UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Trying to revive a Goodmans One Ten receiver

Chris55000 · 13th Oct 2020, 11:30 pm

Hi!

Looking at the pinout at the bottom of the power–supply circuit, VT40 and VT41, are plastic transistors of the TO92b type, and you'll find the BC639 (npn, VT40) and BC640 (PNP, VT41) will be ideal to replace the E5358 (npn) and the E5359 (PNP), and will fit the board exactly the same orientation as the original devices.

Please be aware tho', that simple emitter–follower series stabilisers of this type are NOT short–circuit proof, so take great care not to accidentally short–circuit the ±14V lines whilst making tests!

If either transistor fails immediately after replacing it, there could be an i.c. or decoupling capacitor(s) downstream of VT40 or VT41 defective!

Chris Williams

13th Oct 2020, 11:30 pm	#29
Chris55000 Nonode Join Date: Aug 2007 Location: Walsall Wood, Aldridge, Walsall, UK. Posts: 2,868	Re: Trying to revive a Goodmans One Ten receiver Hi! Looking at the pinout at the bottom of the power–supply circuit, VT40 and VT41, are plastic transistors of the TO92b type, and you'll find the BC639 (npn, VT40) and BC640 (PNP, VT41) will be ideal to replace the E5358 (npn) and the E5359 (PNP), and will fit the board exactly the same orientation as the original devices. Please be aware tho', that simple emitter–follower series stabilisers of this type are NOT short–circuit proof, so take great care not to accidentally short–circuit the ±14V lines whilst making tests! If either transistor fails immediately after replacing it, there could be an i.c. or decoupling capacitor(s) downstream of VT40 or VT41 defective! Chris Williams __________________ It's an enigma, that's what it is! This thing's not fixed because it doesn't want to be fixed!