Date   

Re: 2465 Fan Collet Thingy

Li Gangyi
 

Very quickly drew up a STL for people who wanna try 3D printing the plastic
bit, I believe the original part has a metal stud for the nut to thread
onto, you're gonna have to drill and tap the center for a stud.
Do let me know if you've tested it out and if it works good.

I have access to a small lathe, however I'm not equipped to do slits as of
yet, if there is interest I might get around to adding that capability.

On Sun, Aug 9, 2020 at 12:45 AM Chuck Harris <cfharris@...> wrote:

Log onto your groups.io account. It should open with your "my groups"
screen.
Click on "Tekscopes".

On the left side of the messages screen there is a list of areas associated
with tekscopes. One of them is marked "FILES".

-Chuck Harris

Raymond Cote wrote:
And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle,
stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked
in the group files and there aren’t many. I didn’t see anything relating to
a collet.

Hi Dave,

it was explained somewhere in this thread: go into the files section
and search for "collet".

cheers
Martin







Re: Cut wiring harness

Roy Thistle
 

On Fri, Aug 7, 2020 at 09:18 AM, kim.herron@... wrote:


so large that you can't get the loom back in
place. ...stagger your repair splices so that
you can get it back together.
The obstacle that arose was the bulk, created by the accumulation of splices...getting the spliced loom back in position was not possible... staggering helps... also reducing the number of splices by replacing as many runs as convenient (some are usually easy to do... and then running a constructed loom (of those replacements) in parallel... or sometimes rerouting the new loom more conveniently. I've used inline multi-pole connectors... sometimes panel (or chassis mount) plug and socket... and sometimes terminal blocks (or stacked terminal blocks)... or retrofitted in a junction box.
Some insight is to be gleaned from the amazing number of wire T&M guys mannage to squeeze through the approximately 1cm. by 5cm. opening on the plugins for mux and switch plugins. (all the pairs are connected to screw down, or spring loaded, terminal blocks, on the plugin.) Some insight can be gained from pstn guys who used to do splicing, of multicondutor cable runs, all the time.
Signal carrying pairs need attention as to the point to point re-connection (and splicing), according to the wire/cable used (possibly length too, as well as shielding)... and of course routing.
Although you undoubtedly know, the 556 is almost symmetrical... so getting the power supply working first, and then one beam/channel working...before getting the other... might be a reasonable option.


Re: 7834 Missing Trace

Roger Evans
 

Two more thoughts - does the vertical plugin have an 'Invert' button? That would put the noise at the bottom of the screen if the calibrator is the culprit.

Have you tried all the different voltage output from the calibrator? Is the discrepancy the same for each and for any different V/div settings where you can make a meaningful measurement on two adjacent ranges eg 1V/div and 2V/div for the 4V calibrator output?

Roger


Re: 7834 Missing Trace

Roger Evans
 

You should be able to remove the bottom cover from the scope with a few screws. Whether this gives enough access to pull whatever is left of the release tab with a set of pointed pliers I am not sure. You could start a new thread here on 'how do I remove a 7000 plugin with a broken tab?'

What vertical plugin do you have? If it has two channels then I imagine by now you would have checked both. Nearly all vertical plugins have a 'var' setting which gives a continuously variable Volts/div but this should activate the '>' symbol on the readout and make it obvious that the V/div is not calibrated.

You can put a timebase in the vacant left vertical slot and on auto-trigger it should produce a vertical line if you select the empty slot for the horizontal mode. The line should shift up and down with the position control of the timebase and you might see if the top end displayed any noise (not a very convincing test). If you can arrange for both timebases to trigger from the same external input (maybe the cal output but now you are only relying for it for a trigger signal) then you should get some diagonal lines and any noise would be a bit more obvious. This is all dependent on the left vertical slot actually displaying a trace.

The journey is not ended yet!

Roger


Re: 2465 Fan Collet Thingy

Chuck Harris
 

Log onto your groups.io account. It should open with your "my groups" screen.
Click on "Tekscopes".

On the left side of the messages screen there is a list of areas associated
with tekscopes. One of them is marked "FILES".

-Chuck Harris

Raymond Cote wrote:

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin





Re: 475 With a bowed display. . . .Ideas?

Chuck Harris
 

Hi Michael,

The spot we see is a picture of the active cathode
area, as is collimated and distorted by the grids,
anodes and lenses in the CRT.

Because of slight manufacturing variations that can
make for beam motions that would cause the beam to
completely miss the concentric holes in the shields
and anodes, there is a need for one or two steering
magnets judiciously placed on the neck of the CRT.

If one is missing, your spot could on a worst case
disappear completely. In a less drastic case, it would
chop off part of the circular spot leaving semi circular.

Tektronix used cellophane tape to hold the magnets (if any)
in place on the neck. One steers the beam horizontally,
and one steers it vertically. I have seen the cellophane
tape with empty pockets where the magnet used to go. Usually
the magnet is stuck on the inside of the mumetal shield.

The various elements after the gun that deflect, magnify,
and distort the spherically projected image into a
flat image for display on the screen all affect the
circularity of the spot by making it look like the
wind smeared its shape... they make its shape look more
comet like in appearance.

To be as distorted as you describe (I wish I read that
earlier), you have to have one of your astigmatism,
geometry, or focus elements that is electrically in the
wrong place in the tube. If it is truly like a fish eye
lens, centered on the center of the screen, you probably
have a bad power supply going to one of the pots that
drives the astigmatism, geometry or focus grids.

This is just a guess, but in any case, it is time for you
to verify that all adjustment pots in that area are properly
fed, good, and are somewhere in the center of their range.

Pay particular attention to any circuit complexity that
exists around these grids. Sometimes there are transistorized
distortion circuits that are supposed to warp things into
flat for the screen.

-Chuck Harris

Michael W. Lynch via groups.io wrote:

On Sat, Aug 8, 2020 at 08:22 AM, Chuck Harris wrote:


Typically, when a proper application of the Geometry,
Focus, Astigmatism, Trace Rotation, and other affiliated
adjustments results in a screen that just doesn't look
as pretty as we would like, it means that there has been
an outside physical influence on the CRT (READ: OOPS! BANG!
$%^! & #!!*^! Why Me???)
No signs of major trauma, but this is still a possibility. What confuses me in this regard is the fact the the unfocused spot on the CRT is beautiful and round, one of the best I have ever seen.

The Mumetal shield can get bent, or magnetized.
Not bent, but magnetized? VERY POSSIBLE. I am curious how such magnetization can occur as this issue has come up in other threads as well?

One of the steering magnets (held with Scotch tape) can fall off
of the CRT neck, causing the beam to partially strike one
many internal shield electrodes that looks like a hole in
a plate of metal.
I can look at this when I pull the CRT. Would this not distort the unfocused spot (mentioned above) somehow?

Or, it can be that we are much more nit-picky than tektronix
was originally.
I'm just not that picky. I do not think I am asking too much for the markers to be vertical and consistent across the entire viewing area (or at least within one minor division). If it was just one minor division of deviation, I could live with this, but the outermost vertical markers are about 6 minor divisions "leaned in" at the top of the marker. It is almost like looking through a "fisheye" lens.

If you carefully read the specifications in the manual, you
will often find that we have been spoiled rotten by all of
the CRTs we get that are much better than the specifications
say they could be...
I totally agree. The CRT is one of those items that is a source of constant amazement for me. How they work and withstand decades of use and many times abuse. They are a marvel.

Bottom Line, sounds like I need to pull the CRT and inspect it for obvious damage. I can try another "known good" CRT, as I have one or two that produce very good and well aligned traces in other machines.
if a "Good CRT" shows the same symptoms in this chassis, then I need to look elsewhere.

I was thinking that I had missed some other related adjustment? I guess not?

Thanks for the valuable input.


Re: eBay / PayPal Changes and our alternatives

Dick Wilson at DiLette Sales <cmdrdick42@...>
 

Eastern Airlines had a high concentration of refugees from Cuba. I suppose that I should have said Cuban Americans. They were known to be staunch supporters of their unions and willing to fight for their rights. My own route often included Miami as a layover. I partied with and know several of them personally. I supported their cause. Carl Icahn was a cold blooded corporate raiding SOB whose greed had no bounds.

On Friday, August 7, 2020, 12:28:15 PM EDT, DaveC via groups.io <davec2468=yahoo.com@groups.io> wrote:

Cubans?

Dave


... What totally shocks me given the high percentage of Cubans that were affected, is that he is still walking around.CmdrDick


Re: 2465 Fan Collet Thingy

saipan59 (Pete)
 

And I would add for folks that are going to fabricate a piece: Don't overlook *wood* as a possible material. Wood comes in a zillion types (at a woodworker's supply store), and some types have very useful properties for "making stuff", while being easier to work with (perhaps) than metal or plastic.

Pete


Re: 2465 Fan Collet Thingy

saipan59 (Pete)
 

Hi Ray,
I see the "Files" section in the menu on the left side of the page, when looking at this page:
https://groups.io/g/TekScopes/topics

Here's a link to the "collet" search, which then shows a PDF file:
https://groups.io/g/TekScopes/filessearch?q=collet

Pete


Re: 2465 Fan Collet Thingy

Dave Daniel
 

On Aug 8, 2020, at 12:10, Raymond Cote <@Bluegrass> wrote:

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin





Re: 2465 Fan Collet Thingy

Raymond Cote
 

And just WHERE IS THE FILES SECTION???
I dont see any link to it. Never have
In matters of style, float with the current. In matters of Principle, stand like a rock. “. — Thomas Jefferson —

On Aug 8, 2020, at 06:55, Martin <@musaeum> wrote:

On Fri, Aug 7, 2020 at 01:55 PM, DaveC wrote:
Can you please provide a link to he location of these files? I looked in the group files and there aren’t many. I didn’t see anything relating to a collet.
Hi Dave,

it was explained somewhere in this thread: go into the files section and search for "collet".

cheers
Martin




Re: 7834 Missing Trace

sdferg7@...
 

The trace only gets fuzzy when I have the calibrator signal plugged in, and only the top half. The issue still comes and goes, usually after I change a setting, e.g. the vertical channel. With no signal the only time the trace flickers from moving up and down is when it goes through the trigger.

Unfortunately the scope only came with 1 vertical plugin, in the right slot, and the pull tab is missing. Is there an easy way to get it out without much disassembly? In the manual it seems the only way to get the black follower tracks out is to have their respective plugin removed to access the screws. When I select the empty left vertical plugin slot I get a flat trace slightly tilted clockwise, maybe 1 or 2 degrees.

I also discovered I was mistaken about the 2 dots, they actually appear to be the minimum and maximum of the right horizontal plugin from the calibrator signal I had plugged in. If I select chop with no signal I get 1 brighter dot from the right plugin, still nothing from the left.

I also did more testing on the scope's calibration. Last night after the scope was pretty warm I tried measuring a 1.6V battery at 1V/div which showed on the scope as about 3/4 of a division. This morning I tried the same with the scope cold and it came to almost exactly 1 division. This seems to follow my previous experience with the scope reading lower as it gets warm. The scope also seems to read slightly off on the frequency of the calibrator signal, each period shows as slightly less than 1ms. Of course that could be an issue with the calibrator.

Shane


Re: Tektronix 2230

satbeginner
 

Hi Saroj,

I was busy expanding the GridTied Solar panels we have here, hence again my later response.

In terms of temperature, my personal feeling is: The lower, the better.
In my 2215A('s) I have seen temperatures around 60 - 63 Celsius, a temperature I feel comfortable with.
But on the other hand, you have a 2230, so more electronics to power, so maybe higher temperatures in that scope...

In terms of electrical isolation you must keep using the Mica or more modern isolator, but I would add a TO-220 heatsink at both sides of the metal frame where the FET is mounted.
A bit like in this picture: https://groups.io/g/TekScopes/photo/64919/4?p=Name,,2215+repair,20,1,0,0
The addition of the two TO-220 heatsinks will improve lowering the FET's temperature, also with the FAN mounted in place.
Also, do put that little screw in the side panel back in when you close up the scope, that also helps cooling that part of the power supply.

This brings me to the Molex connector you still see in that picture: I never liked them.
They are very susceptible to corrosion, so it is easy to develop an extra serial resistance which will affect the operating settings of the FET, and might even rise the temperature.

So, in addition of what you see in the picture mentioned above, I would solder the wires directly to the FET after mounting it to the metal frame.

Have a nice weekend,

Leo


Re: 475 With a bowed display. . . .Ideas?

 

On Sat, Aug 8, 2020 at 04:40 PM, Michael W. Lynch wrote:


If it was just one minor division of deviation, I could live with this, but
the outermost vertical markers are about 6 minor divisions "leaned in" at the
top of the marker. It is almost like looking through a "fisheye" lens.

I'd think that's way out of range for the electrical Geometry adjustments that you mentioned earlier, so probably something is wrong of the sort that Chuck describes. It may be worthwhile to quickly check if the Geometry adjustment pot's range reaches the intended 0 to +110V. It's GND-related, so not dangerous to measure, unlike grid- and focus- voltage levels.

Re. the "fisheye" appearance: Is the distortion mostly (radially) symmetrical? In that case, I wouldn't think it could be just a moved magnet.

Trying another CRT seems to make sense. Not too much hassle with a 465/475. Just the usual care with the lingering anode voltage.


BTW, re. the first post, Michael wrote:

"Problem was C1442 was bad. High resistance and almost no capacitance, loading the +15V supply."

The high resistance and low capacitance resulted in your meter showing that the average or RMS voltage was too low so good regulation wasn't possible.
C1442 wasn't loading the +15V supply ("high resistance") but loading the 15V supply wasn't possible, since the regulation circuit received practically unbuffered rectified AC. It's probably what you meant.

Raymond


Re: AWG2021 Sample Waveform Library

Martin Hodge
 

Now if anyone ever comes across the "Check/Adjustment" disk (063-2171-XX) that came with the AWG2021 service manual you are expected to reciprocate! ;)


Re: 475 With a bowed display. . . .Ideas?

Michael W. Lynch
 

On Sat, Aug 8, 2020 at 08:22 AM, Chuck Harris wrote:


Typically, when a proper application of the Geometry,
Focus, Astigmatism, Trace Rotation, and other affiliated
adjustments results in a screen that just doesn't look
as pretty as we would like, it means that there has been
an outside physical influence on the CRT (READ: OOPS! BANG!
$%^! & #!!*^! Why Me???)
No signs of major trauma, but this is still a possibility. What confuses me in this regard is the fact the the unfocused spot on the CRT is beautiful and round, one of the best I have ever seen.

The Mumetal shield can get bent, or magnetized.
Not bent, but magnetized? VERY POSSIBLE. I am curious how such magnetization can occur as this issue has come up in other threads as well?

One of the steering magnets (held with Scotch tape) can fall off
of the CRT neck, causing the beam to partially strike one
many internal shield electrodes that looks like a hole in
a plate of metal.
I can look at this when I pull the CRT. Would this not distort the unfocused spot (mentioned above) somehow?

Or, it can be that we are much more nit-picky than tektronix
was originally.
I'm just not that picky. I do not think I am asking too much for the markers to be vertical and consistent across the entire viewing area (or at least within one minor division). If it was just one minor division of deviation, I could live with this, but the outermost vertical markers are about 6 minor divisions "leaned in" at the top of the marker. It is almost like looking through a "fisheye" lens.

If you carefully read the specifications in the manual, you
will often find that we have been spoiled rotten by all of
the CRTs we get that are much better than the specifications
say they could be...
I totally agree. The CRT is one of those items that is a source of constant amazement for me. How they work and withstand decades of use and many times abuse. They are a marvel.

Bottom Line, sounds like I need to pull the CRT and inspect it for obvious damage. I can try another "known good" CRT, as I have one or two that produce very good and well aligned traces in other machines.
if a "Good CRT" shows the same symptoms in this chassis, then I need to look elsewhere.

I was thinking that I had missed some other related adjustment? I guess not?

Thanks for the valuable input.
--
Michael Lynch
Dardanelle, AR


Re: AWG2021 Sample Waveform Library

Tam Hanna
 

Also sending thanks!


Tam

--
With best regards
Tam HANNA

Enjoy electronics? Join 15k7 other followers by visiting the Crazy Electronics Lab at https://www.instagram.com/tam.hanna/


Re: 475 With a bowed display. . . .Ideas?

Stephen
 

On Fri, Aug 7, 2020 at 11:25 PM, Raymond Domp Frank wrote:

Possibly not:
In the paragraph immediately following your longish quote the OP writes:

"Y Align R1385 and Geometry R1390 will not bring the vertical markers
into proper vertical alignment even though they do have some effect on
the trace by making it less severe. Even though they never "Fix" the
problem."

Raymond
Ok.


Re: FG 504 problems

John Ferguson
 

the next step will be to discover the unobtanium part needed in one of the FG504's is also bad in the other.

john

On 8/8/20 9:06 AM, Chuck Harris wrote:
Tektronix never gets all of the information you need in
anything but the most trivial manuals.

Between what they withhold for proprietary reasons, what
they put in odd places, what they got plain wrong, and
what they simply didn't get around to documenting, there
is always something missing... something to wish for.

I needed access to the boards on a FG504 I am currently
repairing, and so I pulled the cables off of the floating
power supply board and removed it...

It took me an hour to trace all of the unlabeled connectors
back to their origin, so that I could figure out which one
went on which pin.

Yes, I know, I should have taken a picture... but I had another
FG504 in for repair so I figured I could just crib off of it...
except that someone had beaten me to it, and removed all of
the same connectors on that unit... OOPSIE!

Honestly, I am pretty happy that Tektronix did as good of a
job as they did on including pertinent information in their
manuals... I'll hold them to perfection when I can achieve
perfection myself.

-Chuck Harris

Colin Herbert via groups.io wrote:
Thanks for that info, Dan. Would you believe that when my wife brought me a mug of tea in bed this morning, I was reading the FG 504 Manual and noticed where the jumper is marked on the schematic. I think I was thrown as to its circuit location by the physical location on the circuit board. However, that revelation left me with the puzzle of which was the default (non-VCF) position and I was wondering as to how I might investigate that, when I looked at my email and your reply gave me the answer!

I still have some problems with the Function Generator (though I have fixed one) which relate to the symmetry adjustments.

An earlier problem involved the power-rails and one going bad after I'd measured it to be OK. That turned out to be a harmonica-type connector giving bad contact, so I re-seated all of those that I could locate, which solved that problem, but then left me with the question of whether I had put the W20 jumper back properly or not. You have now clarified that for me.

I wonder why this wasn't clearer in the Manual?

Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of Dan G
Sent: 08 August 2020 01:15
To: TekScopes@groups.io
Subject: Re: [TekScopes] FG 504 problems

On Fri, Aug 7, 2020 at 03:41 PM, Colin Herbert wrote:

While its position is shown on
the Internal Adjustments section A3 Loop Board diagram, there appears to be no
indication of which is the default setting and which the VCF input setting. I
cannot locate the jumper on the schematics either.
Hi Colin,

The W20 jumper is shown on schematic <1> ("Triangle Wave Generator" in
post-B040000 service manuals, and "Main Loop" in early editions.) It
is shown in the upper left corner of the schematic, just above "VCF INPUT".

The jumper is in the N/C position when it is placed toward the back of the
plug-in. Moving it to the front of the plug-in routes the VCF Input signal
to P1275.


dan








Re: 475 With a bowed display. . . .Ideas?

Chuck Harris
 

Typically, when a proper application of the Geometry,
Focus, Astigmatism, Trace Rotation, and other affiliated
adjustments results in a screen that just doesn't look
as pretty as we would like, it means that there has been
an outside physical influence on the CRT (READ: OOPS! BANG!
$%^! & #!!*^! Why Me???)

The Mumetal shield can get bent, or magnetized. One of
the steering magnets (held with Scotch tape) can fall off
of the CRT neck, causing the beam to partially strike one
many internal shield electrodes that looks like a hole in
a plate of metal.

Or, it can be that we are much more nit-picky than tektronix
was originally.

If you carefully read the specifications in the manual, you
will often find that we have been spoiled rotten by all of
the CRTs we get that are much better than the specifications
say they could be...

-Chuck Harris

Raymond Domp Frank wrote:

On Sat, Aug 8, 2020 at 01:26 AM, Stephen wrote:


I’m not sure, but that makes me think « geometry »? Maybe??
Possibly not:
In the paragraph immediately following your longish quote the OP writes:

"Y Align R1385 and Geometry R1390 will not bring the vertical markers
into proper vertical alignment even though they do have some effect on
the trace by making it less severe. Even though they never "Fix" the problem."

Raymond