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Re: Recreating an old board for the 7854

 

Well, actress Barbara Feldon is still alive? evidently.? ?She's 88, though, so not nearly as hot as she was in Get Smart.? ? ? ?Jim?Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Clark Foley <clarkfoley@...> Date: 7/20/21 12:49 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Recreating an old board for the 7854 Where is Agent 99 when you need her!


Re: Recreating an old board for the 7854

 

You guys aren't as Smart as you think you are!? ? ? ? ? ? Jim Ford?Sent from my Verizon, Samsung Galaxy smartphone

-------- Original message --------From: Tom Lee <tomlee@...> Date: 7/20/21 12:17 PM (GMT-08:00) To: [email protected] Subject: Re: [TekScopes] Recreating an old board for the 7854 Missed it by that much.Sent from my iThing, so please forgive typos and brevity.> On Jul 20, 2021, at 12:13 PM, Clark Foley <clarkfoley@...> wrote:> > ?Would you believe octal latches? Sorry about that, Chief.> > > > >


Re: Recreating an old board for the 7854

 

Thanks for all the help.

I have about 80% finished with the schematic. I need to find a replacement for the 2N5769 The documentation says this was a "Switching Transistor" but it does not say the switching frequency. But that is the next hurdle that needs to be cleared. I will post the schematic and the board layout when it is finished to make sure I did not make any errors. Also need to get the pin outs for P190. At the moment P190 looks like it is the board edge connector.

All advise is welcome and thanks in advance.

-----Original Message-----
From: [email protected] <[email protected]> On Behalf Of Raymond Domp Frank
Sent: Tuesday, July 20, 2021 3:28 PM
To: [email protected]
Subject: Re: [TekScopes] Recreating an old board for the 7854

On Tue, Jul 20, 2021 at 09:12 PM, Clark Foley wrote:


Would you believe octal latches? Sorry about that, Chief.
Since we're at it:
It's not 8 latches: There are 8 D-type flip-flops in a '374.
Latches pass the input with one control level (the output follows the input, no clock involved) and latch their input value with the control at the other level, much like an analog sample and hold. Compare 7475 (quad latch).
The '374 uses a clock to transfer the data at the D-inputs to the complementary outputs.

Raymond


Re: Recreating an old board for the 7854

 

Where is Agent 99 when you need her!


Re: Recreating an old board for the 7854

 

On Tue, Jul 20, 2021 at 09:28 PM, Raymond Domp Frank wrote:


The '374 uses a clock to transfer the data at the D-inputs to the
complementary outputs.
Sorry, no complementary outputs on the '374, just one Q (true) output for each D input.

Raymond


Re: Recreating an old board for the 7854

 

On Tue, Jul 20, 2021 at 09:12 PM, Clark Foley wrote:


Would you believe octal latches? Sorry about that, Chief.
Since we're at it:
It's not 8 latches: There are 8 D-type flip-flops in a '374.
Latches pass the input with one control level (the output follows the input, no clock involved) and latch their input value with the control at the other level, much like an analog sample and hold. Compare 7475 (quad latch).
The '374 uses a clock to transfer the data at the D-inputs to the complementary outputs.

Raymond


Re: Replace/Repair TM 500 Module Side Panel Latch

 

I have purchased TM500 plugins from reputable sellers (eg. Stewarts of Reading, Telford Electronics) and from less well-known purveyors on eBay and have found several broken latches of this type. The common "fix" seems to be to use a bit of some kind or insulated wire to wrap around the engaging parts. Since the casual observer will have no idea of this "fix" when the plug-in is in a power mainframe and in use, I can't see any problem with it. Of course, if someone were to manufacture facsimiles of the original latches and sell them at pocket-money prices, then I would be interested, but not at something like $50 each - that may be justifiable, but it is not economic, in my opinion. Others with deeper pockets may (and are welcome to) disagree.
Colin.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Jeff Dutky
Sent: 20 July 2021 19:36
To: [email protected]
Subject: Re: [TekScopes] Replace/Repair TM 500 Module Side Panel Latch

Cory,

I have no experience replacing the latch, but I have a side cover that looks exactly like yours, where the latch seems to have broken internally: the slotted side rotates, but the latch side does not. I also have a TM500 "toolbox" with a solid cover and a similar latch mechanism. The latch seems to be made of two parts, the latch side and the slotted side, which snap together on a central shaft. I would expect that you could push the center shaft out of the latch side with a small screwdriver or punch, but I haven't tried this. If your latch is broken like mine, however, you don't have much to lose by experimentation (nor do I, so I will see what I can achieve).

One solution would be to simply glue to the two halves of the latch together, maybe by dripping some epoxy down the hole on the latch side. This would be a fairly permanent fix (you would not be able to take the latch apart again without some amount of destruction) but I imagine a permanent fix is kind of what you are looking for.

-- Jeff Dutky


Re: Looking for data on 9-pin Vacuum time delay relays used in old Tek-scopes

 

These can still be found as NOS on eBay. I bought a 6NO45T, a couple months back for around $10, for a Tek 551 I'm restoring. Turned out I didn't really need it. The main open-air PS relay that the timer triggers was sticky and had dirty contacts.


Re: Recreating an old board for the 7854

 

Missed it by that much.

Sent from my iThing, so please forgive typos and brevity.

On Jul 20, 2021, at 12:13 PM, Clark Foley <clarkfoley@...> wrote:

?Would you believe octal latches? Sorry about that, Chief.





Re: Recreating an old board for the 7854

 

Would you believe octal latches? Sorry about that, Chief.


Re: Replace/Repair TM 500 Module Side Panel Latch

 

Cory,

I have no experience replacing the latch, but I have a side cover that looks exactly like yours, where the latch seems to have broken internally: the slotted side rotates, but the latch side does not. I also have a TM500 "toolbox" with a solid cover and a similar latch mechanism. The latch seems to be made of two parts, the latch side and the slotted side, which snap together on a central shaft. I would expect that you could push the center shaft out of the latch side with a small screwdriver or punch, but I haven't tried this. If your latch is broken like mine, however, you don't have much to lose by experimentation (nor do I, so I will see what I can achieve).

One solution would be to simply glue to the two halves of the latch together, maybe by dripping some epoxy down the hole on the latch side. This would be a fairly permanent fix (you would not be able to take the latch apart again without some amount of destruction) but I imagine a permanent fix is kind of what you are looking for.

-- Jeff Dutky


Re: Recreating an old board for the 7854

 

By the way, U430 and U530 are 74LS374 quad D latches (a.k.a. FF). Nothing fancy; just typical LS stuff.


Re: AA 501A Parts, DM 501A Probes

 

Likely no surprise to most if not all, Sphere in Canada has the AA 501A parts I need, with some caveats: the knob is a dark grey type rather than light grey as originally fitted (no big deal there), and the side panel is missing the 1/4 turn latches. I have a separate thread I started about tips for removing or repairing those, or if there are possibly replacements available.

Anyway, just wanted to follow up.

Thanks again for all the helpful info!

Cory Oace


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