Re: Tek 453 - Q913 Part Number

Miroslav Pokorni

Do not blame Walter, that might be his or Tek's mistake. God knows manuals
have more than a fare share of typos and various other mistakes.

As for detective work, there is something to be desired in drawing
conclusion: 'if both transistors cross reference to the same NTE number,
then those transistors must be same' . Let us keep in mind what is purpose
of NTE numbers: to supply TV repair shops and as a side line a supplier for
home brew projects.

It is true that National Semiconductor makes both transistors on the same
process (#66) and gain seems to be similar for several currents shown in
listing. However, the package is different and transit frequency and turn
off times are quite different:

Package fT toff

2N3251 TO-18 300 250

2N4122 TO-92 450 150


Miroslav Pokorni

----- Original Message -----
From: "Rolynn PRECHTL K7DFW" <>
To: <>
Sent: Friday, November 14, 2003 9:58 PM
Subject: Re: [TekScopes] Re: Tek 453 - Q913 Part Number

Checking the NTE cross reference, both the 2N3251 and the 2N4122 are
PNP, and are crossed to NTE 159.
Darn, it appears I was hornswaggled by the internet again.

Got the info from here......
where it's claimed to be a NPN......

"Transistor type 2N4122 has been assigned the following Tektronix part
Tek Part Number Remarks
151-0493-00 NPN, SI"

I should know better and consult my Tek semiconductor catalog instead of
trusting the www.



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