Date   

Re: 2445 CH 3 and CH 4 vertical setting - volts/ div where ?

Chuck Harris
 

A free pdf file can be found on the BAMA site. You can find it by using
your favorite search engine.

Do you have real probes on those inputs? 10x probes have a resistor that
will identify the attenuation factor to the scope, and the scope will change
its scale readings to be 10x.

There is one selection button for each channel. If pressing one button causes
both channels to change their attenuation, you have a CPU board problem.

-Chuck Harris

vaclav_sal via Groups.Io wrote:

Thanks,I sort-of figured that out by myself late at night.I was using calibrator as a source and that of course is of fixed level.Basically these channels could be used to read 5V logic signals.
But the selection buttons seems to work on botch channels , not on individual channel.That is OK.

Right now I have some kind of vertical magnifier selected since the display on the CRT actually read 1 or 5 volts.I need to find free PDF manual.
Thanks



On Saturday, November 9, 2019, 9:51:53 PM CST, TomC <tomc@...> wrote:


Re: TEK 2430A Changing settings

Harvey White
 

Both of those scopes are very worth saving.  The 7904 is my go-to 7000 series scope.  You may want to look to see which ones have similar power supplies to the 7904, and then do a swap,

I have a 2430A, which was my go-to digital scope until I got a TDS540A, which has the same bandwidth as the 7904.

You  may want to see if you can find a 7904 that can become a donor unit for parts, always recommended.

Harvey

On 11/10/2019 1:05 PM, frank carcia wrote:
Hi Bob,A couple years ago a VP at work signed a 2430A slated for the dumpster to me. It worked fine for a while and then started pulling faults.Reading these threats I learned about the battery and found a service manual on line. Then my beautiful 7904 died that appears to be a power supply issue. I'm debating unloading all of them and picking up a modern light weight scope. I have about 5 different 7000 series scopes and only one works. Not sure how much time I want to put into repairing these things. I have a couple NOS CRTs that I think go in a 7404 and maybe 7904. Frank WA1GFZ
On Sunday, November 10, 2019, 10:52:02 AM EST, Bob Self via Groups.Io <bobmiscmail=yahoo.com@groups.io> wrote:
I have a 2430A that I just replaced the NVRAM modules on and all is well relative to that, but I'm wondering if anyone has any thoughts on another problem that it has had for several years.  The settings keep changing on the scope, the longer it has gone without use, the worse it is.  If it has been on for hours, the problem becomes very infrequent and is tolerable.  I worked on it months ago to no avail.  I checked all the power supplies and re-seated all the connectors and also the eproms.  I monitored the voltage on the bezel switches for a while and did not see any unexpected voltages.  I am open to any ideas on where to look.  I don't have another digital scope to catch occasional events, only a voltmeter and 2465 scope.

Thanks,
Bob WB6OFS







Re: 2465 Fan Collet Thingy

Chuck Harris
 

Hi Siggi,

One thing to think of, if the collet is drawn vertically
by the printer, it is certain to break, but if you draw
it horizontally with long strokes, and in halves, it might
be strong enough.

Especially if it is ABS.

No matter what, I would expect that the threaded section
will have to be done manually with a tap and a short chunk
of threaded rod.

Most slicers will allow you to draw your own paths, if you
wish to go to the effort. Done once, it can be replicated
by anyone.

It wouldn't even be all that hard to build a custom printer
that had an X, Y and R axis. Like a 3d printer lathe.

-Chuck Harris

Siggi wrote:

On Sun, Nov 10, 2019 at 12:15 AM Chuck Harris <cfharris@...> wrote:

I am not sure that an all plastic printed solution will
work... tektronix didn't think so, and made a much more
expensive metal/plastic hybrid.
A home-printed plastic fused-filament collet almost certainly won't work,
those things will delaminate at the shade of a hint of a threat of any
stress in my experience. I'd be surprised if Shapeways and other commercial
services couldn't produce a usable part using SLS in nylon-like plastics
<https://www.shapeways.com/materials/versatile-plastic>.
I did machine a batch of these collets from delrin/acetal, and those will
work just fine - delrin will hold the thread just dandy. (I've been
shipping these out for postage, but I'm out of stock now - alas).
The reason Tektronix used an insert is IMHO not for strength, but because
you can't injection-mold threads, and a secondary machining step on this
collet would be awkward.
Injection molding around an insert is however no big deal, and you can
potentially use the same insert in many different injection-molded parts.
Machining the part from raw stock would also have been expensive in the
day, but the inserts would have dropped out of a screw machine by the
hundreds/minute.

Siggi




Re: So long...

widgethunter
 

Nothing is forever, and, I used to enjoy this group more in the past, myself.Though I am no fan of Facebook, I do enjoy our "Old Tekscopes" group, there.The visual interface is a nice alternative and less demanding to interact with, than composing novels in this text based environment.
Hope to see you there, Craig.Bernd Schroder

-----Original Message-----
From: Craig Sawyers <c.sawyers@...>
To: TekScopes <TekScopes@groups.io>
Sent: Tue, Nov 5, 2019 4:51 pm
Subject: [TekScopes] So long...

Hi all



I've been thinking about this for quite a while. But I think after 18 years on Tekscopes it is
finally time to sign off. In part it is because I think I have said all there is that I can possibly
say on Tekscopes, and in part because I just figured out that I have posted over 4,600 times - an
exceptionally depressing number, even more so when it represents 14% of all posts to Tekscopes ever.
That is one in every seven posts, heaven help us all, that I reckon to be over 800 hours of typing,
not counting the thinking time.



So to the many people who are on this list who have helped me to figure out problems in my stable of
Tektronix gear - my heartfelt thanks. There have been notable assistance above and beyond the call -
as an example, while describing a particular fault in my 7854, one of the list members disconnected
the sampling bridge in his own unit to mimic the fault! And yes, my vertical sampling bridge was
indeed toast. You have all been an inspiration, and I hope that some of you think of me as a friend.
I also hope that over the years I have been able to contribute something to others.



Anyhow - cheers all



Signing off



Craig Sawyers


Re: 3D printed metal

Chuck Harris
 

I am aware that the custom jewelry folks have been
using conventional 3d plastic printers with wax to
make lost wax investment casting patterns.

But...

Have you ever done metal casting? I have, and it
is a whole avocation in and of itself.

I have all the necessary furnaces, ovens, and other
supplies to do it... everything but the time and will.

99% of the time, I can do what I need using my 2-1/2D
router table.

But, I would still like to one day be able to 3d print
a brass widget... without having to sinter it, or investment
cast the part.

Not today, but someday, I am certain.

-Chuck Harris

Ed Breya via Groups.Io wrote:

You could possibly mix old and new technologies by 3D printing the desired part in a lost-wax type of deal. Put a clay mold around it, then melt or burn out the printed stuff, and cast it with metal. Depending on your foundry skills and materials, you can make all sorts of things. Steel and brass would be tricky due to high temperatures needed. Zinc and some of its alloys (pot metal) would be fairly easy.

Ed




Re: 2465 Fan Collet Thingy

Siggi
 

On Sun, Nov 10, 2019 at 12:15 AM Chuck Harris <cfharris@...> wrote:

I am not sure that an all plastic printed solution will
work... tektronix didn't think so, and made a much more
expensive metal/plastic hybrid.
A home-printed plastic fused-filament collet almost certainly won't work,
those things will delaminate at the shade of a hint of a threat of any
stress in my experience. I'd be surprised if Shapeways and other commercial
services couldn't produce a usable part using SLS in nylon-like plastics
<https://www.shapeways.com/materials/versatile-plastic>.
I did machine a batch of these collets from delrin/acetal, and those will
work just fine - delrin will hold the thread just dandy. (I've been
shipping these out for postage, but I'm out of stock now - alas).
The reason Tektronix used an insert is IMHO not for strength, but because
you can't injection-mold threads, and a secondary machining step on this
collet would be awkward.
Injection molding around an insert is however no big deal, and you can
potentially use the same insert in many different injection-molded parts.
Machining the part from raw stock would also have been expensive in the
day, but the inserts would have dropped out of a screw machine by the
hundreds/minute.

Siggi


Re: 3D printed metal

Ed Breya
 

You could possibly mix old and new technologies by 3D printing the desired part in a lost-wax type of deal. Put a clay mold around it, then melt or burn out the printed stuff, and cast it with metal. Depending on your foundry skills and materials, you can make all sorts of things. Steel and brass would be tricky due to high temperatures needed. Zinc and some of its alloys (pot metal) would be fairly easy.

Ed


Re: 7S14 7S11 SAMPLER bias QUESTION

Miguel Work
 

Can you explain the reason please?, thanks

-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de Dennis Tillman W7PF
Enviado el: domingo, 10 de noviembre de 2019 16:56
Para: TekScopes@groups.io
Asunto: Re: [TekScopes] 7S14 7S11 SAMPLER bias QUESTION

Hi Miguel,
Absolutely not!
Dennis Tillman W7PF

-----Original Message-----
From: Miguel Work
Sent: Friday, November 08, 2019 6:56 PM
Subject: [TekScopes] 7S14 7S11 SAMPLER bias QUESTION

<snip>
I possible to feed bias in 7S14 with +-50v and resistors, just like the 7S11?

Thanks
Regards




--
Dennis Tillman W7PF
TekScopes Moderator


Re: TEK 2430A

frank carcia
 

hi Szabolcs,Thanks for the advice I will check it out. The faults appear random so suspect the battery is low and never replaced.Frank WA1GFZ

On Sunday, November 10, 2019, 12:21:51 PM EST, Szabolcs Szigeti <szigiszabolcs@...> wrote:

Hi,

Yes, this could be battery related. First of all  check if it is not
attenuator and trigger ext cal, that is missing. If it is not calibrated,
it will still show up in the self test or the extended test as fail.
First do a self cal and then check what the ext cal menu says. If it says
that the atten and trig are either fail or uncal, then do a calibration for
them. You will only need some DC voltages to do that. If that fixes it, it
is either the battery is empty and calibration is lost after powerup or
somehow other way the calibration got messed up. (You'll need to remove a
jumper to enable ext calibration, study the service manual first!)
If this is not jhte case, then you'll need to examine which tests are
actually failing, go into the extended diag as work your way down the
test-tree to find the failing tests.

Szabolcs


frank carcia <carcia@...> ezt írta (időpont: 2019. nov. 10., V,
3:28):

Hi All,I have a clean 2430A that pulls faults in power on bit. I don't
think the battery has ever been changes.One fault that comes up is
attenuator and another is trigger related. I wonder if this could be
battery related.I have not tried to clean any board contacts or
troubleshoot. I just downloaded the service manual. Any advice welcome to
avoid reinventing the wheel.Thanks,Frank WA1GFZ




Re: TEK 2430A Changing settings

frank carcia
 

Hi Bob,A couple years ago a VP at work signed a 2430A slated for the dumpster to me. It worked fine for a while and then started pulling faults.Reading these threats I learned about the battery and found a service manual on line. Then my beautiful 7904 died that appears to be a power supply issue. I'm debating unloading all of them and picking up a modern light weight scope. I have about 5 different 7000 series scopes and only one works. Not sure how much time I want to put into repairing these things. I have a couple NOS CRTs that I think go in a 7404 and maybe 7904. Frank WA1GFZ

On Sunday, November 10, 2019, 10:52:02 AM EST, Bob Self via Groups.Io <bobmiscmail=yahoo.com@groups.io> wrote:

I have a 2430A that I just replaced the NVRAM modules on and all is well relative to that, but I'm wondering if anyone has any thoughts on another problem that it has had for several years.  The settings keep changing on the scope, the longer it has gone without use, the worse it is.  If it has been on for hours, the problem becomes very infrequent and is tolerable.  I worked on it months ago to no avail.  I checked all the power supplies and re-seated all the connectors and also the eproms.  I monitored the voltage on the bezel switches for a while and did not see any unexpected voltages.  I am open to any ideas on where to look.  I don't have another digital scope to catch occasional events, only a voltmeter and 2465 scope.

Thanks,
Bob WB6OFS


Re: Tek 310 Restoration Candidate ($40) [Taken]

Oz-in-DFW
 

has been spoken for.


Re: 561B Recapping

David Holland
 

FWIW,

In amongst work, other projects, video games, lost motivation, general
apathy, etc... I ended measuring the DC resistance of each transformer
winding, simplifying the schematics down to just resistors for the
transformer windings, the filter capacitors, a few other seemingly
relevant resistors, load resistors, and then simply "measuring" the
ripple currents in MicroCap.

Load resistors for each supply were calculated from the current limits
in the IRB. (Except in the case of the -100V supply, which needs
supply an additional 150mA for HV, in addition to the IRB limit)

Anyways, after the addition of 20% to the so called measurements, I
had something to work with:

(Hopefully the email won't eat my stellar ascii table formatting.)

Supply Xform Rload Comp. Meas+20% Mouser
DCR
+300V 8.05 2000 C78 1.3980A 871-B43540A9337M000
+300V C97A 0.0964A 647-UCY2H220MHD3TN

+125V 6.4 833 C54 2.2392A 661-E92X401ND681MB50
+125V C97B 0.0689A 647-UCY2H220MHD3TN
+125V C97C 0.0689A 647-UCY2H220MHD3TN

-12.2V 0.56 8.1 C36 8.1000A 871-B41605C7109M009
-12.2V 0.36 C47 0.0810A 594-2222-118-36101

-100V 5.31 357 C9 2.1348A 661-E91F351ND182MBA0

I do observe that C11 in my late serial #, is actually tantalum and
seems, according to common wisdom, insufficiently voltage derated.
Its a 6.8u 10V cap, in parallel with a 9.1V zener, and may warrant a
replacement as well.

Is right? - Shrug, I dunno. My Magic-8Ball keeps coming up with "Try
again later", or "Ask someone who cares", but the numbers seem
somewhat reasonable to me.

I've got the Mouser parts in hand, I'll guess I'll give them a whirl
here in a while..

If someone wants the schematic holler, though, its simple enough to reproduce..

Thanks to those whom offered advice...

Cheers!

David



On Mon, Sep 16, 2019 at 7:26 PM David Holland via Groups.Io
<david.w.holland=gmail.com@groups.io> wrote:

Yes, but I'd like to have some replacements in mind... They won't
last forever, and I'm eyeing restoring some assorted plugins of
unknown status, and so, I'd like to have the mainframe in a known
healthy state...

I've also a RM567 sitting on the shelf that is in definite unknown
status that may (or not) need similar diagnosis...

There are approximate current limits in the IRB for the 561A (and by
proxy the 561B) I suppose I can putter around in LTSpice, read some
linear PSU design guides, and make some slightly less wild guesses..

On Mon, Sep 16, 2019 at 2:13 PM widgethunter via Groups.Io
<tubesnthings=aol.com@groups.io> wrote:

If it aint broke don't fix it!!!Running several 561As & 565 in original condition with NO issues.That is the norm for 500 series gear.Bernie Schroder



-----Original Message-----
From: Glydeck via Groups.Io <glydeck=aol.com@groups.io>
To: TekScopes <TekScopes@groups.io>
Sent: Sun, Sep 15, 2019 5:15 pm
Subject: Re: [TekScopes] 561B Recapping

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: TEK 2430A

Szabolcs Szigeti
 

Hi,

Yes, this could be battery related. First of all check if it is not
attenuator and trigger ext cal, that is missing. If it is not calibrated,
it will still show up in the self test or the extended test as fail.
First do a self cal and then check what the ext cal menu says. If it says
that the atten and trig are either fail or uncal, then do a calibration for
them. You will only need some DC voltages to do that. If that fixes it, it
is either the battery is empty and calibration is lost after powerup or
somehow other way the calibration got messed up. (You'll need to remove a
jumper to enable ext calibration, study the service manual first!)
If this is not jhte case, then you'll need to examine which tests are
actually failing, go into the extended diag as work your way down the
test-tree to find the failing tests.

Szabolcs


frank carcia <carcia@...> ezt írta (időpont: 2019. nov. 10., V,
3:28):

Hi All,I have a clean 2430A that pulls faults in power on bit. I don't
think the battery has ever been changes.One fault that comes up is
attenuator and another is trigger related. I wonder if this could be
battery related.I have not tried to clean any board contacts or
troubleshoot. I just downloaded the service manual. Any advice welcome to
avoid reinventing the wheel.Thanks,Frank WA1GFZ




Re: "parting" 2215A

Bob Albert
 

I submit that your unit is not beyond repair.  Most of the problems are in the preregulator, which is easy enough to fix or replace.
Where are you?  If not too far from Los Angeles I'd be willing to help.
Bob

On Sunday, November 10, 2019, 08:34:47 AM PST, vaclav_sal via Groups.Io <vaclav_sal=yahoo.com@groups.io> wrote:

I have a hopeless , dead, case 2215A .
It turns on , but  that is all she wrote.
Nothing else is alive.

It has bean left in wet garage for long time and some components are clearly rusted out.
I just hate to ditch it as is, so I am asking the group which components ( CRT - it did lash once , knobs etc,) are worth saving as future trade items.
Vaclav AA7EJ


Tek 576 Curve Tracer, 3 mechanical parts wanted; Does anyone have a parts unit ?

garp66
 

hi,
Does anyone have a Tek 576 parts unit ?

I am looking for some small mechanical Tektronix parts for my Tek 576:

I have photos of the parts that I can email to you off list.
thank you,
rick

a. ) Multiplier plastic cup, holding the multiplier pot in place:
201-0013-00 "CP, CMPNT MTG: PLASTIC"

This is a small plastic gray(?) cup that helps hold the Multiplier Pot in place on the Tek 576 front panel. It may have a metal retaining clip as well.


b. ) The knobs(coaxial) and extension shaft(coaxial) for the Max Peak Volts / Series resistor assembly. Part #'s and description can be seen in the expanded mechanical drawing that I can email.

My knobs & extension shaft (~ 2" long, extending behind the from panel ) are missing:

c. ) Mechanical linkage:
The outer sleeve parts ( # 13, 11, & 8 ) are White Plastic (as see in the photos) but wonder if the inner rod parts ( # 12, 10, 9 etc) are aluminum or plastic ?

The #1 being the actual rotarty switch.

I need the mechanical Extension Link parts, includes Relevant items include Items 6 ~ 13.

I also need the front panel (coaxial ?) Knobs: Numbers 85 through 88 are the relevant items.

**
Tek 576 mechanical white plastic linkage A
White plastic (& metal) shaft extension parts(long & short white bits) for the rotary switch, shown at the right hand side.

Tek 576 plastic link
Top view of the white plastic (& metal) extension shaft that is missing in my Tek 576.


Re: 2445 CH 3 and CH 4 vertical setting - volts/ div where ?

vaclav_sal
 

Note to myself

do not feed Gremlins after midnight and do not post anything late at nigh also
Just ACQUIRED (was adjured ) 2445 scope and trying to get familiar with the controls.

Vaclav


"parting" 2215A

vaclav_sal
 

I have a hopeless , dead, case 2215A .
It turns on , but that is all she wrote.
Nothing else is alive.

It has bean left in wet garage for long time and some components are clearly rusted out.
I just hate to ditch it as is, so I am asking the group which components ( CRT - it did lash once , knobs etc,) are worth saving as future trade items.
Vaclav AA7EJ


Re: 2754p memory problems

John Miles
 

I have two 2754 spectrum analyzers, one partially working, the other basically
a parts mule. When starting the good one, it tells me it has memory faults and
when stepping past it shows memory bad or missing. I have researched and am
concerned I might do serious damage by swapping the memory board from the
parts unit.
Are there any specific sources you've seen that indicate that damage might occur in this particular case? I wouldn't have a problem swapping the boards myself but maybe you've run into a reference I haven't seen. One question is, what are the Tektronix part #s on the two memory boards? It'll certainly be safe to swap the boards if the first two groups of numbers are the same. The -xx suffix may differ but that's not generally a concern.

-- john, KE5FX


Re: 2445 CH 3 and CH 4 vertical setting - volts/ div where ?

vaclav_sal
 

Thanks,I sort-of figured that out by myself late at night.I was using calibrator as a source and that of course is of fixed level.Basically these channels could be used to read 5V logic signals.
But the selection buttons seems to work on botch channels , not on individual channel.That is OK.

Right now I have some kind of vertical magnifier selected since the display on the CRT actually read 1 or 5  volts.I need to find free PDF manual.
Thanks

On Saturday, November 9, 2019, 9:51:53 PM CST, TomC <tomc@...> wrote:

The channel 3 and 4 volts/div for the 2445 can be anything you want as long as
you want 0.5 volts/div or 0.1 volts/div. It is selected by a pair of push
buttons, one for each channel, between the channel 3 and 4 vertical position
controls.

Tom

On 11/9/2019 6:36 PM, vaclav_sal via Groups.Io wrote:
Just adjured 2445 scope and trying to get familiar with the controls.
Not having much luck asking Mrs Google or reading text only  ( no links / reference  ) manuals.
So - any owner of 2445 can tell me  where / how to  select vertical "Volts/Div" setting for CH 3 and CH 4?
I can read the calibrator on CH3 OK , just cannot figure out how to set the vertical setting for it.
Thanks




Re: 2465 Fan Collet Thingy

EricJ
 

Good grade of aluminum. It has been mentioned that brass would probably work too.

--Eric

On Nov 10, 2019 4:47 AM, Tom Gardner <tggzzz@...> wrote:




Sorry, I know electronics, not materials.

Is that plastic or metal?


On 10/11/19 10:14, EricJ via Groups.Io wrote:
6061 most likely.

--Eric

On Nov 10, 2019 3:01 AM, Tom Gardner <tggzzz@...> wrote:



On 10/11/19 05:41, EricJ via Groups.Io wrote:
I am still getting my new machines set up, but I can probably run off
a
few soon.

What material will that be?