensate the bandwidth, up to some point, with HW and/or SW compensation.

    Reply

• le mazou February 28th, 2013 at 23:26

  murata ref is a BNX002-01.

  > 40dB (1MHz up to 1GHz)

  Reply

• f4eru March 1st, 2013 at 09:38

  Dave ! test it to 50 MHZ !!

  Reply

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  All Programmable Planet - Steve Leibson - Where Have All the ASICs Gone? March 3rd, 2013 at 12:46

  [...] week, while watching a video of my friend Dave Jones tear down an old Fluke 91 ScopeMeter DSO (digital sampling oscilloscope), I [...]