Datasheet at a paid service:
http://www.s-direktnet.de/homepages/sangmeister/daten/halbl/tbf.htm
It is a normal NPN part. Why not replave it with one you can buy
at Donberg? Just try if it works.
And I also found this info:
Technical specifications for the BF311 Function : TV APPLICATION IF
STAGES (TRANSISTOR) Polarity : NPN Material : SILICON Collector-to-
base voltage, dc, emitter open [VCBO Max] : 35 V Collector-to-emitter voltage,
dc, with base open [VCEO Max] : 25 V Emitter-to-base voltage, dc, collector
open [VEBO Max] : 4 V Current, dc (collector-terminal) [IC Max] : 40 mA
Total power dissipation [Ptot Max] : 360 mW Static forward current transfer
ratio (common-emitter) [hFE Min] : 40 Static forward current transfer ratio
(common-emitter) [hFE Typ] : 80 PinOut : 1= B , 2=E , 3=C
Looks like a very replacable device to me.
Regards,
Pieter Hoeben
Date sent: Thu, 01 Jul 2004 12:13:20 -0800
From: Jens Schönfeld
<[EMAIL PROTECTED]>
Subject: Transistor problem
To: Multiple
recipients of list CHIPDIR-L <[EMAIL PROTECTED]>
Send reply to: [EMAIL PROTECTED]
Organization: Fat City Network Services, San Diego, California
> Hi list,
>
> I know this is not a chip-related question, but it's semiconductors, so
> it's at least half on-topic.
>
> I'm repairing my Hameg HM604 oscilloscope, it's not switching off the beam
> on backtrace and during wait-for-trigger. I checked transistors in the
> intensity control area (I have no schematics), and found one transistor
> with funny behaviour - I can measure three diodes, so I'm pretty sure this
> one is in silicon Nirwana.
>
> The question I have is about the pinuot of this type, and how they marked
> the parts back then:
>
> http://think42.com/bf311.jpg
>
> Both these transistors come out of the oscilloscope. The right one behaves
> correctly, assuming that the base is the right pin (I can measure two
> diodes to that pin, and the other two have no connection in either
> direction, which is correct for TO92Z package). The left one has diodes
> between all pins (not shorts!), so I assume it's dead. The question is: Why
> has the TFK one (left on the picture) blue paint on top? Why did Hameg use
> different manufacturers for same-type transistors? There is no other
> transistor with blue marking on top, and it did not look like this one has
> been exchanged before (except someone did a *very* clean repair job). Is it
> some marking to distinguish between TO92 (CBE pinout) and TO92Z (ECB pinout)??
>
> I did not find any reliable data using Google, only some places that say
> this type is obsolete. Any help in finding the right replacement is
> appreciated.
>
> ciao,
> --
> Jens Schönfeld
>
> --
> Author: Jens =?iso-8859-1?Q?Sch=F6nfeld?=
> INET: [EMAIL PROTECTED]
>
> Fat City Hosting, San Diego, California -- http://www.fatcity.com
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