years ago Phillips did a good job of researching transistor substitutions, short of mission critical parts (which nothing in audio circuits is) the number subs for applications is prolific and has been invaluable to me for finding components to accomplish repairs without losing my mind over "exact" part numbers (but try and tell an obsessed audiophile that!)
Whether or not any part could be substituted for one another in a particular application its a matter of finding either one and with the shear number and range of p/n's they needed to be in some sort of locatable order. If I remove a bad 3904, and that's the part that was spec'd from the factory, and I have that p/n in stock, there's no reason to go to a crossover for a substitute. It saves time by simply narrowing down the search to a particular set of drawers vs 15 boxes, 400 bins and 12 cabinets spread all over the place.
The crossover book is more useful to me for finding other brand's that may be the same part in the event that I don't have the very brand that was removed.
I also should have stated that in the same drawer with the 2N2222A's he had TIP130, and TIP32C, and 2N5086, in another cabinet, he had TIP31C's mixed in one big drawer with 2N2222, 2N5087, and 2N3906. Another drawer had more 2N3906's but that one was mixed with some 2N4838 and IRF130, IRL1501 and some odd TO-3 types as well, all jumbled together with some diodes and hardware mixed in too. Then there's the drawers that had sealed bags of completely unrelated parts buried beneath 3" of transistors. He had one drawer marked PNP and another marked NPN but both were a random mix of just about any p/n. I sort of figured that maybe at one time the labels on each drawer were accurate but as time went on it got all jumbled up and he never bothered to fix it. There was probably 30 lbs of misc. parts in the bottom of each cabinet too from where drawers spilled over. Having all the parts in bags prevents spilled items.
Nothing is set in stone either, if over time I see the need to move something, I can do so knowing that what I'm moving is all that there is to move, I won't have to worry about finding more somewhere else.
The crossover book is more useful to me for finding other brand's that may be the same part in the event that I don't have the very brand that was removed.
I also should have stated that in the same drawer with the 2N2222A's he had TIP130, and TIP32C, and 2N5086, in another cabinet, he had TIP31C's mixed in one big drawer with 2N2222, 2N5087, and 2N3906. Another drawer had more 2N3906's but that one was mixed with some 2N4838 and IRF130, IRL1501 and some odd TO-3 types as well, all jumbled together with some diodes and hardware mixed in too. Then there's the drawers that had sealed bags of completely unrelated parts buried beneath 3" of transistors. He had one drawer marked PNP and another marked NPN but both were a random mix of just about any p/n. I sort of figured that maybe at one time the labels on each drawer were accurate but as time went on it got all jumbled up and he never bothered to fix it. There was probably 30 lbs of misc. parts in the bottom of each cabinet too from where drawers spilled over. Having all the parts in bags prevents spilled items.
Nothing is set in stone either, if over time I see the need to move something, I can do so knowing that what I'm moving is all that there is to move, I won't have to worry about finding more somewhere else.
When I was moving recently, I spilled two of those plastic cabinets of SCEWS and NUTS on their sides. They ended up all mixed up, and are still not re-sorted. This might have been why all the transistors are mixed up - that might have not been “intentional”, or even careless. Other than dropping the cabinets of course.
They must have dropped every last one of them then. There wasn't a single drawer or bin that wasn't mixed up to some degree. I think it was more a matter of him either not seeing so well or him knowing it was screwed up and not caring. What was likely tough was needing something any one of the parts in those mixed up bins and having to sort through a thousand of them to find what you need. At least with nuts and bolts the various sizes look different enough to sort out fairly quickly on a few trays, but with the smaller transistors it meant using a comparator scope to quickly view the part numbers. What I was doing was grabbing say 200 at a time, and putting them quickly by hand into a slotted bar and passing them under the viewer, then I'd sort them on the screen in groups it let me do roughly a full bin in about 80 minutes. When different types were mixed up it was easier to separate them but in most cases the parts all looked identical other than the markings on them. Its had to tell a 3904 from 3909 among 10,000 others and five other similar p/n's.
In the way I sorted these out, the transistors and diodes are sorted via the first numeric digit and the number of digits. Regardless of the prefix letters or brand ID. That way regardless of the brand or letters, I know where any part will be simply by the numeric part number. It also best allows for any additions to the drawers down the road. I did separate them by form factor as well, all TO3's are in one set of drawers, all TO220's in another sand so on. It saved space and simplified locating things.
When it came to IC's he had zero organization, it looked like at best he used the first digit to group items together in bins, bags, boxes and jars. They were all over the place, mixed in along side of transistors diodes and resistors. sometimes loose and sometimes in bags that contained maybe one of 10 or 12 part numbers.
What really made a huge difference is the amount of space I saved doing it this way. What was taking up five rooms, my basement, garage and attic now fits in a walk in closet and on five shelves in the spare room with only the bulk barrels being out in the garage yet. I thought about using the area above the garage but that's not heated or air conditioned all the time and the garage apartment isn't built as robust as the house is weight wise. The cabinets of parts are heavy. Besides, if someone needs something and its snowing or pouring rain, I don't need to go out to the garage to find it in a cold or super hot building. All I need to do is walk down the hall into that room to grab what I'm looking for.
In the way I sorted these out, the transistors and diodes are sorted via the first numeric digit and the number of digits. Regardless of the prefix letters or brand ID. That way regardless of the brand or letters, I know where any part will be simply by the numeric part number. It also best allows for any additions to the drawers down the road. I did separate them by form factor as well, all TO3's are in one set of drawers, all TO220's in another sand so on. It saved space and simplified locating things.
When it came to IC's he had zero organization, it looked like at best he used the first digit to group items together in bins, bags, boxes and jars. They were all over the place, mixed in along side of transistors diodes and resistors. sometimes loose and sometimes in bags that contained maybe one of 10 or 12 part numbers.
What really made a huge difference is the amount of space I saved doing it this way. What was taking up five rooms, my basement, garage and attic now fits in a walk in closet and on five shelves in the spare room with only the bulk barrels being out in the garage yet. I thought about using the area above the garage but that's not heated or air conditioned all the time and the garage apartment isn't built as robust as the house is weight wise. The cabinets of parts are heavy. Besides, if someone needs something and its snowing or pouring rain, I don't need to go out to the garage to find it in a cold or super hot building. All I need to do is walk down the hall into that room to grab what I'm looking for.