[sdiy] Pin Outs

[nicolas]

With the fet it sounds like the docs you have found identify the source pin, but are ambiguous about the gate/drain.  But a simple test circuit can most easily identify the gate - its the drain/source ambiguity thats hard to sort out in a test circuit.  So between the two sources of info you should be right ;-)

Cheers,
Nicolas

--- On Wed, 24/2/10, Oren Leavitt <obl64 at ix.netcom.com> wrote:

> From: Oren Leavitt <obl64 at ix.netcom.com>
> Subject: Re: [sdiy] Pin Outs
> To: "David Ingebretsen" <dingebre at 3dphysics.net>
> Cc: "'SDIY List'" <synth-diy at dropmix.xs4all.nl>
> Received: Wednesday, 24 February, 2010, 10:02 AM
> 
> 
> David Ingebretsen wrote:
> > I am not finding a data sheet (well, at least one with
> any extensive info)
> > or pin-outs for a couple of obsolete parts.
> > 
> > 2N5163 n channel jfet
> > 2n4891 UJT
> > 
> > The basic question is, is there a "hand test" I can do
> to determine the
> > pin-out for sure?
> > 
> > I have a simple circuit I could breadboard for the
> UJT, but nothing really
> > for the JFET.
> > 
> > I have some "replacement" parts which have appropriate
> pin outs printed on
> > the envelope they came in, but I also have some of the
> original vintage
> > parts which I would rather use.
> > 
> > The component packages between the original parts and
> the replacements are
> > different subtly.
> > 
> > To complicate matters, I have two vintage version of
> the 2n5163, in similar
> > but different packages, one is a TO-106 I think with a
> flat side by one pin,
> > one does not have a flat on it at all.
> > 
> > JFET:
> >               
>            
> .   apex
> > Pins are in a
> triangle   .   .   base
> of triangle
> > 
> > Package 1: TO-106(?) round with round top flat is
> offset adjacent to one of
> > the pins (vintage)
> > 
> >               
>          .
> >               
>   Flat .   .
> > 
> > Package 2: TO-106(?) round with round top, flat
> opposite middle pin,
> > parallel to base of the triangle (new replacement)
> > 
> > 
> >               
>          .
> >               
>        .   .
> >               
>         Flat
> > 
> > Package 3: TO-106(?) round with round top, no flat
> (vintage)
> > 
> > UJT
> > 
> > Pins are in a triangle, metal housing with a tab
> > Package 1: TO-18(?) tab between triangle apex pin and
> a triangle base pin
> > (new replacement)
> > 
> >               
>      .
> >           
>    tab .   .
> > 
> > Package 2: TO-18(?) tab at an angle, but is between
> the two triangle base
> > pins.
> > 
> >               
>      .
> >               
>    .   .
> >               
>    tab
> > 
> > I found some old schematics which suggest two
> different pin-outs for the
> > JFET, Source, Gate, Drain, and Source, Drain, Gate,
> both suggesting a TO-106
> > round top package was used, but I'm not sure.
> > 
> > I have struck out completely on the UJT. Believe me, I
> have searched every
> > internet datasheet archive I could find.
> > 
> > I have a simple schematic for the UJT which I guess I
> can breadboard and try
> > the replacement I know the pin-out for and then try an
> old part to see. But,
> > I'm a bit at a loss for the JFET.
> > 
> > Thanks
> > David
> > 
> > _______________________________________________
> > Synth-diy mailing list
> > Synth-diy at dropmix.xs4all.nl
> > http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
> > 
> 
> David,
> 
> I do have data for the 2N4891 UJT in a 1973 copy of the TI
> Transistor and Diode data book.
> This shows a plastic package with this pin out (bottom
> view):
> >               
>       Emitter
> >               
>          .
> >               
>   Base2.   .Base1
> >               
>         Flat
> 
> You should be able to test it with a simple relaxation
> oscillator.
> I can send you a scan of the data pages if you wish. There
> are test/measurement circuits provided.
> The tab on your TO-18 version is likely between the emitter
> (middle) and base2 (side).
> 
> - Oren
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