Hi Christian,

what do You think about:

2N3640 -> 2N3906
2N3693 -> 2N3904, 2N2222A, BC337-25

Best

Andreas

Please contact me offlist.

> Am 27.10.2025 um 16:38 schrieb Jon Elson via cctalk <[email protected]>:
> 
> On 10/27/25 05:26, Christian Corti via cctalk wrote:
>> It seems that nowadays you can't get *any* replacement for failing DEC 3639 
>> aka 2N3639 transistors. All parts are obsolete and unobtanium, e.g. 2N3640, 
>> PN3640, MMBT3640 and so on.
>> 
>> So, what can be used instead? The most important electrical parameter is the 
>> storage time. It needs to be *very* low, around 20-30 ns.
> 
> Oh, it apparently is Silicon.  So, an MPSH81 should really do well.
> 
> Jon
> 

Reply via email to