On 02/16/2017 03:59 PM, Jon Elson wrote:
wrote:



I have found that but-for a very few specialized transistors, most of the
general purpose types are now lumped into a much smaller universe of
replacement types. I have never had any problems, ultimately, with finding
replacements - and I keep a variety of testers and checkers to make sure
they will do - but they are not necessarily to OEM spec. Usually much
better.
This particular one was an NPN with an ft of 1400 MHz and 1.2 pF Cob. So,
definitely, a 2N2222 would not cut it.

Jon


You want an MPS5179 or something like that. Rochester and folks like
that still have them. (I bought a thousand or so a couple of years ago.)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510

hobbs at electrooptical dot net
http://electrooptical.net