Date   

Re: Weird 466 horizontal glitch--SOLVED

Mlynch001
 

Power supply voltage and power quality are the foundation of everything else. This was and remains the most important lesson for me when working with these scopes.

--
Michael Lynch
Dardanelle, AR


Re: 2465B - Weak Readout Intensity

flanneltuba@...
 

Thanks, Chuck. I'll do a careful inspection and deoxit cleaning of the Trigger Hybrid chip. I do have a 2465 (two, actually) that I can borrow a known good chip from if necessary as well.

Tony: As for the photos, below is a copy/paste link from the TekScopes Photos gallery of the Album I created earlier, which includes various pictures from this project from day 1 through the present. Nothing spectacular but no doubt familiar "before" type scenes for many of you, showing visibly sad 2465B boards and parts.

Here's the link. Let me know if it does not work: https://groups.io/g/TekScopes/album?id=241733

Thanks,

- Scott


Re: 2465B - Weak Readout Intensity

Chuck Harris
 

That means that the trigger hybrid, which does all of the
time and frequency measurements in the "B" model, is having
trouble triggering on the signals you are presenting to it.

You can try removing the hybrid, and putting a drop of
deoxit on each of its terminals, but most times I find that
the hybrid is bad.

On the bright side, all of the 2465 family trigger hybrids
work in all of the models.

One note, hybrids are wicked easy to break. Be sure that
you have rotated, and wiggled, and set the hybrid flat
down on the board with hand pressure as you are spinning
up the nuts. If you don't, it will sometimes catch the
edge of the ceramic substrate, and crack! You are done.

I use a plastic nut starter, like Heathkit used to include
in their kits, to do the initial nut setting, and finger
tightening: Set all of the nuts, head up, star washer down
on your bench where you can reach them one handed. Install
them, and tighten them as much as the plastic nut setter
will, all the while holding the hybrid down with your other
hand.

When you have done that, use a nutdriver to tighten the nuts
an additional 1/8 to 1/4 turn. This is only to keep the nuts
from working loose due to vibration.

The tightness of the nuts has nothing to do with the quality
of the connections to the hybrid!

-Chuck Harris

flanneltuba@... wrote:

I am finally getting this scope to the point of getting ready to do a full, albeit low precision calibration (+/-10% will be fine for my purposes, and within my reference equipment range). I am seeing one issue with the built in Time/Freq Measurement function. Regardless of the purity of the signal I apply, in the case of the picture, a 5 MHz sine wave from a good source, when I select wither T or 1/T Measurement the alert text "CHx: NOISY OR APERIODIC SIGNAL" is show and no time or frequency measurement is given.

I searched the internet and scoured the manual for any reference to this message, but found nothing.

Perhaps one of you might be familiar with this message/symptom. I will note that I have not yet attempted to do a full calibration on this, but most of the readings are well within reason, if measured by the cursors or screen graticules.

( I posted a picture of the screen shot of this, among others, in the Photos directory on the TekScopes@groups.io web page, but don't know how to link to those pictures here.)

Thanks,

- Scott




Re: 2465B - Weak Readout Intensity

Tony Fleming
 

Let me know where are the pictures, when I went to TekScopes.io there
aren't the picture you are referring to.
Have a great weekend.

On Sun, Feb 23, 2020 at 10:34 AM <flanneltuba@...> wrote:

I am finally getting this scope to the point of getting ready to do a
full, albeit low precision calibration (+/-10% will be fine for my
purposes, and within my reference equipment range). I am seeing one issue
with the built in Time/Freq Measurement function. Regardless of the purity
of the signal I apply, in the case of the picture, a 5 MHz sine wave from a
good source, when I select wither T or 1/T Measurement the alert text "CHx:
NOISY OR APERIODIC SIGNAL" is show and no time or frequency measurement is
given.

I searched the internet and scoured the manual for any reference to this
message, but found nothing.

Perhaps one of you might be familiar with this message/symptom. I will
note that I have not yet attempted to do a full calibration on this, but
most of the readings are well within reason, if measured by the cursors or
screen graticules.

( I posted a picture of the screen shot of this, among others, in the
Photos directory on the TekScopes@groups.io web page, but don't know how
to link to those pictures here.)

Thanks,

- Scott




Re: 547 scope HV transformer problem. One practical solution.

stevenhorii
 

Albert,

Thanks! That was it! I have never seen another one of these.

Steve

On Sun, Feb 23, 2020, 09:38 Albert Otten <aodiversen@...> wrote:


I also had an oddball 7000-series that I
think was a short-lived precursor of the 7854. It had a section in
between
the plug-ins and the display that, like the 7854, had a number of
waveform
computing functions. I don’t recall the number and I no longer have it -
I
sold it at a hamfest. Also, I don’t see it on TekWiki.
Steve, that might have been a 7704A with P7001 DPO.
http://w140.com/tekwiki/wiki/P7001
Albert




Re: 547 scope HV transformer problem. One practical solution.

 

Hi fiftythreebuick,

A thread about the 555 is a great idea. It could be very educative for those of us who have never seen one in person.
For example, you could describe what is your convenience of having a dual beam over a single beam with multiple channels.
And how or if you have done routine maintenance of this scope.

Regards,
Ernesto


Re: 2465B - Weak Readout Intensity

flanneltuba@...
 

I am finally getting this scope to the point of getting ready to do a full, albeit low precision calibration (+/-10% will be fine for my purposes, and within my reference equipment range). I am seeing one issue with the built in Time/Freq Measurement function. Regardless of the purity of the signal I apply, in the case of the picture, a 5 MHz sine wave from a good source, when I select wither T or 1/T Measurement the alert text "CHx: NOISY OR APERIODIC SIGNAL" is show and no time or frequency measurement is given.

I searched the internet and scoured the manual for any reference to this message, but found nothing.

Perhaps one of you might be familiar with this message/symptom. I will note that I have not yet attempted to do a full calibration on this, but most of the readings are well within reason, if measured by the cursors or screen graticules.

( I posted a picture of the screen shot of this, among others, in the Photos directory on the TekScopes@groups.io web page, but don't know how to link to those pictures here.)

Thanks,

- Scott


Re: 547 scope HV transformer problem. One practical solution.

fiftythreebuick
 

If anyone is interested it more info about the 555 it should probably be in a separate thread in order to keep this one on topic...


Re: 547 scope HV transformer problem. One practical solution.

fiftythreebuick
 

Hi Ernesto!

The 555 is my favorite oscilloscope ever... An absolute pleasure to operate, incredible versatility (considering the range of letter & 1 series plug-in units) and the typically excellent design and construction of the 500 series! I have had one at my bench since the mid 70s and hope to keep one operational for as long as I am... 😊

Tom


Re: Weird 466 horizontal glitch--SOLVED

Edward Prest
 

Silly me. 140 volts has a glitch. measures slightly low with dmm but scope shows 120 hz 30 volt glitch.
Its the power supply cap! its amazing the scope runs as well as it does with this fault.


New 2465 Seimens brushless motor

victor.silva
 

I am not associated with this seller.

I found a seller on ebay selling the Seimens 1AD3001-0A brushless motors for a reasonable price.
The shipping is steep for USA Parcel Post, but the total cost to buy is ok.

These motors are used in most of the Tek 2465 and some 2465A, 2465B(w/option 01).

https://www.ebay.com/itm/Siemens-1AD3001-OA-Motor-10-15volts/274013390896

--Victor


Re: 547 scope HV transformer problem. One practical solution.

Albert Otten
 


I also had an oddball 7000-series that I
think was a short-lived precursor of the 7854. It had a section in between
the plug-ins and the display that, like the 7854, had a number of waveform
computing functions. I don’t recall the number and I no longer have it - I
sold it at a hamfest. Also, I don’t see it on TekWiki.
Steve, that might have been a 7704A with P7001 DPO.
http://w140.com/tekwiki/wiki/P7001
Albert


Re: 547 scope HV transformer problem. One practical solution.

stevenhorii
 

I once ran into a former Tek employee at a hamfest where I was looking over
one of the 500-series scopes. He said that in the day when Tek serviced
them, they washed them with water and then warm-air dried them. I will have
to look for that publication to verify what he said. I don’t doubt it would
work with the tube-type scopes but I’d have some concerns about doing that
with the solid state ones. Some of the switches in the plug-ins don’t look
waterproof but also look like they would be difficult to dry out with air.

I’m new to this group, but not to using Tek scopes. My first was a purchase
from DoD Surplus Sales (back before they privatized it). It was a 545A and
was DOA. I found the problem quickly - a bad resistor in the power supply.
I replaced that, and the scope powered right up. I had several of the
500-series after that (a 585, 547, and a 556 - should have kept that one. I
donated the scopes to the lab I was working in when I left. By that time, I
started getting the 7000-series scopes and still have most of those (a
7704A, 7904A, 7104, R7844, 7854). I also had an oddball 7000-series that I
think was a short-lived precursor of the 7854. It had a section in between
the plug-ins and the display that, like the 7854, had a number of waveform
computing functions. I don’t recall the number and I no longer have it - I
sold it at a hamfest. Also, I don’t see it on TekWiki. I still use the
R7844 on occasion, but have mostly turned to the TDS3054C digital. I know
the analog folks have likely instantly put me on their “oust from the
group” list, but it’s a matter of practicality - portability and I’m not
worried about aliasing for the applications I have. I have found the Tek
scopes over the years to be reliable and with all the plug-ins, very
versatile.

Steve



On Sat, Feb 22, 2020 at 15:35 Randy Newman <randy.n.at.home@...>
wrote:

Hi Ernesto.
As a happy 555 owner (beautiful sharp blue trace (p13 phosphor?). Re
washing, check the BAMA (Boat Anchor ....) and look in the tek section for
tektronix magazines....or maybe I am thinking of the w140.com site.
Yes...the latter...see the 111wiki, then section 38 manuals, catalogs, and
other publications...then "Tektronix magazines" Tekscope vol 8 no. 4
1976..has tek's scope washing procedure. This is a 2-parter..don't have the
other issue...might be vol 9 no. 1. Plus there is a wealth of information
on tube and xsistor scopes. I also have a 7834, 7633, and 7623. But I
really like the 555, even with its external supply(!!). Nice garage
heater....some day I will have a real shop area.
Hope this helps!

On Thu, Feb 20, 2020, 9:27 AM Ernesto <ebordon@...> wrote:

Hi John, thank you for pointing me to the world of oscilloscope washing,
cleaning.

I read about the experiences of others and the industry washing
oscilloscopes with water. The hairs on my head used to stand up at the
idea, but now I recognize that it is relatively safe, although it
requires WORK.
I compare it with my long experience of "don't fix what is not broken",
and the good luck I have with my old scope that had a 40 years leave of
absence.

I perfectly cleaned the exterior of my 547, and it is shiny. The inside
is different, with plenty of dust deposited on the tubes and surfaces.
I
like to preserve it like that for its dramatic effect. The instrument
will
be perfect for my grandchildren to play with it when they are a little
bigger, and it may awaken their interest in electronics. I plan to show
them the inside of the scope to be impressed with its age, but after
that
the inside will be off limits to them.

But... if I experience any failures, I feel competent enough to trace
them to the failed component, or particles of dust, and I will remove
just those offending particles.

NOTE: I have a different standard for washing myself, staying clean
inside
and changing my underwear, ha ha ha.

Cheers,
Ernesto






Re: 80E02 80E03 Sample Module Repair

Mark Kahrs
 

These are definitely a return to Tek kind of item, much like the SD heads.
In fact, you might notice a remarkable resemblance between the two heads!
Unless you are lucky, the sampler is a mite toasted... The heads are very
sensitive to static.

Can I presume you've done all the tests in the user manual?

On Sat, Feb 22, 2020 at 12:02 PM dalek <@dalek> wrote:

Hi. Has anyone had any success repairing these modules? I could find
little to no information regarding the servicing of them.
Richard




Re: Repairing my Tektronix 454 oscilloscope need some advice

 

Hi Ed,

Any discussion, information about HV testing of components should be welcomed by us owners of tube oscilloscopes, and as valuable information in general. The ability to have a variable source of HV and a means (well protected) to detect leakage current should be within our test capabilities. I designed a 100 KV supply with a 29 stage ladder to power a minitron tube, and I survived any electrocution to be able to tell about.

Regards,
Ernesto


Re: Weird 466 horizontal glitch-- be aware

Jim Ford
 

D'oh!  (forehead slap)Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Brad Thompson <brad.thompsonaa1ip@...> Date: 2/22/20 5:07 PM (GMT-08:00) To: TekScopes@groups.io Subject: Re: [TekScopes] Weird 466 horizontal glitch-- be aware Ed wrote...Tomorrow  I will squirt cleaner in it. if no joy there,  then scope therails is next.Be aware that control cleaners may contain flammable ingredients. Years ago, I found out the hard way when I sprayed a band switch in a Hallicrafters receiver with power applied. The minute arc caused by switching B+ ignited residual cleaner on the switch and burned a wafer. 73-- Brad AA1IP-- Sent from Postbox <https://www.postbox-inc.com>


Re: Repairing my Tektronix 454 oscilloscope need some advice

toby@...
 

On 2020-02-22 7:10 PM, Ed Breya via Groups.Io wrote:
With all this talk about HV stuff, I think it's a good time to introduce my HV curve-tracer/test box thing. I have been wrapping up the final design and features recently, and it's looking real good, with high utility for all sorts of HV device testing. ...
Anyway, it is moving along and working nicely, so I'll soon be able to put out some info on it. I'll report more as I finalize and draft up documents from my notes. I think some will find the system and design concepts interesting and useful.

Now, this whole deal may be considered OT here, since it isn't about Tek scopes per se, but I think the principles are very useful for checking out many of the problematic HV type components used in our scopes. So Dennis, if you don't want this here, please speak up ASAP, and I will refrain from further discussion.
Please don't refrain. This seems eminently relevant IMHO.

--Toby


Ed




Re: Weird 466 horizontal glitch-- be aware

Brad Thompson
 

Ed wrote...

Tomorrow I will squirt cleaner in it. if no joy there, then scope the
rails is next.
Be aware that control cleaners may contain flammable ingredients. Years ago, I found out the hard way when I sprayed a band switch in a Hallicrafters receiver with power applied. The minute arc caused by switching B+ ignited residual cleaner on the switch and burned a wafer. 73-- Brad AA1IP

--
Sent from Postbox <https://www.postbox-inc.com>


Re: Repairing my Tektronix 454 oscilloscope need some advice

Ed Breya
 

With all this talk about HV stuff, I think it's a good time to introduce my HV curve-tracer/test box thing. I have been wrapping up the final design and features recently, and it's looking real good, with high utility for all sorts of HV device testing. It's basically a low power, variable HV engine, using a 5 kV RMS "static-neutralizing" transformer, with various operating modes. A built in HV probe circuit, and special receivers for DUT return current and DC leakage, provide output signals to a scope and a DVM.

The HV engine has these main functions, selected by a SP8T HV switch:
FLOAT
-DC
-DC/sweep
AC/sweep
+DC/sweep
+DC
FLOAT
DISCHARGE

The AC is variable from ~0 to +/- 7500 V peak
The DC ones are variable from ~0 to 15 kV peak
The maximum steady-state current from any output is around 2 mA (shorted).

The HV probe drives a 1 meg scope input, with 1000:1 ratio, so 1V/kV.

The DUT return receiver absorbs the cold-end current, and drives another 1 meg scope input, with various ranges:
1V/mA, 2 kohm burden
1V/uA, 1 megohm parallel 200 pF burden
LOG (bipolar compression), about 4 mA/400 mV reference level, 1 kohm plus diode parallel 1.5 meg burden

The DC leakage receiver drives a DVM, and has internally selected termination Rs to accommodate DVMs with input R of 1 meg, 10 meg, or 1E9 and up.
It is especially useful for capacitor leakage testing, with low-pass filtering to reduce ripple current and interference. The ranges are:
1 V/mA, tau 1 sec, 2 kohm burden
1 V/uA, tau 1 sec, 1.1 meg burden
1V/uA, tau 11 sec, 1.1 meg burden

The receivers and other ports are protected from faults with spark gaps and other items. No equipment output signal can exceed 30 V.

My test setup with a 5 digit DVM, can resolve to 10 pA - but only after tens of minutes to allow settling of the dielectric absorption, and with maximum filtering, and with line voltage fairly stable (the HV is not regulated). This was on a .01 uf 5 kV ceramic cap - the rectangular type often found in old scopes - stressed at about 6500 V. I'm finding these caps are quite remarkable in performance, despite their age and being used. This particular unit settled at less than 100 pA with 6500 V, so well above E13 ohms, which I'd expect just from a good insulator, without any capacitance included. Of course, this is only at room temperature, with no other stresses applied, but it was quite surprising. I'll be reporting on the caps and other items separately - it's been a lot of fun checking things out, with interesting results.

There are also some other items and functions, jumper-selected on the working deck. These include 4600 pF of HV filter capacitance, clamp circuits to make +/- 2 kV and +/- 200 V, and a high R (160 meg) for DC leakage feed and other very low current uses. The 2 kV clamp makes a 4 kV pp trapezoidal wave, for amplitude calibration of the HV probe/scope combo, and the 200 V one makes a 400 V pp - at one-tenth the risetime - "square" wave, to adjust the probe and cable compensation.

Anyway, it is moving along and working nicely, so I'll soon be able to put out some info on it. I'll report more as I finalize and draft up documents from my notes. I think some will find the system and design concepts interesting and useful.

Now, this whole deal may be considered OT here, since it isn't about Tek scopes per se, but I think the principles are very useful for checking out many of the problematic HV type components used in our scopes. So Dennis, if you don't want this here, please speak up ASAP, and I will refrain from further discussion.

Ed


Re: Weird 466 horizontal glitch

Edward Prest
 

Tomorrow I will squirt cleaner in it. if no joy there, then scope the
rails is next.
While the primary z axis input looks clean, there is vertical board input
one transistor after this z input. very suspect.

On Sat, Feb 22, 2020 at 9:54 AM Mlynch001 <@mlynch001> wrote:

On Sat, Feb 22, 2020 at 08:23 AM, <prest.edward.3@...> wrote:


Good idea.
With beam finder pressed, it does not show the problem.This is an
important
clue!
in xy mode it does glitch too, as every other setting.

I have checked Z output and its clean. (it leaks the z sum even though
its an
input)

more reading the manual with emphasis on the differences with beam on
and off
next i guess
Edward,

I have found that dirty/sticking switches are a major problem in these
old scopes. I have had several 4XX Series scopes across the bench that
were "Cured" by a simple and thorough cleaning of all these type of
switches. Good luck in your repair.

--
Michael Lynch
Dardanelle, AR