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466 TEK Scope problem FOUND! -Question on replacement IC

C

Chris

Jan 1, 1970
0
Hey guys. I have finally found the bad part in my TEK 466 Scope. It is
the Op amp 156-0158-00 Mini-DIP, Motorola, Op Amp, MC1458P1 it says
RCA 827 at the bottom.

Any idea if I can swap this out with one from Radio Shack? Or does it
have to be a Tektronix one of identical make?

If I can swap it, can someone tell me what 8 pin Op Amp model I can
use instead of this one? And will it affect calibration or should it
be ok? -It's the op amp off of the +15v power supply schematic on my
466 scope.

Thank You,
-Chris
 
J

James Sweet

Jan 1, 1970
0
Chris said:
Hey guys. I have finally found the bad part in my TEK 466 Scope. It is
the Op amp 156-0158-00 Mini-DIP, Motorola, Op Amp, MC1458P1 it says
RCA 827 at the bottom.

Any idea if I can swap this out with one from Radio Shack? Or does it
have to be a Tektronix one of identical make?

If I can swap it, can someone tell me what 8 pin Op Amp model I can
use instead of this one? And will it affect calibration or should it
be ok? -It's the op amp off of the +15v power supply schematic on my
466 scope.

Thank You,
-Chris

The 1458 op-amp is a really common part, why not just get the right one?
Here's one of many places selling it
http://www.kelvin.com/Merchant2/merchant.mv?Screen=PROD&Product_Code=600026&Category_Code=ELPCICMI in this case it's a whopping 36 cents.
 
J

Jim Yanik

Jan 1, 1970
0
chris1@oupower_dot_com (Chris) wrote in
Hey guys. I have finally found the bad part in my TEK 466 Scope. It is
the Op amp 156-0158-00 Mini-DIP, Motorola, Op Amp, MC1458P1 it says
RCA 827 at the bottom.

Any idea if I can swap this out with one from Radio Shack? Or does it
have to be a Tektronix one of identical make?

If I can swap it, can someone tell me what 8 pin Op Amp model I can
use instead of this one? And will it affect calibration or should it
be ok? -It's the op amp off of the +15v power supply schematic on my
466 scope.

Thank You,
-Chris

I would not substitute other IC types,you can use a generic 1458,dunno if
RS has them.As another has posted,the 1458 is still available,and
inexpensive.
 
C

Chris

Jan 1, 1970
0
Thanks guys, I ordered the MC1458P from Mouser. I should be all set in
a few days when it arrives. I did notice something cool however.

I'm half tempted to try this because I'm anxious to see it work again
and know that I got everything. I'd hate to still have more bad parts
that I have not yet found.

The Op Amp is a DUAL chip. In the schematic it's clearly using the 2nd
amp and the first side seems to be just sitting there. I bet I could
re-wire my current chip to work if I just utilize pins 1, 2, 3 instead
of the 5,6,7 that it is using now.

I'm very tempted to try this. I will still need to use pins 4 and 8
for the Vcc + / - , but as long as those 2 pins are ok, my idea seems
sound that I could just use the other side of the chip *lol*

Your comments are most appreciated :)

-Chris
 
J

Jim Yanik

Jan 1, 1970
0
chris1@oupower_dot_com (Chris) wrote in
Thanks guys, I ordered the MC1458P from Mouser. I should be all set in
a few days when it arrives. I did notice something cool however.

I'm half tempted to try this because I'm anxious to see it work again
and know that I got everything. I'd hate to still have more bad parts
that I have not yet found.

The Op Amp is a DUAL chip. In the schematic it's clearly using the 2nd
amp and the first side seems to be just sitting there. I bet I could
re-wire my current chip to work if I just utilize pins 1, 2, 3 instead
of the 5,6,7 that it is using now.

I'm very tempted to try this. I will still need to use pins 4 and 8
for the Vcc + / - , but as long as those 2 pins are ok, my idea seems
sound that I could just use the other side of the chip *lol*

Your comments are most appreciated :)

-Chris
I would not substitute other IC types,you can use a generic 1458,dunno
if RS has them.As another has posted,the 1458 is still available,and
inexpensive.

Why bother? Go to Radio Shack,see if they have one,or an ECG equivalent
from a local distributor.
 
C

Chris

Jan 1, 1970
0
Radio Shack doesn't have anything but some stupid shit :) lol. I will
just wait until it comes in the mail I guess :) I did discover last
night that it uses both sides of each Op Amp so I can't do what I was
talking about. I thought it odd that it would only use 1/2 so mystery
solved. I need a 4158 or equivelent. I called all the TV Repair shops
nearby but turned up nothing :( Guess online is my only recourse.
That's kind of a shame.

-Chris

chris1@oupower_dot_com (Chris) wrote in
 
J

Jim Yanik

Jan 1, 1970
0
chris1@oupower_dot_com (Chris) wrote in
Radio Shack doesn't have anything but some stupid shit :) lol. I will
just wait until it comes in the mail I guess :) I did discover last
night that it uses both sides of each Op Amp so I can't do what I was
talking about. I thought it odd that it would only use 1/2 so mystery
solved. I need a 4158 or equivelent. I called all the TV Repair shops
nearby but turned up nothing :( Guess online is my only recourse.
That's kind of a shame.

-Chris

chris1@oupower_dot_com (Chris) wrote in



Why bother? Go to Radio Shack,see if they have one,or an ECG equivalent
from a local distributor.

Don't call TV repair shops,call the local *electronics parts distributor*.
Chances are they sell ECG parts,and there's an ECG version of the 1458.

A TV repair shop isn't going to want to sell you parts.
 
S

Sam Goldwasser

Jan 1, 1970
0
Isn't the MC1458 just a general purpose vanilla flavored op-amp? Why all
the fuss? Almost anything with the industry standard pinout would likely
work, at least as a test. :)

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
J

Jim Yanik

Jan 1, 1970
0
Isn't the MC1458 just a general purpose vanilla flavored op-amp? Why
all the fuss? Almost anything with the industry standard pinout would
likely work, at least as a test. :)

It's a dual op-amp.
 
S

Sam Goldwasser

Jan 1, 1970
0
It's a dual op-amp.

Sorry, yes I know, my slip. The point is that everyone is going obsessive
about getting the exact replacement.

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
J

James Sweet

Jan 1, 1970
0
Sam Goldwasser said:
Sorry, yes I know, my slip. The point is that everyone is going obsessive
about getting the exact replacement.

But... didn't he say he already ordered an exact replacement? It's cheap
enough, why is this thread even still going?
 
S

Sam Goldwasser

Jan 1, 1970
0
But... didn't he say he already ordered an exact replacement? It's cheap
enough, why is this thread even still going?

Beats me. :) But ordering a 50 cent part from Mouser still has a several
dollar shipping and handling charge!

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
A

Asimov

Jan 1, 1970
0
"Jim Yanik" bravely wrote to "All" (16 Nov 03 01:05:08)
--- on the heady topic of "Re: 466 TEK Scope problem FOUND! -Question on replacement IC"

JY> From: Jim Yanik <[email protected]>
JY> A TV repair shop isn't going to want to sell you parts.

I noticed that repair shops in general are not the most sympathetic to
hobbyists. A pox on them! ;-)

.... Techs would rather pee on an electric fence for the light show
 
T

TekMan

Jan 1, 1970
0
Jim Yanik said:
chris1@oupower_dot_com (Chris) wrote in


I would not substitute other IC types,you can use a generic 1458,dunno if
RS has them.As another has posted,the 1458 is still available,and
inexpensive.

The TL072 / TL082 worked well in my repairs.

Also substitutes from PMI did.

But avoid all dual opamp types with BW-gain produkt of more than 3MHz.
Then oscialltion might occur in some cases.

When you look at the circuit, yo usee that the regulation is well
designed, there is no voltage stress on the opamps (everything stays
very well below the maximum supply voltage limits).


HTH,

Andreas
 
S

Sam Goldwasser

Jan 1, 1970
0
If the original op-amp was anything with a "X58", almost anything with
the same pinout will be at least as good! :)

--- sam | Sci.Electronics.Repair FAQ Home Page: http://www.repairfaq.org/
Repair | Main Table of Contents: http://www.repairfaq.org/REPAIR/
+Lasers | Sam's Laser FAQ: http://www.repairfaq.org/sam/lasersam.htm
| Mirror Site Info: http://www.repairfaq.org/REPAIR/F_mirror.html

Important: The email address in this message header may no longer work. To
contact me, please use the Feedback Form at repairfaq.org. Thanks.
 
T

TekMan

Jan 1, 1970
0
Sam Goldwasser said:
If the original op-amp was anything with a "X58", almost anything with
the same pinout will be at least as good! :)

Well sam, but modern types of opamps have similar pinout, but
sometimes MUCH higher BW.
That's the point I wanted to make shure it's noted.
Because it's no fun to run into an oscillating pwr supply problem.


hth,
Andreas
 
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