fitz43's Phase Linear 700 B White Oak Conversion

[Gepetto]

You have one in your new Tek scope Lee. If it has the capabilities that mine does, it has an FFT function in it.

 

[laatsch55]

How do you set up a slew rate test??

 

[Gepetto]

Drive the amp with a low level square wave and measure the rise and fall time from the 10-90% points on the resulting waveform at the amp output. Remember I said low level Lee and do not do this into a speaker.

 

[laatsch55]

Low level as in <100mv??

 

[laatsch55]

yes Joe, this has the FFT capability.

 

[Gepetto]

Low level as in <100mv??

yes that should work fine Lee, you do not need to drive it to the wall to get the slew rate limit.

 

[Gepetto]

yes Joe, this has the FFT capability.

Then you are all set Lee, you have your spectrum analyzer...

 

[laatsch55]

Been on thre phone with Ed. Off now and was studying the users manual and they have a rise time measurement sample test. I believe I can handle it. Jeez, I'll be years figuring out everything this scope can do, amazing stuff!!

 

[laatsch55]

Just took the rise time from the cal square wave. In auto-measure mode you can simultaneously take 5 different measurements!!

 

[Gepetto]

Make sure you load the National Instruments software on your PC so you can plug the scope in via USB to do further tricks. It is the TEK-Visa toolbox.

 

[laatsch55]

So you can recall and do all that post acquisition foolin around on the PC??

 

[laatsch55]

The NI-VISA disc is not here. Will have to go to Tek's website. I'll do that later tonight when you eastern fellers are in bed. Gonna see if I can capture a rise time test and store it.

 

[Gepetto]

Yup that is the idea Lee, and you can print (pdf) scope shots directly off your printer attached to your PC

 

[Gepetto]

It is on the Tek Website for download. They may have to enable you. Some security thing they have going on at Tek. They have high end software that cannot leave the US.

 

[laatsch55]

OK , thanks Joe. So if they're pdf we can export right to our thread post?

 

[laatsch55]

Here we go, first pic right channel, 100mv input 3 watt output., 2nd pic left channel, same conditions.....almost.....

 

[jbeckva]

What did you do with the Zoebel resistor??

Err.. hmm.. stuck it up my nose? (beat the smartass heheh)

Seriously.. just stuck 'em in a parts bin. But if you mean the old ones I put back on the DCP, those I "paired up" like they were and put 'em on end, then ran a solid wire from the tops to the other hole on the pcb.

 

[jbeckva]

Here we go, first pic right channel, 100mv input 3 watt output., 2nd pic left channel, same conditions.....almost.....

Which channel's got the ebil batwings on it?? Ewww!

 

[laatsch55]

The right.

 

[Gepetto]

Hi Lee
In order to measure the slew rate you will have to have your time base down in the 5 or 10 usec per division and look at a single edge. You will be measuring the time it takes to go from 10 to 90% of the voltage swing and then resolve that into V/usec.