Date   

Re: TDS540D issue

alberto.vaudagna
 

You should not directly ask for schematics but ask for some troubleshooting procedures or common problems. 
(In fact the form is the tek support form). 
Another think If you receive  a response where they ask to pay, just place another request.
Than If they respond with come ideas, ask for schematics.
At least this work for me!



2014-02-18 14:21 GMT+01:00 Alberto Vaudagna <alberto.vaudagna@...>:

http://www.tek.com/webform/technical-support-request, you should be register on the site, Just insert your email and a password.
Best regards, Alberto.


2014-02-18 14:11 GMT+01:00 <dukeluca86@...>:

 

Hello, where can i ask for schematics ? What is tek support forum ? Sorry for my noobbines.




Re: TDS540D issue

alberto.vaudagna
 

http://www.tek.com/webform/technical-support-request, you should be register on the site, Just insert your email and a password.
Best regards, Alberto.


2014-02-18 14:11 GMT+01:00 <dukeluca86@...>:

 

Hello, where can i ask for schematics ? What is tek support forum ? Sorry for my noobbines.



Re: TDS540D issue

dukeluca86@...
 

Hello, where can i ask for schematics ? What is tek support forum ? Sorry for my noobbines.


Re: S-6 sampling head

Eino Väänänen
 

Hi Albert,
 
I have attached pictures from 1 kHz, 1 MHz and 10 MHz square waves. Plug-n 7S11 is different than earlier and 1 MHz signal looks better now. 10 MHz signal looks right.
 
Eino
 

Sent: Tuesday, February 18, 2014 12:06 PM
Subject: Re: [TekScopes] RE: S-6 sampling head
 
 

Hi Eino,

You might have a newer S-2 version, not shown in that manual. Then C14 determines transient response, in stead of R13. Before opening the S-2 I would check slower AC response (was suggested earlier), very slow like 1 kHz Scope Calibrator or even DC. If the trace doesn't reflect AC amplitude or DC input level but does respond to Offset then likely it's not R13/C14.
Albert


Re: OT: newly introduced ant species crawls into electronics to die

Geoffrey Thomas
 

That reminds me of the tale recounted many years ago in the pages of Practical Wireless in the 1960's. An engineer was called out to a "wireless set" which had no reception. He opened the back and found the whole of the inside to be covered in some sort of furry substance which he gingerly removed. He questioned the owner as to what it might be, and he/she explained that when they first had the radio reception was poor but they discovered that it improved when someone touched the little socket (Ae) on the back. In an effort to reproduce this they attached a sausage to the Ae socket- it must have worked as they then installed it inside the radio out of sight. The rest is self-explanatory. I think the column it appeared in was by "Cathode Ray".

Geoff.

On 18/02/2014 11:35, Geoff Blake wrote:


Equally off topic:

I have never met spiders or ants emanating from electronic equipment but
have had some strange smells from time to time.

The worst case was when I was in the TV repair business, some 50 years
back. I had a call to a customer regarding a "Strange smell coming from
the TV". This was in the days when it was not unusual to find selenium
rectifiers still used, with the "burnt cabbage" smell when they were
failing, but the TV was still working and it was a Pye V200, which used
a thermionic rectifier. Puzzled I was.

I arrived at the customers home and went into the TV room, yes it was
really honking some. I took a deep breath and removed the back of the
TV. There it was, draped over the rectifier, which was a (Pro Electron)
PY32, which was in the same size envelope as a 6L6G, and partially
cooked. It was particularly foul smelling and I borrowed a set of rubber
gloves to remove it. I also changed the rectifier as much of it had stuck.

After replacing the rectifier the TV still worked and smelt considerably
less.

What was it. I believe it was a mouse, but could have been a small rat,
I didn't look too close.

Geoff

#################################################
Geoff Blake, G8GNZ JO01fq: Chelmsford, Essex, UK


Re: OT: newly introduced ant species crawls into electronics to die

Geoff Blake <geoff@...>
 

Equally off topic:

I have never met spiders or ants emanating from electronic equipment but have had some strange smells from time to time.

The worst case was when I was in the TV repair business, some 50 years back. I had a call to a customer regarding a "Strange smell coming from the TV". This was in the days when it was not unusual to find selenium rectifiers still used, with the "burnt cabbage" smell when they were failing, but the TV was still working and it was a Pye V200, which used a thermionic rectifier. Puzzled I was.

I arrived at the customers home and went into the TV room, yes it was really honking some. I took a deep breath and removed the back of the TV. There it was, draped over the rectifier, which was a (Pro Electron) PY32, which was in the same size envelope as a 6L6G, and partially cooked. It was particularly foul smelling and I borrowed a set of rubber gloves to remove it. I also changed the rectifier as much of it had stuck.

After replacing the rectifier the TV still worked and smelt considerably less.

What was it. I believe it was a mouse, but could have been a small rat, I didn't look too close.

Geoff

#################################################
Geoff Blake,   G8GNZ    JO01fq:   Chelmsford,  Essex,  UK
<geoff@...>    or   <melecerties@...>
Using Linux: Ubuntu 11.04 on Intel or Debian on UltraSparc
and Apple OS X 10.8.2 Mountain Lion on my Macbook Pro.    
                Avoiding Micro$oft like the plague.
#################################################


On 18 February 2014 10:09, Don Black <donald_black@...> wrote:


Sounds like they're bad for YOUR electronics..Don Black.

On 18-Feb-14 5:47 PM, Dave Seiter wrote:
 
But neither are healthy for electronics.  I don't know how many times I've been poking around inside a piece of gear and a large, fat black spider runs out.  No ants yet...

-Dave


From: Don Black
To: TekScopes@...
Sent: Monday, February 17, 2014 10:14 PM
Subject: Re: [TekScopes] OT: newly introduced ant species crawls into electronics to die

 
I believe Arachnids are spiders, not ants (insects).
Don Black.

On 16-Feb-14 12:44 PM, dukeluca86@... wrote:
 
Wow... sounds like aracnattack or other b movies... never heard of this before... where i live (Italy) there's no problem with ants, they are in the ground, we over it... what's this things comin out from my keyboard ?

Seriously, i only had one case once upon a time with aracnid nest in an old tube radio, but very old and comin from eastern europe contry, they nested in the variable capacitor, blocking it.




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Re: OT: newly introduced ant species crawls into electronics to die

Don Black <donald_black@...>
 

Sounds like they're bad for YOUR electronics..Don Black.

On 18-Feb-14 5:47 PM, Dave Seiter wrote:
 
But neither are healthy for electronics.  I don't know how many times I've been poking around inside a piece of gear and a large, fat black spider runs out.  No ants yet...

-Dave


From: Don Black
To: TekScopes@...
Sent: Monday, February 17, 2014 10:14 PM
Subject: Re: [TekScopes] OT: newly introduced ant species crawls into electronics to die

 
I believe Arachnids are spiders, not ants (insects).
Don Black.

On 16-Feb-14 12:44 PM, dukeluca86@... wrote:
 
Wow... sounds like aracnattack or other b movies... never heard of this before... where i live (Italy) there's no problem with ants, they are in the ground, we over it... what's this things comin out from my keyboard ?

Seriously, i only had one case once upon a time with aracnid nest in an old tube radio, but very old and comin from eastern europe contry, they nested in the variable capacitor, blocking it.




This email is free from viruses and malware because avast! Antivirus protection is active.







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Re: S-6 sampling head

Albert Otten
 

Hi Eino,

You might have a newer S-2 version, not shown in that manual. Then C14 determines transient response, in stead of R13. Before opening the S-2 I would check slower AC response (was suggested earlier), very slow like 1 kHz Scope Calibrator or even DC. If the trace doesn't reflect AC amplitude or DC input level but does respond to Offset then likely it's not R13/C14.
Albert

====
Thanks Mike!
Do you mean this manual on TekWIKI site?
It is only manual I have.
 
Eino
 
 

Look at the S-2 service manual, page 5-13, item 7. Your S-2 is likely misadjusted. 
Mike


Re: Epoxy HV Transformer Question

Morris Odell
 

Hi John,

It was mainly done by a mate of mine who is experienced at these things. The winding data is in the public domain, last time I looked it was in the Tekscopes file section. We obtained some winding wire of the gauge specified in the drawings. The transformer was disassembled by cutting off the existing windings and separating the halves of the core by the tea bag method (poring hot water over it, letting it soak and gently separating the two halves). We left the flux equalising winding intact even though I did not reuse the 5642 diodes in the tripler. I replaced them with modern silicon fast HV diodes.

We followed the number of turns (bifilar etc) specified in the drawing but couldn't wind a nice universal pie (unlike Chuck Harris' excellent 547 replacements). We just wound the secondaries as neatly as we could in layers. Insulation was the big problem, we tried different things but eventually found some quality polyester tape. We didn't pot them at all but that hasn't prevented them from working well for years. A test jig was essential for development as it took a few iterations before we got it right with no corona or flashovers.

Hope this helps, it's a long and sometimes frustrating job but very worthwhile to get these great scopes working again.

Morris

-------------------------------------
Posted by: "John Snyder" Kochcal@earthlink.net ykochcal
Date: Tue Feb 18, 2014 1:03 am ((PST))

Morris

Can you enlighten us a bit on how you went about the rewind. Details or
information on Winder/wire/form/insulation/number of attempts to get one
working?

I have been working towards rewinding a 647a.

John

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


Re: Epoxy HV Transformer Question

ykochcal
 

Morris

Can you enlighten us a bit on how you went about the rewind. Details or
information on Winder/wire/form/insulation/number of attempts to get one
working?

I have been working towards rewinding a 647a.

John



I have a 556 too and hate to have to tell you, but it had the problem. It
showed up on the lower beam transformer as that's the one that supplies the
PDA and has a higher power load, but I had them both rewound. If you're
going to do major surgery like that you might as well do them both at the
same time. The HVPSs are sandwiched in difficult positions at the back of
the scope on either side and require a prolonged effort and much profanity
before the job is done. The transformer rewinds were a new experience for me
and my transformer winding mate, and in order to avoid madness and repeated
assembly and disassembly for testing it was necessary to build up a test
jig with a copy oscillator circuit and loads. It works nicely now but as
Stan says in his book, is probably more scopeage than most people need.

Lots of fun!

Good luck,

Morris

I'm the proud new owner of a 556, which as I understand also has the
epoxy transformers. And not one, but two! As of now, it doesn't have the
"disease." I hope it never gets it.


Re: Epoxy HV Transformer Question

Morris Odell
 

I have a 556 too and hate to have to tell you, but it had the problem. It showed up on the lower beam transformer as that's the one that supplies the PDA and has a higher power load, but I had them both rewound. If you're going to do major surgery like that you might as well do them both at the same time. The HVPSs are sandwiched in difficult positions at the back of the scope on either side and require a prolonged effort and much profanity before the job is done. The transformer rewinds were a new experience for me and my transformer winding mate, and in order to avoid madness and repeated assembly and disassembly for testing it was necessary to build up a test jig with a copy oscillator circuit and loads. It works nicely now but as Stan says in his book, is probably more scopeage than most people need.

Lots of fun!

Good luck,

Morris

--------------------------
Posted by: "Cliff White" cn.white@sunbelt-plb.com kf5iyl
Date: Mon Feb 17, 2014 5:33 pm ((PST))

I'm the proud new owner of a 556, which as I understand also has the
epoxy transformers. And not one, but two! As of now, it doesn't have the
"disease." I hope it never gets it.


Re: OT: newly introduced ant species crawls into electronics to die

Dave Seiter
 

But neither are healthy for electronics.  I don't know how many times I've been poking around inside a piece of gear and a large, fat black spider runs out.  No ants yet...

-Dave


From: Don Black
To: TekScopes@...
Sent: Monday, February 17, 2014 10:14 PM
Subject: Re: [TekScopes] OT: newly introduced ant species crawls into electronics to die

 
I believe Arachnids are spiders, not ants (insects).
Don Black.

On 16-Feb-14 12:44 PM, dukeluca86@... wrote:
 
Wow... sounds like aracnattack or other b movies... never heard of this before... where i live (Italy) there's no problem with ants, they are in the ground, we over it... what's this things comin out from my keyboard ?

Seriously, i only had one case once upon a time with aracnid nest in an old tube radio, but very old and comin from eastern europe contry, they nested in the variable capacitor, blocking it.




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Re: Epoxy HV Transformer Question

Andy
 

I had good results removing the epoxy from the HV transformer of a 647.  It was a delicate operation, but it immediately reduced the power consumption of the HV circuit, and eliminated HV problem. 

Andy


Re: OT: newly introduced ant species crawls into electronics to die

Don Black <donald_black@...>
 

I believe Arachnids are spiders, not ants (insects).
Don Black.

On 16-Feb-14 12:44 PM, dukeluca86@... wrote:
 

Wow... sounds like aracnattack or other b movies... never heard of this before... where i live (Italy) there's no problem with ants, they are in the ground, we over it... what's this things comin out from my keyboard ?

Seriously, i only had one case once upon a time with aracnid nest in an old tube radio, but very old and comin from eastern europe contry, they nested in the variable capacitor, blocking it.





This email is free from viruses and malware because avast! Antivirus protection is active.



Re: S-6 sampling head

Eino Väänänen
 

Thanks Mike!
 
Do you mean this manual on TekWIKI site?
It is only manual I have.
 
Eino
 

Sent: Tuesday, February 18, 2014 2:06 AM
Subject: [TekScopes] RE: S-6 sampling head
 
 

Eino-
Look at the S-2 service manual, page 5-13, item 7. Your S-2 is likely misadjusted. 
Mike


Re: Epoxy HV Transformer Question

Chuck Harris <cfharris@...>
 

At some point in the early 1970s, Tek modified the
warranty agreements, and announced that they considered
any scope older than 5 years, I think, was past its
end of life... thus ending its "lifetime guarantee".

In my opinion, that was when the bean counters achieved
critical mass in the company, and the end had already
begun.

-Chuck Harris

Cliff White wrote:

Good. That's what I wanted to hear. :)

I'm the proud new owner of a 556, which as I understand also has the epoxy
transformers. And not one, but two! As of now, it doesn't have the "disease." I hope
it never gets it.

Has anyone here actually tried to contact Tek and make good on that "transformers are
warrantied for the life of the instrument"?

Respectfully,
Cliff White, W5CNW


Re: Epoxy HV Transformer Question

Leon Robinson
 

Tek cancelled that a LONG time ago.
 
Leon Robinson    K5JLR

Political Correctness is a Political Disease.


From: Cliff White
To: TekScopes@...
Sent: Monday, February 17, 2014 7:33 PM
Subject: Re: [TekScopes] Epoxy HV Transformer Question

 
Good. That's what I wanted to hear. :)

I'm the proud new owner of a 556, which as I understand also has the epoxy transformers. And not one, but two! As of now, it doesn't have the "disease." I hope it never gets it.

Has anyone here actually tried to contact Tek and make good on that "transformers are warrantied for the life of the instrument"?

Respectfully,
Cliff White, W5CNW
w5cnw@...
On 02/17/2014 10:43 AM, Chuck Harris wrote:
 
From my anecdotal experience, it would appear that
they are more likely to fail when they are left
unused.

Before I started rewinding 547 transformers, I was
given a 547 that had the transformer disease. It
manifested itself as normal operation for the first
15 minutes, and then the image started to grow in
size (bloom). When that happened, I would turn the
scope off. The next day I would turn it back on,
and then it took 20 minutes before the image bloomed.

This went on for several weeks as I played with the
scope, each time the on time increased somewhat until
it just didn't seem to fail anymore.

So, thinking I had solved the problem, I went on to
other things. At the end of the summer I tried the
scope again, thinking I would calibrate it, and it
worked for only 15 minutes before blooming... Rats!

The pattern repeated. The important thing to note is,
the scope probably went 10 years before the first time
it had an HV failure, and now it was down to a month
or so of disuse before failure. Clearly something had
degraded.

Others have tried baking the transformers for many
months and have achieved limited success... only to
have the transformer again fail after a short while
of sitting unused.

Long before I ever had a 547, I was talking to Deane
Kidd about this and that, and he brought up the transformer
problem... back then Bill Schell was rewinding. He
told me that Tek started to see failures in 547's and
545B's right around the end of their warranty period.
So, Tek took back the scopes, and replaced their transformers
with new old stock transformers... and found they were just
as bad as the transformers they replaced. The went through
their entire stock of transformers and found that virtually
all were bad, causing them to have to do a new run of
transformers just before the warranty was over for 547's.

Naturally, they just followed the exact same recipe
that they had years before, so they are likely doomed
to fail too... but by then the "lifetime" warranty
would be over...

-Chuck Harris

Cliff White wrote:
> Are epoxy transformers (such as in the 547) more or less likely to fail if the scope
> is used regularly versus rarely? Or does it matter?
>




Re: Epoxy HV Transformer Question

Cliff White
 

Good. That's what I wanted to hear. :)

I'm the proud new owner of a 556, which as I understand also has the epoxy transformers. And not one, but two! As of now, it doesn't have the "disease." I hope it never gets it.

Has anyone here actually tried to contact Tek and make good on that "transformers are warrantied for the life of the instrument"?

Respectfully,
Cliff White, W5CNW
w5cnw@...

On 02/17/2014 10:43 AM, Chuck Harris wrote:
 

From my anecdotal experience, it would appear that
they are more likely to fail when they are left
unused.

Before I started rewinding 547 transformers, I was
given a 547 that had the transformer disease. It
manifested itself as normal operation for the first
15 minutes, and then the image started to grow in
size (bloom). When that happened, I would turn the
scope off. The next day I would turn it back on,
and then it took 20 minutes before the image bloomed.

This went on for several weeks as I played with the
scope, each time the on time increased somewhat until
it just didn't seem to fail anymore.

So, thinking I had solved the problem, I went on to
other things. At the end of the summer I tried the
scope again, thinking I would calibrate it, and it
worked for only 15 minutes before blooming... Rats!

The pattern repeated. The important thing to note is,
the scope probably went 10 years before the first time
it had an HV failure, and now it was down to a month
or so of disuse before failure. Clearly something had
degraded.

Others have tried baking the transformers for many
months and have achieved limited success... only to
have the transformer again fail after a short while
of sitting unused.

Long before I ever had a 547, I was talking to Deane
Kidd about this and that, and he brought up the transformer
problem... back then Bill Schell was rewinding. He
told me that Tek started to see failures in 547's and
545B's right around the end of their warranty period.
So, Tek took back the scopes, and replaced their transformers
with new old stock transformers... and found they were just
as bad as the transformers they replaced. The went through
their entire stock of transformers and found that virtually
all were bad, causing them to have to do a new run of
transformers just before the warranty was over for 547's.

Naturally, they just followed the exact same recipe
that they had years before, so they are likely doomed
to fail too... but by then the "lifetime" warranty
would be over...

-Chuck Harris

Cliff White wrote:
> Are epoxy transformers (such as in the 547) more or less likely to fail if the scope
> is used regularly versus rarely? Or does it matter?
>



Re: S-6 sampling head

Mike
 

Eino-
Look at the S-2 service manual, page 5-13, item 7. Your S-2 is likely misadjusted. 
Mike


Re: Model 555 in Detroit area --- free to a "good" home.

Paul Amaranth
 

If anybody is interested in this, I can serve as an intermediary. I have no
interest (or room) for this one myself.

Paul

On Mon, Feb 17, 2014 at 01:44:02PM -0500, Mark Kahrs wrote:
From another list, reposting with permission:

Subject: [rescue] Old oscilloscope free to a good home (detroit metro area)
I picked up an old tektronix 555 a while ago and I haven't had the desire
to fix it up that I thought I would. It supposedly has bad power caps, but
the diagnosis will have to continue after they are replaced if they're not
the only problem. It's a huge 'scope and really quite good looking to me,
but I want the space and would feel bad about scrapping it for parts. I
have a few plug-in modules for it, and they can go with it. It's hitting
the scrapper in a week if I can't get someone to take it by then.

Evan Allen

abzman2000 at google's email service if you know what I mean...
--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@AuroraGrp.Com | Unix & Windows

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