Date   

Re: Tek 576 Curve Tracer HV Replacement Transformer

Chuck Harris <cfharris@...>
 

Tam,

I accept that you are a vulgarian who needs to reference
some elimination or procreation bodily function in every
utterance. Most children out grow of that phase.

...But...

Why do you insist on editing Tektronix out of history?

Danaher started as DMG in 1969, and didn't even incorporate
under the Danaher name until 1984. They didn't buy Tektronix
until 2007.

Danaher didn't exist in any form when the 576 was first
offered for sale.

Danaher didn't exist in any form when the 7000 series was
first offered for sale.

Danaher wasn't even incorporated when the 465 was first
offered for sale... nor when the 2465, its replacement was
first offered for sale... nor the 5000 series, nor the 7904,
nor the 7104.... need I go on?

Do you think that Tektronix is not worthy of being remembered?

You are puzzling me man.

-Chuck Harris

Tam Hanna wrote:

I don't have such a Danaher oscilloscope, but two printers. If anyone wants a part, I'll fart one out.

Tam
---
With best regards
Tam HANNA (emailing on a BlackBerry PRIV)

Enjoy electronics? Join 14k other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/




Re: 2445A slow

Steve
 

I thought I had replied but obviously didn't . I put the 4.7/10 tantalum back in it's proper place. I have some NOS Sprague orange drop 4.7 35's but figured I'd just leave the tent alone and not try and sub in a 35 volt cap where a 10 volt cap even though both are tantalums. I should be getting parts in tomorrow to do the power supply lytics. I looked at the anode board, I have 8 caps and only one is an electrolytic axial cap. I can't see it well enough to know it's value without going into the service manual and I would have to dissasemble the HV supply to raise the board enough to remove it, Problem is I know I don't have any axial caps that size or value. I have 1uf/50 and 2 470/100, i don't do much with axial caps these days unless I'm working on a reel to reel or tube amp so I order them as needed. I'm not sure how critical it is to change that cap or the others on that board but if they are critical then I will order the parts to change them all.
--
Kind Regards,

steve


Tds1001b upgrade?

filozoph@...
 

Recently I bought TDS1001b. I wonder if anyone managed to upgrade it to 1012b. I tried to use the trick from eevblog, somehow after checking for connection any further step give no response. Any clues if it works with “b” version?
Regards
Mark.


Re: Tek 576 Curve Tracer HV Replacement Transformer

Tam Hanna
 

I don't have such a Danaher oscilloscope, but two printers. If anyone wants a part, I'll fart one out.

Tam
---
With best regards
Tam HANNA (emailing on a BlackBerry PRIV)

Enjoy electronics? Join 14k other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Re: Tek 576 Curve Tracer HV Replacement Transformer

Mlynch001
 

I do have a question about the load resistor. I think it is supposed to be about 470K Ohms? Does this need to be a special resistor or can you use a 1/2W metal film resistor?

--
Michael Lynch
Dardanelle, AR


Re: Tek 576 Curve Tracer HV Replacement Transformer

Mlynch001
 

On Tue, Apr 7, 2020 at 03:54 PM, Ernesto wrote:


Hi Michael,

Your design of the box looks excellent. Every diode,cap pair has its own
compartment isolated from the others. (It brings to mind our situation of
social isolation)
Could you add the dimensions of the box, to give an idea of its size?

Ernesto
Ernesto,

Thank you!

The box is the same size as the original 465 Multiplier.

Those dimensions are:
66.5mm - Length
47.0mm - Width
34.5mm - Height

I designed it to use nylon screws which thread into the bottom of the box and to mount through the original mount holes. This allows the part to be more easily removed, without flexing the circuit board up for clearance. The original part used two studs protruding from the bottom of the part and thus were more difficult to extract from the tight space that the multiplier occupies.

I can send the STL file to anyone who would like to print one and try it out.

I have enough materials to build the multiplier, just have not found the time to do so.
--
Michael Lynch
Dardanelle, AR


Re: Tek 576 Curve Tracer HV Replacement Transformer

Chuck Harris <cfharris@...>
 

One of the big problems with the 475's HV xection is
the HV leaking at every joint, and going "tic, tic, tic,..."
as it arcs to the nearest ground like surface.

The 465 uses nearly as much voltage on its anode, so
I can see it now....

I would be more inclined to stand on the shoulders of VARO,
etal, that made the original triplers, and duplicate what
they did. Or, easier still, sift through the wide variety
of triplers that are out in the wild as used, nos, and new
parts.

Potting is pretty easy for stuff like this... transformers
are much harder to get right. A two part RTV... any two
part RTV would be great. I have even used a one part RTV,
but in thin layers... the pourable clear RTV sold as a
windshield sealant works very well. You do have to let it
fully vulcanize before you apply HV... which is why only
thin layers.

-Chuck Harris

Ernesto wrote:

Hi Chuck,

You raise important issues of space and insulation. While the display unit of the 7704 to the right of the CRT is practically empty, the 465 appears to be packed tight inside. But it seems that there is some useful space on top, over the neck of the CRT. Imagine the 6 diodes and 6 caps of the multiplier placed generously apart flat on a narrow and long insulating board. We take a sheet of mylar and wrap it many times around this finished board. Since the scope is an electrically delicate environment we don't want to introduce a 50 khz square wave of several Kvolts radiating around, so we bring from the kitchen a box of aluminum foil and wrap it many many times around the board over the mylar. Now, instead of a cable from the HV supply to the CRT carrying the 15.5 Kvolts, we route the output of the transformer with an insulated wire inside of a medium size plastic tube and also wrapped in aluminum foil, to the start of the ladder. The "multiplier" is placed over the neck of the CRT (over its mumetal shield) and its output is connected straight to the accelerating anode.

The result may not be "pretty". But it will be out of sight, and if it makes the difference between using this excellent scope or throwing it in the garbage, it might be worth the effort.

Regards,
Ernesto


Newly acquired TDS5054B-NV-AV tips and advice wanted

Harold Foster
 

I just got this one in and all seems well. Best guess (original Tek cal date) puts the estimated vintage at around late 2006. Only issue that I can see is that the PCB seems to be slightly loose behind the top-right buttons - everything functions, but wiggles a bit. Other than that, all channels work and the self test and calibration routines pass.

So, what issues typically arise in these? I think the CMOS battery needs to be changed and I'll be inside to tighten the screws on the front board - is there any preventative maintenance or things to check while it is open? What about the availability of software upgrades?

In short, after a *long* string of bad luck (except, thankfully, for a couple of 2465B's and my LT344) i have what begun what I hope will be a happy long term new relationship with my main digital scope. (Which means a perfectly working LT344 with all options is available. Cough, cough.)

Anyway, all help, tips and advice will be greatly appreciated.

TIA,

Hal


Re: Tek 576 Curve Tracer HV Replacement Transformer

 

Hi Michael,

Your design of the box looks excellent. Every diode,cap pair has its own compartment isolated from the others. (It brings to mind our situation of social isolation)
Could you add the dimensions of the box, to give an idea of its size?

Ernesto


Re: Tek 576 Curve Tracer HV Replacement Transformer

 

Hi Chuck,

You raise important issues of space and insulation. While the display unit of the 7704 to the right of the CRT is practically empty, the 465 appears to be packed tight inside. But it seems that there is some useful space on top, over the neck of the CRT. Imagine the 6 diodes and 6 caps of the multiplier placed generously apart flat on a narrow and long insulating board. We take a sheet of mylar and wrap it many times around this finished board. Since the scope is an electrically delicate environment we don't want to introduce a 50 khz square wave of several Kvolts radiating around, so we bring from the kitchen a box of aluminum foil and wrap it many many times around the board over the mylar. Now, instead of a cable from the HV supply to the CRT carrying the 15.5 Kvolts, we route the output of the transformer with an insulated wire inside of a medium size plastic tube and also wrapped in aluminum foil, to the start of the ladder. The "multiplier" is placed over the neck of the CRT (over its mumetal shield) and its output is connected straight to the accelerating anode.

The result may not be "pretty". But it will be out of sight, and if it makes the difference between using this excellent scope or throwing it in the garbage, it might be worth the effort.

Regards,
Ernesto


Re: Tek 576 Curve Tracer HV Replacement Transformer

Mlynch001
 

These things keep surfacing from time to time. Every time I see one, I think that it might be the "last one", but they keep popping up. This interests me, since I have 6 or 7 scopes that use this part. (I know, it is an "addiction")

I have designed a 3D printed enclosure that should hold the necessary components, fit into the same space and that can be potted, as Chuck has stated. I would appreciate the thoughts, suggestions and critique of the design by others. I want to build one, if for no other reason than to say that I DID build one and that it DID work.
Title in Photos:
465/475 HV Multiplier Case
link:
https://groups.io/g/TekScopes/album?id=244462

Feel free to contact me off list if necessary.

--
Michael Lynch
Dardanelle, AR


Re: Tek 576 Curve Tracer HV Replacement Transformer

n4buq
 

Aside from gutting the old potting and replacing the parts, you might try looking for a used/NOS part. Sphere and/or QService appear to be out of stock, but I found a listing for them here:

https://www.surplustechmart.com/lab-test-equipment/oscilloscopes/tektronix-475-465-high-voltage-assembly-152-0552-00-u1432-new-old-stock.html

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Chuck Harris" <cfharris@erols.com>
To: TekScopes@groups.io
Sent: Tuesday, April 7, 2020 10:46:26 AM
Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Replacement Transformer

The principle problem with the 465 and 475 multipliers
is they are packed in a tight space between a couple
of metal shields. Anything you build to replace it will
have to be insulated on at least two sides to handle the
full voltage. Potting is necessary, as the parts have
to be packed pretty tightly to fit the space allowed.

Some have substituted color TV triplers, though I don't
know anything about that.

-Chuck Harris

Ernesto wrote:
Hi John,

I am also thinking about the HV multiplier for my 7704A with a power supply
failure not debugged yet. This part is a 7 stage (X14) multiplier that
provides 21 KV. In case it is bad, I will "create" it one way or another.
There are people with a similar problem who have designed a
do-it-yourself part, in

http://rfscientific.eu/tektronix-7704a-voltage-multiplier-diy-replacement

In your 465 the multiplier gives out a lower voltage, 15.5 KV, and I
suspect that it is a 3 stage (X6). This one should not be difficult to
implement on an insulating board and discrete components. You could bring
out of the HV supply the lower voltage from the transformer and implement
the multiplier all along the CRT, a path that the voltage has to take
anyway, haha. This is what I would do in my 7704, a long strip of 14
diodes and capacitors separated enough that no potting is necessary,
maybe just a plastic cover to avoid someone to put his fingers on it.

Regards,
Ernesto



Re: Tek 576 Curve Tracer HV Replacement Transformer

Chuck Harris <cfharris@...>
 

The principle problem with the 465 and 475 multipliers
is they are packed in a tight space between a couple
of metal shields. Anything you build to replace it will
have to be insulated on at least two sides to handle the
full voltage. Potting is necessary, as the parts have
to be packed pretty tightly to fit the space allowed.

Some have substituted color TV triplers, though I don't
know anything about that.

-Chuck Harris

Ernesto wrote:

Hi John,

I am also thinking about the HV multiplier for my 7704A with a power supply failure not debugged yet. This part is a 7 stage (X14) multiplier that provides 21 KV. In case it is bad, I will "create" it one way or another. There are people with a similar problem who have designed a do-it-yourself part, in

http://rfscientific.eu/tektronix-7704a-voltage-multiplier-diy-replacement

In your 465 the multiplier gives out a lower voltage, 15.5 KV, and I suspect that it is a 3 stage (X6). This one should not be difficult to implement on an insulating board and discrete components. You could bring out of the HV supply the lower voltage from the transformer and implement the multiplier all along the CRT, a path that the voltage has to take anyway, haha. This is what I would do in my 7704, a long strip of 14 diodes and capacitors separated enough that no potting is necessary, maybe just a plastic cover to avoid someone to put his fingers on it.

Regards,
Ernesto


Re: Tek 576 Curve Tracer HV Replacement Transformer

 

Hi John,

I am also thinking about the HV multiplier for my 7704A with a power supply failure not debugged yet. This part is a 7 stage (X14) multiplier that provides 21 KV. In case it is bad, I will "create" it one way or another. There are people with a similar problem who have designed a do-it-yourself part, in

http://rfscientific.eu/tektronix-7704a-voltage-multiplier-diy-replacement

In your 465 the multiplier gives out a lower voltage, 15.5 KV, and I suspect that it is a 3 stage (X6). This one should not be difficult to implement on an insulating board and discrete components. You could bring out of the HV supply the lower voltage from the transformer and implement the multiplier all along the CRT, a path that the voltage has to take anyway, haha. This is what I would do in my 7704, a long strip of 14 diodes and capacitors separated enough that no potting is necessary, maybe just a plastic cover to avoid someone to put his fingers on it.

Regards,
Ernesto

Regards,
Ernesto


Re: 2445A slow

Chuck Harris <cfharris@...>
 

UPW's are a perfectly fine replacement for the 47uf caps.

As to cleaning of the dust, I just use compressed air, 30psi
or so, and all the dust will just go elsewhere.

Don't disassemble the CRT! If you feel a need to clean the
clear implosion protection screen, all you have to do is
remove the plastic ring that goes around the front panel, and
the 5 knobs that are below the CRT.

The HV supply is the Anode supply. The capacitor(s) are right
in your face if you remove the aluminum shield.

I do *not* recommend replacing *any* tantalum cap on *any*
2465 family oscilloscope. Tektronix learned how to perfectly
use tantalum capacitors by the 1980's. In all the years I have
been repairing 2465's, I have never, ever, found even one bad
tantalum capacitor.

You should put back the 4.7uf 10V tantalum capacitor. It needed
to be there.

-Chuck Harris

Steve wrote:

I’ve actually stopped the process and made another order with mouser and bought the proper electrolytic and safety caps. They should be in some time this week. I did change the 4 47uf caps on the A5 board to Nichicon UPW caps. If I did so in error please let me know. I figured the Upw caps would be ok for those though I might be incorrectness. I still haven’t made it to the anode board yet, you say it’s behind the metal cover on the HV supply side? The manual doesn’t show much of it.


Re: 184 Time Mark Gen. - 2nS & 5nS not working

david
 

Thanks for the information guys, looks like I don't have the equipment or the knowledge to fix the 500MHz output. Not going to buy Nuvistors if I won't be able to check the results. My 465 is a 100MHz scope, it shows 130mVpp signal at 200MHz output, so I believe that signal is OK. This 184 is working correctly except for the 500MHz. Only other issue is the 10MHz oscillator frequency does not have enough adjustment range. It is close enough, checking it with a GPSDO at 10MHz it is 9.999xxx, but it is at the limit of adjustment on C11. Any idea why the oscillator is beyond the range of C11 adjustment? Is it just the age of the crystal? Has anyone tried to reduce value of capacitor C11 by putting another cap in series with it? Only need to lower value of C11 a couple pF to fix it. I am amazed at how accurate this 184 is being all analog.
David


回覆︰ Re: [TekScopes] OT Seeking Sencore CA55 Capacitor Analyzer CA55

 

Thanks Greg!


從 iPhone 版的 Yahoo Mail 傳送


星期二, 4月 7, 2020, 01:25 於 Greg Muir via groups.io <big_sky_explorer=yahoo.com@groups.io> 寫道:

Tony,

FYI, there is a Sencore owners group on the web:

https://groups.io/g/SencoreOwnersGroup

Greg


Re: Tek 576 Curve Tracer HV Replacement Transformer

Jim Ford
 

Thanks, Michael, for taking on the transformer resurrection project, for lack of a better phrase.  Although I don't have any vacuum tube scopes (CRTs excepted), so it's unlikely I'd benefit from one.One place where customer service and quality and product longevity still exist (because they must) is products for the military.  That's one of the things that makes me proud to work for Raytheon, as of last Friday now Raytheon Technologies.  The inefficiencies, excessive costs and delays, not so much.I've seen some crazy stuff here, like 14-layer circuit boards when 6 or 8 layers would probably do, front panels machined out of large blocks of aluminum when they could be much thinner and assembled with standoffs costing pennies, and mile-long parts lists with many similar parts that could be easily consolidated.  Not even a thought of how to make things much less expensive. It really irks me, too, that people haven't figured out that development and production are two very different things!  You simply can't apply the same rules to both and expect things to run smoothly!  Duh!OK, rant over.  Thanks for listening. Jim Ford Sent from my Verizon, Samsung Galaxy smartphone
null


Re: Capacitor testing

Roy Thistle
 

On Sat, Apr 4, 2020 at 02:29 PM, Randy Newman wrote:


Which particular [MIL] spec are you referring to?
Hi Randy:
Could it be one of these?
MIL-HDBK-1131A 14 June 2004 SUPERSEDING MIL-HDBK-1131 7 July 1999
Cheers and regards.
Roy


Re: Tek 576 Curve Tracer HV Replacement Transformer

Jim Ford
 

Yes, Dennis, Tek et al are pushing the performance, but only by small increments.  I don't see the innovation like in decades past, unfortunately.  That's what happens in bean-counter-driven companies, which is most of them these days.  Possible exception is military contractors like where I work.   More later in response to Michael Lynch. Jim Ford Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Dennis Tillman W7PF <dennis@ridesoft.com> Date: 4/6/20 8:37 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] Tek 576 Curve Tracer HV Replacement Transformer Hi Dave,Thanks for enlightening me about Tek's commitment to supporting their customers. Prior to releasing a new product Component Testing is necessary to uncover the weaknesses in the design of, and the limitations of, every new component that is in it that your engineers created as well as for every component you buy that is made by another company. Once there is a quantity of the new product in the field the Failure Analysis team takes over. Failure Analysis (regardless of the industry) is a time consuming, expensive, laborious job. China's strategy for the instruments they are flooding the market with is entirely different. They realized that eliminating the Component Testing, Failure Analysis, and Customer Support would reduce the cost of the instrument to a point where the customer would not complain when they were told they could buy a newer model for less than the cost of repair.It appears the Chinese are onto something. The only thing keeping Tek in business is its ability to create instruments with ever increasing performance. Unfortunately those products are so expensive there are comparatively few customers who can afford them.Dennis Tillman W7pF -----Original Message----- From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dave BrownSent: Monday, April 06, 2020 7:13 PMTo: TekScopes@groups.ioSubject: Re: [TekScopes] Tek 576 Curve Tracer HV Replacement TransformerThis thread just irritates me to no end. I will speak from experience of what customer support was like for Tektronix as I was the VP of Manufacturing and Factory Service for the Video and Networking Division. I understand our customer experience and what we did to support them. I did not manage repairs for the 576 but the groups operated with basically the same policy. When a product was phased out, there would be a long term support plan put in place. It would define the number of years Tektronix would fully support a product. Some of the customers were military who had very long (e.g. 20 year) requirements so 10 - 15 and occasionally 20 years would not be unheard of (although I do not know what it was for the 576). This started after the product was retired from sales.During this time Tek would provide full support of repairs for the product. If components were being phased out, we would buy sufficient quantity and eat the cost if they went unused. When the full support period ended, Tek would go to a limited "best efforts" support. If we needed a part and didn't have it, and were still able to buy it, we would research it to see if it was economically feasible. I do remember many conversations about what we had to do to support the customer. I also remember buying used products so we could perform repairs during this best-efforts period. Again, we'd eat the cost of the instrument. What Tek would NOT do is offer support and replacement parts in perpetuity. That just makes no sense.Every product or component has a failure mode. The question is whether it is ever pushed to that point in normal use.  There are a number of 576s out there that the transformers work fine and mine is one such example. I don’t have firsthand knowledge of the failure analysis and conclusions but suspect it was moisture absorption.  The next question is why? Was it deviations in manufacturing or instrument storage and use at high humidity? I don’t know. The fact that Tektronix redesigned the transformer and made it available in the 050-0471-00 kit demonstrates that they cared about their customers. This is one of the many modifications made to the 576 (I scanned the 576 mod summary at the museum).What Tektronix would NOT have done is redesign the transformer for a few customers. The reason is pretty simple. This is by no means intended to be disrespectful of Michael's efforts. What he has done is stupendous and I've ordered a transformer from him. However, his transformer was not evaluated against the full product specifications. He verified functionality in a typical use in a small quantity. The transformer was not evaluated in all revisions of the instrument. It wasn't evaluated in a significant number of instruments. No humidity, altitude, temperature, shake, shock, vibration, transportation,  low-line, high-line, ESD, or EMI tests were done. There was no long term reliability testing done with dissection and analysis. The transformer company certainly didn't do any of these tests either. We actually don't know how long his transformer might last, but it provides repairs to those instruments needing a replacement transformer. This is a different expectation than what a customer buying a Tektronix part for a Tektronix instrument has.Tek went out of their way time and time again in support of the customer. After they had phased out CRT manufacturing because the transition to all digital scopes had occurred, they restarted the operation to manufacture CRTs in support of customer needs. I saw numerous examples in my 34 years at the company and was proud of how Tek took care of their customers.Now that I've shared my observations and experiences, I will not reply on this thread. There's no point in arguing with strangers. By the way, Tektronix still supports their vintage instruments through their support of the vintageTEK museum in a number of ways. I know that firsthand also as I am the museum President.Dave-- Dennis Tillman W7PFTekScopes Moderator

18921 - 18940 of 184517