Tek

I was looking for a microphone module which *might* be suitable for a Clapper circuit mentioned yesterday:

https://wb9kzy.blogspot.com/2025/07/another-project-idea-new-clapper.html

I didn't find it but I did find this little box:

Inside were these two circuit boards:

They are demo freebie boards from Tektronix, something to do with scopes (why a new Tek scope is better than that hunk-a-junk you now have). They both run off of a 9V battery. The bigger one is strictly hardware, the smaller one has a microcontroller.

I saw the older one on Ebay:

https://www.ebay.com/itm/116648786652

$20 ? No thank you please ! And another one with the box and manual for $50:

https://www.ebay.com/itm/156433973966

Again, no thanks.

There is a web page on the older board:

https://w140.com/tekwiki/wiki/Scope_Evaluation_Board

which has the manual, I probably have the manual somewhere but this PDF one is nice ! Even 30 years later my B&K 2190d scope isn't quite up to snuff ! :)

Here are the outputs of the older board on the B&K 2190d: