Date   
Re: Tek 576 Curve Tracer HV Transformer winding

Craig Sawyers
 

My wife yelled "I smell something" so

Did someone mention that you should use an old toaster oven that is not in the house?

John
The mistake was doing something like that when SWMBO was in the house!

Craig

Re: Tek 576 Curve Tracer HV Transformer winding

ykochcal
 

My wife yelled "I smell something" so

Did someone mention that you should use an old toaster oven that is not in
the house?

John

7403N questions

Ed Breya
 

I recently picked up the cheapest 7K scope I ever got - ten bucks for a 7403N with three plug-ins, claimed to be working - but I found it to not be. For that price, I don't care. Presuming I can get it running again without too much grief, I can use the mainframe for a 7D01 or 7D20, IF there's enough juice available to run these power hogs. They make their own readouts, so the "N" (as in No readout built into the mainframe) doesn't matter. The plugs are a 7A18, 7A15A, and 7B50, all very beat up mechanically, but amazingly clean inside. I always save old plug-in carcasses to make custom units anyway, so they will go directly to the parts department. I have some questions then, on this mainframe:

1. Does the 7403N have any chance at all to properly run these big two- or three-wide plug-ins? I recall discussions regarding not having enough power in certain mainframes, so this is likely a major issue here.
2. Is it possible to field-add the readout function to this model? I think that on most higher-level "N" models, it can be fitted later, but I don't know if this one is so bare-bones that there's no provision for upgrading. I have lots of good spare RO boards and cabling, but don't know if the main interface board even has the connections available.

Ed

Re: Tek 576 Curve Tracer HV Transformer winding

Mlynch001
 

Success! I jacked the oven up to 350 and went for broke. My wife yelled "I smell something" so I figured it was hot enough. Gave it a twist as instructed and it popped apart. One outer leg had already fallen off, so I am thinking that the core was already cracked by the earlier attempt. No harm, no foul, super glue to the rescue.

I APPRECIATE all the advice that was given. A special thanks to Chuck Harris for his concise instructions. Now to figure out how to make and wind a new bobbin.

Sincerely,

--
Michael Lynch
Dardanelle, AR

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Mlynch001
 

Tom,

My wife found this very funny! She says that I need to go to the pharmacy and pick up a bottle or three. She says, flat out, "no 400 + scopes for you"!

Alan, Pleased to meet you and to finally learn of your collection and your winning the prize.

--
Michael Lynch
Dardanelle, AR

Re: 561B Recapping

Glydeck
 

I would be interested as well. — George

On Sep 15, 2019, at 1:17 PM, David Holland <david.w.holland@...> wrote:

Anyone recapped a Tektronix 561B, and have some pointers for capacitor
replacement specifications? (ESR/DF & ripple current ratings
particularly)

Looking up the Tektronix part numbers will lead to NSN numbers, which
will give original manufacturers, (Sprague/Mallory), and purported
original part numbers, that I can not find references to.

There's nothing I'm aware of specifically wrong with the scope at the
moment, other than 47 years on those caps - based on the 1972 date
codes, and a serial # in the B19xxx range.

There is also 2 (of 3) tantalum capacitors that don't seem to be
de-rated particularly well (C11 & C31). - (Yes, they look like
tantalum, the NSN's say they are tant., and their tiny physical size
strongly implies it as well.)

I've a DER DE-5000 and a HV supply (Eico 950B) so I could pull them
and measure DF/ESR/leakage/etc to my hearts content, but if I'm going
to remove them, I'd just as soon put new caps back in circuit.

Suggestions? Comments? Cries of Derision?

Thanks,

David


Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

 

Even more powerful is "Angry Spouse 2.0".

On 9/15/2019 7:14 PM, Dave Voorhis wrote:
On 15 Sep 2019, at 23:56, John Williams <books4you@...> wrote:

Umm, I was wondering if you could share the name of the anti-collection medication?
I bet it’s called “Angry Spouse.” :-)


Re: From 2014: Tektronix Announces Winner of Europe's Oldest Working Oscilloscope Contest

Craig Sawyers
 

Hi Alan very pleased to meet you. Thank you for your contributions and congratulations on your win.
Umm, I was wondering if you could share the name of the anti-collection medication? Thanks. John
I'll answer that - there is no known cure!

Craig

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Dave Voorhis
 

On 15 Sep 2019, at 23:56, John Williams <books4you@...> wrote:

Umm, I was wondering if you could share the name of the anti-collection medication?
I bet it’s called “Angry Spouse.” :-)

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

John Williams
 

Hi Alan very pleased to meet you. Thank you for your contributions and congratulations on your win. Umm, I was wondering if you could share the name of the anti-collection medication? Thanks. John

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Mlynch001
 

Dennis,

Well said!

--
Michael Lynch
Dardanelle, AR

Re: 11801 NVRAM

Reginald Beardsley
 

FYI I created a photo album and posted a picture of the 33622A ramp displayed on my 11801 using an SD-26 head at 1 ps/div and 2 mV/div with 1024 samples.

With a trigger signal at 100 kHz, you need a ramp at 100.0001 kHz to test the linearity of the time base. I'm just using the internal timebase, the 33622A set as close as I could and taking the photo at the right moment. It took a couple of tries. I'll try for more rigorous results later.

I'd like to thank be_moulton for suggesting the idea. I had pondered the subject, but lacked the insight needed. It's a great pleasure to have such excellent company join us.

Have Fun!
Reg

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

 

Hi Alan,

Let me be the first (of many) on TekScopes to congratulate you on winning the MDO scope. I was also less than impressed by all the ballyhoo when Tek chose to make a big deal of the Mixed Domain concept as something new. I've been mixing domains with 7000 scopes for years. There are other domains the MSO can't do that they chose to ignore because it would have deflated their marketing hype.

I am appalled that the people at the event have never see a CRT scope and that they would be amazed by the things you demonstrated to them. I'm reminded that "Those who cannot remember the past are condemned to repeat it." You did all of us a favor by sticking it to them about the capabilities of the older laboratory scopes.

Dennis Tillman W7PF

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Alan Ainslie
Sent: Sunday, September 15, 2019 2:54 PM

I confirm - alive and well and taking medication for collecting obession.

The Oldest Tek Scope competition seems so long ago - I did not make any fuss at the time but it was quite an event - I have a 511 which did not work and was therefore disqualified (it does now), and was rather surprised that the 511AD won the day.

I do remember at the handover of the sexy new toy that the staff had never seen a CRT scope! I was pleased to show that a 555 with SA and signal PIs would do mixed domain, as would the 7854 with logic analyser
- the staff were amazed. My jibe about no real progress fell on deaf ears.

I also confess to buying the Fiches recently. I have not got them yet, but will see what we have and see if there is still enthusiasm in the UK to do some automated scanning. I have The Eddystone Radio Museum and Archive, and although I did not do the work, there was a panic when factory blueprints were not to be destroyed and were quickly microfiched. Well after the event the fiches were scanned, but these were individual schematics rather than pages of manuals, so maybe the Tek Fiche task is a much bigger job. But I am sure that we can assemble a small group to look at the challenge and share the outcome.

Regards

Alan




--
Dennis Tillman W7PF
TekScopes Moderator

Re: From 2014: Tektronix Announces Winner of Europe’s Oldest Working Oscilloscope Contest

Alan Ainslie
 

I confirm - alive and well and taking medication for collecting obession.

The Oldest Tek Scope competition seems so long ago - I did not make any fuss at the time but it was quite an event - I have a 511 which did not work and was therefore disqualified (it does now), and was rather surprised that the 511AD won the day.

I do remember at the handover of the sexy new toy that the staff had never seen a CRT scope!  I was pleased to show that a 555 with SA and signal PIs would do mixed domain, as would the 7854 with logic analyser - the staff were amazed. My jibe about no real progress fell on deaf ears.

I also confess to buying the Fiches recently.  I have not got them yet, but will see what we have and see if there is still enthusiasm in the UK to do some automated scanning.  I have The Eddystone Radio Museum and Archive, and although I did not do the work, there was a panic when  factory blueprints were not to be destroyed and were quickly microfiched.  Well after the event the fiches were scanned, but these were individual schematics rather than pages of manuals, so maybe the Tek Fiche task is a much bigger job. But I am sure that we can assemble a small group to look at the challenge and share the outcome.

Regards

Alan

Re: Tek 576 Curve Tracer HV Transformer winding

Mlynch001
 

Chuck,

Thanks! That is what I plan to do. I’m glad to know that breaking them can be repaired with super glue. That makes me more at ease with the whole process. I really appreciate you explaining the process in depth. I will post my results.

Sincerely,
--
Michael Lynch
Dardanelle, AR

Re: Tek 576 Curve Tracer HV Transformer winding

Jim Ford
 

Blaze Pizza cooks theirs in 180 seconds, and Pizza 90 does it in 90.  Must be pretty darn hot ovens!  Thin crust only, of course.  Both are excellent pizzas.Sorry to take it so far OT.Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Dave Daniel <kc0wjn@...> Date: 9/15/19 1:06 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding On 9/15/2019 3:34 PM, Chuck Harris wrote:> Just remember the ferrite is a ceramic mixture,> so it was once heated much hotter than your oven> will ever go.Ha. This reminds me of Jeff Potter's book "Cooking for Geeks", where he intentionally disables the self-cleaning interlock on his range to see how fast he can cook a pizza. ISTR that he got the oven temperature to well over 600^o.DaveD

Re: Tek 576 Curve Tracer HV Transformer winding

Chuck Harris
 

The cores across pretty much everything they made are
equivalent. Some of the later cores had special divots
molded into them for holding a clamp.

-Chuck Harris

ykochcal wrote:

Chuck is the 576 core the same as the 535, 545, and 585? I don't recall off
hand.

If so, there seems to be someone who scrapped a large number of scopes on
the bay and is selling the HV supply assemblies for about $24 in the USA

Searched "Tektronix transformer", sort by best match, but then look for the
worst match at the bottom.

So all is not lost in any case for a 576

John

561B Recapping

David Holland
 

Anyone recapped a Tektronix 561B, and have some pointers for capacitor
replacement specifications? (ESR/DF & ripple current ratings
particularly)

Looking up the Tektronix part numbers will lead to NSN numbers, which
will give original manufacturers, (Sprague/Mallory), and purported
original part numbers, that I can not find references to.

There's nothing I'm aware of specifically wrong with the scope at the
moment, other than 47 years on those caps - based on the 1972 date
codes, and a serial # in the B19xxx range.

There is also 2 (of 3) tantalum capacitors that don't seem to be
de-rated particularly well (C11 & C31). - (Yes, they look like
tantalum, the NSN's say they are tant., and their tiny physical size
strongly implies it as well.)

I've a DER DE-5000 and a HV supply (Eico 950B) so I could pull them
and measure DF/ESR/leakage/etc to my hearts content, but if I'm going
to remove them, I'd just as soon put new caps back in circuit.

Suggestions? Comments? Cries of Derision?

Thanks,

David

Re: Tek 576 Curve Tracer HV Transformer winding

ykochcal
 

Chuck is the 576 core the same as the 535, 545, and 585? I don't recall off
hand.

If so, there seems to be someone who scrapped a large number of scopes on
the bay and is selling the HV supply assemblies for about $24 in the USA

Searched "Tektronix transformer", sort by best match, but then look for the
worst match at the bottom.

So all is not lost in any case for a 576

John

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Chuck
Harris
Sent: Sunday, September 15, 2019 12:35 PM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Transformer winding

Just remember the ferrite is a ceramic mixture,
so it was once heated much hotter than your oven
will ever go.

Good gloves so you don't burn yourself, don't worry
about the winding. Soak it in the oven, and then
remove it and with two hands give the top half and
the bottom half a twist, like you were removing a
jar lid.

If that doesn't work, up the temperature.

If you break it, don't cry. A drop of thin crazy
glue, and carefully aligning it back together, and
you will never know you did it... electrically.

A dry trial fit is a good idea, and a little compressed
air to remove any extra bits of ferrite sand that may
be in the way of a good fit.

-Chuck Harris

Mlynch001 wrote:
John,

I will try this again at a higher temp. You are very certainly right
about this. I have not done any "practice" since I don't have anything to
practice on. I guess this is my "practice" piece? I'm going to cut the
rest of the coil off and then go from there. I appreciate Chuck's offer,
but I really feel the need to try to do this on my own. I may break the
core, I may be successful or, in the end, I may give up and send it to
Chuck. If I break these ferrite cores, I may come crying to Chuck or others
for a replacement set. I appreciate your advice and insight. One way or
the other, I will get this thing fixed. It is a shame that one stupid part
has disabled an otherwise functioning instrument. Before it "cuts off", it
works beautifully.

Sincerely

Re: Tek 576 Curve Tracer HV Transformer winding

Dave Daniel
 

On 9/15/2019 3:34 PM, Chuck Harris wrote:
Just remember the ferrite is a ceramic mixture,
so it was once heated much hotter than your oven
will ever go.
Ha. This reminds me of Jeff Potter's book "Cooking for Geeks", where he intentionally disables the self-cleaning interlock on his range to see how fast he can cook a pizza. ISTR that he got the oven temperature to well over 600^o.

DaveD