Author Topic: 50ohm Coaxial Termination  (Read 2094 times)

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Offline Ranger14

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50ohm Coaxial Termination
« on: March 26, 2016, 02:14:32 am »
I was working on rebuilding my scope and found the data sheet for the Tek 50ohm Coaxial Termination (Part No 011-0129-00) .. My problems come as I am trying to figure out the purpose of using these units on a scope ?? Sorry for the silly questions but I am just trying learn on my own..
 

Offline ade

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Re: 50ohm Coaxial Termination
« Reply #1 on: March 26, 2016, 04:32:44 am »
Great video from w2aew:

 

Offline tggzzz

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Re: 50ohm Coaxial Termination
« Reply #2 on: March 26, 2016, 08:18:59 am »
I was working on rebuilding my scope and found the data sheet for the Tek 50ohm Coaxial Termination (Part No 011-0129-00) .. My problems come as I am trying to figure out the purpose of using these units on a scope ?? Sorry for the silly questions but I am just trying learn on my own..

No apologies necessary.

Scope probes are an important topic since they are an integral part of the measurement being made. Your starter question: what is load conventional high impedance *10 probe has on the circuit? The answer 10Mohm is usually wrong and always simplistic; 100ohm is more accurate in important realistic cases.

FFI on many aspects of theory, practice and safety, have a look at the references in https://entertaininghacks.wordpress.com/library-2/scope-probe-reference-material/
There are lies, damned lies, statistics - and ADC/DAC specs.
Glider pilot's aphorism: "there is no substitute for span". Retort: "There is a substitute: skill+imagination. But you can buy span".
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Offline femtohertz15

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Re: 50ohm Coaxial Termination
« Reply #3 on: April 02, 2016, 08:59:49 pm »
50 Ohm termination is good when you are pushing the bandwidth of the scope, using direct connection to 50 ohm sources or through low-Z probes.  Or for sources or instruments that natively output 50 Ohm.

But, the specs for it are only 0-100Khz, which puzzles me.  Maybe its for audio use?   :-//
 

Offline w2aew

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Re: 50ohm Coaxial Termination
« Reply #4 on: April 04, 2016, 01:56:39 pm »
50 Ohm termination is good when you are pushing the bandwidth of the scope, using direct connection to 50 ohm sources or through low-Z probes.  Or for sources or instruments that natively output 50 Ohm.

But, the specs for it are only 0-100Khz, which puzzles me.  Maybe its for audio use?   :-//

If I'm not mistaken - I think that specific one was a "precision" termination, with an accuracy of something like +/-0.05 ohms.  Wasn't really intended for RF applications, more of a precision reference termination I think.
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Offline BobsURuncle

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Re: 50ohm Coaxial Termination
« Reply #5 on: April 04, 2016, 02:25:07 pm »
I was working on rebuilding my scope and found the data sheet for the Tek 50ohm Coaxial Termination (Part No 011-0129-00) .. My problems come as I am trying to figure out the purpose of using these units on a scope ?? Sorry for the silly questions but I am just trying learn on my own..

Perhaps if you provided some context we might be able to speculate.  For what specific instrument did the manufacturer specify this termination and on which channel (function), and do you have any performance specifications for the instrument and said function?  I doubt this was intended as the scope feedthrough for one of the vertical amplifiers, but rather is intended for DC or low frequency gain calibration of a probe or some other instrument.




« Last Edit: April 04, 2016, 04:07:44 pm by BobsURuncle »
 


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