> These are venerable transistors in a TO5 can. The board is a Siemens > part, which they have made 'obsolete' without replacing it. This is > hardly surprising, as the devices are batch dated '6940' > > The board is basically a set of interconnected discrete bipolar logic > gates, with some intermittent fault. I can find huge gain mismatches, > and I want to replace the low gain devices.
I have to ask why you want to do that. Classically, those circuits were designed so that the low gain devices work just fine. Excessive gain can cause it's own problems. ?? Also, it appears that the SST11x series of JFETs is a clone of the J11x series from a different time than the SST117. I think it's unlikely that a logic board would have been made from JFETs in 1969. -=-=-=-=-=- "http://www.dibsplace.com/design/"; -=-=-=-=-=- DIBs Electronic Design | Dave Baldwin Adapt and overcome. | Buy a book and read it. -=-=--=-=--=-=--=-=--=-=-=-=--=-=--=-=--=-=--=-=--=-=-=-=- -- Author: Dave Baldwin 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).
