[cctalk] Re: Replacements for DEC 3639

The European equivalent for the 2N3639 / 2N3640 is BSX36 And for the 2N3693 is BF365, BF241 and also 2N3664 This according the 'DÖV vergleichstabelle' maybe that's of any help. I didn't check the availability of the parts, but a quick ebay check If it's of any help I do have about 10pcs 2N3639 (NOS) in stock. -Rik -----Oorspronkelijk bericht----- Van: Christian Corti via cctalk <cctalk(a)classiccmp.org> Verzonden: donderdag 30 oktober 2025 09:31 Aan: hupfadekroua via cctalk <cctalk(a)classiccmp.org> CC: Christian Corti <cc(a)informatik.uni-stuttgart.de> Onderwerp: [cctalk] Re: Replacements for DEC 3639 On Wed, 29 Oct 2025, hupfadekroua wrote: I've tested exactly those types. They are all too slow. For example, when you cascade the three independent stages on an R211 module, feed the first stage with a clock of around 1 MHz, and just replace one of the 2N3639 with a 2N3906, the turn-off slope after the last stage will be delayed from around 30ns to 200ns! But we will test the trick with the Baker clamp on the 2N3906. Christian