Oh good, this has been listed on the local ebay classifieds as parts or repair for local pickup
![Face Palm :palm:](https://www.eevblog.com/forum/Smileys/default/xfacepalm.gif.pagespeed.ic.EBDwh1hCfo.png)
I was strong yesterday but contacted the seller just now, let's just hope someone else was faster, I don't need more stuff in the repair pile...
But the diff-amp looks cute and saskia might be interested in the scope once she has settled again
![Laughing :-DD](https://www.eevblog.com/forum/Smileys/default/smiley_laughing.gif.pagespeed.ce._hfWAz_QHO.gif)
Also the Ph-meter looks like it is nixie-based
![Lips Sealed :-X](https://www.eevblog.com/forum/Smileys/default/xlipsrsealed.gif.pagespeed.ic.8oTr2_WWv_.png)
Update on the frequency mixer thingy: quick test shows it somewhat works, obvious flaw is the input stages get as hot as a 2$ pistol when no input signal is present
![Bullshit Detector :bullshit:](https://www.eevblog.com/forum/Smileys/default/BullshitDetector.gif.pagespeed.ce.ySiCs9HSXL.gif)
In fact, power draw halves from 0.3A to 0.15A when giving it input
![Banging Head |O](https://www.eevblog.com/forum/Smileys/default/bangheadonwall.gif.pagespeed.ce.8iLbFYV4Bc.gif)
Running that part of the logic from 5.5V seems obviously a bad choice now but thats what adjustable regulators are for
![ThumbsUp :-+](https://www.eevblog.com/forum/Smileys/default/icon_smile_thumbsup.gif.pagespeed.ce._JElyJQqdB.gif)
Edit: Added a picture of the VFD-Nixie module supposedly inside the Ph-meter. Is it ok to make it a clock if it isn't a "real" nixie?
![Evil >:D](https://www.eevblog.com/forum/Smileys/default/xevil.gif.pagespeed.ic.tdrs7Uj5gu.png)