[MRCA] Mystery Project

[Tim]

Thanks Ray, interesting stroll down #741 Memory Lane!   Remember the
Philbrick Manifold?
I built a 100/50/25 kc crystal calibrator as a school project that used
those RTL logic chips.  Still works!
I had a professor (Nello Sevastopoulos) who was a principal inventor of the
3 terminal regulator at National at the time.  Interesting guy!
Tim
N6CC

On Wed, Apr 26, 2023 at 5:42 AM Ray Fantini <RAFANTINI at salisbury.edu> wrote:

> According to Wiki, In 1963, the first monolithic IC op amp, the μA702
> designed by Bob Widlar at Fairchild Semiconductor, 1968: Release of the
> μA741. The popularity of monolithic op amps was further improved upon the
> release of the LM101 in 1967, which solved a variety of issues, and the
> subsequent release of the μA741 in 1968. The μA741 was extremely similar to
> the LM101 except that Fairchild's facilities allowed them to include a 30
> pF compensation capacitor inside the chip instead of requiring external
> compensation. This simple difference has made the 741 the canonical op amp
> and many modern amps base their pinout on the 741s. The μA741 is still in
> production, and has become ubiquitous in electronics—many manufacturers
> produce a version of this classic chip, recognizable by part numbers
> containing 741. The same part is manufactured by several companies.
>
>
>
> There are a handful of components like the 2N3904, 555 timer and 78XX
> series regulators that are everywhere, but unlike many of the ubiquitous
> components that have come and gone like the 78XX series linear regulators
> that have all gone today being replaced by modern switching regulators the
> 741 op amps are still widely used.
>
>
>
> Fairchild Semiconductor was a true leader in development and manufacture
> of analog integrated circuits, think there RTL logic chips were the basis
> of the Apollo guidance computer, already have one of those chips so now
> with the addition of a uA741 my Fairchild collection will be complete!
>
>
>
> Ray F/KA3EKH
>
>
>
>
>
>
>
> *From:* Mike Feher <n4fs at eozinc.com>
> *Sent:* Tuesday, April 25, 2023 10:34 PM
> *To:* Ray Fantini <RAFANTINI at salisbury.edu>; 'B. Smith' <
> smithab11 at comcast.net>; 'Military Radio Collectors Association' <
> mrca at mailman.qth.net>
> *Subject:* RE: [MRCA] Mystery Project
>
>
>
>
>
> I thought it was crazy Bob Widlar who designed all those early ICs. I
> actually had a couple of beers with him back in the day. 73 – Mike
>
>
>
> Mike B. Feher, N4FS
>
> 89 Arnold Blvd.
>
> Howell NJ 07731
>
> 848-245-9115
>
>
>
> *From:* mrca-bounces at mailman.qth.net <mrca-bounces at mailman.qth.net> *On
> Behalf Of *Ray Fantini
> *Sent:* Tuesday, April 25, 2023 9:07 AM
> *To:* B. Smith <smithab11 at comcast.net>; Military Radio Collectors
> Association <mrca at mailman.qth.net>
> *Subject:* Re: [MRCA] Mystery Project
>
>
>
> It’s a op-amp tester! Relies on almost all seven pin op amps like the 741
> having the same pin configuration.  Think it’s one of those cards that use
> a RC time constant to flash one or both LED in a feedback circuit to make
> it oscillate. Wonder what the bottom pins on the zif socket do?  Or if you
> stuff a dual op amp like a 358 or a quad like a 324?
>
>
>
> Sometimes think the LM741 may be the 6C4 of the linear world, they are
> good for everything. Not just amplifiers but also in filters, DC amplifiers
> and oscillators. Quick search on the internet shows that in 1968 Dave
> Fullagar of Fairchild developed the UA741, think it may still be the most
> popular op amp out there.
>
> Would like to find one of those old TO-99 8 pin round op amps just to sit
> around and look at it!
>
>
>
> Ray F/KA3EKH
>
>
>
>
>
>
>
>
> ______________________________________________________________
> MRCA mailing list
> Home: http://mailman.qth.net/mailman/listinfo/mrca
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:MRCA at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.qth.net/pipermail/mrca/attachments/20230426/28d907d4/attachment.html>