I Always use sockets now Re: [sdiy] IC socket question

[groovyshaman at snet.net]

Hello Cynthia!

Well, mil-grade machined turned-pin gold contact sockets are rippin'
expensive!  Try 3 bucks for an 8-pin and 5 bucks for a 16-pin (at Mouser).
That's brutal for a 40 cent TL072, but I can see your point about older
chips and the death-of-DIP.  Do you use these in all of your new modules?

AMP Diplomate 30u gold dual-leaf sockets are like 35 and 75 cents
respectively.  However, Harry pointed out to me that newer AMP Diplomates do
not seem to have the same insertion force as the NOS ones in his possession.
Hmmm, what effect will this have on reliability?

Another point on reliability - when you solder a leaf-type socket, solder
can wick into the leaf area, and that means rosin can screw up the contacts.
(And if it's water-sol, it could cause corrosion.)  Sealed turned-pin types
shouldn't have this problem.

I don't use sockets when building high quality all-in-one kits (unless
they're recommended).  But, I *do* use sockets for DIY stuff so I can
experiment (read: screw up and recover).

George

----- Original Message -----
From: Cynthia Webster <cynthia.webster at gte.net>
To: patchell <patchell at silcom.com>; <harrybissell at prodigy.net>
Cc: <groovyshaman at snet.net>; <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, December 12, 2002 7:54 PM
Subject: I Always use sockets now Re: [sdiy] IC socket question


> This is interesting to me because I'd been taught to insist on machined
pin
> sockets over all others.  They call them "High Reliability" yet many folks
> here say otherwise!  (I know that they can be pure hell sometimes
> -just getting the chips into them without bending pins!)
>
> Personally I always use military grade machined pin sockets on every chip
> everywhere now, (Gold if possible) because at the rate things are going
with
> surface mount components and miniaturization... even lowly 741 DIP Opamps
> may sell for well over ten-dollars each sooner than you think!
>
> For example I have some CA3094s that have turned out to be quite valuable
> and because I'd been using sockets, I was able to easily salvage them as
> practically good as new.
>
> I'd be curious though to hear if anyone thinks the use of sockets like
this
> actually ~causes~ more reliability problems than they fix?
>
> I usually wait until a PCB board is totally wired to the pots and the
> switches and everything else ~before~ stuffing the chips into the sockets
> for the first time.
>
> Does anyone think this is being too paranoid?
>
> Cynthia
>
> > I will second Harry on this one...The Amp Diplomate is the most trouble
free
> > socket I have
> > used.
> >
> > One place I worked used lots of the machined pin sockets, for
"reliability".
> > We had enough
> > trouble with them that they caused major headaches...but they wouldn't
stop
> > using them...go
> > figure.
> >
> > harrybissell at prodigy.net wrote:
> >
> >> I would not use tin machined sockets at all.
> >>
> >> These have very low contact force and probably should be
> >> gold plated to be reliable....
> >>
> >> OTOH I do use AMP Diplomate sockets in tin... they have a dual
> >> leaf - side wipe that has very high contact force... enough to
> >> establish a gas-tight connection like Wire-Wrap. Never had a
> >> socket failure
> >>
> >> (and I say this with some misgivings, because AMP just fvcked me over
> >> by changing the design of a HD-15 connector, without warning or
changing the
> >> part number....)
> >>
> >> The Diplomate is a 'good' AMP product...
> >>
> >> H^) harry
> >>
> >> --------Original Message--------
> >>
> >> From: groovyshaman at snet.net
> >> To: "synth-diy list" <synth-diy at dropmix.xs4all.nl>
> >> Sent: Dec 12 2002 13:19
> >> Subject: [sdiy] IC socket question
> >>
> >>> Just wondering, do you think there could be any issues down the road
when
> >>> using turned-pin type IC sockets that have tin sleeves and gold
contacts due
> >>> to dissimilar metals?  Or should one stick to all-tin or all-gold?
> >>> George
> >>
> >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> >> Powered by Wild On Web:
> >> Free POP Mail Access - Access your E-mail from Anywhere in the World!
> >> http://www.wildonweb.com
> >> |Awards|Money|Bank|Credit|Dating|Games|Jokes|Vitamins|Magazines|Diet|
> >> |Bookstore|News|Babies|Cards|Homepages|Hobbies|...
> >
> > --
> > -Jim
> > ------------------------------------------------
> > * Visit:http://www.silcom.com/~patchell/
> > *-----------------------------------------------
> > *I'm sure glad Merry Christmas comes just once a year
> > * -Yogi Yorgensen
> > ------------------------------------------------
> >
> >
>
>