Cheap Spectrum Analyzer

[RWebb]

anybody know of anything?

something that runs on a laptop would be ideal

only needs to go up to 15 kHz

[legion]

Amazon.com: spectrum analyzer

[Gogar]

There's an app for that!

[cashflyer]

When I think of a spec analyzer, I think of this thing I use in my shop:


(not my pic)


How is this a spec analyzer???


Looks more like a frequency counter to me.
Where are the coax inputs?!!

[RWebb]

yeh, that that top pic will work - ship it to me and I'll send you a beer

[RWebb]

Just to clarify, I want a gizmo with a microphone on it; the mic feeds into a box (or an interface to a computer) and it then does a process called a transform (I am partial to FFT, but hey - I grew up in Louisiana), and you see (and/or can record) little bars sticking up on the screen of your laptop or device.

Each bar is set along the x-axis at a certain frequency, and the ht. of the bar on the y-axis is the amplitude of that (really those) frequency.

[Pazuzu]

Any "uber wiz bang" digital stereo receiver from the 80s would have one of those...

You probably want one a bit more critical than that, huh?

[masraum]

Google to the rescue??

True Audio: Audio Spectrum Analyzer and Loudspeaker Design Software

Windows 7 Vista XP 2000 NT Music Software: Spectrum Analyzers (Shareware Music Machine)

SpectraPLUS - Audio Spectrum Analyzer

Audio Spectrum Analysis and FFT Spectrum Analyzers

[BRPORSCHE]

We talking oscilloscope?

[imcarthur]

I will ask. I was discussing the need for a sweep of my desktop hifi with a co-worker & he had something that was quick & simple.

Ian

[RWebb]

Originally Posted by Pazuzu

Any "uber wiz bang" digital stereo receiver from the 80s would have one of those...

You probably want one a bit more critical than that, huh?

a bit...

no, these are not oscilloscopes - that is a "time domain" instrument

thx, Ian - I will await your info!

[Aurel]

I sold one of those on e-bay for $5k several years ago. That was something like 90% off the price new.

[stogie25]

Originally Posted by cashflyer

When I think of a spec analyzer, I think of this thing I use in my shop:


(not my pic)


How is this a spec analyzer???


Looks more like a frequency counter to me.
Where are the coax inputs?!!

I hear ya. I was thinking that I use my HP8920 if I am on the bench, or Anritsu handheld if I am out chasing RF interference.

[Eric Coffey]

The best tools for the job are as follows IMO:

Smaart
SysTune
PRAXIS

They have further advantages over stand-alone units and other basic RTA PC programs in that they have FAR more features and have more than one "channel" for comparative analysis (great for comparing pre & post processing effects/response). I am sure there are more out there, but the above choices are among the best.

Also, I believe all of them have free demo/trial downloads as well.

[rick-l]

does that 8590 say 9 kHz to 1.8 Ghz?

$7000 used?

[rick-l]

This is more my speed. The brown truck brought this e-bay purchase to me today (the HP3325 func gen). Notice how stable the output is. I am reading up on fractional - N PLL frequency synthesizers.

Function generator, RMS meter and a piece of graph paper = poor mans network analyzer.

EDIT: I guess a spectrum analyzer would have a tunable bandpass filter.

[cashflyer]

Originally Posted by stogie25

I hear ya. I was thinking that I use my HP8920 if I am on the bench, or Anritsu handheld if I am out chasing RF interference.

I'd really like to get an Anritsu unit, but cannot justify it in the budget.

Originally Posted by rick-l

does that 8590 say 9 kHz to 1.8 Ghz?
$7000 used?

I think that is the range of the 8590. That was just an internet pic I grabbed for illustration. My actual unit is an 8920 that scans 4k to 1g.

As for price, you can find them on ebay at fairly good prices.

[rick-l]

If you can get a sampled waveform into XL there is a discrete Fourier transform that works pretty good.

[imcarthur]

Randy: My cohort suggested:

"You need an external interface (M-audio for example), a measurement mic (like the Behringer ECM8000 $54.99 on Amazon) and software. Free stuff like REW (Room EQ Wizard)"

Ian

[RWebb]

thx much Ian - I'll do just that if the M-audio, etc. is cheap enuff.