Date   
Re: Opamp arithmetic circuits

Albert <aodiversen@...>
 

Considering the climate changes we might have to rivive this one:
http://en.wikipedia.org/wiki/Deltar
(the Dutch wikipedia version gives more details).
Albert

SA501 (067-1090-00) Signature Analyzer

David Gravereaux
 

Are these rare to find? I have an FG5010 that's broken and the manual
to full of logic behaviors for SA501 debugging. DM5010 manual also has
SA outputs, too. Looks like it would be worth having to help fix it,
but a quick search shows little info on them and none seem to be
available through the "normal channels" at this moment.

http://www.slack.com/images/TE/Tek067-1090-00.jpg

Re: Opamp arithmetic circuits

Dan Fish <defish1@...>
 

Nice that AD scanned that classic for the public.  I actually have one of the originals (from my Wavetek days).  I wonder if ArtekMedia could do a more legible job with this?

Dan


On 1/25/2011 12:30 PM, Leon Robinson wrote:
 

Look at this.

www.analog.com/library/analogdialogue/archives/philbrick/computing_amplifiers.html

Leon     K5JLR

Political Correctness is a Political Disease.

--- On Tue, 1/25/11, Gala Dragos wrote:

From: Gala Dragos
Subject: [TekScopes] Opamp arithmetic circuits
To: "TekScopes@..."
Date: Tuesday, January 25, 2011, 7:44 AM

 
Is this the group where I've heard someone talking about building circuits with opamp to emulate arithmetic logic ?
 



Re: Opamp arithmetic circuits

Paul Amaranth
 

A while back I ran across a story/link on one of the the first computer games built
with an analog computer. The game, Tennis for Two, used a scope as a vidoe output
device and was done at Brookhaven. I believe one of the labs, maybe Brookhaven, has
managed to scrounge more or less original parts to recreate the device in somewhat
its original form.

Here's a wikipedia link to that:
http://en.wikipedia.org/wiki/Tennis_for_Two

On Tue, Jan 25, 2011 at 08:37:08PM +0000, Ken Wright wrote:
Hi.
I can remember in the early 70's using op-amps the build analogue computers and
using them to analyse the response of mechanical springs and tuned circuits. It
involved mathematical modelling the device in the S plane then building
integrators and differentiators using op-amps, also a vast amount of scaling
pots.

Regards.
Ken
--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@... | Unix & Windows

Re: Opamp arithmetic circuits

Richard L. Wurdack
 


Yep, we used to do whole airplane simulations that way.
 
D.

----- Original Message -----
From: Ken Wright
Sent: Tuesday, January 25, 2011 12:37 PM
Subject: Re: [TekScopes] Re: Opamp arithmetic circuits

 

Hi.
I can remember in the early 70's using op-amps the build analogue computers and using them to analyse the response of mechanical springs and tuned circuits. It involved mathematical modelling the device in the S plane then building integrators and differentiators using op-amps, also a vast amount of scaling pots.

Regards.
Ken



From: Gala Dragos
To: "TekScopes@..."
Sent: Tue, 25 January, 2011 16:45:40
Subject: Re: [TekScopes] Re: Opamp arithmetic circuits

 

Yes I know the history and what can be done with an opamp, but I remembered that someone from the groups I've subscribed stated that his doing some arithmetic circuits with opamps. I needed some books on the subject as I'm taking a course that supposedly handles just that, the reality being quite different though.

Thanks for the answers, I'll ask around.
 
----------------------------------------------------------------------------------------------------------------------------------

. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!


. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi


. Everybody can learn how to make kids, but not everyone can raise them right!

From: Mike <mikez11@...>
To: TekScopes@...
Cc:
Sent: Tuesday, January 25, 2011 6:12 PM
Subject: [TekScopes] Re: Opamp arithmetic circuits

 
Op-amp is short for "operational amplifier" which was originally developed to implement mathematical "operations" in analog computers. This application has disappeared, of course, but the name stuck.

--- In TekScopes@..., Gala Dragos wrote:
>
> Is this the group where I've heard someone talking about building circuits with opamp to emulate arithmetic logic ?
>





Re: Opamp arithmetic circuits

Ken Wright <lutonman42@...>
 

Hi.
I can remember in the early 70's using op-amps the build analogue computers and using them to analyse the response of mechanical springs and tuned circuits. It involved mathematical modelling the device in the S plane then building integrators and differentiators using op-amps, also a vast amount of scaling pots.

Regards.
Ken



From: Gala Dragos
To: "TekScopes@..."
Sent: Tue, 25 January, 2011 16:45:40
Subject: Re: [TekScopes] Re: Opamp arithmetic circuits

 

Yes I know the history and what can be done with an opamp, but I remembered that someone from the groups I've subscribed stated that his doing some arithmetic circuits with opamps. I needed some books on the subject as I'm taking a course that supposedly handles just that, the reality being quite different though.

Thanks for the answers, I'll ask around.
 
----------------------------------------------------------------------------------------------------------------------------------

. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!


. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi


. Everybody can learn how to make kids, but not everyone can raise them right!

From: Mike
To: TekScopes@...
Cc:
Sent: Tuesday, January 25, 2011 6:12 PM
Subject: [TekScopes] Re: Opamp arithmetic circuits

 
Op-amp is short for "operational amplifier" which was originally developed to implement mathematical "operations" in analog computers. This application has disappeared, of course, but the name stuck.

--- In TekScopes@..., Gala Dragos wrote:
>
> Is this the group where I've heard someone talking about building circuits with opamp to emulate arithmetic logic ?
>





Re: Opamp arithmetic circuits

Leon Robinson
 

Look at this.

www.analog.com/library/analogdialogue/archives/philbrick/computing_amplifiers.html

Leon     K5JLR

Political Correctness is a Political Disease.


--- On Tue, 1/25/11, Gala Dragos wrote:

From: Gala Dragos
Subject: [TekScopes] Opamp arithmetic circuits
To: "TekScopes@..."
Date: Tuesday, January 25, 2011, 7:44 AM

 

Is this the group where I've heard someone talking about building circuits with opamp to emulate arithmetic logic ?
 


Re: Re TEK 5111

Bob W5UQ <w5uq@...>
 

I just ordered extension kits from Jamma.
thanks for info.
Bob
and the beat goes onnnnnn!
W5UQ.com
A25UQ, V31UQ  & VP2EEU
QRZ.com is accurate for all. 


On 1/25/2011 1:00 PM, John Griessen wrote:
 

On 01/24/2011 10:43 AM, Bob W5UQ wrote:
> I need module extenders for this frame.

Is it the same 0.156 in spacing and number of contacts as TM500?

If so, I'm planning to offer extender card/cable kits of that soon.

John
--
Ecosensory Austin TX

Re: Re TEK 5111

Bob W5UQ <w5uq@...>
 

A big thank you for all that information Magnus.
I will use it all.  thanks.
Bob
and the beat goes onnnnnn!
W5UQ.com
A25UQ, V31UQ  & VP2EEU
QRZ.com is accurate for all. 


On 1/25/2011 1:31 PM, magnustoelle wrote:
 

Hi,

a few friendly hints:

1) If you have a benchtop/non-rack version 5000 o'scope, you might want
to remove the top side covers. With the covers of the plug-in also
removed, one can pretty easily access the component side of the plug-in.

2) Yes, the TM500/5000 and the Tektronix 5000 series scopes have the
same 0.156 inches in spacing and 28x2 contacts on the interface. The two
notches are different, though - this was designed on purpose to prevent
accidential insertion into the wrong mainframe.

However, the Tektronix 5000 series scopes have a +200V DC unregulated
supply present at pin 1A, which is *potentially lethal*. So, some safety
precautions are required.

3) The 5110 manual is identical to the 5103N/D11, which you can find on
BAMA: http://bama.edebris.com/manuals/tek/5103n/
Christian has kindly put together a very useful summary about this
irritating name changes; available at
http://www.i9t.net/5000_scopes.html

Note that the above manual is missing the display/CRT circuit section,
which you can access here: http://bama.edebris.com/manuals/tek/5110/
The schematics are sadly almost unreadable.

Artekmedia sells the scans at very reasonable prices. Dave with
Artekmedia is a very helpful and active group member, and I can
personally recommend his service:
http://artekmed.startlogic.com/page2.html
And no, I am not affiliated with artekmedia in any way.

I hope this gets you rolling..

Cheers,

Magnus

Re: Tek 2445

Bob W5UQ <w5uq@...>
 

thanks Bill. 
Now, when time permits, I need to fix my TEK 7905,  465, and 212.   Oh yes...and OS245.

Have a nice day. 73 and  dit dit..
Bob
and the beat goes onnnnnn!
W5UQ.com
A25UQ, V31UQ  & VP2EEU
QRZ.com is accurate for all. 


On 1/25/2011 10:46 AM, William wrote:
 



Bob,

Brag away! We Tek 2445 owners appreciate the insight. This gets filed in my Crimestopper's Textbook fer sure, dude!

tnx es 72,

Bill, k6whp

dit..dit.

--- In TekScopes@..., Bob W5UQ wrote:
>
> Well, I've been putting up with slow to work when turned on..

Re: Re TEK 5111

magnustoelle
 

Hi,

a few friendly hints:

1) If you have a benchtop/non-rack version 5000 o'scope, you might want
to remove the top side covers. With the covers of the plug-in also
removed, one can pretty easily access the component side of the plug-in.

2) Yes, the TM500/5000 and the Tektronix 5000 series scopes have the
same 0.156 inches in spacing and 28x2 contacts on the interface. The two
notches are different, though - this was designed on purpose to prevent
accidential insertion into the wrong mainframe.

However, the Tektronix 5000 series scopes have a +200V DC unregulated
supply present at pin 1A, which is *potentially lethal*. So, some safety
precautions are required.

3) The 5110 manual is identical to the 5103N/D11, which you can find on
BAMA: http://bama.edebris.com/manuals/tek/5103n/
Christian has kindly put together a very useful summary about this
irritating name changes; available at
http://www.i9t.net/5000_scopes.html

Note that the above manual is missing the display/CRT circuit section,
which you can access here: http://bama.edebris.com/manuals/tek/5110/
The schematics are sadly almost unreadable.

Artekmedia sells the scans at very reasonable prices. Dave with
Artekmedia is a very helpful and active group member, and I can
personally recommend his service:
http://artekmed.startlogic.com/page2.html
And no, I am not affiliated with artekmedia in any way.

I hope this gets you rolling..

Cheers,

Magnus

Re: My 465B is busted - should I repair or replace?

rc_engelhardt
 

Thanks for all the replies. I've decided to give it a try, especially since Tom Miller suggested that it could be a power supply.

I downloaded the "bama" manual, but the diagrams were cropped, so I downloaded one from http://manoman.sqhill.com/, but I couldn't pull out the diagrams to separate files (to take to Staples for 11 x 17 printing). I've sent email to http://artekmed.startlogic.com/ to see if their PDF's allow pull-outs.

Thanks again, I'm sure that you will be hearing from me again.

Bob

Oh ... I live in Carlise, MA (NW of Boston)

Re: Re TEK 5111

John Griessen
 

On 01/24/2011 10:43 AM, Bob W5UQ wrote:
I need module extenders for this frame.
Is it the same 0.156 in spacing and number of contacts as TM500?

If so, I'm planning to offer extender card/cable kits of that soon.

John
--
Ecosensory Austin TX

Re: Tek 475 leaking electrolytic from power supply

remarc123
 

Gala Dragos, sorry, You are right, the correct eletrolytic is C1412 = 145v.
I don't want colder bridge, I'd like to konw if this high temperature is acceptable.

Renato

--- In TekScopes@..., Gala Dragos <gala_dragos@...> wrote:

C1452 filter's the unregulated 5V bus bar ! You have measured the wrong place.67V is ok for the unregulated 50V. If you want colder bridges the exchange them with beefier ones, good luck finding some that actually fit in there.

----------------------------------------------------------------------------------------------------------------------------------


. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!


. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi


. Everybody can learn how to make kids, but not everyone can raise them right!


From: remarc123 <renato-marcelino@...>
To: TekScopes@...
Cc:
Sent: Tuesday, January 25, 2011 6:52 PM
Subject: [TekScopes] Re: Tek 475 leaking electrolytic from power supply



I replaced C1442 and C1472, this second one was leaking, now the oscilloscope is working.
I used Epcos electrolytics B41851 - 105ºC, I don't konw if Epcos is a good choise for this power supply.

Temperatures:
CR1442 and CR1462 works with more than 60ºC, impossible to hold it with my fingers, is it normal for these two bridge rectifier?

Measures voltages:
110v = 111.2v
50v unreg = 67v (is it high?)
105/160v = 10.2v measured on positive pin of the C1452 (why this big difference?)
The others voltages are normal.

Renato

--- In TekScopes@..., Mark Robinson <mark.robinson@> wrote:

Hi Renato,

Save yourself a headache later on while you are in there and cast a very hairy
eyeball over the bridge rectifiers too. All those in my 464 went faulty, some
intermittently.

Replace all the caps too. A big soldering iron is a must. The WCTPN is between
45-60W so a 60W iron may not be any advantage though I think I used my WCPTN
with an 800°F 1/4" chisel bit. An iron on each pin would make the job quick if
you have enough hands.

Good luck.

On 17/01/11 06:12, remarc123 wrote:
Next week I will buy a 60 watts iron solder, may weller WTCPT and Hakko 936 was
not good to remove big caps.

Renato

--- In TekScopes@... <mailto:TekScopes%40yahoogroups.com>, Gala
Dragos <gala_dragos@> wrote:
>
> I've replaced my tektonix 475 filter capacitors recently and only found one
capacitor that uses the negative terminal as a jumper, the -15V capacitor. This
was quickly resolved with insulated wires on the other side of the pcb.
>
> From: Tom Miller <tmiller@>
> To: TekScopes@... <mailto:TekScopes%40yahoogroups.com>
> Cc:
> Sent: Sunday, January 16, 2011 3:54 AM
> Subject: Re: [TekScopes] Re: Tek 475 leaking electrolytic from power supply
>
> Just a little hint or a variation of removing the caps:
>
> After you suck the solder out, reheat the joint and wiggle the cap back and
> forth as the solder re-cools. The board will flex enough to make a cold
> solder joint. Do this for each
> terminal starting with the one ground opposite the plus terminal. Then do
> one
> of the other grounds, then the plus terminal. The last ground gets reheated
> as
> you remove the cap. Keep the amount of heat down as it is very easy to pull
> the plated through hole out of the board.
>
> As mentioned before, the capacitor body is a part of the circuit and you
> must
> jumper the three ( really only two if you study it carefully) ground
> (negative) pads
> together.
>
> Regards,
> tom
>
> >From: gridleakrick
> >To: TekScopes@... <mailto:TekScopes%40yahoogroups.com>
> >Sent: Saturday, January 15, 2011 6:23
> > PM
> >Subject: [TekScopes] Re: Tek 475 leaking
> > electrolytic from power supply
> >
> >
> >Renato,
> >After you have cleared the solder from the foil and hole, grab
> > the capacitor's solder tab with needlenose pliers and wiggle it back and
forth
> > a bit to break it loose. Then the capacitor should just slide right out. If
> > you can't break a tab free and wiggle it back and forth, then you haven't
> > removed all the solder. Sometimes it helps to resolder the connection then
use
> > the solder sucker again.
> >
> >Rick
> > In TekScopes@,
> > "remarc123" <renato-marcelino@> wrote:
> >>
> >> Hi
> > all,
> >>
> >> My Tek 475 died when I was using it, the trace
> > disappeared and turned off the fan and lights on panel.
> >> I turn off it,
> > wait some minutes and turn on again, it ran a few minutes and then stopped
> > definitely.
> >> I remove the case and looking at the pcb I turn on again
> > and I saw some smoke coming from near the tranformer.
> >> Immediately I
> > turn off it and I noticed some liquid on pcb coming from electrolytics of the
> > power supply.
> >> I don't understand oscilloscope circuits, but I'd like
> > to fix it, I'm trying to remove electrolytics from the power supply to see
> > wich one is leaking, but it's very very difficult.
> >> The first
> > electrolytic I tried to take out, one pad released from the pcb, is it welded
> > on both side of the pcb?
> >> I'm using Weller WTCPT for this job.
> >>
> > Pls, can someone explain to me how to remove it?
> >>
> >> Tks,
> >> Renato

Re: Interesting Custom Plug-in, SALE!

jmassen418a@...
 

Gala,

Yes payment was recieved. I had a small problem with the small falt rate box. The 2976-E pouch provided by USPS does not fit the small flat rate box. I gave it to the postman with a ps2976 form this morning. She said it was okay, we will see.

jerry


gala_dragos@...

-----Original Message-----
From: Gala Dragos <gala_dragos@...>
To: jmassen418a <jmassen418a@...>
Sent: Tue, Jan 25, 2011 11:27 am
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Did you received my payment ?


----------------------------------------------------------------------------------------------------------------------------------


. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!



. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi



. Everybody can learn how to make kids, but not everyone can raise them right!



From: "jmassen418a@..." <jmassen418a@...>
To: gala_dragos@...
Cc:
Sent: Sunday, January 23, 2011 5:40 PM
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Gala,

You are right. The difference is more than I would have thought. I won't be able to double box but I am sure they will be safe. I am out of small flat rate boxes but have ordered some and should have them in 3 or 4 days. The total will be 33.25USD. Much better.

jerry






-----Original Message-----
From: Gala Dragos <gala_dragos@...>
To: jmassen418a <jmassen418a@...>
Sent: Sun, Jan 23, 2011 6:09 am
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Unfortunately 44USD for shipping is a bit pricey. If you could send it through "USPS Priority Mail International Small Flat Rate Box" service which is only 14USD. I do not need a tracking number, but an insurance would be nice.

Here is the link I am using to view prices:
http://www.usps.com/prices/priority-mail-international-prices.htm

Prices may vary at you local post office, that is why I've asked for you to calculate shipping.

Thanks.


----------------------------------------------------------------------------------------------------------------------------------


. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!



. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi



. Everybody can learn how to make kids, but not everyone can raise them right!



From: "jmassen418a@..." <jmassen418a@...>
To: gala_dragos@...
Cc:
Sent: Sunday, January 23, 2011 12:14 AM
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Gala,

A usps medium flat rate box to Romania is 43.23USD. Please send 63.23 to
jmassen418a@... via paypal.

Thanks,

Jerry






-----Original Message-----
From: Gala Dragos <gala_dragos@...>
To: jmassen418a <jmassen418a@...>
Sent: Sat, Jan 22, 2011 2:57 pm
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Well, since I'm using these parts to restore a scope that I own, I cannot ask you to rip out an useful plugin. I would really like to get an original part in. If it is no trouble to you, then I want the 311-1192-00s .

As for the shipping, unfortunately I do not live anywhere near USA. I live in Eastern Europe, in Bucharest, Romania. If you still wish to send the pots to me, then calculate the shipping costs.

Also, I don't mean to offend you or anything, but the packaging must be pretty good as we have one heck of a postal service here, the kind that manages to break stuff. Usual transit time takes 2 to 6 weeks via USPS, which is just fine by me.


Entire shipping address:

To: Galalae Dragos Ionut
City: Bucharest
Country: Romania
Address: Burebista, nr 2, bl D14, ap 62, sc 2
ZipCode: 031108

Thanks.


----------------------------------------------------------------------------------------------------------------------------------


. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!



. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi



. Everybody can learn how to make kids, but not everyone can raise them right!



From: "jmassen418a@..." <jmassen418a@...>
To: gala_dragos@...
Cc:
Sent: Saturday, January 22, 2011 10:32 PM
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Hi,

I can send you 2 311-1192-00s but I will have to charge $10 each. I will have to pull one from a nother plugin. I have several Allen-Bradley CL-213655 controls that I have used to replace the 311-1192-00. These are new parts. The slope switch is push-pull but is at least as good as left-right. I wired mine as pull as for neg slope. I can send you the CL-213655s for 7.50 each. Shipping will be extra at $5 for usa.

That would be a total of $25 for the old 311-1192-00s or $20 for the CL-213655s.
paypal jmassen418a@...

please send your shipping address.

jerry






-----Original Message-----
From: Gala Dragos <gala_dragos@...>
To: jmassen418a <jmassen418a@...>
Sent: Sat, Jan 22, 2011 12:39 pm
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!


Any parts for tektronix 475/465 ?

Here is something that I've been looking for:

311-1192-00 - 2 pcs , there are a few equivalents for this one (311-1190-00 / 311-1647-00 / 311-2303-00)

Description: potentiometer 10k ohms, dual shafts, center one tied to a rotating switch, external one tied to the potentiometer; used for trigger level and slope adjustment


It has been used in many tek scopes and plugins, hence the equivalents.

Thanks.


----------------------------------------------------------------------------------------------------------------------------------


. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!



. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi



. Everybody can learn how to make kids, but not everyone can raise them right!



From: "jmassen418a@..." <jmassen418a@...>
To: TekScopes@...
Cc:
Sent: Saturday, January 22, 2011 8:30 PM
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in, SALE!





Hi,

I have way too much stuff to list, well over a hundred plugins and SC503,SC504, 7704,7704As,7603s, 7904s, TM5006A, TM506A, 500 series AM503s, PS501-1s. Please respond off list for checked units and parts units and spare parts. I need to get my work load down. It make take a while to respond but I will.

jerry






-----Original Message-----
From: Gala Dragos <gala_dragos@...>
To: TekScopes <TekScopes@...>
Sent: Sat, Jan 22, 2011 11:52 am
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in





Maybe you can make a list for whoever is interested ?


----------------------------------------------------------------------------------------------------------------------------------


. Microsoft broke the Volkswagen world record: Volkswagen only made 22 million bugs!



. It is time for us to stand and cheer for the doer, the achiever, the one who recognizes the challenge and does something about it.
-Vince Lombardi



. Everybody can learn how to make kids, but not everyone can raise them right!



From: "jmassen418a@..." <jmassen418a@...>
To: TekScopes@...
Cc:
Sent: Saturday, January 22, 2011 7:35 PM
Subject: Re: [TekScopes] Re: Interesting Custom Plug-in




I have had a couple of 7M13s but the 9 or 10 character limit cooled my interest. before I retired from Tyco Power Systems, I had a TEK DSO, 754 i think. Your could write to the screen but it would have been so much better if a keyboard could have been attached. Maybe I will find a way to score a modern scope with more toys built in. Right now I have a house full of plugins and mainframes that I need to get rid of so i can buy more toys.

jerry






-----Original Message-----
From: Dennis Tillman <@Dennis_Tillman_W7PF>
To: TekScopes <TekScopes@...>
Sent: Sat, Jan 22, 2011 11:24 am
Subject: RE: [TekScopes] Re: Interesting Custom Plug-in





Jerry,

The 7M13 already does exactly what you want for the onscreen readout, and it is much easier to use and much more flexible. Plus they are almost given away on eBay. Since they don’t “do much” nobody wants them.

There were several plugins for the 545, 547, and 549 that never migrated to the 7000 series such as the type O Operational Amplifier and the type Q Transducer / Strain Gauge Plugin. The 7A17 could be used to build 7000 equivalents of these. There were some other 500 series plugins whose time has come and gone such as the type R Transistor Rise Time plugin and the type S Diode Recovery Time plugin. By the time the 7000 series came out the semiconductor industry had little need for these so they were never ported to the 7000.

According to one of my friends at Tek who would know this, one of the interesting 7000 plugins that never made it into production was a logarithmic amplifier. I always wondered why there wasn’t one of these for the 7000. It seemed like an obvious idea to me. I am told there was an engineering prototype.

I am still intrigued by the circuit in the 7A17 manual for the X/Y Multiplier plugin. Someday if I find the time I will build it into my 7A17. This is a no brainer since Tek already came up with the circuit for it customized to the 7A17.

Dennis


From: jmassen418a@...




Hi,



When I bought this module I had ideas floating about my weary old skull of building a mainframe slot tester. It would be a nice challange. It just isn't reasonable. The character generator circuit could be used to display each of the supply voltages. A small load circuit might be added. The reality is that if your mainframe is in good enough condition to display the readout, it just isn't needed. EG&G did research on nuclear weapons triggers and such. Maybe this was part of it's genesis. Maybe I could use it to display cuss words.



jerry





-----Original Message-----
From: Dennis Tillman <@Dennis_Tillman_W7PF>

I think Leon’s speculation is very prescient.

I would go one step further and add that, since Jerry’s unit is so professionally made, it might have been built as part of a military contract.

Adding to Leon’s speculation I suspect it was a small production run of custom test equipment, made in conformance to the specifications called out in some military contract.



I think we are finally getting to the bottom of this.




Dennis




From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Leon Robinson

Sent: Friday, January 21, 2011 1:46 PM

To: TekScopes@...

Subject: Re: [TekScopes] Re: Interesting Custom Plug-in



Annotation for a camera?



Leon K5JLR

Re: 7854 focus control

Ed Breya
 

It's one of those dual blue Bourns types, about 2cm square, with full-length rivets in the corners. I can drill or grind out the rivets and repin if necessary. If I fail to properly execute the rewiring or break something, then I'll have to take it apart and pull the pot board, so I may end up getting to that if I don't have an exact replacement.

Also, on closer inspection of the pot mounting, I saw that the leads were bent very sharply close-in to compensate for slight misalignment with the board holes. I believe this pot is a cermet type, so the element is very brittle, and may have eventually cracked due to lead stress. I hope I don't aggravate the situation during my repair.

Ed

--- In TekScopes@..., "David C. Partridge" <david.partridge@...> wrote:

Is this one of the ones where the pot can be opened by prying up the tabs on the rear?

If so I've had good success in repairing these. Even the Bourns/Spectrol 5 and 10 turn pots are sometimes amenable to repair ...

Re: Opamp arithmetic circuits

John Rehwinkel <jrehwin@...>
 

On 1/25/2011 11:45 AM, Gala Dragos wrote:
 
Yes I know the history and what can be done with an opamp, but I remembered that someone from the groups I've subscribed stated that his doing some arithmetic circuits with opamps. I needed some books on the subject as I'm taking a course that supposedly handles just that, the reality being quite different though.
Have a look at the manual for the type O plug-in (this is TekScopes, after all).  It's an operational amplifier plug-in, and the manual has a lot of good data and examples on how to use op-amps to do various things.  There's the danger that you might want to go out and get a type O plug-in to play with, but that's the sort of danger most of us live with every day.

- John

SC504 AC coupling Switch

jmassen418a@...
 


HI,
 
I have a SC504 with an AC coupling switch that does not latch when pushed. I cannot find anything in the archives. Is there a fix for this problem?
 
jerry

Re: 7854 focus control

 

Is this one of the ones where the pot can be opened by prying up the tabs on the rear?

If so I've had good success in repairing these. Even the Bourns/Spectrol 5 and 10 turn pots are sometimes amenable to repair ...

Regards,
David Partridge

-----Original Message-----
From: TekScopes@... [mailto:TekScopes@...] On Behalf Of Ed Breya
Sent: 25 January 2011 16:40
To: TekScopes@...
Subject: [TekScopes] Re: 7854 focus control

I know what you mean, but it's wired (on the board) with the wiper and CCW end tied, so the bulk of the resistance - about 950 k out of 1 meg - is shorted out and not available. The pot acts open over most of its rotation, then jumps to around 50 k to 0, where the wiper bridges the gap in the element at the last few CW degrees of rotation. I plan to disconnect the wiper lead from the CCW and hook it to CW, so it will run 0 to 950 k, then open (and out of control) near the CW end. I may put in an extra shunt R or zener to keep it from going extreme when it opens up. I also noticed there is a "focus preset" adjustment in the cathode circuit that hopefully will allow re-centering of the range if needed. I could even put in a separate pot on the front panel, but I don't want to spoil the appearance - this one looks brand new.

Ed

--- In TekScopes@..., "Albert" <aodiversen@...> wrote:

Ed, you probably mean unhook the lead from one end of the pot and hook it to the other end. Simpler: an additional wire between both ends (and avoid the near CW position when focussing).
Albert

---
Otherwise, I am thinking about performing in situ surgery on the board to unhook the wiper from one end, and then hook it to the other end. The break is very close to the CW end, and the pot is connected as a variable resistor only, so it should be possible to reverse the sense, and still work over most of the rotation. he manual.
---
Ed



------------------------------------

Yahoo! Groups Links

Re: Tek 475 leaking electrolytic from power supply

Gala Dragos
 

C1452 filter's the unregulated 5V bus bar ! You have measured the wrong place. 67V is ok for the unregulated 50V. If you want colder bridges the exchange them with beefier ones, good luck finding some that actually fit in there.
 
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From: remarc123
To: TekScopes@...
Cc:
Sent: Tuesday, January 25, 2011 6:52 PM
Subject: [TekScopes] Re: Tek 475 leaking electrolytic from power supply

 
I replaced C1442 and C1472, this second one was leaking, now the oscilloscope is working.
I used Epcos electrolytics B41851 - 105ºC, I don't konw if Epcos is a good choise for this power supply.

Temperatures:
CR1442 and CR1462 works with more than 60ºC, impossible to hold it with my fingers, is it normal for these two bridge rectifier?

Measures voltages:
110v = 111.2v
50v unreg = 67v (is it high?)
105/160v = 10.2v measured on positive pin of the C1452 (why this big difference?)
The others voltages are normal.

Renato

--- In TekScopes@..., Mark Robinson wrote:
>
> Hi Renato,
>
> Save yourself a headache later on while you are in there and cast a very hairy
> eyeball over the bridge rectifiers too. All those in my 464 went faulty, some
> intermittently.
>
> Replace all the caps too. A big soldering iron is a must. The WCTPN is between
> 45-60W so a 60W iron may not be any advantage though I think I used my WCPTN
> with an 800°F 1/4" chisel bit. An iron on each pin would make the job quick if
> you have enough hands.
>
> Good luck.
>
> On 17/01/11 06:12, remarc123 wrote:
> > Next week I will buy a 60 watts iron solder, may weller WTCPT and Hakko 936 was
> > not good to remove big caps.
> >
> > Renato
> >
> > --- In TekScopes@... , Gala
> > Dragos wrote:
> > >
> > > I've replaced my tektonix 475 filter capacitors recently and only found one
> > capacitor that uses the negative terminal as a jumper, the -15V capacitor. This
> > was quickly resolved with insulated wires on the other side of the pcb.
> > >
> > > From: Tom Miller
> > > To: TekScopes@...
> > > Cc:
> > > Sent: Sunday, January 16, 2011 3:54 AM
> > > Subject: Re: [TekScopes] Re: Tek 475 leaking electrolytic from power supply
> > >
> > > Just a little hint or a variation of removing the caps:
> > >
> > > After you suck the solder out, reheat the joint and wiggle the cap back and
> > > forth as the solder re-cools. The board will flex enough to make a cold
> > > solder joint. Do this for each
> > > terminal starting with the one ground opposite the plus terminal. Then do
> > > one
> > > of the other grounds, then the plus terminal. The last ground gets reheated
> > > as
> > > you remove the cap. Keep the amount of heat down as it is very easy to pull
> > > the plated through hole out of the board.
> > >
> > > As mentioned before, the capacitor body is a part of the circuit and you
> > > must
> > > jumper the three ( really only two if you study it carefully) ground
> > > (negative) pads
> > > together.
> > >
> > > Regards,
> > > tom
> > >
> > > >From: gridleakrick
> > > >To: TekScopes@... > > > >Sent: Saturday, January 15, 2011 6:23
> > > > PM
> > > >Subject: [TekScopes] Re: Tek 475 leaking
> > > > electrolytic from power supply
> > > >
> > > >
> > > >Renato,
> > > >After you have cleared the solder from the foil and hole, grab
> > > > the capacitor's solder tab with needlenose pliers and wiggle it back and
> > forth
> > > > a bit to break it loose. Then the capacitor should just slide right out. If
> > > > you can't break a tab free and wiggle it back and forth, then you haven't
> > > > removed all the solder. Sometimes it helps to resolder the connection then
> > use
> > > > the solder sucker again.
> > > >
> > > >Rick
> > > > In TekScopes@,
> > > > "remarc123" wrote:
> > > >>
> > > >> Hi
> > > > all,
> > > >>
> > > >> My Tek 475 died when I was using it, the trace
> > > > disappeared and turned off the fan and lights on panel.
> > > >> I turn off it,
> > > > wait some minutes and turn on again, it ran a few minutes and then stopped
> > > > definitely.
> > > >> I remove the case and looking at the pcb I turn on again
> > > > and I saw some smoke coming from near the tranformer.
> > > >> Immediately I
> > > > turn off it and I noticed some liquid on pcb coming from electrolytics of the
> > > > power supply.
> > > >> I don't understand oscilloscope circuits, but I'd like
> > > > to fix it, I'm trying to remove electrolytics from the power supply to see
> > > > wich one is leaking, but it's very very difficult.
> > > >> The first
> > > > electrolytic I tried to take out, one pad released from the pcb, is it welded
> > > > on both side of the pcb?
> > > >> I'm using Weller WTCPT for this job.
> > > >>
> > > > Pls, can someone explain to me how to remove it?
> > > >>
> > > >> Tks,
> > > >> Renato
>