Date   

Re: Cure tracer with digital scope

Bert Haskins
 

On 4/23/2021 6:11 PM, wallydoc via groups.io wrote:
After a great deal of reading and lots of manipulation, (And a little luck) I finally hit on a combo that actually gives me a trace very much like the analog scope!

I never occurred to me to turn the sweep (horizontal control) on the digital scope. It's x-y right?? NO!
Could you elaborate on this?

What sweep setting are you using?

Maybe some pictures?

I now know the x-y mode is a math function of the two traces and not a true x-y plot.
You would have thought that would have registered with at least two remaining neurons since the x-y function is in the Math Menu.

These gol-darn new-fangled things actually can work well.

And the trace is Magenta!! Far Out!




FS: Tektronix TDS3064B with 4 new Keysight A2783 500 Mhz probes

Ken Eckert
 

The scope started life as a TDS3014B. I've done the upgrade in bandwidth to 600 Mhz and it has the TDS3ENG module that gives all the options.

I can provide photos showing the fast rise test on all 4 channels showing it meets the 600 Mhz BW.

Complete with cover and I think I have the manuals too.

If you are interested, send me a PM and we can go from there.


FS: Tektronix 1502B and 1503C TDR

Ken Eckert
 

I have a nice clean Tek 1502B and a 1503C for sale. A on very quick check, it looks like they both work fine.

The Tek 1502B LCD backlight doesn't does not work.The strip chart recorder on the 1502B was not tested.

Photos on request.

If you are interested please PM me and we can discuss it further


Re: Cure tracer with digital scope

wallydoc
 

After a great deal of reading and lots of manipulation, (And a little luck) I finally hit on a combo that actually gives me a trace very much like the analog scope!

I never occurred to me to turn the sweep (horizontal control) on the digital scope. It's x-y right?? NO!
I now know the x-y mode is a math function of the two traces and not a true x-y plot.
You would have thought that would have registered with at least two remaining neurons since the x-y function is in the Math Menu.

These gol-darn new-fangled things actually can work well.

And the trace is Magenta!! Far Out!


Photo IMG_20210423_234002_01.jpg uploaded #photo-notice

TekScopes@groups.io Notification <noreply@...>
 

The following photos have been uploaded to the 485 troubleshooting horizontal B sweep album of the TekScopes@groups.io group.

By: satbeginner <castellcorunas@...>


Re: 485 service manual is causing brain oscillations

satbeginner
 

Again sorry, no attachments...

I added my page to this album:

https://groups.io/g/TekScopes/album?id=262133

Leo

Op vr 23 apr. 2021 om 23:44 schreef satbeginner via groups.io
<castellcorunas=gmail.com@groups.io>:

This is what My manual says: (sorry for the poor picture..)
The last time I calibrated my 485 this worked...

Leo
[image: IMG_20210423_234002_01.jpg]

On Fri, 23 Apr 2021, 22:51 Ondrej Pavelka, <info@vintageaudiorepairs.eu>
wrote:

Hello to the group,

Is anybody on here familiar closely with 485 calibration? In particular
the Auto Focus section.

There is a time continuum breach making my brain go into feedback loop
and
self destruct.

It's point 13) If I simplify it, it says put 3MHz in Channel 1, display
nice 2 divisions high sinewave and adjust focus and astigmatism at low
intensity for sharp trace. That works perfectly.
Next step is to raise intensity to 50V and check if focus bias does
anything, if it does you continue the procedure if it does not you are
advised to skip forward to 13. This is where my brain melts. Because 13
is
definitely skip backwards and it says nothing about how to resolve this
situation.

In my case focus bias does nothing with Z out voltage at all nor does it
anything with actual focus.

Any ideas?










Re: 485 service manual is causing brain oscillations

satbeginner
 

This is what My manual says: (sorry for the poor picture..)
The last time I calibrated my 485 this worked...

Leo
[image: IMG_20210423_234002_01.jpg]

On Fri, 23 Apr 2021, 22:51 Ondrej Pavelka, <info@vintageaudiorepairs.eu>
wrote:

Hello to the group,

Is anybody on here familiar closely with 485 calibration? In particular
the Auto Focus section.

There is a time continuum breach making my brain go into feedback loop and
self destruct.

It's point 13) If I simplify it, it says put 3MHz in Channel 1, display
nice 2 divisions high sinewave and adjust focus and astigmatism at low
intensity for sharp trace. That works perfectly.
Next step is to raise intensity to 50V and check if focus bias does
anything, if it does you continue the procedure if it does not you are
advised to skip forward to 13. This is where my brain melts. Because 13 is
definitely skip backwards and it says nothing about how to resolve this
situation.

In my case focus bias does nothing with Z out voltage at all nor does it
anything with actual focus.

Any ideas?






Re: Cure tracer with digital scope

Bert Haskins
 

On 4/23/2021 4:36 PM, TomC wrote:
Digital scopes generally suck in X-Y mode. You may be out of luck.

Tom
The one I've been working on has been showing great promise as a curve tracer.





On 4/23/2021 10:24 AM, wallydoc via groups.io wrote:
I have a B+K curve tester that I can use with my Tex 475 quite nicely. I did get it to work with an HP 1980 scope but that is more complicated.
When I set up my Agilent 54810 dig scope to X vs Y all I get is junk.
Hopefully there is someway to get the dig scope to work with the old curve tester.
Any suggestions?

I still have that 5CP1 CRT for give away and also a CRT tester, if anyone is interested.
I am in Indianapolis IN

Wally KC9INK







485 service manual is causing brain oscillations

Ondrej Pavelka
 

Hello to the group,

Is anybody on here familiar closely with 485 calibration? In particular the Auto Focus section.

There is a time continuum breach making my brain go into feedback loop and self destruct.

It's point 13) If I simplify it, it says put 3MHz in Channel 1, display nice 2 divisions high sinewave and adjust focus and astigmatism at low intensity for sharp trace. That works perfectly.
Next step is to raise intensity to 50V and check if focus bias does anything, if it does you continue the procedure if it does not you are advised to skip forward to 13. This is where my brain melts. Because 13 is definitely skip backwards and it says nothing about how to resolve this situation.

In my case focus bias does nothing with Z out voltage at all nor does it anything with actual focus.

Any ideas?


Re: Cure tracer with digital scope

TomC
 

Digital scopes generally suck in X-Y mode. You may be out of luck.

Tom

On 4/23/2021 10:24 AM, wallydoc via groups.io wrote:
I have a B+K curve tester that I can use with my Tex 475 quite nicely. I did get it to work with an HP 1980 scope but that is more complicated.
When I set up my Agilent 54810 dig scope to X vs Y all I get is junk.
Hopefully there is someway to get the dig scope to work with the old curve tester.
Any suggestions?
I still have that 5CP1 CRT for give away and also a CRT tester, if anyone is interested.
I am in Indianapolis IN
Wally KC9INK


Re: Cure tracer with digital scope

Bert Haskins
 

On 4/23/2021 1:24 PM, wallydoc via groups.io wrote:
I have a B+K curve tester that I can use with my Tex 475 quite nicely. I did get it to work with an HP 1980 scope but that is more complicated.
When I set up my Agilent 54810 dig scope to X vs Y all I get is junk.
Hopefully there is someway to get the dig scope to work with the old curve tester.
Any suggestions?

I still have that 5CP1 CRT for give away and also a CRT tester, if anyone is interested.
I am in Indianapolis IN

Wally KC9INK
I am (slowly due to family issues ) working on this.

I have two digital scopes, a Tek and a Hantek and neither one is close to being useful on a CT.

I am working on a mod for one of my STM32F3 digital scopes that I think will work out nicely for this.

Full color and al sorts of other goodies to work with.

For the meantime though analog rules.

-Bert





Cure tracer with digital scope

wallydoc
 

I have a B+K curve tester that I can use with my Tex 475 quite nicely. I did get it to work with an HP 1980 scope but that is more complicated.
When I set up my Agilent 54810 dig scope to X vs Y all I get is junk.
Hopefully there is someway to get the dig scope to work with the old curve tester.
Any suggestions?

I still have that 5CP1 CRT for give away and also a CRT tester, if anyone is interested.
I am in Indianapolis IN

Wally KC9INK


Re: 485 super weak brightness control

Ondrej Pavelka
 

Hi Tom,

Thanks for the encouragement but there is more to fix still ahead of me. I
can get nice sharp trace only at lowest intensity settings the auto focus
circuit isn't working correctly, and there is weird behaviour of trigger
holdoff and I think the list will still grow somewhat but main thing g is I
can see the light at the end of the tunnel thanks to the people on here.

On Thu, 22 Apr 2021, 20:52 Tom Lee, <tomlee@ee.stanford.edu> wrote:

Gratulujeme, Ondrej! You're almost all the way there.

-- Cheers,
Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070
http://www-smirc.stanford.edu

On 4/22/2021 08:09, Ondrej Pavelka wrote:
Guys,

New Relays arrived and nearly all is healed. When B is selected all works
flawlessly, when A is selected everything works up till the 521 range. In
521 it's not displaying properly. More in the video

I'm so happy it's nearly there now!

https://youtu.be/xCO4kJbXaMw






On Fri, 26 Mar 2021, 01:21 Raymond Domp Frank, <hewpatek@gmail.com>
wrote:

On Fri, Mar 26, 2021 at 12:48 AM, Ozan wrote:

I agree sometimes stepping back and looking with fresh eyes helps. Let
us know
when you want to bounce off ideas again.
Ozan
I fully concur, Ozan.

Raymond













Seeking correct diagram of the SA 7L13

Attilio
 

Regards to all,
I have a discrepancy between the 7L13 manual and the Tune Control board installed in my 7L13. The board is equipped with an IC DS75494N and is powered at about 8 Vdc (on the board there is also an LM340) and also the FREQUENCY knob is not the push-pull type. The manual reports an integrated powered at 5Vdc and there is no LM340 regulator.
The clutch coils that insert the Tune Control potentiometers have a DC resistance of approximately 50 ohms.

So I'm looking for a 7L13 diagram consistent with my 7L13.
You can help me ?

--Cheers
Attilio


Re: 7L12 spur at 210MHZ - Request for test results or suggestions?

Jean-Paul
 

Cliff I just setup the 7L12 and used the HP 8640B RF gen setup at 201 MHz and levels from -90 dBm to -30 dBm. Past -100 dBm the noise floor was obscuring.

The signal was clearly visible and no spurs were seen at 210 MHz or elsewhere.

The SN of my 7L12 is B2139xx and it has the LED ref lev readout.

Hope this is useful.....

Jon

PS: I can only marvel at the electronics, packaging and mechanical design of the classic SA plugins.


Re: 7L12 spur at 210MHZ - Request for test results or suggestions?

Jean-Paul
 

Cher Cliff I have a fine 7L12, used in 7904 or 7603 mainframe and never noticed any spurs at all.

I do not have a 7584 mainframe and do not seen how the mainframe can affect my spur.

Please uploading a screen capture of the spur, diagram of setup, and photos of the front panel set-up, so easier to check this on my unit.

Bon journée, Best Regards


Jon


Re: 7L12 spur at 210MHZ - Request for test results or suggestions?

Ed Breya
 

Don't know if this helps, but 210 MHz is twice 105 MHz, which is as I recall one of the LOs or IFs in the frequency plan. If it's one of the LOs, there could be leakage somewhere getting into the front end. It may be as simple as a loose connector or ground or shielding - or not.

Ed


Re: 7L12 spur at 210MHZ - Request for test results or suggestions?

Cliff Carrie
 

Has anyone seen the 7L12 spur at 210MHz as described above? I'm about to launch into a full recal of my unit to see if I can eliminate it. Before doing that, I would love to know if this is a common occurrence. If it is, I may just live with it rather than go through a long recal with the risk of no improvement. Tek says no spurs should be seen above -100db at any frequency setting and this spur reaches -80 on my unit. It's the only spur it has.

Regards, Cliff Carrie
________________________________
From: TekScopes@groups.io <TekScopes@groups.io> on behalf of Cliff Carrie <cliffcarrie@hotmail.com>
Sent: Sunday, April 4, 2021 10:58 PM
To: TekScopes@groups.io <TekScopes@groups.io>
Subject: [TekScopes] 7L12 spur at 210MHZ - Request for test results or suggestions?

For 7L12ers: Can you run a quick test, please?

I have been restoring a 7L12 for a while now. First was the Weinschel input attenuator, toasted by excessive input. A long rebuild using parts cannibalized from a similar but physically incompatible Weinschel unit. Next was a loss of 20dB through the 30KHz bandpass filter which responded to vibration around the prefilters (possibly cracked solderwork - gone for now),

The unit now passes all performance tests except one, the test for spurs (Item 7, Page 3-4 of the manual). There is only one spur above the -100dB noise floor, -80 to -85dB at 210MHz (2nd harmonic of the105MHz IF). It does not respond to changes in the input attenuator setting but does respond accurately to changes in the Gain Selector or Variable Gain controls. Switching in the 300Hz video filter drops the noise floor to about -106db and suppresses the spur to about 2db above this (-104db). The other video filters and the video processor have no effect. It's not an image (tunes in the correct direction), and it seems not to be a harmonic (tunes at the normal rate). Note that the dB figures refer to the 1st mixer input and are 30db lower than the displayed Reference Level (per the Tek manual).

Could anyone with a 7L12 and ideally in a 7854 run this test from Page 3-4 and look for a spur at 210MHz (or at other frequencies as well) and post the results? My 7L12 is stock, SN B192xxx, with the LED Reference Level readout and LO output jacks.

The setup is: No input cables, RF attenuator at 30db, gain selector fully CCW, and variable gain in CAL detent. The Reference Level should show 0dbm on screen and in the LEDs. Set the Span/Div to 1MHz, the Resolution Bandwidth to 30KHz, and the Time/Div to Spectrum and Cal. In 2db/Div, set the baseline to the bottom graticule line. Switch to 10db/Div and tune to around 210MHz, looking for a spur. Also, do a manual tuning scan from 0 to 1800MHz looking for other spurs.

Results and comments gratefully received.

Cliff


Re: 485 super weak brightness control

Carl Hallberg
 

When I wrote my reply, I didn't have the 485 book in front of me. If you look at foldout <10> you will see there are timing resistors for "A"  and timing resistors for "B". I don't think it is cap either.  Been many years since I looked at diagram.  Still think it is resistor, maybe not.  There is also interaction of 5,2,1  because of some paralleling values. Look at switch diagram at bottom of page.
Carl

On Thursday, April 22, 2021, 12:26:41 PM CDT, Ondrej Pavelka <info@vintageaudiorepairs.eu> wrote:





Hi, thanks for The suggestion but based on my understanding the B sweep
generator is used for both The A sweep as well as B sweep. So that cannot
be the cap. That would also impact B sweep



On Thu, 22 Apr 2021, 18:18 Carl Hallberg via groups.io, <n9ess=
yahoo.com@groups.io> wrote:

Check timing resistor, capacitor for faster B sweep. Might be the problem.
Mine was for slower sweeps.  See my email of Sept 21, 2017.
Carl W9CJH




On Thursday, April 22, 2021, 10:09:58 AM CDT, Ondrej Pavelka <
info@vintageaudiorepairs.eu> wrote:





Guys,

New Relays arrived and nearly all is healed. When B is selected all works
flawlessly, when A is selected everything works up till the 521 range. In
521 it's not displaying properly. More in the video

I'm so happy it's nearly there now!

https://youtu.be/xCO4kJbXaMw






On Fri, 26 Mar 2021, 01:21 Raymond Domp Frank, <hewpatek@gmail.com> wrote:

On Fri, Mar 26, 2021 at 12:48 AM, Ozan wrote:


I agree sometimes stepping back and looking with fresh eyes helps. Let
us know
when you want to bounce off ideas again.
Ozan
I fully concur, Ozan.

Raymond















Tek 050-2562-03 upgrade kit for 2430A

 

I found one of these, complete with 7 EPROMS 160-6491-01 to 160-6497-01, and a SONY Low power
SRAM, CXK58257AP-12L. these are some upgrade for the 2430A scope (marked right on them). I don't have
any details on the kit, there is no paperwork with it, so as-is.

These are all 1991 date codes, so EPROM contents can be iffy at that age, however, they can be read out and re-programmed to refresh the image, or used as is. If you can use them, they have to ship in a small box, so can't go for free, but $20 plus shipping would do it. I am not brave enough to try a padded bag.

There's also lots of free Tek stuff up on the stuff page, and general goodies at the bottom in the free section. never know, something might catch your eye. https://www.sphere.bc.ca/test/stuffday.html

does anybody have an RPR for the 050 kits or 160 parts? I did not see anything on the tekwiki site.

all the best,
walter (walter2 -at- sphere.bc.ca)
sphere research corp.

4681 - 4700 of 186256