Whatever happened to the LM3820 AM radio chip?

J

Joerg

Guest
Just curious: When checking my parts inventory I saw that I still have a
few LM3820 radio chips and was looking for the data sheet on the web.
Zilch. National does not even recognize the part and Alldatasheet
doesn't find it either.

What happened to it? Was this chip just a sparkler that whizzed away
into the night?

Regards, Joerg

http://www.analogconsultants.com
 
"Joerg" <notthisjoergsch@removethispacbell.net> wrote in message
news:SbBkd.20028$6q2.19523@newssvr14.news.prodigy.com...
Just curious: When checking my parts inventory I saw that I still have a
few LM3820 radio chips and was looking for the data sheet on the web.
Zilch. National does not even recognize the part and Alldatasheet doesn't
find it either.

What happened to it? Was this chip just a sparkler that whizzed away into
the night?
Click to expand...
They made several interesting radio chips that sank without trace, like the
LM373 IF amp/detector.

Leon
 
Just curious: When checking my parts inventory I saw that I still have a
few LM3820 radio chips and was looking for the data sheet on the web.
Zilch. National does not even recognize the part and Alldatasheet
doesn't find it either.
Click to expand...
Datasheet can be found online at: http://www.bgmicro.com/pdf/lm3820.pdf

greetings,
Tom
 
I have most of the Old Data Books from Various IC Manufacturers and I
do Have the documentation for this LM3820.

So if you need it, Just Email me.
But you MUST put the word "Electronic" in the "Subject" Line or it
automatically get filtered as JUNK MAIL.

Take care........Gary
***********************************************************************
Joerg <notthisjoergsch@removethispacbell.net> wrote in message news:<SbBkd.20028$6q2.19523@newssvr14.news.prodigy.com>...
Just curious: When checking my parts inventory I saw that I still have a
few LM3820 radio chips and was looking for the data sheet on the web.
Zilch. National does not even recognize the part and Alldatasheet
doesn't find it either.

What happened to it? Was this chip just a sparkler that whizzed away
into the night?

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
 
Hi Gary,

Thanks to all of you. I do have the data sheet but was just wondering
why such chips vanish so fast. At least they could leave legacy data
available.

Regards, Joerg

http://www.analogconsultants.com
 
Joerg <notthisjoergsch@removethispacbell.net> wrote in message news:<SbBkd.20028$6q2.19523@newssvr14.news.prodigy.com>...
Just curious: When checking my parts inventory I saw that I still have a
few LM3820 radio chips and was looking for the data sheet on the web.
Zilch. National does not even recognize the part and Alldatasheet
doesn't find it either.

What happened to it? Was this chip just a sparkler that whizzed away
into the night?
Click to expand...
The LM3820 was great for analog-tuned AM receivers, but since those
days a few gotchas:

1. Everything is digitally tuned today
2. Everything is FM with AM only added on as an afterthought

Basically, nobody's interested in buying good AM receivers any more,
they're only interested in digital readouts and FM. (That's not
stricly true, auto radios still have passable AM sections, but they
aren't as good as they used to be.)

There are exceptions (GE SuperRadio, etc.)

Automotive OEM AM receivers from the 70's and 80's are wonderful machines.
Especially the slug-tuned ones. They work in the cold and the hot, they
have tuned antenna input stages, etc.

At some point in working with a young web developer in the 90's I realized
that kids today don't know what "radio buttons" actually refers to.

The NE602/NE612 is not exactly a drop-in equivalent to the LM3820 but
it's respectable in its own ways (a pretty good mixer in particular).
It doesn't have an IF stage so most of the schematics you find using
it as a direct conversion receiver, but there's nothing stopping you
from using it differently.

Tim.
 
In article <kTOkd.40754$QJ3.17872@newssvr21.news.prodigy.com>,
Joerg <notthisjoergsch@removethispacbell.net> wrote:
Hi Gary,

Thanks to all of you. I do have the data sheet but was just wondering
why such chips vanish so fast. At least they could leave legacy data
available.

Regards, Joerg

http://www.analogconsultants.com
Click to expand...
Isn't that a second source of a Cherry or Sprague part? (I've got
a Sprague databook that lists a ULN-3820, but says contact the
mfgr. for data).

One of the big guys in car radios probably wouldn't use it unless
there was a second source, and when they quit using it ...

Mark Zenier mzenier@eskimo.com Washington State resident
 
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