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Re: Recreating an old board for the 7854

 

There is an early prototype of that fixture. It allows the analog scope to function without any other digital cards. The prototype is a subset of 067-0912-00. It is pictured on Kurt R¡¯s tekwiki page for the 067-0912-00 fixture. It allows selecting Vert and Horiz display modes. It reduces the 7854 to a 7804N. Contact Dennis Tillman. I gave him a board a couple of years ago. He made an offer to this group to have a few made but nobody was interested at that time.


Re: Replace/Repair TM 500 Module Side Panel Latch

 

On Tue, Jul 20, 2021 at 07:01 PM, sweetbeats wrote:


I added a new album titled TM 500 Side Panel Latch with a picture of the part
I¡¯m talking about¡­not sure how to link that here¡­apologies.
/g/TekScopes/album?id=266281

Raymond


Replace/Repair TM 500 Module Side Panel Latch

 

Greetings!

Does anybody have any experience removing or repairing the 1/4 turn latches found on the side panels of some TM 500 modules, or are there replacements available?

I added a new album titled TM 500 Side Panel Latch with a picture of the part I¡¯m talking about¡­not sure how to link that here¡­apologies.

Cory Oace


Re: FIXED! Shock Mount Replacement for Type D and Type H 500-series plugins (was [TekScopes] Another interesting Tektronix web site)

 

UPDATE

Looks like you get the same hollow-ball shock mounts in any of the following DJI RC copter ¡°Zenmuse¡± camera mount parts kits:

Part 42 for H3-3D;
Part 3 for H4-3D; and
Part 7 for Z15.

They are for sale (multiple sellers) at ebay and Amazon. These contain four to eight of the part you want and are cheaper than direct-sourcing the Barry Controls 275-1N, which is around $10 each.

Dave Wise

From: [email protected] [mailto:[email protected]] On Behalf Of Dave Wise via groups.io
Sent: Thursday, July 15, 2021 4:29 PM
To: [email protected]
Subject: FIXED! Shock Mount Replacement for Type D and Type H 500-series plugins (was [TekScopes] Another interesting Tektronix web site)

FIXED!

"DJI ZH3-3D Damping Rubber Set (Part 42)", less than $10 at ebay.
This is four bags of four different isolators, for an RC helicopter camera mount, one of DJI¡¯s ¡°Zenmuse¡± series.
The ridged ones are too soft.
The ball shaped ones (two bags, gray marked "A40" and white "30")
are, as far as I can tell, *perfect* drop-in replacements.

From my repair notes:

These are 348-0007-00.
348-0087-00 plus 361-0113-00 (used in 1A6 and 1A7) might work too.

One of the three replaced way back
when is now severely crazed. Bad batch of rubber?
I tried Julian Bunn's fan mount rejuvenation procedure
(see "Another interesting Tektronix web site" at Tekscopes
at groups.io). Soak in olive oil 1/2 hour, boil in water
5 minutes. No effect, must be a different rubber.

Original part 348-0007-00 is a hollow rubber ball approx
15mm dia across equator, with a 12mm OD flange at each end.
Rubber is about 1.5mm thick. Neck OD 9mm, neck to neck 11mm.
Clearance hole for #8 screw. Chassis holes are 5/16" (8mm).

Dave Wise

From: David Wise
Sent: Monday, June 21, 2021 5:12 PM
To: [email protected]
Subject: RE: [TekScopes] Another interesting Tektronix web site

Maybe 275-1N or 7110-0.5 or 7110-1.0 . The latter can be had for $8 each at <> .

Dave Wise

From: [email protected] [mailto:[email protected]] On Behalf Of stevenhorii via groups.io
Sent: Monday, June 21, 2021 3:52 PM
To: [email protected]
Subject: Re: [TekScopes] Another interesting Tektronix web site

All on this thread,

There are Barry mounts which come in various sizes and damping abilities:

<>

Scroll down the pages of this distributor¡¯s Web site until you get to ¡°Ball
mount series¡± which sounds like what you are looking for.

I have no conflict of interest with this company. I have seen Barry mounts
used quite a bit in various pieces of equipment when isolation from
vibration is important.

Steve Horii



On Mon, Jun 21, 2021 at 14:34 Dave Wise <david_wise@...> wrote:

Thank you, Daniel, for your research and ideas.

The natural shape is a hollow ball. It must have been molded.
The screw plays no role in normal use; it limits motion extremes to keep
the cushions from tearing or coming out of the mounting holes.

I replaced all the cushions in my D and H, maybe ten years ago, with
new-old-stock I bought from Stan Griffiths. (They all have the same orange
paint stripe.) Most are fine but one is a mosaic of cracks. I¡¯ve read
that making rubber is not 100% science. I figure there was a bad batch.

A solid ball with a hole through the middle would be too stiff unless the
rubber was exceptionally soft.

Another TekScopes member created a photo album, "541 Flip-flop fan
mounts", in which he created fan mounts from the sole of an old sandal. It
seems to me that I could combine that with your tubing idea.

- Long screw or stud, nuts, washers
- Thick-wall latex or silicone tubing, with 5/16¡± outside diameter (slip
fit in the mounting hole) when the screw is in
- Three foam rubber disks with 5/16¡± hole

- Put screw through tubing
- Thread first disk onto it
- Slide into first mounting hole
- Thread second disk onto it
- Slide through second mounting hole
- Thread third disk onto it
- Add washer and nut just snug

The foam rubber disks cushion axial motion, the tubing cushions radial
motion, and the screw holds it all together.

I will look around for an old mouse pad. Cut into disks with scissors and
hole with a paper punch. This just might work!

Dave Wise

From: [email protected] [mailto:[email protected]] On Behalf Of
Daniel Koller via groups.io
Sent: Sunday, June 20, 2021 5:42 PM
To: [email protected]
Subject: Re: [TekScopes] Another interesting Tektronix web site

Hi all,
I took a look at my D. My shock mounts are not gray - they are black.
They are just so oxidized on the surface they look grey, but they darkened
up with rubbing.
They have the consistency of latex surgical tubing, which makes me
wonder if A) that is what they are made of, and B) maybe that is what they
can be made of. I think if allowed to expand fully, they would be closer
to "I" shaped - a tube with flanges on the ends, rather than "ball
shaped". They take on the ball shape because they are compressed in their
mounts. You might be able to approximate them with surgical tubing. I
don't know if latex can be formed like thermoplastics, but if so, you could
try heating a section of tubing and blowing into it to bulge it out.
Donno. But making a flange would be hard. That might have to be molded.
Regarding molding hollow things - maybe mold the solid part, then
freeze it and drill out the center in a drill press? Keep it frozen in the
mold until drilled. Might be able to cast it in RTV that way. But the
resulting part will still be stiffer, in my opinion, than the original,
just based on poking at the ones I have on the chassis.
Another possible option is to 3D print. I have been playing with a very
soft thermoplastic polyeurethane (TPU) in my 3D printer. One needs a
special extruder with very little clearance between the extruder gears and
the feed tube, OR a direct extruder that goes right into the print head, in
order to be able to "push" the plastic through. But it does work, and I
have successfully printed lens caps and gaskets. I have not yet tried
stand-offs and vibration mounts, but I do plan on printing a door bumper
for a car, which has some of the features of the D's mounts. In the end,
the consistency will be a bit stiffer than RTV I think. There is
"Ninjaflex" TPU available, which is even softer, but I have not tried it
yet.
Ok, and lookie here:
<>
<
<>
Rubber balls. You still need to put a hole through them. The
dermatologist can provide the answer. Just go have a mole removed and ask
them for the hole-punching razor tool they use to circumscribe the mole.
I saved one or two and they are about 3 and 5 mm in diameter or so, with
various sizes available. This is cheap if insurance pays for the
service. Otherwise, you can get biopsy punches on amazon.


<>
<
<>
I think careful use of one of those punches can put a neat hole through
a rubber ball, and rubber washers seem to be available in plenty of sizes
on the interwebs! Good luck.
I'd be curious to know how you replace these. My 503 has latex
isolation mounts in parts of the circuitry. I'm betting they are getting
pretty dried up.
Dan

On Sunday, June 20, 2021, 04:16:31 PM EDT, teamlarryohio <
larrys@...> wrote:

Been far too long, but the ones I used were the same type generally as the
fan mounts. Otoh, McMaster has a huge variety of hardware bits.
G'luck!
-ls-














Re: Working on the HV Section of a 533A

 

I use a TC-201 with 700F screwdriver tip. You want mass more than temperature. Silver-bearing solder. In and out quick. Careful not to wedge the tip in the slot, it will break it.

FWIW,
Dave Wise

From: [email protected] [mailto:[email protected]] On Behalf Of ¸é±ð²Ô¨¦±ð via groups.io
Sent: Tuesday, July 20, 2021 8:22 AM
To: [email protected]
Subject: Re: [TekScopes] Working on the HV Section of a 533A

Jeff-
working on older parts the oxide on the leads impedes "solder-ability",
so just a gentle cleaning. scotch-brite(red/green/grey), I use whatever
is nearby (green/grey at the bench).
Re the tips they do go bad with time/use I would run with the
screwdriver, the long conical generally does not have the mass to do
fast transfer of heat. it is not so much the temp ( to a point) as is
the quick heat/in&out, try the 800 it may work but beware of burning the
rosin. too much heat is just as bad as not enough. Those high temps were
not allowed ( and for good reason) to be found in the rework area or at
our engineering benches the govt oversight would have a fit, I caused
enough grief with procedures that got things done and fixed properly
before my ECN could be approved. I hid most of my unapproved tools 99%
of the time.
I like the Weller gun for tip interchangeability and one could shape the
tip as needed. they are not ESD safe! as you know every tool has its
applications and limitations. ( they are inexpensive now days ~$5 used
at garage sales etc...best one has nuts to hold the tips but beware of
stripped threads...they kept making modifications to the attachment
point until it worked poorly )
¸é±ð²Ô¨¦±ð


On 7/20/21 12:15 AM, Jeff Dutky wrote:
¸é±ð²Ô¨¦±ð,

What I've got is a Weller TC202 with a TC201P iron that I inherited from my father, with three tips (long conical #8, screwdriver #7, and narrow screwdriver #6). From a Weller tech sheet I found online it looks like these are 800¡ãF, 700¡ãF and 600*F respectively. I was using one of the screwdriver tips when I was having trouble with the ceramic strip, so I should try the long conical tip instead (which will let me get into the terminal slot better than the screwdriver tips did. I was using them because I had heard that the broader tip transferred heat better, but maybe an extra 100 or 200 degress is worth more than surface conduction).

I should also order a few extra tips: the ones I have belonged to my father and date from some time in the 80s, and they already had a fair amount of use when they came to me.

I'll be sure to get myself some scotch brite pads too.

-- Jeff Dutky





.


Re: Working on the HV Section of a 533A

 

Jeff-
working on older parts the oxide on the leads impedes "solder-ability", so just a gentle cleaning. scotch-brite(red/green/grey), I use whatever is nearby (green/grey at the bench).
Re the tips they do go bad with time/use I would run with the screwdriver, the long conical generally does not have the mass to do fast transfer of heat. it is not so much the temp ( to a point) as is the quick heat/in&out, try the 800 it may work but beware of burning the rosin. too much heat is just as bad as not enough. Those high temps were not allowed ( and for good reason) to be found in the rework area or at our engineering benches the govt oversight would have a fit, I caused enough grief with procedures that got things done and fixed properly before my ECN could be approved. I hid most of my unapproved tools 99% of the time.
I like the Weller gun for tip interchangeability and one could shape the tip as needed. they are not ESD safe! as you know every tool has its applications and limitations. ( they are inexpensive now days ~$5 used at garage sales etc...best one has nuts to hold the tips but beware of stripped threads...they kept making modifications to the attachment point until it worked poorly )
¸é±ð²Ô¨¦±ð

On 7/20/21 12:15 AM, Jeff Dutky wrote:
¸é±ð²Ô¨¦±ð,

What I've got is a Weller TC202 with a TC201P iron that I inherited from my father, with three tips (long conical #8, screwdriver #7, and narrow screwdriver #6). From a Weller tech sheet I found online it looks like these are 800¡ãF, 700¡ãF and 600*F respectively. I was using one of the screwdriver tips when I was having trouble with the ceramic strip, so I should try the long conical tip instead (which will let me get into the terminal slot better than the screwdriver tips did. I was using them because I had heard that the broader tip transferred heat better, but maybe an extra 100 or 200 degress is worth more than surface conduction).

I should also order a few extra tips: the ones I have belonged to my father and date from some time in the 80s, and they already had a fair amount of use when they came to me.

I'll be sure to get myself some scotch brite pads too.

-- Jeff Dutky




.


Re: Working on the HV Section of a 533A

 

531/535/541/545 are the first generation of 500-series scope. 533 is second-gen, 533A is third. Black Beauty and Good-All from this era use plastic film insulation just like modern caps. In general they are no more likely to be bad than a modern cap.
That said, some also contain a layer of paper (Sprague trademark ¡°DiFilm¡±), which by now has caused the cap¡¯s Dissipation Factor to increase. In most applications, it doesn¡¯t matter.
The 1nF cap that resonates the transformer primary is sensitive to DF however, and a lossy one can prevent oscillation. Something to watch for but not in the ¡°front row¡± of suspects. If you have a bad cap in the HV section, it¡¯s most likely to be one of the 10kV-20kV ¡°doorknobs¡±. Now and then they short-circuit. The ceramic disks Tek used are very high quality, better in some ways than modern caps unless you really shell out the dollars.

My 500-series mainframes are still using their original electrolytic caps. If it was my scope, I¡¯d just power the thing up.
If you test the electrolytics in-circuit, remove all the tubes first. (Note where each one goes, some are aged/screened/matched.) Otherwise you will ruin some by puncturing the heater-cathode insulation. That¡¯s why Tek uses a time-delay relay.

It¡¯s good you¡¯re cleaning the ceramic strips; there are a couple of ¡°sore spots¡± where high potential between adjacent terminals causes silver migration which will eventually arc over and (at the least) ruin the strip. The SNAP! made me jump a foot. Rather than replace the strip (lower left corner of the B sweep chassis, that¡¯s not present in your model), I started an experiment by grinding off the flashed-on silver and painting the spot with corona dope. Not to suppress corona but to forestall further migration. I don¡¯t know if it helps, ask in ten years.

Be sure you¡¯re not leaving any conductive residue behind, it will just hurry the strip to its doom sooner.

HTH,
Dave Wise
535, 535A, 545, 547

From: [email protected] [mailto:[email protected]] On Behalf Of Mark Vincent via groups.io
Sent: Monday, July 19, 2021 7:32 PM
To: [email protected]
Subject: Re: [TekScopes] Working on the HV Section of a 533A

Jeff,

Brenda is right about the corona dope. Leave those strips in. Clean them to remove dust. I have not seen any of the black beauties any good. These are a wax condenser in a plastic case. I replace them on sight. The Good-all ones I also replace on sight. Replacements I use are Sprague Orange Drops or other high quality ones at 630V, e.g. Panasonic. Radial types work fine to replace axial.

Mark


Re: Working on the HV Section of a 533A

 

Put the neon lamp at the end of a one foot plastic rod.

Harvey

On 7/20/2021 8:24 AM, Keith wrote:
Hi Jeff,
Well, glad you are cautious...we don¡¯t need any ¡°did you hear about Jeff...¡± posts popping up. ?

Still, and fwiw, you don¡¯t have to get very close with the neon bulb, in fact, not as close as you get with your HV probe, and of course you can still wear your rubber gloves with the neon bulb too. Personally I find it quite safe, as I¡¯m merely hovering a nonconductive object several inches away from the general area, versus putting contact pressure and therefore pushing my hands toward a definite live multi-kV point with a probe. But I surely get your point, safety first!

And of course since you have the probe, why not use it and get the data, instead of just an indicator of possible function. (He said...enviously)

Because SOME OF US (eye-roll) aren¡¯t lucky enough to have a snazzy 40k HV probe ?

Cheers!
Keith





Re: What's another good plugin to get for a 544 with 1A1?

 

re: Ebay sky high.


I almost hate to rub it in, but did you see the link I put up the other day, from eBay? A fellow in Corona California selling six plug in modules he had gotten from a storage unit purchase. He had very little idea what he had. He sold them for $25 - for all six!

Sadly, the auction was almost over when I first found it and it ended at a weird time too, but I did throw it up on the forum in hopes that someone here would get it.

So I reckon there are still a few plug-in bargains, even on fleabay, but yeah not like ten years ago for sure.


Cheers

Keith


Re: Working on the HV Section of a 533A

 

Hi Jeff,
Well, glad you are cautious...we don¡¯t need any ¡°did you hear about Jeff...¡± posts popping up. ?

Still, and fwiw, you don¡¯t have to get very close with the neon bulb, in fact, not as close as you get with your HV probe, and of course you can still wear your rubber gloves with the neon bulb too. Personally I find it quite safe, as I¡¯m merely hovering a nonconductive object several inches away from the general area, versus putting contact pressure and therefore pushing my hands toward a definite live multi-kV point with a probe. But I surely get your point, safety first!

And of course since you have the probe, why not use it and get the data, instead of just an indicator of possible function. (He said...enviously)

Because SOME OF US (eye-roll) aren¡¯t lucky enough to have a snazzy 40k HV probe ?

Cheers!
Keith


Re: [OT] Datasheet for NC7033 or NCR7033 NVRAM needed.

 

Many thanks!!!

I am often amazed by the expertise and help available on the web.

Thanks again,

Dave

On 20/07/2021 01:23, Tom Lee wrote:
Early yes, standard not so much.

The 7033 is an MNOS (sic) EAROM. The underlying enabling principle was
discovered when Gordon Moore punked the entire industry into chasing
nitride gates as the solution to MOS's notorious threshold shift
problem. Nitrides turned out to be even more unstable then
sodium-contaminated oxide (Intel had already pissed away big bucks
finding that out; Moore helped everyone else experience the pain). That
instability was exploited to make EAROMs, but they could never really
stabilize the instability, if you get my meaning. These devices could
not tolerate many write cycles. Their primary use was as channel
memories in TVs and cable boxes, where reprogramming was a very rare event.

The datasheet is the last appendix of the following:


Hope this helps. Good luck!

-- Cheers,
Tom


Re: Working on the HV Section of a 533A

 

¸é±ð²Ô¨¦±ð,

What I've got is a Weller TC202 with a TC201P iron that I inherited from my father, with three tips (long conical #8, screwdriver #7, and narrow screwdriver #6). From a Weller tech sheet I found online it looks like these are 800¡ãF, 700¡ãF and 600*F respectively. I was using one of the screwdriver tips when I was having trouble with the ceramic strip, so I should try the long conical tip instead (which will let me get into the terminal slot better than the screwdriver tips did. I was using them because I had heard that the broader tip transferred heat better, but maybe an extra 100 or 200 degress is worth more than surface conduction).

I should also order a few extra tips: the ones I have belonged to my father and date from some time in the 80s, and they already had a fair amount of use when they came to me.

I'll be sure to get myself some scotch brite pads too.

-- Jeff Dutky


Re: Working on the HV Section of a 533A

 

Jeff-
what i used and found worked best is the old 100/140W weller solder gun, actual temp? I do not know , in and out fast. I am sure one of the chisel tips would also work if they have enough mass. the ones available at work were too low temp for the job and not enough heat quick transfer. So...I ended up bringing my own tools from my shop.
a little extra rosin also helps , but start with clean leads and surfaces ( scotch brite pad works great here) .
on the caps note the outside foil side and try and match locations. the mylars may or may not have an outside foil. orange drops do sometimes not marked.
test/verify with a scope and your hand...
¸é±ð²Ô¨¦±ð

On 7/19/21 9:13 PM, Jeff Dutky wrote:
¸é±ð²Ô¨¦±ð and Harvey,

The scope still has it's emergency spool of silver solder, apparently unused, but I also bought three 0.35 oz coils of Kester 62/36/2 silver solder when I was working on the 475 or 475A HV sections a few months ago.

When you say "high heat" ¸é±ð²Ô¨¦±ð, what temperature are we talking about? I already replaced one blown resistor in the LV section, and I used my old Weller iron (the kind with the magnetic tips that you have to change to select the temperature). It was not easy to do, but I think some of that was because I did not clean the area very well before applying the heat. I also have a surface mount rework station with a soldering iron attached, and it allows me to adjust the temperature with a dial. What temperature should I be using on the ceramic strips?

I'm was already planning to test all the electrolytic cans, so testing the axial leaded caps is only a little more work. I'm glad that mylar caps will do as replacements, as I already happen to have a good supply of those that I have been using on some EICO instruments.

-- Jeff Dutky




Re: Working on the HV Section of a 533A

 

Then there is the other trick of powering-on, if safe to do so, and turning
out the room lights for a few seconds. (Stand back)
This should show any arcing or flashovers in the HV compartment. Sometimes
a smell of Ozone,
I once did this with a 536, and one of the HV rectifier tubes was lit up
like a blue Neon sign.
Usual warnings apply: HV = High Vigilance !!

Tim

On Tue, 20 Jul 2021 at 05:13, Jeff Dutky <jeff.dutky@...> wrote:

¸é±ð²Ô¨¦±ð and Harvey,

The scope still has it's emergency spool of silver solder, apparently
unused, but I also bought three 0.35 oz coils of Kester 62/36/2 silver
solder when I was working on the 475 or 475A HV sections a few months ago.

When you say "high heat" ¸é±ð²Ô¨¦±ð, what temperature are we talking about? I
already replaced one blown resistor in the LV section, and I used my old
Weller iron (the kind with the magnetic tips that you have to change to
select the temperature). It was not easy to do, but I think some of that
was because I did not clean the area very well before applying the heat. I
also have a surface mount rework station with a soldering iron attached,
and it allows me to adjust the temperature with a dial. What temperature
should I be using on the ceramic strips?

I'm was already planning to test all the electrolytic cans, so testing the
axial leaded caps is only a little more work. I'm glad that mylar caps will
do as replacements, as I already happen to have a good supply of those that
I have been using on some EICO instruments.

-- Jeff Dutky






Re: Working on the HV Section of a 533A

 

¸é±ð²Ô¨¦±ð and Harvey,

The scope still has it's emergency spool of silver solder, apparently unused, but I also bought three 0.35 oz coils of Kester 62/36/2 silver solder when I was working on the 475 or 475A HV sections a few months ago.

When you say "high heat" ¸é±ð²Ô¨¦±ð, what temperature are we talking about? I already replaced one blown resistor in the LV section, and I used my old Weller iron (the kind with the magnetic tips that you have to change to select the temperature). It was not easy to do, but I think some of that was because I did not clean the area very well before applying the heat. I also have a surface mount rework station with a soldering iron attached, and it allows me to adjust the temperature with a dial. What temperature should I be using on the ceramic strips?

I'm was already planning to test all the electrolytic cans, so testing the axial leaded caps is only a little more work. I'm glad that mylar caps will do as replacements, as I already happen to have a good supply of those that I have been using on some EICO instruments.

-- Jeff Dutky


Re: Working on the HV Section of a 533A

 

Kieth,

That's an interesting trick to know about, but I already invested in a 40 kV probe (and heavy rubber gloves) back when I was working around the HV section of my 475. I think I'll stick to the HV probe. I haven't worked long enough around HV to lose my skittishness about it, and "holding a neon bulb near the HV section" while it's operating is well outside my comfort zone.

-- Jeff Dutky


Re: Working on the HV Section of a 533A

 

Jeff-
make sure you use silver bearing solder on the ceramic strips. sometimes the strips can be cleaned...but ya have new ones on the way moot point. too much heat too long will also cause the silver to come loose from the ceramic...use high heat get in and get out! ( don't ask how i know.....)
personally ,I have had mixed luck with the old oil/paper caps. I would look at those last they may be just fine. tek used pretty good ones!. however, ..If they are cracked they go otherwise... replacement - mylar have been fine in some of my restorations. some will say Orange drops....both will work fine and are most likely superior in the long run.
¸é±ð²Ô¨¦±ð

On 7/19/21 6:52 PM, Jeff Dutky wrote:
Fresh off of several victories with my 7603 and plug-ins, I turned my attention tonight to the 533A and found the courage to peek inside the left half of the HV section (the section on the opposite side from the CRT, with the five 5642 rectifier tubes). The section was entirely covered in soot, which is expected where you have high voltage, but after I got done cleaning the soot off of everything a possibly serious problem became apparent: two of the ceramic terminal strips at one end of the row of rectifiers was still pitch black.

I have uploaded pictures of the HV section to this album: /g/TekScopes/album?id=266270

I have already ordered replacement ceramic terminal strips, but I don't really know what I'm doing. I assume that I will need to unsolder the rectifier tubes both to replace the terminal strips, and to verify that there isn't more damage to components beneath the rectifiers.

I'm also wondering if I'm going to need to replace those black axial leaded capacitors that can be seen in the foreground. I think that there are more like that elsewhere in the scope, but I have done a detailed inventory yet. If I need to replace them, what do I replace them with?

Any advice is appreciated.

-- Jeff Dutky




Re: Working on the HV Section of a 533A

 

I've heard that you need to be careful how you solder to those ceramic strips.? What I did hear is that you do not put the iron tip in the notch.? Pleas check to make sure I got it right.

Harvey

On 7/19/2021 10:03 PM, Brenda via groups.io wrote:
Hi Jeff! Great to see you are working on your 533A! I have one as well, but it's in really bad shape on the inside. Those 2 back strips is perfectly normal. My 535A and my 545A is like that as well. I read somewhere on the forum that it's called corona dope, since that is where the 10KV is. I think that you will find that after a really good cleaning of the HV board that everything will be just fine. You really do want that coating to be on those last 2 strips, but don't worry, it's really hard to get off. As far as those 2 Black Beauties goes, most likely, those will be just fine. It's a "newer" scope as by this time, Tektronix got rid of the bad capacitors as your HV section has ceramic and those will be just fine as well. I have a few scopes that use these Black Beauties with the red writing to be fully functional. The ones with the yellow writing are most likely going to be very leaky.

Brenda





Re: Working on the HV Section of a 533A

 

Keith,

I have not done that trick in some time. I have done it before. Great way to test for high voltage being present.

Mark


Re: [OT] Datasheet for NC7033 or NCR7033 NVRAM needed.

 

The story I'd heard was that Intel learned that silicon nitride is excellent at gettering or otherwise blocking sodium. They pissed away a fortune trying to make a good gate insulator out of the stuff, but threshold stability was even worse than for the oxide they were trying to replace. That Intel was experimenting with nitride was not a well-kept secret, and Moore was asked at a conference about it. His reply was "We found pretty much what we expected." Interpreting that as "nitride is good", AMD and others immediately ramped up their research into nitrides, pissed away fortunes, then angrily approached Moore at yet another conference about his earlier statement. His reply was, "Engineers always expect disappointment, and so we found pretty much what we expected."

-- Tom

--
Prof. Thomas H. Lee
Allen Ctr., Rm. 205
350 Jane Stanford Way
Stanford University
Stanford, CA 94305-4070

On 7/19/2021 18:19, Jim Ford wrote:
Yeah, Tom, I remember reading about Gordon Moore or somebody else at Intel meeting with a gentleman from another semiconductor house and revealing the sodium issue in exchange for the solution to another vexing process problem.? I don't remember the details, but the story was hilarious!? Laugh out loud funny!? Maybe you know the details?? ? ? ?Jim Ford?Sent from my Verizon, Samsung Galaxy smartphone
-------- Original message --------From: Tom Lee <tomlee@...> Date: 7/19/21 5:23 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] [OT] Datasheet for NC7033 or NCR7033 NVRAM needed. Early yes, standard not so much.The 7033 is an MNOS (sic) EAROM. The underlying enabling principle was discovered when Gordon Moore punked the entire industry into chasing nitride gates as the solution to MOS's notorious threshold shift problem. Nitrides turned out to be even more unstable then sodium-contaminated oxide (Intel had already pissed away big bucks finding that out; Moore helped everyone else experience the pain). That instability was exploited to make EAROMs, but they could never really stabilize the instability, if you get my meaning. These devices could not tolerate many write cycles. Their primary use was as channel memories in TVs and cable boxes, where reprogramming was a very rare event.The datasheet is the last appendix of the following: this helps. Good luck!-- Cheers,Tom-- Prof. Thomas H. LeeAllen Ctr., Rm. 205350 Jane Stanford WayStanford UniversityStanford, CA 94305-4070 7/19/2021 16:48, David Slipper wrote:> Sorry for the OT but I'm getting desperate - it's supposed to be a > standard early NVRAM but it and it's data-sheet seem to be unobtanium.>> Regards,> Dave>>>>> >>