Date   

Re: TDS544A with strange display #photo-notice

 

Siggi wrote:

I don't think there should be anything on the CRT board that follows
the dot clock... I also don't think there's anything on the CRT board
that's per color, other than on the LCD driver board.
I think that the per-color part of this is probably explained by the order of the color shutter actuation, but I can't quite make it make sense either. If we simply had something that was being saturated from the all-wite sections (it's pretty clear that the all white sections at the end of the scan are causative) then we would expect ANY solid color block at the end of a scan to result in bleeed-over on the start of the next scan line. Why we don't see that is hard to explain.

I like the idea of swapping control lines on the shutter to see if we can make the bleed-over change colors, that would likely narrow down the region in which the malfunction lives.

-- Jeff Dutky


Re: TDS544A with strange display #photo-notice

Siggi
 

On Sun, Mar 7, 2021 at 4:02 PM durechenew via groups.io <durechenew=
yahoo.com@groups.io> wrote:

No, the blue trace is not compromised, but your observation is correct;
the scope is set to display vectors, not dots, therefore, from time to time
a vector might be missing because there was not enough time to capture the
needed points of start and end (that's a guess) - remember that at slow
scan speed the number of samples are fairly low and increase with scan
speed.
I beg to differ. Try to switch that particular signal to one of the other
channels, my $0.02 says the trace dropouts will follow the trace color.


Idea of oscillation came to my mind too but I had to abandon it. The blue
layer of shutter is ON for a certain amount of time while everything that
needs to be blue is displayed by CRT. So those vertical stripes on blue
must be on screen; no connection to shutter functionality, otherwise
everything that is on screen (including the trace) would be chopped. Plus
is doesn't explain why those stripes are waving - like a flag (each
horizontal line in that area has those oscillations occurring for a longer
or shorter period of time during the frame).
The length of the blue stripes clearly follows the amount of white content
on the previous line and/or the line with the stripe.


And it's not oscillation because those would not be synchronized with
vertical raster lines (if you take a closer look, the second vertical line
is perfectly aligned with one of those vertical stripes and so is every
second vertical line; that tells me that those blue lines are synchronized
with a clock, not random frequency.
Good point, I can't explain that.
I don't think there should be anything on the CRT board that follows the
dot clock... I also don't think there's anything on the CRT board that's
per color, other than on the LCD driver board.
I don't know exactly how the raster scan occurs on these screens, but I'd
suspect the full raster is scanned for each color, changing the LCD shutter
between a full frame scan. ... time passes ... It's rather interesting that
there are 12 lines from the LCD driver board to the LCD shutter. It would
be unnecessarily complex and awkward to have an LCD that matches the CRT's
dot pitch - what the hell is going on there? IDK - what is LCS_CLK - it's
brought out to the LCD shutter logic.

My scope has also that possibility to check the colors, but I didn't
discover any possibility to change anything (maybe different scopes with
the same basic design have that feature enabled).

Per the manual: https://download.tek.com/manual/070871001.pdf:
To bring up the Color menu:
1. Press DISPLAY to show the Display menu.
2. Press Settings in the main menu until you select Color from the pop-up
menu (see Figure 3-4)

Good luck,
Siggi


Re: TDS544A with strange display #photo-notice

durechenew@...
 

Hi Siggi,
No, the blue trace is not compromised, but your observation is correct; the scope is set to display vectors, not dots, therefore, from time to time a vector might be missing because there was not enough time to capture the needed points of start and end (that's a guess) - remember that at slow scan speed the number of samples are fairly low and increase with scan speed.
I did not recap the video stage; as I remember, there is no SMD cap on any of those board (only through-hole components).
Idea of oscillation came to my mind too but I had to abandon it. The blue layer of shutter is ON for a certain amount of time while everything that needs to be blue is displayed by CRT. So those vertical stripes on blue must be on screen; no connection to shutter functionality, otherwise everything that is on screen (including the trace) would be chopped. Plus is doesn't explain why those stripes are waving - like a flag (each horizontal line in that area has those oscillations occurring for a longer or shorter period of time during the frame).
And it's not oscillation because those would not be synchronized with vertical raster lines (if you take a closer look, the second vertical line is perfectly aligned with one of those vertical stripes and so is every second vertical line; that tells me that those blue lines are synchronized with a clock, not random frequency.
My scope has also that possibility to check the colors, but I didn't discover any possibility to change anything (maybe different scopes with the same basic design have that feature enabled).
TT


Re: quality 0.050 hex key

stevenhorii
 

Yes - these sound like the Wiha ones. Made in Germany. The inch set is in a
yellow plastic holder. The metric set is in a red plastic holder.


On Sun, Mar 7, 2021 at 14:26 Gary Robert Bosworth <grbosworth@gmail.com>
wrote:

I bought a set of miniature hex wrenches thru Amazon. They were made in
Germany and they are perfect. The number on them is 35393. They are in a
small yellow plastic holder.

On Sun, Mar 7, 2021, 10:40 stevenhorii <sonodocsch@gmail.com> wrote:

I needed a better-quality set of small hex keys than the ones I had (like
you, they rounded off and became ineffectual, but this was not after the
first few uses). I wound up purchasing metric and imperial sets made by
Wiha. The inch set is five wrenches from 0.028 to 5/64. The metric set is
five wrenches from 0.7 to 2mm. I bought them through, where else, Amazon.

I have removed small stuck set screws when the Allen sockets got too beat
up by removal attempts by using a left-twist drill. These are available
down to fairly small sizes. I bought my set directly from Drill Hog. They
make bits in various alloys besides high-speed steel - including cobalt,
molybdenum, and niobium steels. The smallest bit in the left-hand set is
1/16” though. They sell individual letter- and number-size bits in
various
alloys. They also sell square and spiral “Easy-outs”. I have no conflict
of
interest with these folks. These bits cost more, but they are made in the
US and warrantied “for life” whatever that means. I got tired of bits
supposedly HSS and titanium nitride coated that were dull after drilling
just a few holes in relatively soft metals (aluminum, brass). The
cobalt-alloy bits I bought from Drill Hog are very well made and have
stood
up well to these same metals and to some mild steel drilling.










Re: quality 0.050 hex key

Gary Robert Bosworth
 

I bought a set of miniature hex wrenches thru Amazon. They were made in
Germany and they are perfect. The number on them is 35393. They are in a
small yellow plastic holder.

On Sun, Mar 7, 2021, 10:40 stevenhorii <sonodocsch@gmail.com> wrote:

I needed a better-quality set of small hex keys than the ones I had (like
you, they rounded off and became ineffectual, but this was not after the
first few uses). I wound up purchasing metric and imperial sets made by
Wiha. The inch set is five wrenches from 0.028 to 5/64. The metric set is
five wrenches from 0.7 to 2mm. I bought them through, where else, Amazon.

I have removed small stuck set screws when the Allen sockets got too beat
up by removal attempts by using a left-twist drill. These are available
down to fairly small sizes. I bought my set directly from Drill Hog. They
make bits in various alloys besides high-speed steel - including cobalt,
molybdenum, and niobium steels. The smallest bit in the left-hand set is
1/16” though. They sell individual letter- and number-size bits in various
alloys. They also sell square and spiral “Easy-outs”. I have no conflict of
interest with these folks. These bits cost more, but they are made in the
US and warrantied “for life” whatever that means. I got tired of bits
supposedly HSS and titanium nitride coated that were dull after drilling
just a few holes in relatively soft metals (aluminum, brass). The
cobalt-alloy bits I bought from Drill Hog are very well made and have stood
up well to these same metals and to some mild steel drilling.






Re: Introduction and issue with a 1A1 plugin

cmjones01
 

Mine's the second version too. The grid current adjust pots look pretty
easy to get to, on the rail just above the a Nuvistor housing, but I
wouldn't want to do it without an extension cable for the plugin.

The easiest test would simply be to swap over the two Nuvistors on channel
2 and see if the offset changes. Then at least we know if we're trying to
solve the right problem.

Chris


On Sun, 7 Mar 2021, 15:56 Pwrelectronics, <chippewa1953@centurylink.net>
wrote:

Yes, this one is the nuvistor type. Compared to the info on W140 site,
mine is the 2nd version. I downloaded the manual there for the 1st version
so hopefully close enough?

I will have to make a go through the cal procedure at least for the
basics. Looking at the schematic for those input nuvistors, I assume that
grid current zero pot must change the bias. I have adjusted the .005v/cm
balance pot (front panel screwdriver) on both channels to get them to not
move around when putting in variable gain settings or invert. After doing
that, channel 1 works pretty well but not channel 2, as this AC/DC coupling
is not right.

That pot is almost not accessible from the bottom and a plastic tool
certainly needed and a very thin one at that. The photo in the manual is
not accurate compared to my unit in that seems to be more wires and stuff
blocking.

thanks,

JH






Success! 5S14N becomes 5S14 with readout

Szabolcs Szigeti
 

Hi,

I have successfully retrofitted the 5S14N sampling plugin with readout for
use with the 54xx scopes, by basically recreating the 7S14 readout board
and wiring it in, thus creating a 5S14.

See the photos: https://groups.io/g/TekScopes/album?id=261631

If there is any interest, I'm willing to do a little description of the
project, and share the design files.
I have a couple of PCBs which I can give out for the price of the postage.
Mostly probably useful in the EU, elsewhere it will likely be cheaper just
to get them from China.

Let me know if anyone is interested, then I'll take the time in the coming
days to do a writeup on it, as while it is not a complex project, there
were some obstacles, which may be interesting to share.

Szabolcs


Re: quality 0.050 hex key

stevenhorii
 

I needed a better-quality set of small hex keys than the ones I had (like you, they rounded off and became ineffectual, but this was not after the first few uses). I wound up purchasing metric and imperial sets made by Wiha. The inch set is five wrenches from 0.028 to 5/64. The metric set is five wrenches from 0.7 to 2mm. I bought them through, where else, Amazon.

I have removed small stuck set screws when the Allen sockets got too beat up by removal attempts by using a left-twist drill. These are available down to fairly small sizes. I bought my set directly from Drill Hog. They make bits in various alloys besides high-speed steel - including cobalt, molybdenum, and niobium steels. The smallest bit in the left-hand set is 1/16” though. They sell individual letter- and number-size bits in various alloys. They also sell square and spiral “Easy-outs”. I have no conflict of interest with these folks. These bits cost more, but they are made in the US and warrantied “for life” whatever that means. I got tired of bits supposedly HSS and titanium nitride coated that were dull after drilling just a few holes in relatively soft metals (aluminum, brass). The cobalt-alloy bits I bought from Drill Hog are very well made and have stood up well to these same metals and to some mild steel drilling.


Re: quality 0.050 hex key

snapdiode <snapdiode@...>
 

Never heard of Kroil but any product that advertises itself with "unseize the day" deserves a shot...


Re: quality 0.050 hex key

Bill Riches
 

After setting some Kroil drip in overnight - I would tighten set screw just a bit and then loosen - screw would come out.
73,
Bill, WA2DVUCape May, NJ

On Sunday, March 7, 2021, 12:56:37 PM EST, walter shawlee <walter2@sphere.bc.ca> wrote:

The 0.050 key is so  small that it's easily worn down or the screw
insert it widened.
the best answer so far for this problem for me has been to start with a
fresh key, and hit the
setscrew with some de-oxit, get it around to the threads, and shake any
excess out. let it sit overnight.
then, the fresh key will usually break the screw out.

I bought a really top shelf set of straight drivers, but nothing beats
having the oxidation around the
screw threads dissolved first.

all the best,
walter

--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
+We're all in one boat, no matter how it looks to you. (WS2)
+All you need is love. (John Lennon)
+But, that doesn't mean other things don't come in handy. (WS2)
+Nature is trying very hard to make us succeed, but nature does not depend on us.
We are not the only experiment. (R. Buckminster Fuller)


Re: TDS544A with strange display #photo-notice

Siggi
 

Looking at the photos closer, it appears the blue trace is also compromised
- there look to be some dropouts on the vertical edges here and there?
Did you re-cap the CRT driver board when you fixed up the leaked SMD caps
on the other boards? If you squint at this just right, it looks like maybe
you have decaying oscillation on blue after the last line displayed white
at the end.

On Sun, Mar 7, 2021 at 11:50 AM Siggi via groups.io <siggi=
undo.com@groups.io> wrote:

Hey TT,

My first thought was something on the LCD driver board too. My TDS784D
allows me to set different color schemes, and maybe even to pick the colors
for different screen elements (I don't remember that I ever played with
this).
If your scope has the same, maybe you can narrow this down by playing with
the colors, see whether and how different color and brightness settings
affect this display defect?

Siggi

On Sun, Mar 7, 2021 at 10:28 AM durechenew via groups.io <durechenew=
yahoo.com@groups.io> wrote:

Hello Jeff,

You are correct that the CRT is monochrome and the LCD shutter at the
front is enabling the color; however, there must be some display on CRT,
for the time a specific color layer of the shutter is enabled, to show on
the screen. In this case the whole display (monochrome CRT + shutter) is
displaying correctly the CH4 blue trace (white on CRT and blue LCD layer
ON), but the CRT, during the same period of time, is displaying something
unintended, due to some defective (or un-powered) part.
I'll try to better understand the schematic (as of now I have a general
idea how this works, but I don't know or understand all the details) and,
in the meantime, I'll try to see if there isn't something that I missed
at
the right time, like a corroded trace in some hidden place or, plainly, a
defective part.
Hopefully other people might have encountered something similar and might
be available to provide some insight...
Thank you
TT










Re: quality 0.050 hex key

 

The 0.050 key is so  small that it's easily worn down or the screw insert it widened.
the best answer so far for this problem for me has been to start with a fresh key, and hit the
setscrew with some de-oxit, get it around to the threads, and shake any excess out. let it sit overnight.
then, the fresh key will usually break the screw out.

I bought a really top shelf set of straight drivers, but nothing beats having the oxidation around the
screw threads dissolved first.

all the best,
walter

--
Walter Shawlee 2
Sphere Research Corp. 3394 Sunnyside Rd.
West Kelowna, BC, V1Z 2V4 CANADA
Phone: +1 (250-769-1834 -:- http://www.sphere.bc.ca
+We're all in one boat, no matter how it looks to you. (WS2)
+All you need is love. (John Lennon)
+But, that doesn't mean other things don't come in handy. (WS2)
+Nature is trying very hard to make us succeed, but nature does not depend on us.
We are not the only experiment. (R. Buckminster Fuller)


Re: quality 0.050 hex key

snapdiode <snapdiode@...>
 

I don't have a grinder. But China does...


Re: quality 0.050 hex key

Daniel Koller
 

I'm thinking if you already have a bunged up screw that has nohex left, you can grind down a wrench to "expand" it, then tap it in, and try to turn....   But that's a last resort.
Dan

On Sunday, March 7, 2021, 11:43:31 AM EST, snapdiode via groups.io <snapdiode=yahoo.com@groups.io> wrote:

Well, maybe on set screws that have never been abused, sure, but what can you do when the previous owner did all kinds of crap?

If size doesn't matter, why

"if you grind the tool from the bottom to the right point, you can get the slightly wider shoulder to engage"

That's why I want slightly bigger tools.


Re: TDS544A with strange display #photo-notice

Siggi
 

Hey TT,

My first thought was something on the LCD driver board too. My TDS784D
allows me to set different color schemes, and maybe even to pick the colors
for different screen elements (I don't remember that I ever played with
this).
If your scope has the same, maybe you can narrow this down by playing with
the colors, see whether and how different color and brightness settings
affect this display defect?

Siggi

On Sun, Mar 7, 2021 at 10:28 AM durechenew via groups.io <durechenew=
yahoo.com@groups.io> wrote:

Hello Jeff,

You are correct that the CRT is monochrome and the LCD shutter at the
front is enabling the color; however, there must be some display on CRT,
for the time a specific color layer of the shutter is enabled, to show on
the screen. In this case the whole display (monochrome CRT + shutter) is
displaying correctly the CH4 blue trace (white on CRT and blue LCD layer
ON), but the CRT, during the same period of time, is displaying something
unintended, due to some defective (or un-powered) part.
I'll try to better understand the schematic (as of now I have a general
idea how this works, but I don't know or understand all the details) and,
in the meantime, I'll try to see if there isn't something that I missed at
the right time, like a corroded trace in some hidden place or, plainly, a
defective part.
Hopefully other people might have encountered something similar and might
be available to provide some insight...
Thank you
TT






Re: quality 0.050 hex key

snapdiode <snapdiode@...>
 

Well, maybe on set screws that have never been abused, sure, but what can you do when the previous owner did all kinds of crap?

If size doesn't matter, why

"if you grind the tool from the bottom to the right point, you can get the slightly wider shoulder to engage"

That's why I want slightly bigger tools.


Re: 3T77 tunnel diodes (again)

Albert Otten
 

I'm still puzzled why I can see events that occur repetitively every 500 ns (the 1 MHz square wave)
down to 20 ns/div but not 10 ns/div... I can use the X10 expander mode at 20 ns/div (e.g. 2 ns/div)
and see it perfectly - that's how I took the pictures.
At fast time/div settings the 3T77A Time Position control can cover at least 45 sweep lengths. At 10 ns/div that would mean a time interval (starting at the trigger event) of 450 ns. That's just not enough to cover the falling edge after 500 ns. X10 and Expansion do not increase that 450 ns time interval. Assuming still 45 sweeps lengths at 20 ns/div that setting would should work.

Also hooked up my GR 220-920 MHz oscillator to both heads (the S-2 and S-4).
It displays sine waves nicely up to about 500 MHz. At 620 MHz the trigger is starting to lose function
so the traces get noisy, a bit better with the Smooth switch on, but at 800 MHz it's useless.
That can be better. I just tested my 564/3T77A/3S76 the same way. Triggers without any need to readjust trigger level over that whole
frequency range. I used the Tek version of that GR oscillator set at 0.5 V pp. Both with internal triggering (not possible with 3S2) and with external triggering. Nice stable wine waveform with some visible distortion (depending on frequency); these generators are not perfect.
For external triggering I used a GR power divider which reduces amplitudes to 0.25 V pp. I didn't use SYNC.

So now what?
For observing fast rise time of a signal under study you will usually need to display the edge that produces the trigger event, not an edge in a next signal period (or half way as you did). So you need either a signal delay line or a pretrigger signal.
This holds for equivalent time sampling.
You might try to obtain a random sampling time base unit like the 3T2. In random mode you can view the signal before, around or after the trigger event. But don't expect miracles of this. (Read some comments on random sampling with the 7T11(A)).

Albert


Re: Sold - Re: [TekScopes] Tektronix books lot on ePay

toby@...
 

On 2021-03-07 9:47 a.m., Jouko Koskinen wrote:
Scanned books:
https://www.davmar.org/concepts.html

BR,
Jouko

Thanks for the link!

--Toby






Re: quality 0.050 hex key

Daniel Koller
 

I'll resurrect my own boring response!   Wera Hex Plus!
https://www-de.wera.de/en/great-tools/hex-plus/

It's not the size that matters, but the shape and material.  In this case, the drivers are hardened steel.
I have direct experience with these tools.  As an on going work project, I test the breaking torque of 0-80 stainless steel and black-oxide coated steel screws.   For the stainless steel screws, the hex in the head rounds off before they reach their breaking torque.  For the black oxide screws, the tool typically rounds off.  The only tool capable of gripping the hex 100% of the time is the Wera.  
  If you can't get it out with a Wera, you are going to have to drill the set screw out.  I note also that the Wera tools have a taper to them near the top of the ground steel tip -  a "shoulder" between the tip and the rounded shaft of the tool. So, if you grind the tool from the bottom to the right point, you can get the slightly wider shoulder to engage the screw, and so effectively "widen" the tool a bit as necessary for that one set screw that has been rounded out.   I have not had to do this yet, but I have in the past ground down standard hex keys to get a more square profile in the bottom of the socket, and that has helped.
Dan

On Sunday, March 7, 2021, 10:39:24 AM EST, snapdiode via groups.io <snapdiode=yahoo.com@groups.io> wrote:

I resurrect my own boring thread.
Since I got both 1.27mm and 1.30mm keys to help remove those devil-spawned set screws, I wondered if 1.28 and 1.29mm sizes would help removing the tough ones.
So I asked the eBay seller if he could get his supplier to make these sizes.
What think ye?


Re: 3T77 tunnel diodes (again)

 

On Sat, Mar 6, 2021 at 9:01 PM Charles <charlesmorris800@centurytel.net> wrote:

I'm sure I could make one of some sort (Googling "homemade tunnel diode" comes up with a LOT of results) but one that will have an Ip near 20 ma, trigger up to 1 GHz per the manual, and fit in the clip is a tall order ;)
OK, well then put your money where your mouth is. You have to start
somewhere. Start with a slower diode, document the whole process on
youtube, so it can be recreated by others. Mention that you'd need a
diode that triggers to 1GHz or more, but need a cleanroom and a
smaller process. Someone with a cleanroom will inevitably show up and
pick up where you left off. The community is great at sharing projects
like that which have hit a snag of some sort, especially if you're
trying to recreate some obscure lost technology. If you write to
Hackaday they will run it, and someone relevant will see it. This is
basically how all the home-manufacture stuff gets done, and it's not a
long shot that this will happen. So I suggest go for it.

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