High Jens, I haven't found a trace of BF311 in my database, numbers start with BF316. Regarding the blue paint, all I can tell you is, that I have some old Tektronix oscilloscope boards, which are full of rare marked transistors, blue painted Motorola signed, but numbers you will never find anywhere. Seem common stuff. I guess those are selected and tested items, but who would know.
Cheers Friedel On 1 Jul 2004 at 12:13, Jens Schönfeld wrote: > 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 this type is obsolete.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 > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB CHIPDIR-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). Friedel Bruening Bolivian Instruments Casilla 4856 Santa Cruz Bolivia Mobile : ++591-773-92119 Tel/Fax : ++591-3-3580572 e-mail : [EMAIL PROTECTED] -- Author: Friedel Bruening INET: [EMAIL PROTECTED] Fat City Hosting, San Diego, California -- http://www.fatcity.com --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
