Date   
Re: Scope face focus anomaly

Fabio Trevisan
 

Hello Gary,
Not specifically related to your 7514, I want to share 2 of my last (and
pretty much all) experiences with my 464 (focus related)....
As you've seen from some of the other folks answers focus seem to be
influenced by quite a few of the inner elements (or, let's call them
intermediate anodes) that are not directly related to the focus electrode
itself.
My first experience was when my 464 was still recent on my hands and it had
a nasty overall focus.
It wouldn't focus well over the entire screen.
It had, back then, a major vertical high freq response imbalance (too much
high freq gain, or too low lo-freq gain, which was my main concern).
As the troubleshooting evolved I found an opened (burnt) resistor on the
vertical output amplifier's biasing.
As soon as I replaced the resistor, I noticed a great improvement in focus
(after I readjusted a number of trimpots that were set wrong partially
compensating the bias imbalance).

Lesson learnt (as I understood):
Focus is affected by inadequate balance between voltages of symmetrically
opposed electrodes, such as the vertical or horizontal plates, so, the
average of the varying voltages at the upper and lower plates must remain
constant and at a value that is correct in relation to the voltages of the
preceding and next electrodes in the electron beam's path.
If the upper plate is at an average level of, say, 60V (example), and if
the lower is at 40 (average being 50) and if 50 is the right voltage for
the vert plates, overall the focus may be right, but as the trace moves up
or down, the average between them doesn't remain constant and the focus
becomes modulated by the vertical signal.
A defect on the vertical amplifier that may be causing an imbalance of such
top and bottom plates'voltages, may affect adversely the focus in the
up-down direction.

My second experience was after I dismantled the oscilloscope to replace its
power supply caps and, in the process, I may have dislodged the "geometry"
trimppt from its correct adjustment.
As I just powered up the scope after reassembly, the focus was once again
awful, but luckily I also noticed that waveforms were distorted (Sort of
pin-cushion distotyion).
As soon as I properly re-adjusted the geometry trimpot, focus improved
again back to what it was.

Brgrds,

Fabio

On Jul 18, 2017 11:12 PM, "Gary Robert Bosworth @grbosworth
[TekScopes]" <TekScopes@...> wrote:



Thanx Stephen. I will see if there is a shield adjustment. I know very
little about CRTs.

Gary


On Tue, Jul 18, 2017 at 2:56 PM, sbell@... [TekScopes] <
TekScopes@...> wrote:



The setting of the CRT's vertical shield voltage seems to have a
considerable effect on the ability to obtain a well focused spot. I am not
familiar with the 7514 but if it has a adjustment for this voltage you
could try tweaking it to see if it results in improved focus.
On my 7834 I was unable to obtain a good spot with the shield voltage
adjustment procedure detailed in the manual so after going through the
complete CRT set-up procedure I had to further tweak the shield voltage to
obtain best overall focus.

Stephen

[Non-text portions of this message have been removed]


--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247 <(310)%20317-2247>

[Non-text portions of this message have been removed]

Re: Scope face focus anomaly

Gary Robert Bosworth
 

Thanx Stephen. I will see if there is a shield adjustment. I know very
little about CRTs.

Gary


On Tue, Jul 18, 2017 at 2:56 PM, sbell@... [TekScopes] <
TekScopes@...> wrote:



The setting of the CRT's vertical shield voltage seems to have a
considerable effect on the ability to obtain a well focused spot. I am not
familiar with the 7514 but if it has a adjustment for this voltage you
could try tweaking it to see if it results in improved focus.
On my 7834 I was unable to obtain a good spot with the shield voltage
adjustment procedure detailed in the manual so after going through the
complete CRT set-up procedure I had to further tweak the shield voltage to
obtain best overall focus.

Stephen






--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247


[Non-text portions of this message have been removed]

Re: CRT Tube (in good shape) for Tek464 / Tek466

 

In previous post ....

"The recommended replacement for all 4x6 CRT"
should be
"The recommended replacement for all 46x CRT"

/Håkan

Re: CRT Tube (in good shape) for Tek464 / Tek466

 

Please be aware that the 464 and 466 do not have the same CRT.
Actually they could use the same CRT if they are within the same S/N range i.e either
below or above B080000. The recommended replacement for all 4x6 CRT's is 154-0750-00.
If the scope is below B080000 some minor modifications must be done. The kit P/N is 050-0762-14.

/Håkan

Re: Scope face focus anomaly

s.r.bell@...
 

The setting of the CRT's vertical shield voltage seems to have a considerable effect on the ability to obtain a well focused spot. I am not familiar with the 7514 but if it has a adjustment for this voltage you could try tweaking it to see if it results in improved focus.
On my 7834 I was unable to obtain a good spot with the shield voltage adjustment procedure detailed in the manual so after going through the complete CRT set-up procedure I had to further tweak the shield voltage to obtain best overall focus.

Stephen

Re: Curve Tracer Adapers

Chuck Harris
 

Fundamentally, there is no difference beyond the
pin assignment.

Curve tracers, like the 576 only have E,B, and C
pins. The FET adapters typically assign B to the
Gate, E to the Source, and C to the Drain.

The standard TO220 packaged FET's have the pins
slightly scrambled from the bipolar configuration.

Banana plugs, with short wires and alligator clips
are often very handy... keep the wires around one
or two inches long.

-Chuck Harris

brentleew2003@... [TekScopes] wrote:

I want to purchase an adapter for my 576 I recently purchased, but I'm not sure what the difference between the Transistor, FET or combination version is. A couple of questions- 1. Are the 013-0098-00, 013-0098-01 and 013-0098-02, wired differently, or is it just labeling. 2. Is the bar at top front for emitter/source grounding or separating the two sides, and finally what are the pushbuttons on the sides for. I have not seen documentation for these as yet. Thanks and Cheers,
Brent





------------------------------------
Posted by: brentleew2003@...
------------------------------------


------------------------------------

Yahoo Groups Links



Re: CRT Tube (in good shape) for Tek464 / Tek466

Fabio Trevisan
 

Hello Colin,

Thanks for the heads up.
I didn't go all the way to check the actual part number for the 466 CRT,
but I had a vivid recollection of having read (here at Tekscopes or
elsewhere) that indeed they were different at the beginning, but later, Tek
started using the same tube for the 464 as for the 466, only that the ones
for the 466 were "selected" to meet the 466 Fast Writing specs, while the
other, less yielding CRTs, that couldn't meet those specs would be labeled
after the 464's part number.
I tended to believe on the former because even on my 464, it has the
"reduced scan" graticule, although it obviously don't have such.

Since I don't own a 466, what I need indeed is a tube that can work on the
464.

Rgrds,

Fabio


2017-07-18 16:50 GMT-03:00 'Colin Herbert' colingherbert@...
[TekScopes] <TekScopes@...>:



Hi Fabio,

Please be aware that the 464 and 466 do not have the same CRT. I got caught
on that one some time ago. I bought a parts-mule 466 with the idea it would
have a spare tube for my 464 - mistake. The 464 will accept 154-0749-00 as
you say - it has a P1 phosphor. It will also accept a 154-0722-00 which has
a phosphor similar to P1. If you want to check this for yourself, go to:

http://www.reprise.com/host/tektronix/reference/crt.asp

which is on Bill & Stan's Tektronix resource site (a useful source of info
on all sorts of Tek stuff). The 466 has the reduced scan facility, hence a
different CRT

Good Luck with getting a better CRT for your 464, it may not be so
difficult
in Brazil as you think, as someone might be driving from the USA down
south.
It's much worse for me in the UK.

Colin.

From: TekScopes@... [mailto:TekScopes@...]
Sent: 18 July 2017 20:06
To: TekScopes@...
Subject: [TekScopes] CRT Tube (in good shape) for Tek464 / Tek466

Hello folks at Tekscopes,

My Tek 464 + DM44 is, if I can say, finally repaired / restored.

All issues it had are solved and it's well calibrated to the specs or
better.

Nevertheless, since the very beginning I knew its CRT was worn out, so much
that I even tried to do some rejuvenation, without success.

I would like to know if any of the group would have a CRT for the 464 /
466, that you know not to be worn out, and which you would be willing to
part.

I know that by now, this is no longer an economically sound decision, since
I spent far way more on this 464 than it probably worth, but, on the other
hand, it would be just a shame that this scope is now in perfectly working
condition and yet, not being satisfactory on the trace brightness
department.

If there's anyone, I still don't know how we would manage to get it here to
Brazil as shipping of such a part seems rather scary to me and I`m not even
sure if / how difficult it would be to embark a plane with a part like that
(as hand luggage), should I be travelling near some of you at some point.
I`m afraid that since Sept 11, the dangerous goods list became quite
comprehensive and airlines in general would refuse boarding of items that
may implode, such a s a CRT.

The part number is 154-0749-00

KRgrds,

Fabio

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[Non-text portions of this message have been removed]

Re: CRT Tube (in good shape) for Tek464 / Tek466

Colin Herbert
 

Hi Fabio,



Please be aware that the 464 and 466 do not have the same CRT. I got caught
on that one some time ago. I bought a parts-mule 466 with the idea it would
have a spare tube for my 464 - mistake. The 464 will accept 154-0749-00 as
you say - it has a P1 phosphor. It will also accept a 154-0722-00 which has
a phosphor similar to P1. If you want to check this for yourself, go to:



http://www.reprise.com/host/tektronix/reference/crt.asp



which is on Bill & Stan's Tektronix resource site (a useful source of info
on all sorts of Tek stuff). The 466 has the reduced scan facility, hence a
different CRT



Good Luck with getting a better CRT for your 464, it may not be so difficult
in Brazil as you think, as someone might be driving from the USA down south.
It's much worse for me in the UK.



Colin.



From: TekScopes@... [mailto:TekScopes@...]
Sent: 18 July 2017 20:06
To: TekScopes@...
Subject: [TekScopes] CRT Tube (in good shape) for Tek464 / Tek466





Hello folks at Tekscopes,

My Tek 464 + DM44 is, if I can say, finally repaired / restored.

All issues it had are solved and it's well calibrated to the specs or
better.

Nevertheless, since the very beginning I knew its CRT was worn out, so much
that I even tried to do some rejuvenation, without success.

I would like to know if any of the group would have a CRT for the 464 /
466, that you know not to be worn out, and which you would be willing to
part.

I know that by now, this is no longer an economically sound decision, since
I spent far way more on this 464 than it probably worth, but, on the other
hand, it would be just a shame that this scope is now in perfectly working
condition and yet, not being satisfactory on the trace brightness
department.

If there's anyone, I still don't know how we would manage to get it here to
Brazil as shipping of such a part seems rather scary to me and I`m not even
sure if / how difficult it would be to embark a plane with a part like that
(as hand luggage), should I be travelling near some of you at some point.
I`m afraid that since Sept 11, the dangerous goods list became quite
comprehensive and airlines in general would refuse boarding of items that
may implode, such a s a CRT.

The part number is 154-0749-00

KRgrds,

Fabio









<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_cam
paign=sig-email&utm_content=emailclient>

Virus-free.
<http://www.avg.com/email-signature?utm_medium=email&utm_source=link&utm_cam
paign=sig-email&utm_content=emailclient> www.avg.com

CRT Tube (in good shape) for Tek464 / Tek466

Fabio Trevisan
 

Hello folks at Tekscopes,

My Tek 464 + DM44 is, if I can say, finally repaired / restored.

All issues it had are solved and it's well calibrated to the specs or
better.

Nevertheless, since the very beginning I knew its CRT was worn out, so much
that I even tried to do some rejuvenation, without success.

I would like to know if any of the group would have a CRT for the 464 /
466, that you know not to be worn out, and which you would be willing to
part.

I know that by now, this is no longer an economically sound decision, since
I spent far way more on this 464 than it probably worth, but, on the other
hand, it would be just a shame that this scope is now in perfectly working
condition and yet, not being satisfactory on the trace brightness
department.

If there's anyone, I still don't know how we would manage to get it here to
Brazil as shipping of such a part seems rather scary to me and I`m not even
sure if / how difficult it would be to embark a plane with a part like that
(as hand luggage), should I be travelling near some of you at some point.
I`m afraid that since Sept 11, the dangerous goods list became quite
comprehensive and airlines in general would refuse boarding of items that
may implode, such a s a CRT.

The part number is 154-0749-00

KRgrds,

Fabio

Curve Tracer Adapers

brentleew2003@...
 

I want to purchase an adapter for my 576 I recently purchased, but I'm not sure what the difference between the Transistor, FET or combination version is. A couple of questions- 1. Are the 013-0098-00, 013-0098-01 and 013-0098-02, wired differently, or is it just labeling. 2. Is the bar at top front for emitter/source grounding or separating the two sides, and finally what are the pushbuttons on the sides for. I have not seen documentation for these as yet. Thanks and Cheers,
Brent

Re: Instruction/Data Sheet of 067-1413-00 (Calibration Head for CSA803 and 11800 Series) available.

Kurt Rosenfeld
 

Tekwiki is happy to host any/all Tek-related docs.

Re: Scope face focus anomaly

Mark Wendt
 

On 07/18/2017 10:28 AM, David @DWH [TekScopes] wrote:
On Tue, 18 Jul 2017 07:38:39 -0400, you wrote:

On 07/17/2017 07:30 PM, David @DWH [TekScopes] wrote:
It might depend on exactly which 7000 mainframe it is. Some of them
have an adjustment for the shield voltage or the common mode
deflection voltage which can affect the focus over the surface of the
screen.
Could it also possibly be an astig adjustment? I've seen that fix a few
display focus anomalies in the past.

Mark
There are other CRT adjustments which can cause the focus to change at
different CRT beam positions. The astigmatism control should not do
it.
Okay, I'm not that familiar with the 7514 scope. I've had astig adjustments fix some focus problems on other CRT's.

Mark

Re: Scope face focus anomaly

Roger Evans
 

Are the signal displays also out of focus? If so, does it happen suddenly across the split storage screen or steadily get worse as you move down? The read out can often jitter but I would have thought that was visually different unless the phosphor persistence is longer than other 7k frames. The jitter is usually very much less if you set the readout board to display only between sweeps.

Roger

Re: Scope face focus anomaly

 

On Tue, 18 Jul 2017 07:38:39 -0400, you wrote:

On 07/17/2017 07:30 PM, David @DWH [TekScopes] wrote:
It might depend on exactly which 7000 mainframe it is. Some of them
have an adjustment for the shield voltage or the common mode
deflection voltage which can affect the focus over the surface of the
screen.
Could it also possibly be an astig adjustment? I've seen that fix a few
display focus anomalies in the past.

Mark
There are other CRT adjustments which can cause the focus to change at
different CRT beam positions. The astigmatism control should not do
it.

Re: Scope face focus anomaly

 

I do not have any documentation for the 7514 so cannot point to any
specific causes or adjustments.

On the 7834 there is an adjustment for the average horizontal plate
voltage which as I recall, had an effect on the focus from top to
bottom.

I would do the basic maintenance checks like power supply voltages and
then do the z-axis calibration procedures which include the geometry,
astigmatism, and stigmator if present and then any adjustments like
the average horizontal plate voltage if it is included on the 7514.

On Mon, 17 Jul 2017 21:55:57 -0700, you wrote:

David: It is a 7514. I could live with it, but a fuzzy bottom readout is
an embarrassment. Any ideas what the problem is?
Gary

Re: Instruction/Data Sheet of 067-1413-00 (Calibration Head for CSA803 and 11800 Series) available.

Mark Wendt
 

On 07/18/2017 02:46 AM, eggeja2@... [TekScopes] wrote:
Hi to All,

Some time ago I asked for the Instruction/Data Sheet on this device. I now I have it. Free to all. Contact me off list and I will send it to you. By the way I'am still looking for documentation on the 067-1331-00 Device (Sampling Head Simulator).

Greetings to All,

Egge Siert

Egge,

Maybe put it up on Tekwiki or KO4BB?

Mark

Re: Scope face focus anomaly

Mark Wendt
 

On 07/17/2017 07:30 PM, David @DWH [TekScopes] wrote:
It might depend on exactly which 7000 mainframe it is. Some of them
have an adjustment for the shield voltage or the common mode
deflection voltage which can affect the focus over the surface of the
screen.
Could it also possibly be an astig adjustment? I've seen that fix a few display focus anomalies in the past.

Mark

TEK 2711 Spectrum Analyzer

Willy Guevara <willgivs@...>
 

Hi Guys,
Just want to share repair done to one of my Tek 2711.

The unit does not booth up continuously
and the following are displayed on the crt:

CFC loopback :failure
CFC loopback :failure
CFC loopback :failure
CFC loopback :failure
Cannot read 100MHZ red osc bits

My initial impression is that there is a problem with the reference
oscillator and the CFC board but since it is hard to remove the osc board
and do voltage check as well as the cfc board,I decided to check the power
supply of the unit. I found out that there was no reference 5V from the
PWM(IC-280). There was problem with the PWM -TL594cn. After replacing it,
the unit passed all the diagnostics and the unit is now working well.

I hope this will help just in case same problem will be encountered.

Bregards,
Willy


Sent from my IOS-X

Instruction/Data Sheet of 067-1413-00 (Calibration Head for CSA803 and 11800 Series) available.

Egge Siert
 

Hi to All,


Some time ago I asked for the Instruction/Data Sheet on this device. I now I have it. Free to all. Contact me off list and I will send it to you. By the way I'am still looking for documentation on the 067-1331-00 Device (Sampling Head Simulator).


Greetings to All,


Egge Siert

Re: Scope face focus anomaly

Gary Robert Bosworth
 

David: It is a 7514. I could live with it, but a fuzzy bottom readout is
an embarrassment. Any ideas what the problem is?
Gary


On Mon, Jul 17, 2017 at 4:30 PM, David @DWH [TekScopes] <
TekScopes@...> wrote:



It might depend on exactly which 7000 mainframe it is. Some of them
have an adjustment for the shield voltage or the common mode
deflection voltage which can affect the focus over the surface of the
screen.

On 17 Jul 2017 00:33:27 +0000, you wrote:

Anyone know what to do when the top row of readout data on a 7000 Series
scope is perfectly in focus, but the bottom row is slightly out of focus?



--
Gary Robert Bosworth
@grbosworth
Tel: 310-317-2247


[Non-text portions of this message have been removed]