On Sat, 10 May 2008 16:01:35 -0700 PhattyMo <phattymo at (no spam) not.net> wrote in
Message id: <4826294b$0$89867$815e3792 at (no spam) news.qwest.net>:
Franc Zabkar wrote:
On Fri, 09 May 2008 11:00:30 -0400, JW <none at (no spam) dev.nul> put finger to
keyboard and composed:
On Fri, 09 May 2008 07:51:20 +1000 Franc Zabkar
fzabkar at (no spam) iinternode.on.net> wrote in Message id:
iur6249jf7tva5b2lunkgdjldmlvpcj4jh at (no spam) 4ax.com>:
On Wed, 07 May 2008 13:11:38 -0400, JW <none at (no spam) dev.null> put finger to
keyboard and composed:
Trying to repair a Keithley 616 with a bad ranging board. It needs two
parts. One is a dual channel J-FET and is marked ITS30092; the other is
an op-amp with the markings ITS6214. Does anyone know of a cross, or even
who the manufacturer is? (Must be before my time...)
Thanks for any help!
I'm guessing they are specially selected Intersil parts.
Have a look at the IT500-IT505 dual N-channel J-FETs:
http://www.datasheetarchive.com/pdf/1824055.pdf
Maybe someone has an Intersil catalogue or databook from around that
time (early 1980s ???).
Thanks Franc, Intersil makes sense. It's starting to look like I'll need a
donor unit.
I would think that you could refer to the schematics in the manual ...
http://www.keithley.com/support/data?asset=5258
... and find a modern op-amp and dual J-FET with much better specs.
See
http://www.intersil.com/products/pt/parametric_table_13437.asp
You may even be able to get a free sample:
http://www.intersil.com/samples/index.asp
Here are two dual N-channel J-FETs that may fit the bill:
http://www.linearsystems.com/datasheets/LS843-5.pdf
http://www.linearsystems.com/datasheets/LSK389.pdf
Here are more choices:
http://www.linearsystems.com/products.html#GlossD
You can request samples here:
http://www.linearsystems.com/contact_us.html
- Franc Zabkar
Thanks Franc, but I was never much good at figuring out what specs are
important when cross-referencing other than voltage and current.
Especially with something as sensitive is this piece.
I have a couple donor Keithley benchtop DMM boards.. I can dig them out
and take a look for those parts,if you like.
Thank you for your generous offer, PhattyMo, but I spent a few hours
digging through our "graveyard" and found the pieces I need in another
piece of equipment.