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From: Joerg <news@analogconsultants.com>
Newsgroups: sci.electronics.design
Subject: Re: Fast sampler
Date: Tue, 11 Mar 2025 12:20:30 -0700
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On 3/10/25 8:22 AM, john larkin wrote:
> On Sun, 9 Mar 2025 19:22:19 -0400, "Tom Del Rosso"
> <fizzbintuesday@that-google-mail-domain.com> wrote:
> 
>> Phil Hobbs wrote:
>>> Hi, All,
>>>
>>> Late last year we did a fast sampler/TDR with nice clean 60 ps edges.
>>>
>>> We're gearing up to actually sell them, so I did a short technical
>>> writeup on the design, which may be of interest.
>>>
>>> <https://electrooptical.net/News/a-high-performance-time-domain-reflectometer>
>>>
>>> Cheers
>>>
>>> Phil Hobbs
>>
>> Why is a LASER ruler that can measure distances in air with 2mm accuracy
>> $16,
>>
>> and an OTDR for measuring fiber $600?
> 
> Most rangefinders use sine modulation and measure phase shift, which
> doesn't involve picosecond timing or expensive wideband signal
> processing. And they report one number, not a graph. OTDRs are much
> more complex than rangefinders.
> 
> And the markets are different too.
> 

Also, if a range finder fails to display an accurate result it's usually 
not a big deal. So it doesn't have to be hi-rel or anything. If a TDR 
like the one I designed fails that can make the evening news. Nobody 
wants to be on the evening news in a context like that.

-- 
Regards, Joerg

http://www.analogconsultants.com/