ID'ing parts

[woolie]

As an exercise I am reverse engineering some of the pedals I own.  No intentions of showing these to anyone, purely for my education of what I like and how I could make something even more my own.

One of the Caps on the pedal I am trying to figure out looks like a Silver Mica cap and says CD 98J.  My rudimentary studies have suggested that this would be a Silver Mica 98pF with a +/-5% accuracy.
The CD part I think would be Cornell Dubilier (manufacturer).

Here is the rub, I can't find any major supplier that sells a 98pF Mica cap.  So it sounds like I am reading it wrong.
Any clues appreciated.

Also, I have found no explanations of how to determine diodes.  I clearly see the +/- clipping diodes in the circuit, I just can't figure out which they are.  I can't see any markings other than the ->| direction.  I think I see an S on one of them (can't see all around the diodes without unsoldering the mess.  It is a point to point (well, actually a tag strip circuit).

A third one, which I'm sure is no big deal is that the electrolytic caps are Sprague and orange.  The same thing (as far as I can tell, and that is the rub) at Mouser.com are dark grey.  Either they are the same and Sprague have changed they color for some reason.

So, this noob would really appreciate any hints or tips.


W.

[Earthscum]

Honestly, if it's an out-of-production pedal, I don't think there's much problem sharing the circuit. ESPECIALLY if it's an out-of-production "vintage" circuit.

In-production pedals are, of course a different story.

Anyways, you can always post pics here of the parts in question. If you tell us what circuit it is, someone here may know exactly what a certain "mystery" part is. Very helpful folk!

[LucifersTrip]

Here is the rub, I can't find any major supplier that sells a 98pF Mica cap.  So it sounds like I am reading it wrong.
Any clues appreciated.

the problem in identifying many components is that the manufacturer just uses a house number rather the standard we are used to. It'd be very cool to always see a 2N718 labeled as such, but it could also be labeled CXJ44LP (just a made up example)

If the company (Philips, RCA, GE, etc)  name is written on the component, sometimes you can find a chart online....or in that specific company's manual....which may also be online

[Enzo]

Does your meter measure capacitance?  Worse case, remove the part and measure it.

Your CD 98J looks more like a date/lot code to me.  ANy chance more print is hidden down lower or on the reverse side?

What is it you want to determine about diodes? Anoce and cathode are identified by the stripe.  The stripe end is the cathode, and the anode is whatever end is left over.    In the case of clipping diodes wher two of them are wired in parallel facing opposite directions, well, what's to know?  One faces each way, so it affects things both ways.  Doesn;t matter which end of the pair goes which way, it is the same.   If you want to identify the actual type number, that can be more dificult.  For the most part, you have regular rectifying diodes, and you have zeners.  Yes ther are all manner of specialty diodes, but mostly I see those two.  LEDs light up and all, but they are in my view just a special case of rectifier.   

Zeners have a voltage and a wattage rating.  If you cannot read the tiny print, then you can usually identify the wattage by its size, and if it is working, the voltage by measuring across it.   If you see a number like 744 on one, look again to see if ther is a 1N4 right above that - 1N4744.

Rectifiers come in shapes and sizes.  For the most part, in battery powered circuits, voltage doesn;t matter.  You'd have to hunt for something with so low a rating as to be in danger.  The common 1N400X series of 1 amp rectifiers are everywhere.  We see them in power supplies in particular.  The smaller, and also common glass "switching" diodes can be used for VERY light duty in power supplies, but are more likely used in the other circuitry.  1N4148 being very common.  I forget the 1Sxxx number of the comparable Asian type.

Aside from the light they can provide, LEDs are useful because they have a higher voltage drop across their junction than a common 1N4148 or something.  In fact different color LEDs have different voltage drops.  If voltage drops are important, you can put two or three 1N4148 in series, or use one LED.  Silicon diodes have a junction voltage of about half a volt or so.  Old germanium diodes have a smaller drop, and if in doubt, a diode test on your meter can determine which.  Ther are also special diodes like Shottky diodes with lower voltage drops.

SO one can get a good idea what kind of diode they are looking at with a few tests.

I don't know if any of that is helpful, but there you go.