A short rant about part numbering...

[iomegaman]

So I was rebuilding my Nikko Alpha-1 amplifier...and tracked down to a bad power transistor an NEC 2SB600...

The Japanese who built this unit in the 70's were very meticulous and of course there are a LOT of obsolete parts...
When they show the power amp boards in the schematic they kind of cheat the actual build by putting all the positive transistors on the left channel and all the negative transistors on the right channel...due to my own lack of "take a damn picture before you take it apart" I has to take apart the entire left channel (wherein is the failure) and what they ACTUALLY did was sandwich the transistors both negative and positive on each side, so that there are 3 power transistors per side, both +/-...on each side with wiring harnesses connecting the sides...(you have to pay attention because on the schematic it shows both types of transistors PER side, but only LABELS them as one type...obvious typo...ie: the left side ONLY labels the transistors as SB600's when in truth both SB600 and SD555's exist per side.

So now obviously have to track down in the actual schematic how they are wired because I removed all of them on one side to test and left the wiring harness hanging...with no pictures of how to put it back.

Here's my rant...

Why in the hell is there not a standard numbering naming nomenclature for parts?

In my limited approach it would seem wise to make NEGATIVE power transistors numbered with ODD numbers and positive transistors numbered with EVEN numbers...just makes sense right?

And I'm sure the industry has moved a bit towards this in the last 50 years, but still...

On the schematic the negative power transistors are numbered Q4/6/8/10/12/14

The positive power transistors are Q3/5/7/9/11/13

Just freaking dumb...kinda like me not taking a picture of the harness before I disassembled it.

 

[pucho812]

What one person thinks is right others will think is wrong.
while we all can agree on some practices as being ok. The detail change from company to company.
Case in point, I have to chase down 2-3 part numbers due to revisions and other decisions vs my previous employer which has had the same design and part number for 20 years without issue

 

[JohnRoberts]

This is a matter of perspective. Manufacturers have good reasons for numbering components the way they do.

If you were the only customer they would work to accommodate you. I suspect they have more other customers with different priorities.

JR

 

[cyrano]

In my limited approach it would seem wise to make NEGATIVE power transistors numbered with ODD numbers and positive transistors numbered with EVEN numbers...just makes sense right?

Isn't that wat Philips did? Like in the BD135/136?

 

[scott2000]

when in truth both SB600 and SD555's exist per side.

I'm half up getting ready for our garage sale tomorrow but doesn't the legend say this?

 

[iomegaman]

I'm half up getting ready for our garage sale tomorrow but doesn't the legend say this?

Actually damn it. I was going by the parts list in the back pages...never noticed the legend.
Crap. And I know better because legends are important in all blueprints and in government work take precedent over other readings (in my experience).
I hate being wrong but appreciate being corrected thanks!

 

[john12ax7]

I find it annoying that there is no standard for pot tapers. A is audio and B is linear right? Well no, not always.