Date   

Re: 3d printable front cover for 2465B

Mark Hatch
 

Bert,

It took a half spool of PETG. I purchased the spool at amazon for ~$23, so material cost would be in the range of $12 (was electricity). It took 2.5 days to print!

The real cost here was my time trying to get the design exactly right on Fusion 360 so that the cover would "snap" in place like the original. Figured I must have put 15-20 hours into that!

If you are making something for your own project, then it is quicker because the number of contraints are much less so fewer test prints.

Just be aware that 3d printers are a hobby and a half... Unless you pay the big bucks for something above $1k, you will always be tweaking and playing with it. Sort of like a teenager from the 50's and their Chevy (or Ford ;-) )

Regards,

Mark


What is a Telex 453A?

Robert Simpson
 

Saw this in Craigslist
https://sfbay.craigslist.org/scz/atq/d/felton-vintage-oscilloscope/7270622648.html

Looks very similar to a Tektronix 453A

Bob


Re: Extracting a buggered knob grubscrew

stevenhorii
 

I have not seen Torx screws on the older Tek equipment, so I looked it up.
Torx screws were apparently invented in 1967 but not patented until 1971. I
found this for history buffs:

https://www.hausoftools.com/blogs/news/history-and-origin-of-torx

By the way, one way I have removed stuck grub screws (aka set screws) is to
use an appropriate diameter left-handed twist drill bit (of course operated
in the drill or by hand in a counter-clockwise direction). I had a Tek
plug-in I was salvaging parts from. One of those shaft couplers with two
small Allen grub screws was absolutely stuck. The other came out easily. A
left-handed drill bit that grabbed the Allen recess (rather than just spin
in it) got it right out. Since the bit was smaller in diameter than the
threaded hole, there was no damage to the existing threads. The only thing
I noticed was that the head of the stuck grub screw was rusted - the other
was not. The threads in the coupler were also fine - no oxidation there.

Steve Horii

On Mon, Feb 1, 2021 at 3:28 PM Joseph Orgnero <josepho@shaw.ca> wrote:

In my experience Tek uses only Torx screws on their equipment, trying to
use
Allen or Bristol wrenches is asking for trouble.
Jose Orgnero VE7LBI

-----Original Message-----
From: Jeff Kruth via groups.io
Sent: Monday, February 01, 2021 11:56 AM
To: TekScopes@groups.io
Subject: Re: [TekScopes] Extracting a buggered knob grubscrew

While I am sure there are many tips that others have, I found a thin hot
soldering iron pressed into the iron screw socket head will sometimes add
enough heat(expansion) to get things going. I have also filed cheap
jewelers
screwdrivers into an appropriate sized chisel point and, using friction
fit,
tapped them into the end of the reamed out set screw with a small hammer.
This can then be grasped with a small pair of vice grips and the screw may
give.YMMVJeff Kruth In a message dated 2/1/2021 2:46:57 PM Eastern
Standard
Time, snapdiode=yahoo.com@groups.io writes:
They are typically 1/20" or 0.050" keys. Sometimes it's Bristol drive but
if
someone forced a hex key in there it's probably not a Bristol drive
anymore.

Unfortunately I have found no way to extract a stuck set screw of that
size.
You might try a 1.3mm key, sometimes they really are 1.3 and not 1.27 so
you
get a bit more grip. I don't know, seems random.












--
Jose Orgnero






Re: 3d printable front cover for 2465B

Bert Haskins
 

On 2/2/2021 10:45 AM, Mark Hatch wrote:
I designed a basic front cover for the Tek2465B to protect it while shipping and to allow me to stand the device on its nose to remove the cover and work on it.

You can view/download it here: https://www.thingiverse.com/thing:4746764

It requires a bigger 3d Printer to print (i.e. no Ender 3's). Even with my CR-10, I had to stand it upright to print.

I have only printed one of these, and it "fits" my scope (late model 2465B) with a little sanding and filing. I have included the Fusion 360 files so that you can modify it if you like. Given it is likely to be printed vertically, the design really begs for some breakaway supports to be designed into the model. Using the builtin "tree support" of Cura required more post processing than I would have liked. Perhaps there is an expert that will under take this challenge. :-)

I have no idea whether it will fit other 2465 models.

Mark
If you will pardon my asking, what is the materials cost for something like this?

The reason I'm asking is that I often do special instrumentation projects and they always work fine but I'm seldom happy with the way they look.

I would really like a good excuse to buy a 3-D printer.

Thanks.

  Bert





Re: Extracting a buggered knob grubscrew

n4buq
 

I was being a bit facetious. We (I) tend to think of LH drill bits as a very specialized tool when, in fact, like its RH cousin, it drills a hole. I do see your point, though. The same thing could happen with drill presses where the chuck screws on with RH threads.

It's unfortunate that their low demand drives their price up so much but I suppose that's how it is with most anything.

Thanks,
Barry - N4BUQ

----- Original Message -----
From: "SCMenasian" <scm@menasians.com>
To: TekScopes@groups.io
Sent: Tuesday, February 2, 2021 10:02:20 AM
Subject: Re: [TekScopes] Extracting a buggered knob grubscrew

Many tools, including some lathes and hand drills rely on the right-hand
sense of rotation to keep the chuck firmly screwed on the spindle. Some may
have "safety screws" in addition, but not all. I'd cringe if I had to drill
a large diameter hole with my lathe, using a left hand drill. There would be
nothing to prevent the chuck screwing off the spindle.






Re: Tektronix CRT and LCD color

David Kuhn
 

"The TDS6xx and 7xx digital scopes used this approach for color."

And they are some of the prettiest color scopes I have ever seen next to
new ones out today. Their contrast is outstanding! I have three of that
1ghz series in my junk room waiting repair of the power supplies and data
acq boards.

Dave

On Tue, Feb 2, 2021 at 11:32 AM n49ex via groups.io <n49ex=aol.com@groups.io>
wrote:

The TDS6xx and 7xx digital scopes used this approach for color.






Re: Tektronix CRT and LCD color

n49ex
 

The TDS6xx and 7xx digital scopes used this approach for color.


Re: Tek 576 alignment without calibration fixture?

 

Oh, thanks Hakan!

I didn't notice that one, I was using my own original paper manual.

cheers
Martin


Re: Tektronix CRT and LCD color

snapdiode
 

It's the DLP rainbow effect.


Re: 2235 Horizontal Calibration Issue

Ozan
 

Maybe I’ll check those 2 diodes and the 300ohm resistor, but I’m sure
they’ll probably be ok.
The transistors and 300 ohm are inside the chip, you can see schematic of the chip at:
https://w140.com/tekwiki/images/4/49/Tek_155-0124-00.pdf

If you want to confirm the currents are OK another way is to measure voltage drop across 47-ohm resistors R780 and R770. Schematic shows 100mV delta-V is expected on these resistors.

Ozan


Re: Extracting a buggered knob grubscrew

Chuck Harris <cfharris@...>
 

Grainger is a B-to-B only store. They won't sell to you,
from their stores, unless you have a business, and an account.

They are easier to deal with over the internet.

-Chuck Harris

Dale Chayes wrote:

Historically (I haven’t bought from either in 4-5 years) you will get a significantly better price from McMaster or Grainger if you create an account.
I have no financial connection to either (other than spending my money there occasionally.)f

On the left-hand drilling front, use high quality (high speed steel - HSS) bits, some light lubricant to save the drill bits, go slowly, and carefully - drilling out broken off 1/2” bolts is another matter….

I think the heat and vibration generated by the drilling process also contribute to loosening stuck threads.

-Dale

On Feb 2, 2021, at 10:54 , Bruce Atwood <CCDman1@outlook.com> wrote:

With regard to left hand drill bits, at the Ohio State Imaging Sciences Lab our motto was, when it comes to mechanicals: "If McMaster doesn't have it, you don't need it".
https://www.mcmaster.com/

Keep them separate from the RH drill bits because running a drill bit backwards will dull it very rapidly.










Re: Tektronix CRT and LCD color

Chuck Harris <cfharris@...>
 

Tektronix used it on several digital scopes, but I have
run into in mostly on the logic analyzer 1241.

The problem with the LCD shutter, that makes me avoid them
like the plague, is if you move your eyes, they will
change color while your eyes are in motion. It is very
distracting.

Those that remember the Apollo Moon landing, that had
color TV sets, will likely remember seeing strange videos
from inside of the capsule where the camera burst into
primary color halos whenever it was moved.

NASA used a similar shutter technology to reduce the
bandwidth required to send live color video over slow
telemetry channels.

-Chuck Harris

greenboxmaven via groups.io wrote:

I was wandering YouTube and found a demonstration of a JVC color video monitor that
used a Tektronix invention- a B&W CRT with an LCD color filter over it to produce
field sequential color.  What scopes used this? Did Tektronix ever make a video
monitor using the technology?   The pictures looked very good on the monitor, and you
would never have to deal with purity, convergence, and de-guassing.  There was a
similar idea sold in about 1971 that used a mechanical belt color filter in front of
a small B&W tv. The video signal was picked off at the picture tube socket, decoded
for NTSC, and returned to the tube for the color filter in place at the moment. It
worked fairly well, but small color TVs were becoming more affordable by the minute
and the converter did not sell.

      Bruce Gentry, KA2IVY







Re: Extracting a buggered knob grubscrew

Dale Chayes
 

Historically (I haven’t bought from either in 4-5 years) you will get a significantly better price from McMaster or Grainger if you create an account.
I have no financial connection to either (other than spending my money there occasionally.)f

On the left-hand drilling front, use high quality (high speed steel - HSS) bits, some light lubricant to save the drill bits, go slowly, and carefully - drilling out broken off 1/2” bolts is another matter….

I think the heat and vibration generated by the drilling process also contribute to loosening stuck threads.

-Dale

On Feb 2, 2021, at 10:54 , Bruce Atwood <CCDman1@outlook.com> wrote:

With regard to left hand drill bits, at the Ohio State Imaging Sciences Lab our motto was, when it comes to mechanicals: "If McMaster doesn't have it, you don't need it".
https://www.mcmaster.com/

Keep them separate from the RH drill bits because running a drill bit backwards will dull it very rapidly.





Re: Extracting a buggered knob grubscrew

SCMenasian
 

Many tools, including some lathes and hand drills rely on the right-hand sense of rotation to keep the chuck firmly screwed on the spindle. Some may have "safety screws" in addition, but not all. I'd cringe if I had to drill a large diameter hole with my lathe, using a left hand drill. There would be nothing to prevent the chuck screwing off the spindle.


Tektronix CRT and LCD color

greenboxmaven
 

I was wandering YouTube and found a demonstration of a JVC color video monitor that used a Tektronix invention- a B&W CRT with an LCD color filter over it to produce field sequential color. What scopes used this? Did Tektronix ever make a video monitor using the technology? The pictures looked very good on the monitor, and you would never have to deal with purity, convergence, and de-guassing. There was a similar idea sold in about 1971 that used a mechanical belt color filter in front of a small B&W tv. The video signal was picked off at the picture tube socket, decoded for NTSC, and returned to the tube for the color filter in place at the moment. It worked fairly well, but small color TVs were becoming more affordable by the minute and the converter did not sell.

Bruce Gentry, KA2IVY


Re: Extracting a buggered knob grubscrew

Bruce Atwood
 

With regard to left hand drill bits, at the Ohio State Imaging Sciences Lab our motto was, when it comes to mechanicals: "If McMaster doesn't have it, you don't need it".
https://www.mcmaster.com/

Keep them separate from the RH drill bits because running a drill bit backwards will dull it very rapidly.


Re: Extracting a buggered knob grubscrew

Chuck Harris <cfharris@...>
 

Travers Tool Co. has a nice set of left hand drill bits,
and for a far better price than Grainger.

The problem with ez-outs is most try to use one that is
too big.

The ex-out works by grubbing into the screw with a taper,
and when you torque it, it will expand the screw and
lock it into the hole.

Try to use an ez-out that is no larger than 1/2 the diameter
of the screw you are trying to remove. If it doesn't come
out "ez" it won't come out with an ez-out.

A left hand drill bit doesn't expand the screw, as it
cuts the screw away. The friction, heat, and occasional
grabbing action usually will cause the screw to wind right
out of the hole.

-Chuck Harris

David Slipper wrote:

Where did you get your set of left-handed drills ???

On 02/02/2021 12:31, - wrote:
  I have a set of them and I keep them in their own protective box and they're
used only to remove stubborn set screws and broken bolts. For me left hand
bits work *much* better than Easy Outs for removing broken bolts and
buggered set screws.

On Mon, Feb 1, 2021 at 8:43 PM Bob Albert via groups.io <bob91343=
yahoo.com@groups.io> wrote:





3d printable front cover for 2465B

Mark Hatch
 

I designed a basic front cover for the Tek2465B to protect it while shipping and to allow me to stand the device on its nose to remove the cover and work on it.

You can view/download it here: https://www.thingiverse.com/thing:4746764

It requires a bigger 3d Printer to print (i.e. no Ender 3's). Even with my CR-10, I had to stand it upright to print.

I have only printed one of these, and it "fits" my scope (late model 2465B) with a little sanding and filing. I have included the Fusion 360 files so that you can modify it if you like. Given it is likely to be printed vertically, the design really begs for some breakaway supports to be designed into the model. Using the builtin "tree support" of Cura required more post processing than I would have liked. Perhaps there is an expert that will under take this challenge. :-)

I have no idea whether it will fit other 2465 models.

Mark


Re: Extracting a buggered knob grubscrew

Michael A. Terrell
 

- wrote:
As a last resort you can drill out the screw. But always use a *left
hand* drill bit. I've found that most of the time a *left hand* bit will
dig in and will turn the screw and cause it to unscrew itself from the hole
and will leave the threads relatively unscathed. Left hand bits aren't
easy to find but you can order them. I have a set of them and I keep them
in their own protective box and they're used only to remove stubborn set
screws and broken bolts. For me left hand bits work *much* better than Easy
Outs for removing broken bolts and buggered set screws.
<https://www.grainger.com/category/machining/drilling-and-holemaking/drill-bits?attrs=Cutting+Direction%7CLeft+Hand&filters=attrs>


Re: Extracting a buggered knob grubscrew

Jim Strohm
 

Good question. Part of the answer probably is cost, because you can get a 1/16” to 1/2” RH drill bit set for $15 at Harbor Fright, and throw the whole set away after breaking four or five bits. This is cheaper than buying individual replacement bits.

A small set of “lefties” costs a whole lot more. But ... the very first time you really need a leftie bit, you’d pay almost any amount AND fill up the gas tank on the Snap-On tool truck.

Jim N6OTQ

Sent from my quenched-gap spark transmitter.

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