Foxhole Distortion? (DIY razor blade diode clipping)

[EBK]

And, if you are interested, and can follow it, here is my layout:

[iainpunk]

hey, i think i get it, just an mxr dist+ wit a pot in between the diodes and op amps.
i'm not really in to the whole stripboard/vero thing, i chose the pad per hole side in "the war of the prototype boards".

i also think there is a good middle ground, which still gives you the possibility to make the circuits compact, but also has the ease of use of vero (ignore the arrow)

[Gus]

Have you seen this page?

http://www.sparkbangbuzz.com/

http://sparkbangbuzz.com/zinc-oxide-diode/zinc-oxide-diode.htm

[EBK]

Have you seen this page?

http://www.sparkbangbuzz.com/

http://sparkbangbuzz.com/zinc-oxide-diode/zinc-oxide-diode.htm

Interesting. Thanks for sharing!  I have to melt some pennies now to try this zinc blob diode.

[j_flanders]

Or these:
http://halestrom.net/darksleep/blog/011_copper_diodes/
https://hackaday.com/2016/05/01/home-made-diodes-from-copper-oxide/
https://www.instructables.com/id/How-to-make-a-copper-oxide-diode/

I have many other links but they're on another computer. (includes the ones Gus posted)

Last year I spent countless hours trying to replicate some of the experiments to use them in a distortion pedal.
But I had a real hard time getting them to work. Really frustrating.
At one point I found myself oxidizing and 'blueing' every kind and piece of metal I could find around the house.
Eventually the wife gave me 'that' look. Made me feel like a 10 year old. 

Some kinda seemed to work but were still behaving weird:
-it clipped in both directions, I did not need two diodes. 
-it needed quite a bit of current and even a just little too much current destroyed the diode or 'contact point'.

[EBK]

This evening, I did some quick tests to see if my DCA55 would believe I had a diode.  Depending on the spot the pencil touched, I got one of three results on the screen:
1) No device
2) Unknown/faulty device
3) Depletion mode P-channel MOSFET (source and drain terminals)


I'm guessing that third result, if any, is probably indicative of the diode operation.  I would've guessed it would report it as a Schottky diode though....

[EBK]

No clipping yet.



Not giving up.

[duck_arse]

have you tried the blade edge as yet? not for shaving. obvs, but for diode-ing. [perhaps stand the blades cutting edge up, w/ pencils wrinting points down.]

[amptramp]

Here's a classic galena detector with variable arm position to find the best point:



This used to be a standard for crystal radios.  As well as these, Philmore used to make crystal radios with the cat's whisker contact already placed in the best position and sealed under a glass dome:



This gives you a better view of the dome:

[EBK]

I've started experimenting with a new probe made out of an old acoustic guitar string (phosphor bronze).  The winding is the whisker, and the stiff core provides an adjustable spring.

Again, no idea if what I am doing makes sense.

I think I need to clean and retorch the blade.  There is a lot of pencil graphite on it from moving the pencil probe about a thousand times.