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AM501 Stuff (op-amp references)


Kuba Ober
 

On Monday 05 February 2007 23:41, you wrote:
Beside collecting TM500 plugins, anyone actually usem, in particulars,
the AM501. Just got two of em.

I'd like to use a FG504 & FG501A plus other signal generators to
create all different types of waveforms. Integrating,
differentiating, ...

Any suggestions? Any neat experiements?

Specificatioins of the AM501? Comparisons with modern OP-Amps?
Anything that has got banana jacks on it *may* perform poorly for anything
above a few kilohertz due to parasitics, unless you put the feedback path next
to the chip. It does have a place to solder components inside, BTW. The
op-amp inside of AM501 can be replaced by a more modern chip, if you wish so.

The plugin itself was designed for teaching op-amps, and has little utility
beyond that methinks.

For source of great op-amp circuits, download this *excellent* book:

Applications Manual for Computing Amplifiers for Modeling, Measuring,
Manipulating & Much Else.


Then you'll want to get Troubleshooting Analog Circuits by Bob Pease, which
has an excellent section on real life op-amp behavior.

All in all, a good source of experimentation data is
, which has tons of analog computation
applications etc.

Cheers, Kuba


jones_chap
 

Thanks. You beat me to the second question! I did wanna know if I
could "upgrade" knowing that better op-amps exist.

I've downloaded the book and will check it out later and added the
site to my Audio & Electronics Bookmarks.

Interesting note about "anything with banana plugs" is that when
playing around with the AM501 plugins was a sensitivity of the output
based upon the proximity of my hand near the jacks. Wild and crazy
things would happen as I got anywhere near 'em, sorta. One was much
more sensitive than the other.

Do ya have any recommendations for a replacement. I'd even be willing
to spend more than the few cents that some of these cost--maybe even
like $5--15 per chip!

: )

Thanks again.


J Forster
 

From: "jones_chap" <jones_chap@...>

[snip]

Interesting note about "anything with banana plugs" is that when
playing around with the AM501 plugins was a sensitivity of the output
based upon the proximity of my hand near the jacks. Wild and crazy
things would happen as I got anywhere near 'em, sorta. One was much
more sensitive than the other.

The noise, etc. is capacitively coupled to your circuitry. Reduce the
values of the components in the FB loop and it will go down or use a
grounded aluminum foil shield.
-John


Johnny Chapman
 

Interesting note, I was using the BNC connections. I
also noted that I had some ground noise, and at really
low output levels, sometimes the desired signal would
be swamped by line current. But yes, I believe I
sorta know what you're talking bout.

I cleared some of it up by grounding the op-amp to the
frame with the signal gen in it.

An interesting note, I've had this problem with tubed
rf alignment equipment. I solved it by swapping the
ground and signal test points!

I later read from a Tek measurement something or
another, that it was just a kludge fix as floating the
scope : (

Thanks. I hope to actually stop playing and doing
more directed studying.

Thanks.



____________________________________________________________________________________
Don't pick lemons.
See all the new 2007 cars at Yahoo! Autos.


Ashton Brown
 

Note that there are BNC adaptors on an extruded oval alloy shield which shrouds right down to the faceplate plane (at least hP sold these - probably others.) Wish I had a few more of these. With the shield physically connected to the black/common binding post, you have ..almost.. a fully shielded 'can'. Worked fine for the few-???V noise floors of the various sensitive good AC meters du jour.

(My lovely Racal-Dana 9300, good down to Boltzmann noise and to a phenomenal MHz top-end RMS, ~20 MHz at 6:1 crest IIRC? - natch was already BNC equipped.) Very handy with it's output amp sent to an accurate DC DVM, when you care about <0.1% relative levels.

Ergo "binding posts" need not be a huge handicap - anywhere near audio freq.

Ashton


J Forster wrote:

From: "jones_chap" <jones_chap@...>

[snip]

Interesting note about "anything with banana plugs" is that when
playing around with the AM501 plugins was a sensitivity of the output
based upon the proximity of my hand near the jacks. Wild and crazy
things would happen as I got anywhere near 'em, sorta. One was much
more sensitive than the other.

The noise, etc. is capacitively coupled to your circuitry. Reduce the
values of the components in the FB loop and it will go down or use a
grounded aluminum foil shield.


Kuba Ober
 

On Wednesday 07 February 2007 19:05, you wrote:
Thanks. You beat me to the second question! I did wanna know if I
could "upgrade" knowing that better op-amps exist.

Interesting note about "anything with banana plugs" is that when
playing around with the AM501 plugins was a sensitivity of the output
based upon the proximity of my hand near the jacks. Wild and crazy
things would happen as I got anywhere near 'em, sorta. One was much
more sensitive than the other.

Do ya have any recommendations for a replacement. I'd even be willing
to spend more than the few cents that some of these cost--maybe even
like $5--15 per chip!
Well, the deal is this: there's no easy way to get performance out of a better
chip if you have large, uncontrolled and *variable* parasitics. That's what
your hand waving is :)

The way to fix it is to use your op amp in the circuit, not in the plugin.

A faster op-amp may even start oscillating just from the fact that it's inside
of the AM501 wiring harness. Probably the only road to improvement is to use
a similarly slow op-amp, but a more DC-accurate one. The AM501 is not really
useable for much beyond simple school-type experiments. It wasn't meant to
be! It was specifically designed for use in educational setting AFAIK.

I have lots of unused OP177 chips, if you want a few just let me know
off-list. They are good replacements for 741 and friends -- similarly slow,
but much more precise.

Cheers, Kuba


Stan and Patricia Griffiths
 

Hi Ashton,



You might want to watch my eBay sales for the next several weeks. I am
helping a widow dispose of a HUGE estate left by a very smart Tektronix
microwave engineer. Right now, we have 90 auctions on with lots of
terminators, adapters, attenuators, etc. and will have lots of other stuff,
too. I have seen some of those BNC/binding post ¡°cans¡± in among the other
stuff and I have more than I will ever use already. When I say HUGE estate,
I mean a 2500 square foot house with a full basement absolutely FULL of
stuff . . . upstairs and down . . . you can barely walk around in it . . .
in some cases, you can¡¯t! The stuff is packed so densely that you simply
can¡¯t see all of it until some of it gets sold. Also, there are 8 storage
lockers full and one of them is about the size of a 4 car garage. Some of
the aisles between the shelves are packed full, too, so you can¡¯t see all of
the stuff in the storage lockers either. This guy had ALL kinds of stuff.
Lots of Tek. Lots of HP. Machine tools. Hand tools. Hundreds of musical
instruments. thousands of books, 6 Mercedes Benz cars. One Porsche.
Motorhome. Guns. Several early Edison phonographs and lots of wax
cylinders. Tons of parts . . . all kinds. I will not live to see the end
of this estate sale. Unfortunately, it is 40 miles from my house . . . My
eBay name is w7ni. Take a look. I already sold the Bird wattmeter and a
nice Tek 191, sorry. Coming soon: LC130 meter, TM501, 321A, P6015 HV
probes, 109, 2710, etc. etc. Also lots of 11K mainframes and plugins and
7K, too, if I can figure out a good way to ship them. I think I¡¯ll keep the
576 . . . The widow is keeping the 492A since that was one of the
engineer¡¯s projects. I think this guy was KING of the pack-rats.



Stan



_____

From: TekScopes@... [mailto:TekScopes@...] On Behalf
Of Ashton Brown
Sent: Wednesday, February 07, 2007 10:34 PM
To: Tekscopes
Subject: Re: [TekScopes] Re: AM501 Stuff (op-amp references)



Note that there are BNC adaptors on an extruded oval alloy shield which
shrouds right down to the faceplate plane (at least hP sold these -
probably others.) Wish I had a few more of these. With the shield
physically connected to the black/common binding post, you have
..almost.. a fully shielded 'can'.
Worked fine for the few-?V noise floors of the various sensitive good AC
meters du jour.

(My lovely Racal-Dana 9300, good down to Boltzmann noise and to a
phenomenal MHz top-end RMS, ~20 MHz at 6:1 crest IIRC? - natch was
already BNC equipped.) Very handy with it's output amp sent to an
accurate DC DVM, when you care about <0.1% relative levels.

Ergo "binding posts" need not be a huge handicap - anywhere near audio freq.

Ashton


 

Hi Stan, It looks like the Tektronix engineer you¡¯re talking about is
a huge winner of the ¡°He who dies with the most ¡°toys¡± wins!!!¡±
contest¡­God bless him!!
Although the other part of the saying is ¡°He who dies BROKE with the
most toys wins¡±¡­ Sounds like he left his widow in good shape
financially¡­God bless him and her.

Stan, I bought some Tek Blue paint today from Patricia and if this
¡°bonanza¡± of Tek antiquities that you just acquired is what it sounds
like , I¡¯ll be buying more stuff!!

To the Group¡­. I bought some ¡°Tek Blue¡± paint from Stan and Patricia
(today) and some last fall that I used to paint/ touched up about ten
400 series cabinets with INCREDIBLE results !!!.
It¡¯s lacquer and it¡¯s stinky but what a job it does!!! If you have a
Tek scope that you ¡°love¡± buy a can of Stan and Patricia¡¯s ¡°Tek Blue¡± ¡­
highly recommended !!!!

On a different subject¡­ as usual, Deane Kidd comes up ¡°large ¡°again!!
Who else would have a ¡°timing IC Tek # 155- 0021 xx ??? that fixes a
broken 7904 so beautifully !!!
What I love about Deane the most is that you E-mail him and ask him for
a ¡°hen¡¯s tooth¡± and he replies with an email describing four different
potential Tek part numbers and then asks ¡°what color do you want?¡±

Seriously folks, we are all fortunate to have Stan and Patricia and
Deane E. Kidd as invaluable resources of Tektronix knowledge and parts!

Regards to all,

Ron Simmons

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On
Behalf Of Stan and Patricia Griffiths
Sent: Friday, February 09, 2007 10:03 PM
To: 'Ashton Brown'
Cc: TekScopes
Subject: RE: [TekScopes] Re: AM501 Stuff (op-amp references)

Hi Ashton,

You might want to watch my eBay sales for the next several weeks. I am
helping a widow dispose of a HUGE estate left by a very smart Tektronix
microwave engineer. Right now, we have 90 auctions on with lots of
terminators, adapters, attenuators, etc. and will have lots of other
stuff,
too. I have seen some of those BNC/binding post ¡°cans¡± in among the
other
stuff and I have more than I will ever use already. When I say HUGE
estate,
I mean a 2500 square foot house with a full basement absolutely FULL of
stuff . . . upstairs and down . . . you can barely walk around in it . .
.
in some cases, you can¡¯t! The stuff is packed so densely that you simply
can¡¯t see all of it until some of it gets sold. Also, there are 8
storage
lockers full and one of them is about the size of a 4 car garage. Some
of
the aisles between the shelves are packed full, too, so you can¡¯t see
all of
the stuff in the storage lockers either. This guy had ALL kinds of
stuff.
Lots of Tek. Lots of HP. Machine tools. Hand tools. Hundreds of musical
instruments. thousands of books, 6 Mercedes Benz cars. One Porsche.
Motorhome. Guns. Several early Edison phonographs and lots of wax
cylinders. Tons of parts . . . all kinds. I will not live to see the end
of this estate sale. Unfortunately, it is 40 miles from my house . . .
My
eBay name is w7ni. Take a look. I already sold the Bird wattmeter and a
nice Tek 191, sorry. Coming soon: LC130 meter, TM501, 321A, P6015 HV
probes, 109, 2710, etc. etc. Also lots of 11K mainframes and plugins and
7K, too, if I can figure out a good way to ship them. I think I¡¯ll keep
the
576 . . . The widow is keeping the 492A since that was one of the
engineer¡¯s projects. I think this guy was KING of the pack-rats.

Stan

_____

From: TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com
[mailto:TekScopes@yahoogrou <mailto:TekScopes%40yahoogroups.com> ps.com]
On Behalf
Of Ashton Brown
Sent: Wednesday, February 07, 2007 10:34 PM
To: Tekscopes
Subject: Re: [TekScopes] Re: AM501 Stuff (op-amp references)

Note that there are BNC adaptors on an extruded oval alloy shield which
shrouds right down to the faceplate plane (at least hP sold these -
probably others.) Wish I had a few more of these. With the shield
physically connected to the black/common binding post, you have
..almost.. a fully shielded 'can'.
Worked fine for the few-?V noise floors of the various sensitive good AC

meters du jour.

(My lovely Racal-Dana 9300, good down to Boltzmann noise and to a
phenomenal MHz top-end RMS, ~20 MHz at 6:1 crest IIRC? - natch was
already BNC equipped.) Very handy with it's output amp sent to an
accurate DC DVM, when you care about <0.1% relative levels.

Ergo "binding posts" need not be a huge handicap - anywhere near audio
freq.

Ashton

[Non-text portions of this message have been removed]



[Non-text portions of this message have been removed]


Stan and Patricia Griffiths
 

Hi Larry,

You might have known him. His name was Larry Lockwood.

Stan

-----Original Message-----
From: Larry Snyder [mailto:larrys@...]
Sent: Friday, February 09, 2007 7:35 PM
To: w7ni@...
Subject: RE: [TekScopes] Re: AM501 Stuff (op-amp references)

Stan, is this anyone whose name I might recognize from the 70's-80's?
thanx,
-ls-


Stan and Patricia Griffiths
 

Hi Ron,



Thanks for the kind words. By the way, the original Tek paint is lacquer,
too, and I got it from the same place Tek did . . .



Stan & Patricia



_____

From: Ron Simmons [mailto:RJSimmons@...]
Sent: Friday, February 09, 2007 7:47 PM
To: 'Stan and Patricia Griffiths'; 'Ashton Brown'
Cc: 'TekScopes'
Subject: RE: [TekScopes] Re: AM501 Stuff (op-amp references)



Hi Stan, It looks like the Tektronix engineer you're talking about is a
huge winner of the "He who dies with the most "toys" wins!!!" contest.God
bless him!!

Although the other part of the saying is "He who dies BROKE with the most
toys wins". Sounds like he left his widow in good shape financially.God
bless him and her.



Stan, I bought some Tek Blue paint today from Patricia and if this "bonanza"
of Tek antiquities that you just acquired is what it sounds like , I'll be
buying more stuff!!



To the Group.. I bought some "Tek Blue" paint from Stan and Patricia
(today) and some last fall that I used to paint/ touched up about ten 400
series cabinets with INCREDIBLE results !!!.

It's lacquer and it's stinky but what a job it does!!! If you have a Tek
scope that you "love" buy a can of Stan and Patricia's "Tek Blue" . highly
recommended !!!!



On a different subject. as usual, Deane Kidd comes up "large "again!! Who
else would have a "timing IC Tek # 155- 0021 xx ??? that fixes a broken 7904
so beautifully !!!

What I love about Deane the most is that you E-mail him and ask him for a
"hen's tooth" and he replies with an email describing four different
potential Tek part numbers and then asks "what color do you want?"



Seriously folks, we are all fortunate to have Stan and Patricia and Deane E.
Kidd as invaluable resources of Tektronix knowledge and parts!



Regards to all,



Ron Simmons