Date   

Re: tektronix 2465b rom.

James Theonas
 

Thank you my friend!

On Saturday, July 11, 2020, 5:12:06 PM GMT+3, Chuck Harris <cfharris@...> wrote:

Yes, and no...

You know what the values should be, and you know
relatively where they exist in the calibration file,
but you have no idea how, or where, they exist in
the 2K RAM.

Tektronix went out if its way to avoid telling you
that little tidbit of information.

Looking at your screen pictures, and looking at the
data in a hex editor, you can probably figure out
where in the 2K byte RAM the constants are, but you
also have to figure out where the checksums for the
whole file exist.

I know there is a routine in the EPROM that lets
you write back the calibration data, but it is not
available to the unwashed masses.  Someone told me
about it once many, many, years ago, but I remember
nothing about it, only that it exists.

Well, that's not quite true, I recall it is a simple
button press from within the EXER02 routine.

Tektronix would never use such a routine, outside
of development, as they would simply recalibrate the
scope to restore any errant calibration data.

-Chuck Harris

James Theonas via groups.io wrote:
Hi guys! I opened exerciser 2 on my scope and copied all the data from 00 to ff by looping through all of them as I was recording a video. If I input the said data in my programmer and flash a new chip will it work? Is that all that is needed?

Thanks everyone for the fantastic people in this group!




Re: Looking for

Kurt Swanson
 

I have a 7J20. Unfortunately, I don't have the sampling head. I've had it for a long time, and when I got it, I knew it was uncommon, but I figured a sampling head would eventually turn up. No such luck - at least so far.
I got it wanting to do some optical spectroscopy work, and still would like to get it working for that purpose.

If anyone has a sampling head, let me know, otherwise I might reluctantly let this one go for sale or trade (and I do mean reluctantly).

Regards - Kurt


Re: New member with a currently-dead 2465

Siggi
 

On Fri, Jul 10, 2020 at 8:02 PM Tom Miller <@tmiller> wrote:

Just replace U2556. It is a cheap part. Cut the leads close to the chip
package, remove the package, then unsolder and remove each pin one at a
time. Clear the holes and put in a new 74LS04. I wager a cheeseburger
that is the problem.
In an over-the-counter repair shop, this would be sage advice, and I'm not
sure I'd take you up on that bet.
I believe Vincent is, however, more interested in the journey than the
destination, and by measuring and thinking through all the things, you
learn more :).


Re: Cleaning TM500 module pushbutton switches

J Mcvein
 

Early on e.g. 1960's, WD-40 used fish oil. It changed to petroleum
around the 1970s when fish oil became more valuable as a food
supplement. That has not stopped the salmon fishermen out here
from spraying their herring baits with it. Old practices die hard.

JimMc

-----Original Message-----
From: "Greg Muir via groups.io" <big_sky_explorer=yahoo.com@groups.io>
Sent: Friday, July 10, 2020 9:18pm
To: TekScopes@groups.io
Subject: Re: [TekScopes] Cleaning TM500 module pushbutton switches



Roy,

My experience with WD40 came when working on a project in Hawaii under high humidity conditions. The stores sold WD40 in gallon cans because everyone was using it to prevent their tools from rusting.

I followed the crowd and applied heavy coatings to anything ferrous with the stuff. Some of the tools went for several months before they were brought into use. But when they came out it was found that the WD40 coating on them had turned into something similar to Cosmoline and required washing it off with solvents to clean them before they could be used.

Obviously the tools did not rust. But there was something at play here that made the WD40 very messy. May have been the humidity. And from that I decided that WD40 was not very useful other than for storing things and loosening frozen items.

I’m wondering if WD40 Company has changed the formulation since then.

Greg


Re: New member with a currently-dead 2465

Siggi
 

On Fri, Jul 10, 2020 at 7:33 PM Vincent Mallet <vmallet@...> wrote:

Tested +5V and GND pins of U2556 and they are as expected.
I tested the 3-4 inverter by bringing pin 3 to +5V or GND (like you
mentioned, although using a 22R shunt briefly instead as this is what I had
laying around) and hmm I didn't see much reaction on its output 4.
That's not too surprising. The only inverter input where it is reasonable
to do is the 1-2 inverter. The input there is weakly biased, rather than
being positively driven from another logic output.


Surprising things happened next when I tested the 1-2 inverter. I started
by putting my scope probe on pin 1 to make sure my 22R shunt was having the
desired effect on the input. The input was sitting at about 1.05V. I
briefly applied +5V to pin 1 (via 22R) and bam! I started seeing a sine on
pin 1. The sine had a 840mV pk-pk amplitude sitting right above a 1V
offset, 10Mhz. I touched pin 1 again and a 2.24V pk-pk sine appeared (again
sitting right above 1V), and I saw something appear on the 2465 display!
The scope had booted up! Things vanished shortly after.

I redid the experiment after putting another probe on TP505 U2092-37 and I
saw different results. Once I got a nice 2.24V pk-pk sine on pin 1 which
gave me a 1.25Mhz (almost) square on TP505 which is matching the expected
value from the service manual. It lasted 5s, then the pin1 sine shrunk to
~840mV pk-pk again. Touched it again and I got a 400mV pk-pk (offset 1V)
but this one was ~30Mhz! The resulting TP505 more-or-less square wave was
at 3.75Mhz, three times the expected frequency. Touched it again and pin 1
sine became a not-so-sine wave, 10Mhz, 560mV pk-pk.

Sounds like there's something just marginal in the oscillator. If you catch
the oscillator napping, you can infer the values of the biasing resistors
(R2571/R2573/R2553) by the voltage drop across them. You also want to
validate that the output of the 1-2 inverter is making the right output
voltages. Low is below 0.8V and high is above 2.0V, if the output is in
between there, you're nowhere. Same for the inputs. You measured 1.05V,
which is in no-man's land, so now you need to figure out why. Either the
biasing resistors have drifted (this happens with carbon comp resistors in
particular) or your 1-2 inverter is marginal or bad, or there's leakage
somewhere.


I pulled the legs of C2565, C2566, C2572 to measure them with an LCR
meter.
C2565: 84.5pF (specs: 82pF, 5%)
C2566: 33.3pF (specs: 33pF 5%)
C2572: 100.1nF (specs: 100nF 20%)

I do not know how to measure leakage current yet.
If you catch the circuit in a non-oscillating state, you can measure the
voltage drops across the respective resistors. From Ohm's law and the
resistor nominal values, you should then be able to guestimate the current
going through them. If things don't add up, you either have resistors that
are out of spec, or you have leakage through the capacitors - measuring the
resistors will tell you which. You can probably get quite near the truth
by measuring the resistors in-circuit.


I should have access to a better desoldering tool soon and I'll pull the
resistors and U2556 so I can measure / test them out of circuit.

Good luck!
Siggi


Re: Tek 465 Turns on, No Dot, No Trace

Stephen
 

On Fri, Jul 10, 2020 at 12:10 PM, Tom Miller wrote:


Can you go back and measure all the other low voltages in the HV
circuit? The base being positive so much says the HV oscillator is not
running.
I think now I understand what you asked me to do. If you were referring to these wave forms shown before the CRT section I should be expecting at different points, I don’t. Point 87 (J6-10) and 88 are just fat and blurry traces. Nothing like the square waves shown in the service manual. Of course I used the same settings (5ms/50mV)


Re: FG-504 not-so odd behavior

John Ferguson
 

with the FG 504 set at start freq 10, stop freq 40, multiplier at 10^2, sweep off,

measured on my 2445b, Sine freq 982.3 Hz, Sawtooth 975.9 Hz and Square wave 24.5 mHz.

The square wave is an asymmetrical  sine wave, not the Sawtooth I was expecting.

Since I have two of these things and this one at least does this, and also the sweeps and other functions, all except a square wave, and the other one does nothing, this might be the one to fix.

What do you think?


john


Re: DP512 12 GHz Digital Prescaler

Holger Lübben
 

HI!

A german Tektronix fan constructed three plugins:

1) RO510 10MHz Rubidium Oszillator. Two protoypes were built.
http://w140.com/tekwiki/wiki/RO510

2) DP512: A 12GHz 1:1000 prescaler. One prototype was built. It worked up to 14GHz.

3) GS510: A 10MHz Oszillator based on a trimble GPS module. One prototype was built
http://w140.com/tekwiki/wiki/GS510

All prototypes were constructed around this card:
http://w140.com/tekwiki/wiki/SD_TEK_500_Prototype_Card

There was a plan to finish the construction and to sell these plugins. But unfortunately the constructor died.
None of the involved people had any relationship to Tektronix.

Holger


Re: Tektronix Blue paint - source in the UK ??

Stephen Hanselman
 

I’m not sure about folks outside of the US but if it were me I’d take a side panel down to the paint store and have them color match it. I’ve used this method on my house where it works well, no reason it shouldn’t work on test equipment

Regards,

Stephen Hanselman
Datagate Systems, LLC

On Jul 11, 2020, at 04:26, Colin Herbert via groups.io <colingherbert=blueyonder.co.uk@groups.io> wrote:

There has been communication on Tek blue paint ever since I joined this Forum. May I respectfully suggest that you have a search through the past posts to find all you can. There is a lot of information there, though a good deal relates to US providers, I am sure that some UK-dwelling members have contributed.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of chris gare
Sent: 10 July 2020 11:41
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tektronix Blue paint - source in the UK ??

I'm from the UK and don't quite understand the "Bluebase 79126" reference? The the other colors are fine as they are in Ounces?

Help please anyone!

Chris







Re: DP512 12 GHz Digital Prescaler

stevenhorii
 

I believe at one time a company called Spectracom built a TM500 rubidium
frequency standard plug-in.

On Sat, Jul 11, 2020 at 04:36 Egge Siert <eggeja2@...> wrote:

Hi Joe,

From a German eBay Member (I assume a former Tektronix Germany employee) I
got the following answer:

"Guten Tag, ja ich weiß es, es sollte mal einen Eigenbau eines Prescalers
bis 14 GHZ werden, das Projekt wurde aber nie gestartet.

Mfg Klaus Chudzinski"

The earlier mentioned Rubidium Standard Plug-In was in fact a 10MHz GPS
Standard named GS510. Pictures of it are now in the posession of TekWiki.

Greetings,

Egge Siert




Re: tektronix 2465b rom.

Chuck Harris
 

Yes, and no...

You know what the values should be, and you know
relatively where they exist in the calibration file,
but you have no idea how, or where, they exist in
the 2K RAM.

Tektronix went out if its way to avoid telling you
that little tidbit of information.

Looking at your screen pictures, and looking at the
data in a hex editor, you can probably figure out
where in the 2K byte RAM the constants are, but you
also have to figure out where the checksums for the
whole file exist.

I know there is a routine in the EPROM that lets
you write back the calibration data, but it is not
available to the unwashed masses. Someone told me
about it once many, many, years ago, but I remember
nothing about it, only that it exists.

Well, that's not quite true, I recall it is a simple
button press from within the EXER02 routine.

Tektronix would never use such a routine, outside
of development, as they would simply recalibrate the
scope to restore any errant calibration data.

-Chuck Harris

James Theonas via groups.io wrote:

Hi guys! I opened exerciser 2 on my scope and copied all the data from 00 to ff by looping through all of them as I was recording a video. If I input the said data in my programmer and flash a new chip will it work? Is that all that is needed?

Thanks everyone for the fantastic people in this group!




Re: Looking for

stevenhorii
 

I am interested in the 7J20/J20 for light source spectrometry. I have an
Ocean Optics fiber-optic one that works for what I usually need, but hey,
one that works with my Tek 7000-series scopes would be neat (and useful).

In my experience, you never know what you can find until you ask. Years
ago, I put an advert is Sky and Telescope for a NASA Apollo Command Module
optical unit assembly (the “space sextant” used to update the Command
Module inertial navigation system) and found a person who had one for sale!
He bought it when the company that made it (Kollsman Instrument) moved
their headquarters.

Just for fun, I put my name into eBay search and got a hit. It turns out
that a clever seller had a copy of the SPIE Medical Imaging Proceedings and
he put the names of all the paper authors in the description. It was the
Proceedings from the first meeting so I bought it (later donated it so it
could be scanned and put online).

Only 40 made is really rare. I have used a Tektronix J16 photometer - a
great instrument and Tek made a lot of those (but it doesn’t do
spectrometry - just precision photometry). At the time I was measuring
luminance of CRTs and the uniformity across the tube face (medical imaging
stuff).

Thanks for letting me know how rare the 7J20/J20 are. I’ll stick with the
Ocean Optics unit - but if someone offered one for sale at less than the
price of a new Tek Mixed Domain scope, I’d consider it!

On Sat, Jul 11, 2020 at 05:40 Colin Herbert via groups.io <colingherbert=
blueyonder.co.uk@groups.io> wrote:

I think if you find one of those, that it will be protected by unicorns.
According to Dennis Tillman in TekWiki, there were only about 40 made. If I
understand correctly from past discussion on this "holy grail" plug-in,
Dennis has one (not for sale).
As I also understand it, the likelihood of anyone having a legitimate
purpose for owning and using one, other than simple collection, is almost
zero. As a retired Research Chemist, I am aware of what it is capable of
doing and I would love to own one, but (1) it would sit on a shelf most of
the time and (2) it would reduce my bank-balance significantly.
Give it up...
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of
stevenhorii
Sent: 10 July 2020 21:41
To: TekScopes@groups.io
Subject: [TekScopes] Looking for

I am looking for a rare 7000-series plug-in: A 7J11 optical spectrum
analyzer with the external detector head. I know that these are uncommon as
I don't think Tek made many of them (high price). If anyone knows of one
for sale, let me know off-list. Thanks!








Re: Tektronix Blue paint - source in the UK ??

Chuck Harris
 

What exactly don't you understand about the Bluebase
79126 reference?

I am guessing here, but I think you might have a difficulty
in understanding the technology of making a particular
color paint.

The most efficient way to mix custom colors is to start
with a handful of base colors, which amount to about
99% of the bulk of the gallon of paint.

Once you have a base stock color, then you can calculate
what, from a panoply of tinting colors, you need to add to
that base stock to get the desired color.

Bluebase 79126 is one paint manufacturer's base color.

-Chuck Harris

chris gare wrote:

I'm from the UK and don't quite understand the "Bluebase 79126" reference? The the other colors are fine as they are in Ounces?

Help please anyone!

Chris




Re: My first scope, a Tektronix 11401 with option 2D extended memory and two 11A34 plugins and an 11A33 plugin.

Precaud
 

It takes a brave person to admit to liking and using an 11k-series scope :)

I have a couple and "like" them in remote-controlled applications, but hands-on operation is a different matter. The digitizer is excellent (if you need 10 bits), I love the large display, and the 11k preamps are superb. I think the entire user interface was designed with remote programming in mind. Even after years of occasional use I can't remember how to do some basic, simple stuff from the front panel. Because of this, it has earned a spot on the floor next to the bench, deployed only when needed.


How To Select An Oscilloscope

Carl Moon <carl.moon@...>
 

Here’s a quick review of what’s important to know about the wide assortment of scopes and scope features available today.

https://prezhost.com/2020/06/25/how-to-select-an-oscilloscope/


tektronix 2465b rom.

James Theonas
 

Hi guys! I opened exerciser 2 on my scope and copied all the data from 00 to ff by looping through all of them as I was recording a video. If I input the said data in my programmer and flash a new chip will it work? Is that all that is needed?

Thanks everyone for the fantastic people in this group!


Re: Tektronix Blue paint - source in the UK ??

Colin Herbert
 

There has been communication on Tek blue paint ever since I joined this Forum. May I respectfully suggest that you have a search through the past posts to find all you can. There is a lot of information there, though a good deal relates to US providers, I am sure that some UK-dwelling members have contributed.
Colin.

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of chris gare
Sent: 10 July 2020 11:41
To: TekScopes@groups.io
Subject: Re: [TekScopes] Tektronix Blue paint - source in the UK ??

I'm from the UK and don't quite understand the "Bluebase 79126" reference? The the other colors are fine as they are in Ounces?

Help please anyone!

Chris


Re: R7704+7A18+7B53A in Newport Beach, CA to part with

ChrisBeee
 

Hi Dave,
Abc Xyz did not report back so far, so the scope can be yours. I will send you a PM to clarify details.
Chris

@Abc Xyz: Sorry, but even in 'modern' times where salutations and signatures in messages mainly have become outdated and obsoleted, I am expecting at least a minimum of etiquette. Especially when I offer something to part with where the receiver can set the price. There is no free lunch.


Re: Tek 465 Turns on, No Dot, No Trace

Stephen
 

I notice something I didn’t pay attention to before. That is TP1486 should go from 15V to 75V depending on the position of the Intensity control knob. However, mine goes from 15V to only 31V with the intensity maxed out...
Hmmmmm.... Interesting... There is definitely something there as well.

PS: Where do I lift the HV multiplier lug?


Most scarce Modules (TM500/5000, 7000) and Calibration Fixtures/Service Aids seen in the past.

Egge Siert
 

Hi to All,

Inspired by the 7J20 and J20 scarcity remarks.There are other items. Seldom seen. Sometimes only once. Recently many overpriced 067-XXXX-99 Fixtures pop up on eBay and also TekWiki has a lot of these new ones archived. Those I didn't mean. I mean the items you cannot find with google and other search engines. But they exist in the wild.

Greetings,

Egge Siert