HP 3582A ?

Hank,

Does the 3582A have a tracking oscillator output? That is, does it have an output whose frequency corresponds to the center of the frequency band that is input to the analyzer is currently (at that point in time) responding to?

If not, then to see the frequency response of (let's say) a microphone then you're going to have to stimulate the microphone/speaker with some type of broadband noise (e.g., white noise). If so then you can merely drive the sound source (amplifier driving a speaker) with the tracking oscillator and hook the microphone (may need a preamp) to the input of your beautiful new analyzer.

The biggest problem you're going to have to somehow come up with an acoustic source that has a know output vs. frequency (when plotting the mike's response) or know input vs frequency (when plotting your speaker's response).

There are calibrated microphones and sound sources available but they're VERY expensive.

Bob

Bob The 3582A has a periodic and random noise source but no tracking osc. It has on-screen digital readout for freq. and amplitude. It also does FFT of which I know very little! It's really too complex for what I'm trying to do but its what I have.

Hank,

The best thing for you to do is to pack it up an send it to me. ;-)

One of the things that an FFT will give you (as compared with a simple tunable filter) is that it can provide you with amplitude AND phase information for a give complex waveform. If you're just looking for amplitude response then I'm not sure you need to be concerned with its FFT function. It's also easier, with the FFT, to control the resolution bandwidth (the filter's bandwidth).

I think you should should just hook up a microphone (with any necessary preamplification) and play with it. Sing some notes. Pluck some strings. See what happens. Then, hook up its random noise source output to an amplifer/speaker and see what you get. You should see the frequency response of the amplifier/speaker/microphone/preamp combination. You'll get the idea.

Have fun, Bob

Bob That's what I've been doing but my results are garbage because I don't know how to set it up and the ops manual is not enough. I have no problems using the HP 141T and it's various plugins or the HP 8590 but this thing escapes me. But I'm willing to learn but poking around and trial and error is getting frustrating. I'll have to see if this group has any experienced users.

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Why don't you just use a PC, a sound card and some software?

etc...

I downloaded it and it doesn't work! So back to what I have and hope someone knows more on how to operate it.

Well the etc meant keep googling for stuff like this.

The FFT nature of the beast is there to dramatically speed up the measurements. The manual points out that it is 100x faster than the

3580A (the predecessor, swept tuned). It probably is not overkill for what you want to do (as long as your workbench is strong enough ;-)

The apparent complexity of being able to select different windows is to allow you to optimise response depending on what you are doing. For example, set the output to the "periodic" signal, loop it to the input and compare results with the different windows.

If you also try random noise, you will note how much slower the response "stabilises" compared with periodic noise/uniform window.

Regards Ian

(I first had that box demo'd to me in the 1970's!)

FYI I just got my eBay CD with the ops and service manual and first glance tells me that it has what I need. It's 202 pages and much more comprehensive than the Agilent download and has examples on how to use it. Thanks to all who tried to help me.

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73 Hank WD5JFR