Date   

Re: Tek 455 Vertical deflection question

Mark Vincent
 

James,

See if R4134, CH1 bal, helps. This is an internal adjustment.

Mark


Re: Tek 455 Vertical deflection question

James55
 

Hi Mark,

swapping the leads makes no difference, in that the trace or spot remains towards the bottom of the screen.

@ Ozan.

Intensity still affects the Y position - with the wires swapped too.


One more observation is that in X-Y mode, whilst in Channel 1, the spot descends about a division whilst moving from right to left, whereas in Channel 2 it remains straight.


James


Re: Tek 455 Vertical deflection question

Mark Vincent
 

James,

How about swapping the vertical leads to the neck pins to see if the problem tracks. Use test leads if necessary if the wires are too short. The additional length is fine in this case. That will help point in the right direction to the problem.

Mark


Re: Tek 455 Vertical deflection question

Ozan
 

On Sat, May 28, 2022 at 05:25 PM, James55 wrote:

after removing the vertical and horizontal modules, giving all the
connectors a good clean, the X-Y spot appears immediately.
It's still preferring the lower half of the screen but at least it is there.

Whilst it was apart I visually checked under the CRT for anything loose or
poorly soldered, but without anything new presenting itself.

If anyone has any ideas, I am all ears.
Does intensity still influence Y position?
Ozan


Re: Tek 455 Vertical deflection question

James55
 

Roger,

after removing the vertical and horizontal modules, giving all the connectors a good clean, the X-Y spot appears immediately.
It's still preferring the lower half of the screen but at least it is there.

Whilst it was apart I visually checked under the CRT for anything loose or poorly soldered, but without anything new presenting itself.

If anyone has any ideas, I am all ears.


James


Re: 7633 CRT off level

Andy Warner
 

That all makes perfect sense. I can see the spring loaded screws you
mention and that Zen showed photos of.

Thanks all.

On Sat, May 28, 2022, 15:35 Jeff Dutky <jeff.dutky@gmail.com> wrote:

The storage CRTs in the 7613/23/33 are indeed smaller than the (gloriously
large) CRT in the 7603, and there is likely to be more room for play, as
the chassis is the same size for all the 76x3 scopes.

The mechanics for the storage scopes should be fairly similar, though
there are more connections to the storage CRT than to the non-storage CRT.

Here are the removal instructions from the 7633 manual:

A. REMOVAL.

1. Remove the head radiator/Low-Voltage Regulator circuit board assembly
as described previously.
2. Remove the CRT base socket from the rear of the CRT.
3. Loosen the two screws located on each side of the CRT socket until the
tension of the springs on these screws is released. Then, press in on the
screws to be sure that the CRT clamp is loose.
4. Disconnect the deflection-plate connectors. Be careful not to bend
these pins.
5. Disconnect the P1830 plug (storage cable assembly).
6. Disconnect the CRT anode plug from the jack located on the rear and
left side of the CRT shield. Ground this lead to the chassis to dissipate
any stored charge.
7. Remove the four screws securing the CRT bezel to the front panel.
Remove the plastic faceplate protector, light filter, and the graticule
light assembly.
8. Hold one hand on the CRT faceplate and push forward on the CRT base
with the other. As the CRT starts out of the shield, grasp it firmly. Guide
the anode lead and the storage cable assembly through the cutout in the CRT
shield as the CRT is removed.

Step #3 is the important one, and is probably what you will need to do in
order to adjust the rotation of the CRT in the chassis.

I have a 7633, but I have not done anything with the CRT, so I am only
guessing.

-- Jeff Dutky







Re: 7633 CRT off level

 

The storage CRTs in the 7613/23/33 are indeed smaller than the (gloriously large) CRT in the 7603, and there is likely to be more room for play, as the chassis is the same size for all the 76x3 scopes.

The mechanics for the storage scopes should be fairly similar, though there are more connections to the storage CRT than to the non-storage CRT.

Here are the removal instructions from the 7633 manual:

A. REMOVAL.

1. Remove the head radiator/Low-Voltage Regulator circuit board assembly as described previously.
2. Remove the CRT base socket from the rear of the CRT.
3. Loosen the two screws located on each side of the CRT socket until the tension of the springs on these screws is released. Then, press in on the screws to be sure that the CRT clamp is loose.
4. Disconnect the deflection-plate connectors. Be careful not to bend these pins.
5. Disconnect the P1830 plug (storage cable assembly).
6. Disconnect the CRT anode plug from the jack located on the rear and left side of the CRT shield. Ground this lead to the chassis to dissipate any stored charge.
7. Remove the four screws securing the CRT bezel to the front panel. Remove the plastic faceplate protector, light filter, and the graticule light assembly.
8. Hold one hand on the CRT faceplate and push forward on the CRT base with the other. As the CRT starts out of the shield, grasp it firmly. Guide the anode lead and the storage cable assembly through the cutout in the CRT shield as the CRT is removed.

Step #3 is the important one, and is probably what you will need to do in order to adjust the rotation of the CRT in the chassis.

I have a 7633, but I have not done anything with the CRT, so I am only guessing.

-- Jeff Dutky


Re: A flexible 7k extender?

John Griessen
 

On 5/27/22 14:14, bronxway@gmail.com wrote:
Hello John,
Are the PCB boards still available for the 7K extenders?
Alternatively - are the design files available?
I got a bounce trying to send to one who requested, so I put a zip file of the Gerbers on my server.
I run my own mail server and it occasionally gets blacklisted by some ISPs.

If you want the pcb-rnd files (for editing and changing) email me again for that.


The fab files make boards like this:
https://www.ecosensory.com/tek/TEK_7K_FLEX_production-board-2.jpg
https://www.ecosensory.com/tek/TEK_7K_FLEX_production-board-3.jpg

assembled:
https://www.ecosensory.com/tek/TEK_7K_FLEX_assy-01-sm.jpg
https://www.ecosensory.com/tek/TEK_7K_FLEX_assy-06-sm.jpg
https://www.ecosensory.com/tek/TEK_7K_FLEX_assy-08-sm.jpg
https://www.ecosensory.com/tek/TEK_7K_FLEX_assy-08-sm.jpg

RS-274X fab file:
https://www.ecosensory.com/tek/tek_7k_flex_rev-2.1.zip

There are no schematics -- straight through extender.

--
John Griessen -- building lab gear for biologists
Albuquerque NM blog.kitmatic.com


Re: 7633 CRT off level

Andy Warner
 

The tube is not loose.
Thanks for the photos, Zen - I will attack the problem with renewed
enthusiasm, and report back. I don’t think the storage tube screen is as
large as the non-storage tubes in the 76xx series; but given the similar
chassis, I am hopeful the mechanics are similar.

Appreciate all the responses.
On Sat, May 28, 2022 at 14:05 David <vexorg.calibra@gmail.com> wrote:

If it was missing then you’d think it would be loose.

Is the tube loose?





--
Andy


Re: 7633 CRT off level

David
 

If it was missing then you’d think it would be loose.

Is the tube loose?


Re: 7633 CRT off level

Mlynch001
 

465/475 etc. have rubber support cushions on each corner, I don’t know if the 76xx series uses a similar construction? A missing rubber cushion/spacer can allow the CRT to tilt.

--
Michael Lynch
Dardanelle, AR


Re: 7633 CRT off level

Zentronics42@...
 

Sorry about the late weigh in on this. I have added 3 photos of a 7603 Tube don’t have a 7633 in the lab but I expect it to be very similar. The 76XX tubes are much larger than the normal 7000 series frames. They are more like a 576 tube than anything else. They are supported buy 4 plastic inserts and have a non typical clamping mechanism to them does not look like it would be too awful to remove the tube and realign. I suspect one of the plastic supports has either shifted or degraded. If I need to add some pictures let me know and I will see what I can do. I have a 7603 that is a terminal case.

To get to the tube clamp it helps to remove the LV supply to just get it out of they way. A complete unhook is not needed. The 76xx scopes also have a "service" position for the LV supply that might be useful in this case.

Photos - https://groups.io/g/TekScopes/album?id=275418

Zen

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Roger Evans via groups.io
Sent: Saturday, May 28, 2022 10:12 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7633 CRT off level

I haven't taken the CRT out of a 7000 series but I have removed some others and when they come out they reveal four (removable) rubber pieces which fit in each front corner and serve as shock absorbers. I imagine if the CRT had been refitted badly with one or more of these wedged corner pieces out of place then that would account for the present misalignment. The manual should describe CRT removal in detail. First time I removed a CRT I was very wary (removing the anode connector and then having to push on the CRT) but it was not a difficult task.

Regards,

Roger


3 photos uploaded #photo-notice

Group Notification <noreply@...>
 

The following photos have been uploaded to the Tektronix 76xx Tube supports ( https://groups.io/g/TekScopes/album?id=275418 ) album of the TekScopes@groups.io group.

* Clamp with Arrows.JPG ( https://groups.io/g/TekScopes/photofromactivity?id=3436466 )
* Tube Supports bottom.JPG ( https://groups.io/g/TekScopes/photofromactivity?id=3436467 )
* Tube Supports Top.JPG ( https://groups.io/g/TekScopes/photofromactivity?id=3436468 )

*By:* Zentronics42@gmail.com


Re: A flexible 7k extender? I'm thinking about it (was: 7B92 with no repeating sweep)

Roy Kalawsky
 

Hi

I too would like to build an extender for my 7k scope. Waited years to get one of these in great condition - then I managed it - all working. I have a few plug-ins that I would love to get going. These scopes are do much better than the modern digital stuff.

Cheers Roy


Re: A flexible 7k extender? I'm thinking about it (was: 7B92 with no repeating sweep)

John Griessen
 

On 5/27/22 14:14, bronxway@gmail.com wrote:
Hello John,
Are the PCB boards still available for the 7K extenders?
Alternatively - are the design files available?
I sold out and have not reordered parts. Yes, RS-274X and pcb-rnd files are available -- I'll send you a zip of the project dir. It's just a straight through, so no schematic.

--
John Griessen -- building lab gear for biologists
Albuquerque NM blog.kitmatic.com


Re: 7633 CRT off level

Roger Evans
 

I haven't taken the CRT out of a 7000 series but I have removed some others and when they come out they reveal four (removable) rubber pieces which fit in each front corner and serve as shock absorbers. I imagine if the CRT had been refitted badly with one or more of these wedged corner pieces out of place then that would account for the present misalignment. The manual should describe CRT removal in detail. First time I removed a CRT I was very wary (removing the anode connector and then having to push on the CRT) but it was not a difficult task.

Regards,

Roger


Re: 7633 CRT off level

n4buq
 

From what I can see, the 7633 is like most of the other 7000 scopes where the CRT is rectangular and isn't exactly rotatable. I had the CRT out of my 7514 a couple of weeks ago and the fit for that is very tight and rotating it wouldn't be possible. I think my 7704A is very much the same (although maybe not quite as tight of a fit).

Perhaps the entire mounting mechanism is adjustable?

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "Andy Warner" <andyw@pobox.com>
To: "tekscopes" <TekScopes@groups.io>
Sent: Saturday, May 28, 2022 8:31:11 AM
Subject: Re: [TekScopes] 7633 CRT off level
That was what I expected with my experience with other Tek CRTs of similar
vintage, but after taking a look at the internals (without going through a
lot of disassembly, admittedly), the clamp location wasn't leaping out at
me. As I said, the mechanical drawings in the service manual didn't shine a
lot of light on the situation.

On Sat, May 28, 2022 at 7:29 AM David C. Partridge <
david.partridge@perdrix.co.uk> wrote:

If my memory is working right, I think there should be a plastic "clamp"
at the far end of the tube (I think it is inside the mu-metal shield but
maybe not). This can be undone and the CRT rotated.

There is however a bit of a catch - these clamps have a tendency to fall
apart when disturbed ☹.

HtH
David

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Andy Warner
Sent: 28 May 2022 12:34
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7633 CRT off level

I wasn’t clear. The CRT is physically rotated in its mount. So that neither
the graticule or the rectangular masking is perfectly horizontal.

I’ve matched the trace to the graticule, using the trace rotate, but they
are both not level. Looking for advice on physically rotating the tube,
from anyone with experience of this mainframe.






--
Andy



Re: 7633 CRT off level

Andy Warner
 

That was what I expected with my experience with other Tek CRTs of similar
vintage, but after taking a look at the internals (without going through a
lot of disassembly, admittedly), the clamp location wasn't leaping out at
me. As I said, the mechanical drawings in the service manual didn't shine a
lot of light on the situation.

On Sat, May 28, 2022 at 7:29 AM David C. Partridge <
david.partridge@perdrix.co.uk> wrote:

If my memory is working right, I think there should be a plastic "clamp"
at the far end of the tube (I think it is inside the mu-metal shield but
maybe not). This can be undone and the CRT rotated.

There is however a bit of a catch - these clamps have a tendency to fall
apart when disturbed ☹.

HtH
David

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Andy Warner
Sent: 28 May 2022 12:34
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7633 CRT off level

I wasn’t clear. The CRT is physically rotated in its mount. So that neither
the graticule or the rectangular masking is perfectly horizontal.

I’ve matched the trace to the graticule, using the trace rotate, but they
are both not level. Looking for advice on physically rotating the tube,
from anyone with experience of this mainframe.






--
Andy


Re: 7633 CRT off level

 

If my memory is working right, I think there should be a plastic "clamp" at the far end of the tube (I think it is inside the mu-metal shield but maybe not). This can be undone and the CRT rotated.

There is however a bit of a catch - these clamps have a tendency to fall apart when disturbed ☹.

HtH
David

-----Original Message-----
From: TekScopes@groups.io <TekScopes@groups.io> On Behalf Of Andy Warner
Sent: 28 May 2022 12:34
To: TekScopes@groups.io
Subject: Re: [TekScopes] 7633 CRT off level

I wasn’t clear. The CRT is physically rotated in its mount. So that neither
the graticule or the rectangular masking is perfectly horizontal.

I’ve matched the trace to the graticule, using the trace rotate, but they
are both not level. Looking for advice on physically rotating the tube,
from anyone with experience of this mainframe.


Re: 7633 CRT off level

Andy Warner
 

I wasn’t clear. The CRT is physically rotated in its mount. So that neither
the graticule or the rectangular masking is perfectly horizontal.

I’ve matched the trace to the graticule, using the trace rotate, but they
are both not level. Looking for advice on physically rotating the tube,
from anyone with experience of this mainframe.

On Sat, May 28, 2022 at 02:35 David <vexorg.calibra@gmail.com> wrote:

There’s a trace rotation adjuster under the trig source options on the
front panel





--
Andy

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