Date   

Re: 555 Attributes, facets, benefits and General Discussion

Roy Morgan
 

Some decades ago (2 or 3) I had a different dual trace scope but am unsure of the model number. It was the size of the 545 with no separate power unit. It had two vertical channels and time base without any plug-ins as I remember. The bandwidth was modest, meant for medical/physiology use.

It must have been the 502. Maybe I will discover it buried in my long-neglected storage unit.

Roy

Roy Morgan
K1LKY Western Mass

On Feb 26, 2020, at 2:33 AM, Tim Phillips <timexucl@gmail.com> wrote:

from Tim P (UK)
re the 555, I've often wondered why the timebases were made plug-in.


Re: 555 Attributes, facets, benefits and General Discussion

bill koski
 

I've never seen a 555 up close and personal but I have a 556 that I bought for 25 bucks with the full manual at a HAM/Antique radio fest. From what I know it's very similar to the 555 but has it's own power supply built in.
Other than a vertical driver tube and maybe 1 or 2 other tubes I've been running it as I bought it. It had a single and a dual trace plugin with it. I've since acquired 5 or 6 plugins from a flea market for about 10 bucks each. All had tubes and needed little more than cleanup. I then got a single bay (535?) with another 4 complete plugins.
Checked out the plugins but not the scope itself yet.
Fortunately I got to all those plugins before any audiophiles did to strip the tube out of them. ( I'm actually a tube audio nut myself but would never strip a Tek unit for an audio project!!!)
I built a cart for the 556 and it sits next to my bench always ready for action.
It too has quite an inrush when turned on. I have an old analog TV in my office and before I did some rewiring I could watch the picture get narrower and lights dim when I switch on the 556!
It used to be a "Hey watch this" moment when I had friends over:)
I love using it. Though it's only rated for 50 MHz I've easily locked on 100MHz+ signals (heavily attenuated.)
The internal construction of those scopes is a work of art to look at in my opinion.
I've not done a calibration on anything yet but with the plugins I use most form the basic checks I've done things seem to be pretty close to nut on. I'm sure it's been decades since a calibration was done on anything and possibly much not touched since it left the factory.

BTW while I'm here I do have a 1L5 spectrum analyzer plugin that I bought (cost more than the 2 scopes and all the other plugins put together) I don't believe it is working. I've checked the FET in it and did find 1 lytic that was bad but it appears to still have some problems. I need to make an extension cable to check it further and then that may become a discussion for another time here other than to ask if there is any common things to look for that goes bad on those?


Re: Tektronix 2467B Auto Measure Faulty?

Leandro Lindemann
 

The service manual states that a Fluke 5820A calibrator is required to calibrate the 2467. This instrument is inaccessible here in Brazil.

I believe that there must be other instruments capable of being used. Can someone tell me what they would be?
 
I intend to rent the instruments I need here in Brazil. I really want to resolve this defect.

Thanks.


Re: High Voltage Curve Tracer project

 

Testing tubes, CRTs, flyback perf.?


Re: 555 Attributes, facets, benefits and General Discussion

Tim Phillips
 

from Tim P (UK)
re the 555, I've often wondered why the timebases were made plug-in.
Was it just for servicing, or was someone at Tek thinking about specialised
units (TDR, sampling, etc)?
According to Stan's book, the only variants were the 21A / 22A with
improved triggering.


On Wed, 26 Feb 2020 at 06:44, Randy Newman <randy.n.at.home@gmail.com>
wrote:

Just to chime in. I got a 555 some years back with 2 CA, and a D. I have
since added a W, and 1A7. I’ll not mention the initial price, as it was
phenomenal. The crt has the purple/blue phosphor for photographic
use....beautiful, sharp trace. I also have 3 7000 series scope, but really
enjoy the 555. Also love the dual-beam feature!

On Tue, Feb 25, 2020, 3:18 PM fiftythreebuick <ae5i@netdoor.com> wrote:

Ernesto expressed interest in a thread about the Type 555, so let's see
if
it'll fly! :-)

For any bench project within the vertical bandwidth of the 555, it's my
favorite oscilloscope and has been since I used one for the first time in
1976. I'll never forget the first time I ever saw one. I had been
using a
502A and a 533A on an instrumentation project and went into the
instruments
lab to get a different plug-in unit for the 533A, and when I opened the
door, there, in the middle of the room, on a 500/53A cart, was a 555!
Well, the heavens opened, the sun broke through and the angels sang and I
instantly knew that one day I *HAD* to have one! I used it as the main
scope on the remainder of the project that I was working on and
immediately
found it to be my favorite of all the scopes I had ever used. It was
less
than a year later that I was unpacking my first one.

I really enjoy the versatility of the mainframe. With the entire range
of
letter and 1 series plug-in units available, you can do just about
anything
with it. The fact that it's dual beam is quite handy. I have done
comparisons using a 1S2 in each beam, so as to have two identical TDR
traces at the same time. Being able to have a spectral display and a
time
domain display of a circuit on the same screen simultaneously is
extremely
convenient, particularly for screen photos. Using either a pair of Type
M
plug-in units or a pair of Type 1A4 Plug-in units gives 8 traces (not 3
or
4 full function traces and more that are only logic or without full
sensitivity/etc) that are all identical and all with the same
functionality. Being able to watch the timing of 7 different points in
an
instrument has been EXTREMELY handy before, for me.

Plus, it has the attributes that are found on most other 500 series
mainframes: razor sharp trace from a non-mesh CRT, controls big enough
to
be very convenient, the finest design possible, best choice of materials
possible, etc, etc....

The first one I ever got turned out to be a bit of an oddity: it's a
MOD101D, which means operable on 60 or 400 cycles! I have the info and
the
parts, and one day I hope to get the subchassis fabricated for the rest
of
the frequency switching circuit and finish restoring it. There were only
20 of them made like that one.

A bit of useful repair info: if any of the large 10 ohm carbon resistors
in the bottom of the power supply ever fail, don't replace it with a
metal
film resistor. My buddy tried that and it turned out that the metal film
resistor could not take the inrush current when the unit was powered up
from cold, and would blow open intermittently. We put an old carbon
resistor back in and never had another problem. We also took a look at
the
inrush current with a storage scope and it was quite significant.

Well, hope this starts a fun thread!

Tom AE5I






Re: 555 Attributes, facets, benefits and General Discussion

Randy Newman
 

Just to chime in. I got a 555 some years back with 2 CA, and a D. I have
since added a W, and 1A7. I’ll not mention the initial price, as it was
phenomenal. The crt has the purple/blue phosphor for photographic
use....beautiful, sharp trace. I also have 3 7000 series scope, but really
enjoy the 555. Also love the dual-beam feature!

On Tue, Feb 25, 2020, 3:18 PM fiftythreebuick <ae5i@netdoor.com> wrote:

Ernesto expressed interest in a thread about the Type 555, so let's see if
it'll fly! :-)

For any bench project within the vertical bandwidth of the 555, it's my
favorite oscilloscope and has been since I used one for the first time in
1976. I'll never forget the first time I ever saw one. I had been using a
502A and a 533A on an instrumentation project and went into the instruments
lab to get a different plug-in unit for the 533A, and when I opened the
door, there, in the middle of the room, on a 500/53A cart, was a 555!
Well, the heavens opened, the sun broke through and the angels sang and I
instantly knew that one day I *HAD* to have one! I used it as the main
scope on the remainder of the project that I was working on and immediately
found it to be my favorite of all the scopes I had ever used. It was less
than a year later that I was unpacking my first one.

I really enjoy the versatility of the mainframe. With the entire range of
letter and 1 series plug-in units available, you can do just about anything
with it. The fact that it's dual beam is quite handy. I have done
comparisons using a 1S2 in each beam, so as to have two identical TDR
traces at the same time. Being able to have a spectral display and a time
domain display of a circuit on the same screen simultaneously is extremely
convenient, particularly for screen photos. Using either a pair of Type M
plug-in units or a pair of Type 1A4 Plug-in units gives 8 traces (not 3 or
4 full function traces and more that are only logic or without full
sensitivity/etc) that are all identical and all with the same
functionality. Being able to watch the timing of 7 different points in an
instrument has been EXTREMELY handy before, for me.

Plus, it has the attributes that are found on most other 500 series
mainframes: razor sharp trace from a non-mesh CRT, controls big enough to
be very convenient, the finest design possible, best choice of materials
possible, etc, etc....

The first one I ever got turned out to be a bit of an oddity: it's a
MOD101D, which means operable on 60 or 400 cycles! I have the info and the
parts, and one day I hope to get the subchassis fabricated for the rest of
the frequency switching circuit and finish restoring it. There were only
20 of them made like that one.

A bit of useful repair info: if any of the large 10 ohm carbon resistors
in the bottom of the power supply ever fail, don't replace it with a metal
film resistor. My buddy tried that and it turned out that the metal film
resistor could not take the inrush current when the unit was powered up
from cold, and would blow open intermittently. We put an old carbon
resistor back in and never had another problem. We also took a look at the
inrush current with a storage scope and it was quite significant.

Well, hope this starts a fun thread!

Tom AE5I




Re: High Voltage Curve Tracer project

John Griessen
 

On 2/25/20 3:08 PM, G Hopper wrote:
That looks rather nicely laid out. Clearly will be a beast when you're
done!
Yes, the spacings look like you're ready for 40kV!


Re: Tektronix 2467B Auto Measure Faulty?

Leandro Lindemann
 

I'm trying to understand where to start looking for the defect and I really appreciate any help.

Checking the service manual, there is a defect flowchart. In the Parametric measuremet trobleshooting section I have the 1st doubt:

The first first question is:

Is volts Acurate? (Must be timing measurement)

If the answer is no, check triger system
If so, perform cal 01 and cal 09.

My doubt is, is the measure of time that needs to be checked measured by the Auto function or manually?

From the video, you can see that using the Auto option the displayed waveform is outside the time base, but without using the Auto function everything is normal.

Thanks.


Re: Tektronix 2467B Auto Measure Faulty?

Leandro Lindemann
 

Vídeo with the fail:

https://youtu.be/9RO12A-TQbs


555 Attributes, facets, benefits and General Discussion

fiftythreebuick <ae5i@...>
 

Ernesto expressed interest in a thread about the Type 555, so let's see if it'll fly! :-)

For any bench project within the vertical bandwidth of the 555, it's my favorite oscilloscope and has been since I used one for the first time in 1976. I'll never forget the first time I ever saw one. I had been using a 502A and a 533A on an instrumentation project and went into the instruments lab to get a different plug-in unit for the 533A, and when I opened the door, there, in the middle of the room, on a 500/53A cart, was a 555! Well, the heavens opened, the sun broke through and the angels sang and I instantly knew that one day I *HAD* to have one! I used it as the main scope on the remainder of the project that I was working on and immediately found it to be my favorite of all the scopes I had ever used. It was less than a year later that I was unpacking my first one.

I really enjoy the versatility of the mainframe. With the entire range of letter and 1 series plug-in units available, you can do just about anything with it. The fact that it's dual beam is quite handy. I have done comparisons using a 1S2 in each beam, so as to have two identical TDR traces at the same time. Being able to have a spectral display and a time domain display of a circuit on the same screen simultaneously is extremely convenient, particularly for screen photos. Using either a pair of Type M plug-in units or a pair of Type 1A4 Plug-in units gives 8 traces (not 3 or 4 full function traces and more that are only logic or without full sensitivity/etc) that are all identical and all with the same functionality. Being able to watch the timing of 7 different points in an instrument has been EXTREMELY handy before, for me.

Plus, it has the attributes that are found on most other 500 series mainframes: razor sharp trace from a non-mesh CRT, controls big enough to be very convenient, the finest design possible, best choice of materials possible, etc, etc....

The first one I ever got turned out to be a bit of an oddity: it's a MOD101D, which means operable on 60 or 400 cycles! I have the info and the parts, and one day I hope to get the subchassis fabricated for the rest of the frequency switching circuit and finish restoring it. There were only 20 of them made like that one.

A bit of useful repair info: if any of the large 10 ohm carbon resistors in the bottom of the power supply ever fail, don't replace it with a metal film resistor. My buddy tried that and it turned out that the metal film resistor could not take the inrush current when the unit was powered up from cold, and would blow open intermittently. We put an old carbon resistor back in and never had another problem. We also took a look at the inrush current with a storage scope and it was quite significant.

Well, hope this starts a fun thread!

Tom AE5I


Re: High Voltage Curve Tracer project

toby@...
 

On 2020-02-25 3:05 PM, Ed Breya via Groups.Io wrote:
Here are some pictures that should give a pretty good idea of what it is - or at least what it looks like.

https://groups.io/g/TekScopes/album?id=241896
This is artistry. I'm in awe.

--Toby


I'll put up some descriptive info later.

Ed



Re: High Voltage Curve Tracer project

G Hopper
 

That looks rather nicely laid out. Clearly will be a beast when you're
done!

Look forward to more info.

On Tue, Feb 25, 2020 at 12:05 PM Ed Breya via Groups.Io <edbreya=
yahoo.com@groups.io> wrote:

Here are some pictures that should give a pretty good idea of what it is -
or at least what it looks like.

https://groups.io/g/TekScopes/album?id=241896

I'll put up some descriptive info later.

Ed




Re: High Voltage Curve Tracer project

Miguel Work
 

WTF do you need to test?

-----Mensaje original-----
De: TekScopes@groups.io [mailto:TekScopes@groups.io] En nombre de Ed Breya via Groups.Io
Enviado el: martes, 25 de febrero de 2020 21:05
Para: TekScopes@groups.io
Asunto: [TekScopes] High Voltage Curve Tracer project

Here are some pictures that should give a pretty good idea of what it is - or at least what it looks like.

https://groups.io/g/TekScopes/album?id=241896

I'll put up some descriptive info later.

Ed


High Voltage Curve Tracer project

Ed Breya
 

Here are some pictures that should give a pretty good idea of what it is - or at least what it looks like.

https://groups.io/g/TekScopes/album?id=241896

I'll put up some descriptive info later.

Ed


Re: Tektronix 2467B Auto Measure Faulty?

Leandro Lindemann
 

Hello.

I hope to be able to resolve this defect with the help of the experienced technicians of this group. I hope that someone will have the patience and willingness to help me. In my ignorance, I think it is not a calibration problem, because if so, when restoring Nvram data the problem would have been solved.

I will hope and wait for instructions for the checks I need to carry out.


Re: Tektronix 2467B Auto Measure Faulty?

Jelcke de Boer
 

Hello,
I have the same problem with my 2465B.
Auto setup and measurements not working
"Noisy or Aperiodic signal"
The problem was there when I got the scope rest seems to work fine.
So far I tried full recap, dc balance, loaded known good calibration into the nvram.
Measured voltages on the main header. (all seem fine)
Replaced hybrid U500 Ab trigger

No luck yet.
Someone suggested Cal 09 have not tried that yet.

Please keep us informed if you find a solution.

Thanks


Re: Real Colors on 7000 Series Modules and Mainframes.

Chuck Harris <cfharris@...>
 

Fluorescent lamps are mercury vapor lamps, and mercury vapor, when
ionized, emits predominantly blue and ultraviolet. The phosphors
that coat the tube turn this high energy UV into visible light, but
at only about 30% efficiency, as I recall.

Ordinary window glass, and the flint glass in the fluorescent lamp
bulb's envelope are almost opaque to UV, so they stop most of it,
but not even close to all.

Before I replaced the 7" circuline fluorescent bulb in my magnifier
lamp with LED, I used to get sunburn on my hands from all of the work
I did close to the fluorescent bulb. I could feel the backs of my
hands tingle from the UV.

-Chuck Harris

Dave Seiter wrote:

I can't add anything except that I thought those colors were too deep, but since the "tek" logo is blue, it's a later model.  My 7B15s are all pretty washed out, and my later 7104s are as well.  In fact, all the units in my office now seem really washed out, even though the sun never shines directly in, and the metal blinds are usually closed.  Besides sunlight, I wonder if the dyes were effected by fluorescent light as well.
-Dave


Re: Tektronix 2467B Auto Measure Faulty?

Leandro Lindemann
 

I searched a lot here on the group and found this topic that I believe has the same defect as my scope:

https://groups.io/g/TekScopes/topic/2465b_dc_balance_parametric/7649054?p=Created,,,20,1,0,0&jump=1

To my knowledge, if my problem was loss of calibration data, when I restored Nvram data the problem. Shouldn't it be over? I imagine that when I run DC Auto Balance, the circuit that controls this part does not work correctly and the error is recorded in Nvram. Therefore, I cannot run the test, because that way the scope is out of use. Until now it is usable, without the functionality of automatic measurements.

Is my thinking right?


Re: Tektronix 2467B Auto Measure Faulty?

Leandro Lindemann
 

Thank you for your help.

I'll try to explain it better:

When I bought the scope, when connecting it to 220V (voltage from the mains network) the Rifa capacitors exploded. That was 2 years ago. At that time, I ordered all the electrolytic capacitors + SMD + Nvram from Digikey. I changed both, and before changing the Nvram I did the data backup.

After that, the scope worked perfectly, with no calibration error indicated in the service mode and with all the automatic measurement functions operating perfectly.

Yesterday, when doing a medication for a waveform, I decided to press the Auto key and realized the problem. At this time, I accessed the service mode, no errors reported.

I got the instruction manual and after reading the question of DC Auto Balance, I decided to try it. It was after doing this procedure that the vertical displacement of the trace became absurd when using the volts-div switch.

I don't remember if I entered the service mode after that, but I certainly turned the scope on and off and no error was indicated in the CRT.

After that, I did the data backup on Nvram and the displacement of the trace was solved, but the automatic measurements do not work. Enter service mode, no error.

There must be a relationship between DC auto balance defects and automatic measurements.

Regarding calibration, I have an HP3324A function generator, another Hitachi V1100 scope, HP 8656B RF generator, frequency meter and HP power supplies.

Could the scope lose calibration alone? Without indicating error?


Re: Tektronix 2467B Auto Measure Faulty?

Jean-Paul
 

Leandro, did you do a complete calibration? What was the cal status before backup of NVRAM?

Did you do a DC bal?

Your description points to lack of CAL.

Do you have the required CAL generators?

Ciao

Jean-Paul

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