DIY Curve Tracer

[mogliaa]

Back to the tracer subject again! Today officially completed this project that I think took me 6 months at least. I completed the chassis (bottom plate was still missing) and here it is:

http://www.bartola.co.uk/valves/wp-c...1/img_2995.jpg

An example of the 6e5p in triode mode:
http://www.bartola.co.uk/valves/wp-c...p-triode-2.jpg

Now time to trace some curves.
cheers,
Ale

[jackinnj]

Congratulations!

[mogliaa]

Originally Posted by jackinnj

Congratulations!

Thanks. I may have to improve the PLL. When it get warm it drifts and require readjustment. Need an PLL expert to give me a hand here!

[TheGimp]

Very Nice Job Ale. Congrats.

[mogliaa]

Originally Posted by TheGimp

Very Nice Job Ale. Congrats.

Thanks Steven. Actually you made me start this project and helped me all along...

[avincenty]

Ale, great job! See you have been busy tracing.

I built a camera hood that works great for me. It is made of 1/4 inch hard foam that is used for posters. The hood is light and strong and snaps tightly against the oscilloscope screen frame.

[mogliaa]

Alfredo,
That's great! How do you manage getting the right exposure with the camera hood? Can you get to see the screen grid lines well defined? please post some pictures of the results
thanks
ale

[jackinnj]

you'll improve the contrast of the pictures if you put some black tape over the foil facing the scope.

My Canon G12 has a "TV" setting which is useful when I pull pictures off the 576 curve tracer, 2465B or HP3577. You can then use "Graph Grabber" to obtain XY values for spice models. Much easier to use than my Fuji D-Cam.

[avincenty]

Originally Posted by mogliaa

Alfredo,
That's great! How do you manage getting the right exposure with the camera hood? Can you get to see the screen grid lines well defined? please post some pictures of the results
thanks
ale

I had some pictures but they are gone Murphy's law hit me last week. I gave my daughter a macbook as graduation present, she turned it on, the damned thing saw the Readynas Network Drive.... Ran the copy utility that comes with the mac against her old Notebook. But the Readynas drive appears automatically and had nothing to do with the copy. She figured the stuff wasn't hers, deleted it without asking She honestly thought it was on her local drive. Wiped out everything in the drive. Lots of it was being backed up daily to another drive, but my DIY working directory wasn't. Spend a full day trying to recover the lost data to no avail. Since it was deleted as a network drive there was no undelete. I purchased some recovery software but it didn't really help. I guess I learned a lesson.

I will set the tracer back on the bench (working on something else) and get some pictures. Pretty sure I was using Aperture priority mode and there was a difference depending which oscilloscope I was using. For the curve tracing I have mostly been using the analog storage oscilloscope as it works like a charm. That one has more emitted light as it has no refresh problem and mostly I use the hood to get rid of nasty reflections from a upper garage door window in from of my bench. If I use the tek oscilloscope then I need to pay more attention to the settings.

I will get you some samples as soon as I can.

Alfredo

[mogliaa]

In this digital era a backup is mandatory, but we all learn it one way or another! Hope you haven't lost too much. Worst is when you lose pictures etc

Yes, reflections are horrible. I mostly taken most of my picture during the day and have a window as well on my attic just behind the oscilloscope. I guess that if I build a hood and is completely dark not sure if the grid lines will come up properly...will need to test
cheers
ale