Date   

Tektronix S-30 Delta Standards

Liam Perkins
 

The guy wants a grand. I offered $75.00 saying, "This is a calibration
standard and you not only don't show it being used, you don't show the
inside of the enclosure. Those who might want this are intelligent, your
asking price is insulting.
https://rover.ebay.com/rover/0/e11021.m43.l3160/7?euid=cf69b9838e1647e6bf846e8ba77d193e&bu=43210791575&ut=RU&segname=11021&crd=20210522150432&osub=-1%7E1&ch=osgood&loc=https%3A%2F%2Fwww.ebay.ca%2Fulk%2Fitm%2F144047914508&sojTags=bu=bu,ut=ut,ch=ch,segname=segname,crd=crd,url=loc,osub=osub
Liam


Re: Tektronix 2465B Square wave noise on active readout. #photo-notice

satbeginner
 

I live in Macisvenda, pedanía de Abanilla, Murcia.
It's in the north east of Murcia, 3 km from Alicante province.
So if you want we can have a look together, or I can have a look for you.

Or I can buy it from you, maybe we can take this out of the tekscopes group.

You can reach me at:
castellcorunas at gmail dot com

Think about it and let me know how you want to proceed.

Leo


Re: Tektronix 2465B Square wave noise on active readout. #photo-notice

@Antonio90
 

I'm in Toledo, 1h from Madrid. I also travel sometimes to Tenerife and Valencia.


Re: Tektronix 2465B Square wave noise on active readout. #photo-notice

satbeginner
 

What is your location please?
If you are in Spain maybe we can work together?

Leo


Re: Tektronix 2465B Square wave noise on active readout. #photo-notice

@Antonio90
 

I've been reading the service manual to see the procedure for A1 removal. It doesn't look trivial at all. Also, the NVRAM has not died yet, but will die soon. I'm not confident enough on my skills to remove the A1 board without damaging anything, nor to stick stuff into the CRT to pull the connections out. I don't have a programmer for the Dallas nor decent desoldering equipment, and costs are going to add up.

So, I'm selling it. Will be listing it on ebay, unless someone here wants it.

Thank you everyone for your help.


A6302 Current probe analysis and modification

Twig
 

I hope this is not breaking etiquette for TekScopes, but I thought some might be interested in a recent post to another forum that describes the analysis and modification of a bad A6302 current probe. The link is https://www.eevblog.com/forum/testgear/tektronix-a6302-current-probe-analysis-and-modification/

The short version is that the bad probe was showing about 85% of the correct level at DC and low frequency.Turned out that the Hall device was detecting a nulled magnetic field with less counter-current through the probe sensing coil than normal. Very odd issue. A crude but effective modification to the probe got the response back to 100% at DC and low frequency.

The modification was to shunt the sensing coil in the probe with a small resistor (4.9 ohms). Counter-intuitive, perhaps, but it did the job.

There are a number of measurements in the linked post, including characterization of the Hall device output versus input current. Perhaps some of that information may be helpful to others who are investigating the behavior of an A6302.


Re: does anyone have one of the 1960's era Tek Circuit Computers?

Michael W. Lynch
 

I would Love to have one of these. Looking at the File on TEKwiki it looks like just the thing that I could use and learn from. If anyone gets into reproducing these, I would be all over such a project.


--
Michael Lynch
Dardanelle, AR


Re: FS: Tex P6021 Current Probe

Liam Perkins
 

This is sold, thx everyone.
I'll get pix of the Type 134 Current Probe Kit up tomorrow

On Fri, May 21, 2021 at 8:14 PM Liam Perkins via groups.io <hifi=
telus.net@groups.io> wrote:

It seems as though this is sold, will advise tomorrow AM

On Fri, May 21, 2021 at 7:36 PM Liam Perkins via groups.io <hifi=
telus.net@groups.io> wrote:

This is for sale standalone, its manual along with added pix of this
particular probe on pg. ii is available here:



https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/35_Tektronix/Tek_P6021_Current_Probe/Tek_P6021_Current_Probe_070-0947-05_with_Pix.pdf

Although I couldn't get pix of the pole faces they are mirror finish
and probe itself looks to have seen little use.

It'll run directly with the 7A14 120MHz Current Probe Amplifier, a
good
copy of the manual for which is here, noting that I got all "silly
buggers"
and just for fun swapped in a pretty color pic of the plug-in:



https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/35_Tektronix/Tek_7A14_120MHz_Current_Probe_Amplifier.pdf

There are a couple 7A14s on eBay at the moment, here:



https://www.ebay.com/itm/284239099114?hash=item422df874ea:g:HSwAAOSwSElgY1p6

and here:



https://www.ebay.com/itm/112963196259?epid=27018601617&hash=item1a4d219563:g:vwQAAOSwPWZa4mMl

$US200.00 plus postage at the service level that suits you.

I might end up suffering some seller's remorse because the P6021/7A14
is a very convenient piece of kit . . .

Best,
Liam










Re: does anyone have one of the 1960's era Tek Circuit Computers?

Renée
 

I loaned mine and it was never returned....so that makes a few of us in need of want or replacement.
Renée

On 5/22/21 9:21 AM, cheater cheater wrote:
If this goes anywhere, I'd love to buy remade ones. Printing online is
such great quality. You can even print on aluminium. It's great.

On Sat, May 22, 2021 at 4:00 PM Doug <dmeek@ncf.ca> wrote:
https://w140.com/tekwiki/wiki/File:Tektronix_Circuit_Computer_1961.pdf






Re: does anyone have one of the 1960's era Tek Circuit Computers?

 

If this goes anywhere, I'd love to buy remade ones. Printing online is
such great quality. You can even print on aluminium. It's great.

On Sat, May 22, 2021 at 4:00 PM Doug <dmeek@ncf.ca> wrote:

https://w140.com/tekwiki/wiki/File:Tektronix_Circuit_Computer_1961.pdf





Re: Challenging 2465 PS repair

satbeginner
 

Hello all,

many thanks for all the response you gave!

I think the 2 Ohm in series on the 5VD is where I will start when I'm ready to test the complete PS.
I agree, the PS probably won't need a full load to get normal regulation.

The manual says when to start testing the Primary switcher, to remove several of the comb-connectors in between the two PCB's.
I think I will start there, because when I tested the PS the first time it literally went up in flames, so to clean it up I had to remove the carbonized parts of the PCB and also the burned components, leaving a nice hole in the PCB ;-)

So, to test I have to rebuild the PS first, I can put most of the components back in their original place, but I will need to put some solid wires in as a replacement for some of the tracks that went MIA during the fire.

After the rebuild, I have a Philips grid isolated "Variac" , I will use that to see how voltage build-up will be on the capacitors and the primary switcher IC, and test as described in the manual.
BTW, in the first picture I posted for the combined R/C dummy-load, I forgot the Diode, I have that in place now.

To be continued, I will keep you all posted.

Stay safe,

Leo


Re: does anyone have one of the 1960's era Tek Circuit Computers?

Doug
 


Re: Tektronix 2465B Square wave noise on active readout. #photo-notice

@Antonio90
 

@Egge Siert

Thank you very much. I guess somebody replaced it. At least, the wima caps in the PSU and the tantalums in place of A5 electrolytics seem to point to this scope being serviced after it's production.

Sorry if I only post questions and not any progress or effort on my part, I'm trying to understand at least superficially the scope via the service manual, but I have very little time right now (new job, lots of extra hours to learn).
Anyway, I've been reading parts of the service manual, and provided that:
1. The scope works well as long as the readout is off, so the normal signal path is OK.
2. The "intruder" waveform varies normally in the X axis as the timebase and sweep vary, so it doesn't seem to effect the horizontal stuff.
3. The depicted amplitude is, visually, always the same. The volts/division knob doesn't have any effect, I always see the same 1/2 division amplitude in the CRT, so the noise is being injected like that directly, either to the Vertical Channel Switch or the Vertical Amplifier.
4. Channels 3 and 4 don't depict the alien waveform whether the readout is on or not, however, the readout values (timebase and volts/div) are still on top of screen instead of bottom.

The problem should be either between the readout and the vertical channel switch (Readout Vertical Out), or somewhere betwerr the VCS and the VA. Maybe there are more options, but that looked like a good place to start. So I have been probing around the READOUT VERT OUT line (figure 6) and, voilà, R480 (78,7KOhms,) between the 15V rail and the Diff Amp U475B failed open. I made a quick patch with a 80KOhm resistor to check, and powered it up just enough time to see the readout and cursors, and it seems to work well enough: depicts frequency, no strange waveforms, and it doesn't shift up out of screen when I click the "auto" button.

So, before I power it up again, I will buy some 0.1% resistors of the appropriate values to substitute R480 and, maybe, R490, and also list and replace all components affected by the liquid damage, or whatever it was.

I guess I will have to remove the A1 board. Will be reading the manual about that but, does anybody have any tip, video or post about the process? I suppose it is not a very good idea to do the component swap from the top.


Re: Tektronix 2465B Square wave noise on active readout. #photo-notice

Egge Siert
 

Hi to All,

Regarding my remark about the newer Controller Boards in early 2465B's. In my Files I read the following (out of a SMD-Board Description of Qservice):

" This board is backwards compatible with ALL SMD Versions having Part Numbers ending in -00, -01, -02 , -03 , -04, -05

It can also be used in older B Series Oscilloscopes to replace the older Discrete Component Controllers
and eliminate the need for a separate Readout Board as this board contains all readout circuitry,

Using it in any older serial number instruments (below B050000 ) is limited to standard instruments only.
Options fitted in low serial oscilloscopes will not work with new controllers. "

Greetings,

Egge Siert


Re: Replacing the 5CT1N/7CT1N external cable

Szabolcs Szigeti
 

Hi,

I agree, these are very useful plugins.
I was wondering why Tek did not make it a double width module to fit a
vertical and a horizontal bay. That would have left space for extra
functions and readout would have been possible.


Szabolcs

Dennis Tillman W7pF <dennis@ridesoft.com> ezt írta (időpont: 2021. máj.
21., Pén 16:50):

I first posted this 5 years ago. I thought it might be helpful to resend it
for anyone with a disintegrating extendable cable on their 5CT1N / 7CT1N.
Pomona Electronics is the manufacturer. The Pomona part number is 3202-18.
The 18 indicates it is an 18" long wire.
It has a single banana plug on one end and that unusual plastic push-on BNC
connector at the other end.
That's the good news. The bad news is it appears to be obsolete. Pomona no
longer makes it but their web site says there are 5 of them in stock at;
Ralphs Electronics
3112 Cameron Street
Lafayette, LA 70506
United States
http://www.ralphselectronics.com
sales@ralphselectronics.com
I had no luck connecting to this web site but maybe the email address will
work.
No price was listed which concerns me.

Occasionally these cables show up on eBay which is where I got mine.

Two very good alternate solutions other members have come up with:
1) Install an isolated BNC connector in the hole on the front panel so you
can connect the 5CT1N/7CT1N to the vertical or horizontal amplifier with a
short BNC to BNC cable.
Personal Note: I don't know why it would need to be an insulated BNC
connector since both the 5CT1N/7CT1N plugin and the plugin the cable goes
to
are grounded to each other.
2) Replace the bad cable with a short BNC cable. Cut the BNC connector off
one end and solder it to the point the old cable was connected to inside
the
5CT1N/7CT1N.

For anyone who doesn't own a full size 575, 576, 577 this plugin is an
excellent must have alternative for testing
transistors/FETs/MOSFETs/Rectifiers/Zeners/Tunnel Diodes/Vacuum Tubes/etc.
It is quite versatile and my hat's off to the engineer who fit all this
capability into a plugin. Someday I hope to meet him in person and tell him
just how useful I have found it to be.

Dennis Tillman W7pF




--
Dennis Tillman W7pF
TekScopes Moderator






Re: does anyone have one of the 1960's era Tek Circuit Computers?

Jean-Paul
 

Bonjour cher Walter,

During the 1970s...1980s I bought Tek equipment like the Audio Analyzers and generators new.

A Tektronix factory rep visited my laboratory often. They gave me the circuits concepts books and two of these "Tektronix Circuit Computers".

Now, 50 years later (!) I still use these unique circular slide rules, no other such exists, and the millions of websites and apps for RLC computation are no substitute.

One got damaged at a customers field visit, the larger base part got sliced on a briefcase hinge, the other is broken, after 50 years, the plastic cursors become brittle.

You find them occasionally on epay for $50-150.

But, I have no access to the laboratory for a while, but I am happy to send you photos and scans by end of Summer. Please contact me via PM or emails with a reminder end of July if no one else has assisted.

Bon journée et bon courage

Jon


Re: Bridge rectifier specs - replacement/upgrade

Dave Peterson
 

Thanks all for your inputs.
I need to become more familiar with the rectifier packages. I spent the afternoon tearing down the 5440 to get the PS out. I'm glad I did. One of the rectifiers is mounted to the rear of the body as a heat sink, and I wouldn't have been able to get a good look at it otherwise.
So I can tell that these three rectifiers all have different packages. The KBP210G is in a KBP package, but I don't know what the other two are. I'll have to do some more research. The lookup tool in Mouser seems to be one way to figure it out: KBP, KBU, GBU, etc. seem to be other varieties. Haven't hit a good web result yet either.

I'm inclined to replace only the 152-0488-00 as it seems to be a common failure part in Tek scopes. I see now that if this rectifier dies in the 5440 it will disable all the other supplies as it drives all the regulators. The 200v has it's own discrete diode rectifier, and that's the one supply that is working.
Dave

On Friday, May 21, 2021, 11:12:12 AM PDT, Harvey White <madyn@dragonworks.info> wrote:

double the current, at least double the voltage.

Higher voltage ratings don't make a difference here, just adds some safety.

Current ratings can be important, so if possible double at least.  You
may have to compromise depending on how the rectifier is mounted in the
power supply.  Heat sinks can be good.

Harvey


On 5/21/2021 11:52 AM, Dave Peterson via groups.io wrote:
Hi All!

I have a 5440 who's LV PS is dead, dead, dead. I'm going to do a large cap replacement, and would like to replace/upgrade the three bridge rectifiers as well.

I've already selected my replacement caps and have the appropriate adapters lined up.

I did some research on finding a replacement rectifier for a 465 152-0488-00, and found that these are commonly replaced with something like a KBP210*, where * is a variety of letters that seems to correspond to variations of current/voltage specs. For example, I've found this Mouser listing:

https://www.mouser.com/ProductDetail/621-KBP210G

I'm learning that in the 465 this particular rectifier is prone to failure. Presumably the original part was operating near its limits, and these newer parts exceed the operating conditions experienced in these scopes. This Tek part number is the same for one rectifier in the 5440 as well.

So far my selection process has been more qualitative than based on knowledgeable selection of specifications. I have two other rectifiers in the 5440, CR848 and CR875, which appear to have the same specs from the electrical parts list: 2.5A, 50v.

I presume these are the forward current and the reverse voltage breakdown requirements. A) is my interpretation correct, B) what are the opinions regarding other specs to consider, and what are appropriate increases in specs? Is forward voltage something to be concerned with, reverse current, surge current, etc.?

Thanks for any input you can provide.
Dave






Re: FS: Tex P6021 Current Probe

Liam Perkins
 

It seems as though this is sold, will advise tomorrow AM

On Fri, May 21, 2021 at 7:36 PM Liam Perkins via groups.io <hifi=
telus.net@groups.io> wrote:

This is for sale standalone, its manual along with added pix of this
particular probe on pg. ii is available here:



https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/35_Tektronix/Tek_P6021_Current_Probe/Tek_P6021_Current_Probe_070-0947-05_with_Pix.pdf

Although I couldn't get pix of the pole faces they are mirror finish
and probe itself looks to have seen little use.

It'll run directly with the 7A14 120MHz Current Probe Amplifier, a good
copy of the manual for which is here, noting that I got all "silly buggers"
and just for fun swapped in a pretty color pic of the plug-in:



https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/35_Tektronix/Tek_7A14_120MHz_Current_Probe_Amplifier.pdf

There are a couple 7A14s on eBay at the moment, here:



https://www.ebay.com/itm/284239099114?hash=item422df874ea:g:HSwAAOSwSElgY1p6

and here:



https://www.ebay.com/itm/112963196259?epid=27018601617&hash=item1a4d219563:g:vwQAAOSwPWZa4mMl

$US200.00 plus postage at the service level that suits you.

I might end up suffering some seller's remorse because the P6021/7A14
is a very convenient piece of kit . . .

Best,
Liam






FS: Tex P6021 Current Probe

Liam Perkins
 

This is for sale standalone, its manual along with added pix of this
particular probe on pg. ii is available here:


https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/35_Tektronix/Tek_P6021_Current_Probe/Tek_P6021_Current_Probe_070-0947-05_with_Pix.pdf

Although I couldn't get pix of the pole faces they are mirror finish
and probe itself looks to have seen little use.

It'll run directly with the 7A14 120MHz Current Probe Amplifier, a good
copy of the manual for which is here, noting that I got all "silly buggers"
and just for fun swapped in a pretty color pic of the plug-in:


https://www.pearl-hifi.com/06_Lit_Archive/15_Mfrs_Publications/35_Tektronix/Tek_7A14_120MHz_Current_Probe_Amplifier.pdf

There are a couple 7A14s on eBay at the moment, here:


https://www.ebay.com/itm/284239099114?hash=item422df874ea:g:HSwAAOSwSElgY1p6

and here:


https://www.ebay.com/itm/112963196259?epid=27018601617&hash=item1a4d219563:g:vwQAAOSwPWZa4mMl

$US200.00 plus postage at the service level that suits you.

I might end up suffering some seller's remorse because the P6021/7A14
is a very convenient piece of kit . . .

Best,
Liam


Re: does anyone have one of the 1960's era Tek Circuit Computers?

Mark Huffstutter
 

Hi Walter,
I long ago lost the one I had many years ago.....
Have You seen the work Ed Nisley was ding in that rgard?
Some interesting links there too.

Mark

https://softsolder.com/2019/12/23/homage-tektronix-circuit-computer-pen-plotter-version/

-----Original Message-----
From: TekScopes@groups.io [mailto:TekScopes@groups.io] On Behalf Of walter shawlee
Sent: Friday, May 21, 2021 2:18 PM
To: TekScopes@groups.io
Subject: [TekScopes] does anyone have one of the 1960's era Tek Circuit Computers?

These were large cardboard circular slide rules with lots of useful calculations
specific to electronics. does anyone have one for sale, or would anybody take one
apart, and make a good scan of the faces so one can be made locally?

any help appreciated,
regards,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.

4241 - 4260 of 186837