btcg
New Member
Spent the day unpacking and putting away several parts shipments I'd ordered of late.
One of the packages was a pack of 10 npn transistors I'd ordered from All Electronics (allelectronics.com), Catalog # MPSA06-HM
As AE will do, it lists the part number as being essentially the same: MPSA06
Having different drawers (I use those plastic wall units with 50 small plastic tray/compartments), I wanted to see whether I could toss them in with the generic npn's (like the 2n3904). So I popped open my trusty (even if it's 14 years old) NTE crossbook and crossed it.
To my surprise, the transistor crossed to an NTE 287: a 300v transistor.
Now, I'm immediately suspicious. The transistor in front of me is in a TO-92 case. Although there are many higher voltage transistors in that package, I thought I'd better take a look at one of the actual transistors, and verify.
Lo & behold, the number on transistors is different: 1103ca
Again, refering to my trusty cross book, I look up the 1103 (from experience I knew, it's actually 2n1103), and find that this transistor is actually equivilient to the NTE 123ap, a 75 v transistor (a famous one, at that)
75v vs 300v: a pretty big difference.
Now, in fairness, for the low voltage circuits I'll be using them in (24 volts & below), this error is no real issue.
But had a friend brought over an old tv with a video problem, using that transistor might have ended up in smoke.
The lesson here: beware of these surplus vendors, and always verify their cross-referencing.
One of the packages was a pack of 10 npn transistors I'd ordered from All Electronics (allelectronics.com), Catalog # MPSA06-HM
As AE will do, it lists the part number as being essentially the same: MPSA06
Having different drawers (I use those plastic wall units with 50 small plastic tray/compartments), I wanted to see whether I could toss them in with the generic npn's (like the 2n3904). So I popped open my trusty (even if it's 14 years old) NTE crossbook and crossed it.
To my surprise, the transistor crossed to an NTE 287: a 300v transistor.
Now, I'm immediately suspicious. The transistor in front of me is in a TO-92 case. Although there are many higher voltage transistors in that package, I thought I'd better take a look at one of the actual transistors, and verify.
Lo & behold, the number on transistors is different: 1103ca
Again, refering to my trusty cross book, I look up the 1103 (from experience I knew, it's actually 2n1103), and find that this transistor is actually equivilient to the NTE 123ap, a 75 v transistor (a famous one, at that)
75v vs 300v: a pretty big difference.
Now, in fairness, for the low voltage circuits I'll be using them in (24 volts & below), this error is no real issue.
But had a friend brought over an old tv with a video problem, using that transistor might have ended up in smoke.
The lesson here: beware of these surplus vendors, and always verify their cross-referencing.