News:

Forum may be experiencing issues.

Main Menu

Diode questions/help

Started by selfdestroyer, December 01, 2013, 11:16:19 AM

Previous topic - Next topic

selfdestroyer



The Story:
I just got a bunch of random diodes from a friend of mine. He said they were from his dad's estate and was just siting in a box in his garage. I was excited since I love finds like that. Now I got a huge lot of transistors not that long ago and only 2-5% of them were unmarked and I had to use my DCA Pro to figure out (ballpark) what they were. Just like I did with the transistors, I started sorting everything by case size/color/make and then started looking at each one looking for identifying markers. I only have 25% of them with numbers (I can still read) on them. Some are glass with color rings and they were easy to identify but others are little black or blue ones with no marks on them. So I ran to the computer and started searching on "identifiying Diodes" and 99% of everything I found was on color rings or text/numbers on the diodes but nothing about other identifying factors like color, size etc.

The question:
Is there a list out there of Vf numbers to cross ref a diode? Are there any other significant values other than the forward voltage when building stompboxes? I do not understand this at all and the articls I find are WAY over my head at this point.

I have a few diodes that look like a mullard transistor and they say "holland CF 6316" on them with a 0.300Vf and I can't find anything online on them. At the end of the day I just want to see if I can use some of these old diodes in some pedals.

Cody

rullywowr

It's tiny print on some of those diodes but they will usually say what they are on some of the packages.  For the ones with the color stripes, there is an ID code (like resistors).  I found a chart here which may be helpful.

http://www.tpub.com/neets/book7/24k.htm

Of course half the fun may be just socketing your pedal and swapping some of these diodes in there until you find that "rad mojo toan" that everybody salivates over.



  DIY Guitar Pedal PCB projects!

croquet hoop

#2
Quote from: rullywowr on December 01, 2013, 04:50:16 PMOf course half the fun may be just socketing your pedal and swapping some of these diodes in there until you find that "rad mojo toan" that everybody salivates over.

You don't need to hear how the diode looks to know it gives mojo. If it it looks cool, then it's mojo. Uncommon = even more mojo.

More seriously, beging with fv measurement and start from here. Diodes with forward voltage from 0.25 (some germaniums) to 2+ volts (LEDs) are useful in pedals, so I am sure you'll find plenty of builds where to use this nice stash.

DutchMF

Quote from: croquet hoop on December 01, 2013, 05:07:06 PM
You don't need to hear how the diode looks to know it gives mojo.

This made my day......... ;)

Paul
"If you can't stand the heat, stay away from the soldering iron!"

midwayfair

Don't worry about part numbers. Just sort them by composition and Fv and them try them in your favorite distortion circuit. But here's a quick list of some representative Fv from my measurements for diodes that appear in circuits:

Germanium
1N100/1N60: .23-.28V
1N695: .25-.3VV
1N19x: .25-.3V (I think Smallbear's generics are this series)
1N270: .28-.33V (however, some might be lower)
1N34A: .32-.38V

selfdestroyer

Thanks for the info people. I will start measuring them and socketing them in a test circuit and see what happens.

Bret608

I've had similar fun trawling through all the old, weird diodes where I work. Those are in labeled bins, but they are mixed up on occasion.

Those ones that look like black resistors might be zeners. I found some here called 1n645--the forward voltage fell somewhere between the usual germanium and silicon. Also, I see some black and grey that look just like the 1n695s I got from Small Bear recently. Wonder what those are?

selfdestroyer

Quote from: Bret608 on December 02, 2013, 04:22:19 PM
I've had similar fun trawling through all the old, weird diodes where I work. Those are in labeled bins, but they are mixed up on occasion.

Those ones that look like black resistors might be zeners. I found some here called 1n645--the forward voltage fell somewhere between the usual germanium and silicon. Also, I see some black and grey that look just like the 1n695s I got from Small Bear recently. Wonder what those are?

Cool thanks for the info. I am going to spend a few minutes tonight to get the reading from them and bag them up for future use. Some of these just look so cool I want to use them just for that factor. lol