HP 3581 Wave Analyzer (and PC!)

[dchisholm]

Originally Posted by ymwong

Hi,

The original link to the operational instructions is broken. Would appreciate if it can be fixed.

Try "Hewlett-Packard Model HP 3581A-C Wave Analyzer Operating and Service Manual (03581-90000), February 1976"

Dale

[cliffyk]

That link is 9 years old!

However you can download the operating and service manual from Agilent-click here...

[ymwong]

Thanks!

[jackinnj]

fwiw, i replaced the battery pack in my 3581 a few weeks ago.

[davada]

Originally Posted by cliffyk

The missing ingredient on most "affordable" digital instruments is the 3581A's 90+db dynamic range (properly adjusted the noise floor is -95db), that's why I hang on to mine (and a couple parts machines). I capture the output in two ways:

• Via feeding the Y output to a digital scope, matching up the sweep times, and using the external trigger option¹ to simultaneously trigger both the 'scope and the 3581A;
  
  These are captures of wave analysis of the 1kHz outputs of a Leader 1300s function generator, and a Kikusui ORC-11 audio generator.
  
  
  
  The vertical scale is 20dB/div (rescaled from the 0-5V output of the 3581A), the horizontal 1kHz/div (by setting the 3581A to a 200s 10kHz span, and the 'scope to 20s/div).
  
  
• Using a 10-bit ADC card to capture both the X and Y outputs and display same using a Windows application of my own design;
  
  Here is a capture of the Leader 1300s output using the 10-bit ADC (an AWC-GP3) and my app:
  
  

One comment: I had to fine tune the timing resistor (R45 on the A3 board) to get the sweep time sufficiently accurate to track the 'scope's sweep. The 3581A's sweep spec of +/- 5% did not cut it as compared to an average scope's horizontal accuracy of 10ppm (0.001%).

By tweaking--through trial and error--the value of R45 (it's mounted on posts, I used paralleled resistors to get the final value) I got the wave analyzer's sweep to +/- 0.01%--close enough.

-------------------------------------------------
¹ I used a simple circuit built in to a BNC connector to simultaneously trigger the 3581A and the scope:



It's just a 50Ω resistor from the center conductor in series with a NC momentary switch, to ground. This pulls the trigger input low (the specs say anything < 470Ω) inhibiting the sweep. Pressing the switch lets the line go high (5.0V) and the sweep begins.

Connecting this to a BNC T let's you trigger both instruments.

Hi cliffyk,

Would you be willing to share the "Windows application of my own design;" and perhaps more details of you setup?

I have a 3581C which would be more useful with visual features.

I scored a load of Terayon 1000 series gateways and controllers from work that are loaded with useful parts including high speed Burr Brown 10 bit ADCs.

Actually I have way more of this Terayon stuff than I can possibly use if anyone is interested.

Thanks,

David.

[cliffyk]

David,

I would be pleased to send you the source code (VB6)-- however I have used a graphing engine (csDrawGraph) for which I have a multiple server, but "in-house" only, license. All that it does could be duplicated with plain 'ol VB picturebox stuff, or some other Cartesian graphing tool.

For the ADC I used a AWC-GD3 10-bit I/O card, it has an RS-232 interface supporting sample rates up to 200S/s w/ VB6.

The app is pretty modular, and uses a single basic module to pretty much encapsulate the ADC device initialisation and I/O. The routine identifiers are tagged as gp3xxx however using same IDs, search and replace, or aliased redirections would handle using some other ADC device.

Send me a "real" email (cliffyk@paladinmicro.com) and we can talk more...

[jackinnj]

csDrawGraph is not expensive at $60 for a single license.

[davada]

Thanks cliffyk,

I have a few other projects on the go right now.

I am interested in this and I will have a look at the info you provided. If I have more questions I'll contact at your email address.

Cheers,

David.