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Help deciding on a tool to run frequency response curves / graphs

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mapleLC:
I am in the process of setting up my lab, and I have the requirement to run frequency response graph on different types of components.

My understanding is that a Spectrum Analyzer is required for this?  I see some of these units out there, they look 20 or 30 years old.  Has this need I have been solved a better way from then until now?  Perhaps using a PC, or a cheaper piece of lab gear?

I am seeing these analyzers over $1300, which is too much for the frequency with which I need to use it, but I do need it, and also need it to be pretty accurate.

alm:
What kind of frequency do you need? Do you need the level, or also the phase? If you are talking audio frequencies, then a (USB) sound card with the right software (like RMAA, REW or Daqarta) might well be sufficient. The software will usually give some recommended sound cards that are known to work well with it. The resolution and dynamic range should be quite good (better than a scope).

For up to a few dozen MHz a function generator plus digital storage scope (DSO) might work. The Digilent Analog Discovery is more convenient and should have a higher resolution than your normal DSO? For RF and higher I'd think either a spectrum analyzer with tracking generator, or even better a vector network analyser (VNA). There are some very cheap hobby-grade VNAs that might be sufficient like NanoVNA and LiteVNA. This forum has some long threads about them. They are not super accurate, but you'd have to quantify what you need.

TimFox:
Watch out for the details on spectrum analyzers:  most units now in production can go to very high frequencies > 1 GHz, but only down to 9 kHz.  Also, they typically have 50 ohm input impedance.

Grandchuck:
Tim is correct.  The graphs you posted are in the audio range.  Perhaps a scope with a built-in function generator would serve well.  The sound card idea is also a good one.

mapleLC:

--- Quote from: TimFox on April 03, 2022, 02:12:35 pm ---Watch out for the details on spectrum analyzers:  most units now in production can go to very high frequencies > 1 GHz, but only down to 9 kHz.  Also, they typically have 50 ohm input impedance.

--- End quote ---


--- Quote from: Grandchuck on April 03, 2022, 03:15:47 pm ---Tim is correct.  The graphs you posted are in the audio range.  Perhaps a scope with a built-in function generator would serve well.  The sound card idea is also a good one.

--- End quote ---

https://eevblog.com/forum/testgear/rigol-ds1054z-function-generator-fft/

My scope doesn't have it... argh.  It's a great idea, that way the scope can serve 2 needs.

Regarding the sound card, that would serve for line level components, but I don't see how I could it with a set of speakers... would u just eliminate the voltage and pass the signal right to speakers?

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