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Re: 012-0482-00/01

 

Jeff: All of my 012-0482-00/01 (have ! 10-15!) are RG-223/U cable.

I have never seen one made with RG-58U.

Do you know the exact specs, eg VSWR, frequency resp, ?

Enjoy,


Jon
Re: P6610 physcial measurement amplifier

 

¿ªÔÆÌåÓý

likewise little info I can find either.

There is one sensor probe on eBay right now that shows some info.

If that helps.

Dave 'KBV

(Ex Tek UK, during the Harpenden and Maidenhead years.)
P6610 physcial measurement amplifier

 

In my collection of probes, I have a P6610 physical measurement amplifier and three P6610 pressure transducers. ?I don't have any documentation and a search of the usual sources has come up empty. ?Wondering if anyone here knows anything about this probe or, better yet, has some documentation they would be willing to share.
Thanks - Bill?
012-0482-00/01

 

Due to a mistake on a drawing Tektronix had 012-0482-00/01 cables made with RG-58/U cable.
They have now corrected the error and have the 012-0482-00/01 made with RG-223/U cable.
--
Jeffeelcr
Re: Tektronix TDS754D - failing acquisition module tests

 

jlacerte: that's the exact direction I started heading from a point on. I realized the "short" between pins?2 and 3?of the SRAMs was not a solder?bridge, but something internal to one of the chips. I was actually?measuring a little under 10 ohms between those address buses (A14 and A16).?

I got to this?last night and I have a quick update?on this. I've replaced at this point seven of the eight SRAM chips on that address bus (U201-U208, only U204 is still the original part). This is because once I replaced U203, the low resistance condition between A14 and A16 (a bit less than 10 ohms) ceased occurring. I am pretty confident this was an issue and it was causing part of the errors?(those directly?pointing to "U20X" ICs).?

I still have a failed acquisition module.?

I currently have two errors:
  • ERROR: diagnostic test failure digHFStepDiag
  • ERROR: diagnostic?test failure digDataFormatDiag, ERROR!!BYTE mode, in demux 200, i=4... (the rest of it is out of view; can anyone recall how to wrap/unwrap error codes text?).
Ideas welcome. Thank you.?
Radu.?

On Tue, Feb 18, 2025 at 10:45?PM tgerbic via <tgerbic=[email protected]> wrote:
I have a 754D and a 784D.? I really like these scopes except for the display size. I occasionally will hook up a 13" to 15" color display and set on the edge of the bench while I am working.
?
If I remember right there are a bunch of mods that can be done with jumpers, caps and recalibration. You can turn a 754D into a 784D.? May try this one day but I have a good working 784D already.? You may want to look into the upgrades once you have gotten all the fixes done to your current scope.
--
T. Gerbic
Central California
Scope Instruction Manuals Available

 

While cleaning out a storage building, I uncovered two Tektronix Instruction manuals.? One is for the 515/515A scope and the other for the RM529 scope.? If anyone would like either, you may have them free (of course a donation would not be turned down) plus shipping charges.? Please let me know soon if interested.
Re: Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

 

Hello again:

Use Dolph CC1105 Dip, vacuum oven dry



Low VOC, not a varnish but a resin.

MG Chemicals
4228A ¨C Red Insulating Varnish is OK for spot touchup but cannot full impregnate the entire transforner.

Jon
Re: Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

 

I didn¡¯t impregnate my 453, I only laid a bead of corona dope at each end (and let it set) to keep wire from sinking to lower layers. Still working, years later.

Dave Wise
Re: Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

 

On Fri, Oct 18, 2024 at 11:05 PM, Froggie the Gremlin wrote:
Dolph electrical varnish, heat cure
Do you mean Dolph's ... a vonRoll trademark?
They do produce impregnation 'resins' for transformer manufacture, and repair.
That doesn't seem... to me... to be something you can get at your local hardware store.
?
MG Chemicals sells
4228A ¨C Red Insulating Varnish
I think that is available, (Amazon etc.)
Contains a list of chemicals that may induce fear, and panic.... but otherwise okay by me.
?
But how are you going to impregnate the winding(s)?
Usually, you do that under a vacuum, where the air gets displaced by the 'varnish'
not the best idea if using high VOC resins.
?
Re: Tektronix TDS754D - failing acquisition module tests

 

I have a 754D and a 784D.? I really like these scopes except for the display size. I occasionally will hook up a 13" to 15" color display and set on the edge of the bench while I am working.
?
If I remember right there are a bunch of mods that can be done with jumpers, caps and recalibration. You can turn a 754D into a 784D.? May try this one day but I have a good working 784D already.? You may want to look into the upgrades once you have gotten all the fixes done to your current scope.
--
T. Gerbic
Central California
Re: Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

 

Thanks - I think you may be right - would be much easier to wind thus too!

I think I found your description of layer with retrace


Alan

On Tue, 18 Feb 2025 at 17:47, Dave Wise via groups.io
<d44617665@...> wrote:

To me that doesn't look like sections - the ridge is pitched. I think it's a foil shield with a spiral drain wire.
I only know older transformers, but every one of those was wound progressive-universal.
That doesn't mean that a rewind has to be the same, I did my 453 by hand using layer winding with retrace. It's documented in the TekScopes group.

Dave Wise

________________________________
From: [email protected] <[email protected]> on behalf of Alan Bain via groups.io <alan.bain@...>
Sent: Tuesday, February 18, 2025 7:33 AM
To: [email protected] <[email protected]>
Subject: Re: [TekScopes2] Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

Here's a photo of the innermost (high voltage winding). The drawing
just specified 544 turns of #38 AWG wire, but looking at the photo it
appears as if it might be sectionally wound with 11 sections. I've
only ever wound these on divided formers which this one clearly is
not.



Does anyone know any more?

Alan

On Sat, 19 Oct 2024 at 07:05, Froggie the Gremlin via groups.io
<jonpaul@...> wrote:

We used Dolph electrical varnish, heat cure.

The silocones are not reccomended for transformer impregnation as air voids can form.

The wdg lay is optimized if perfect lay, L>R rather then cris cross.

Jon
Re: Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

 

¿ªÔÆÌåÓý

To me that doesn't look like sections - the ridge is pitched.? I think it's a foil shield with a spiral drain wire.
I only know older transformers, but every one of those was wound progressive-universal.
That doesn't mean that a rewind has to be the same, I did my 453 by hand using layer winding with retrace.? It's documented in the TekScopes group.

Dave Wise

From: [email protected] <[email protected]> on behalf of Alan Bain via groups.io <alan.bain@...>
Sent: Tuesday, February 18, 2025 7:33 AM
To: [email protected] <[email protected]>
Subject: Re: [TekScopes2] Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning
?
Here's a photo of the innermost (high voltage winding).? The drawing
just specified 544 turns of #38 AWG wire, but looking at the photo it
appears as if it might be sectionally wound with 11 sections. I've
only ever wound these on divided formers which this one clearly is
not.



Does anyone know any more?

Alan

On Sat, 19 Oct 2024 at 07:05, Froggie the Gremlin via groups.io
<jonpaul@...> wrote:
>
> We used Dolph electrical varnish, heat cure.
>
> The silocones are not reccomended for transformer impregnation as air voids can form.
>
> The wdg lay is optimized if perfect lay, L>R rather then cris cross.
>
> Jon
>
>
>
>
>
Re: Tek 7904 HV transformer T1310 part 120-0742-00 insulation burning

 

Here's a photo of the innermost (high voltage winding). The drawing
just specified 544 turns of #38 AWG wire, but looking at the photo it
appears as if it might be sectionally wound with 11 sections. I've
only ever wound these on divided formers which this one clearly is
not.



Does anyone know any more?

Alan

On Sat, 19 Oct 2024 at 07:05, Froggie the Gremlin via groups.io
<jonpaul@...> wrote:

We used Dolph electrical varnish, heat cure.

The silocones are not reccomended for transformer impregnation as air voids can form.

The wdg lay is optimized if perfect lay, L>R rather then cris cross.

Jon
Re: Tektronix TDS754D - failing acquisition module tests

 

Hi,
I was having the memory error on my 754D, U206 and U208 were specified in the log in different test runs. I did initially replace U206 and U208 without success. All the 308pins on the QFP controller had good solder joints. While probing for solder bridges after installing the new chips, I managed to catch two consecutive pins shorted.
?
Turns out this short was NOT a solder bridge, it was a bad SRAM chip with the pins (25-26) internally shorted! Not any one already replaced. I had to remove 7 chips from the gang before finding the bad one.
?
-> Note that the 8 gang is split 4 on top side and 4 on bottom side.
?
It is logical that if two address or data bits are shorted (I did not check de spec), the diagnostic will fail on the first chip tested.
?
No more error! Yay. Now, I have to find a more affordable LCD solution than the one on ebay....
?
Cheers.
Re: JB Weld "Plastic Bonder" 24XX case repair

 

That is a very common problem with these scopes. The cause is
assembling the case incorrectly. How do you do it incorrectly?
Typically, by not making sure that the blue aluminum case body is
settled into the RF gasket grove all the way around the front panel.

When the case is correctly assembled, the back panel will be
under very little force when the four screws are tight against
the metal studs that pass thru the plastic to protect the back
cover from the screw's pressure.

The way I fix cracked backs is to fit all the pieces back together
and use a drop of acrylic solvent weld applied in the closed cracks
with a needle applicator.

The repair is invisible for the most part.

-Chuck Harris



On Thu, 06 Feb 2025 15:42:22 -0800 "Don Brown, N3DEB"
<dbawatsonville@...> wrote:
Posted this in other Tek scope group, did not want to leave y'all out!

Note to group, my 2465B scope had cracked rear tan plastic cover. JB
Weld "Plastic Bonder" tan color is a 2 part polyurethane adhesive
with a great color match and adhesion. Should work other models I
would think.

I uploaded photo to Photos folder here:

/g/TekScopes/album?id=300551
Re: JB Weld "Plastic Bonder" 24XX case repair

 

I have had very good results with "Plastic Bonder" also but must caution that I had the opposite experience with "Plastic Welder" by the same company.? Be careful not to confuse the two.
?
Chuck
JB Weld "Plastic Bonder" 24XX case repair

 

Posted this in other Tek scope group, did not want to leave y'all out!
?
Note to group, my 2465B scope had cracked rear tan plastic cover. JB Weld "Plastic Bonder" tan color is a 2 part polyurethane adhesive with a great color match and adhesion. Should work other models I would think.

I uploaded photo to Photos folder here:

/g/TekScopes/album?id=300551
Re: FS: Tektronix probes, calibration fixtures, gadgets

 

This stuff is sold or pending:
?
price for group: shipping
(1) HP 8495H attenuator (sma, programmable)
?
price for group: shipping
(1) Agilent 16752A logic probe cable set (4 pods)
?
price for group: ?200
(1) 013-0098-01 transistor curve tracer fixture
(3) 013-0124-00 integrated circuit curve tracer fixture
(2) 013-0101-00 TO-66 curve tracer fixture
?
price for group: shipping
(5) 015-0580-00 pocket signal generator
?
price for group: ?50
(1) 012-1372-00 tekprobe interface cable
?
thanks,
bill
Re: 2467B Sweep test waveforms

 

Hm, let me try again with the attachments, now using the groups.io web interface. A sweep gate first - here I get a low level of +190 mV and a high level of 3.1V:
At waveform 35, half of the "low" time it seems to go below 0V? Again I see levels about 500mV above the expectation:
Here from the B sweep gate waveforms - I get something like 0V to 2.4V on both:
Now some schematics snippets:
(skipping the section with U975 inbetween)
?
- Michael
2467B Sweep test waveforms

 

Hi all,

I'm one more of those people who can't pass by when they see the shape
and colors of something Tektronix. Now I'm working on a 2467B and while
it seems to be working well, there was one thing I wanted to resolve
before finishing my calibration efforts.

It's a late model I think; some date codes are from 1995, the serial is
B053790.

I started measuring the test waveforms from the service manual (070-
6863-01) in the trigger, sweep, horizontal amp and Z-amp sections
(reson below). What I am confused about is that several sweep gate and
sweep waveforms initially look okay on my scope but I don't see the
same levels. And looking at the schematics, the test waveforms don't
make sense to me.

Waveform 31, for example, is supposed to reach -0.2V. But I assume U700
outputs 0V or 3V on the SG# pin, and Q745 cannot pull it lower than
GND. What does? CTO by charging the "** part of ECB" capacitor?! I
normally work in the digital domain and I always struggle with these
analog things.

For the B trigger, waveform 38 is easy, it's just 0V or 3V on SG#.
But then waveform 39 follows and quite unexpectedly drops down to -
0.5V. Again, the PNP transistor doesn't seem to explain that.

These A and B "sweep gate not" signals are interconnected and also
enter U985 and U975 (the "measurement PAL"). The latter seems to get
pretty warm, but I see no obvious malfunction.

I read the circuit description on page 3a-21 of the manual but it did
not give me an answer.

So any help making sense of these waveforms is greatly appreciated!

As for the reason for looking into this, I had some difficulties doing
the "high drive focus" and "writing rate threshold" adjustments on page
5-6 of the manual. Triggering seemed unstable, although this might be
normal (the manual talks about a "flashing sinewave"). Later I noticed
that at fast sweep times, something like 2 DIV of the trace seemed to
be missing between the triggering edge and the start of the trace on
the display. An explaination was given on the other list [1] about how
this is expected behavior due to propagation delay in digital logic and
I can actually see the triggering edge, thanks to the delay line.

I'm attaching some screenshots/pages from the manual for the reader's
convenience (or at least I'm trying).

- Michael

[1] /g/TekScopes/topic/11350057
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