[sdiy] transistor substitution?

[Mountain Man]

I'm wondering if the "sometimes" means "occasionally" or "under some
conditions"?  If it's door #2, a bit about how to choose would be helpful.
Oh, and thanks for sharing this, Tom, I know it's going to keep me sane :)

Elby


"tomg at efm" wrote:

> It's not a big list, so far everything I've tried works
> with these substitutions and from this list most special
> function devices can be built.
>
> small npn - 2N3904
> small pnp - 2N3906
> med npn - TIP29
> med pnp - TIP30
> large npn - 2N3055
> large pnp - 2N2955
> npn-pair - 2SC1583
> pnp-pair - 2SA978
> n-fet - 2N3819
> p-fet - 2N5461
> high speed n-fet switch - J112 (2N4392)
> signal diode - 1N4148 (1N914)
> single opamps - TL071 ( sometimes a LM741)
> duals - TLO72 ( sometimes a LM1458)
> quads - TL074  ( sometimes a LM324 )
>
> The 123 is a small gp npn - 3904
>
> Tom
>
> > This is such a recurring question...  And although
> > I have no answer for this directly, I think it
> > begs a better solution than for people to keep
> > having to dig around for the answers.
> >
> > I have several megs of free webspace.  I would be
> > happy to put up a simple page which lists parts
> > and subs.  If any of you have the time, please
> > send me (privately) parts substitution info and
> > I'll put it up.  This will be a SIMPLE type
> > of page with a line item for each part with
> > it's cross reference to suitable subs.  The
> > site I will use has no banner ads or popup
> > windows.
> >
> > I also think that we REALLY need an FAQ, but that's
> > another issue.
> >
> > If there is no interest in doing this, I'll know by
> > the lack of emails about it.
> >
> > "Thom Somneevich" <thom_s4 at hotmail.com> wrote:
> > >Hello all,
> > >I'm gathering the parts for the EMS filter; does anyone know of a
> substitute
> > >for the bc109c transistor other than the nte123a (which is what Mouser
> calls
> > >up when I search for the former)? The nte123 is $1.50 a pop, which I'll
> pony
> > >up if I have to, but... you understand.
> > >Thanks,
> > >thom
> > >_________________________________________________________________
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> > >
> > >
> >
> > -- Scott Gravenhorst | LegoManiac / Lego Trains / RIS 1.5
> > -- Linux Rex         | RedWebMail by RedStarWare
> > -- FatMan: www.teklab.com/~chordman
> > -- NonFatMan: members.xoom.com/_XMCM/chordman/index.html
> >
> >