Date   

Re: Massive document depository

 

I replicated just the HP and Tek parts of this archive locally some
time ago and it came out to 12.6G for HP and 38.5G for Tek. The last
update I did was on the 5th of this month and I see no differences
from that time to now.

I ran a compression test which only gained about 10% so there is no
way even just the Tek archive could be made to fit on less than
several DVDs. I would however consider the whole thing amendable to
distribution via Bittorrent or similar.

On Thu, 24 Dec 2015 23:42:56 -0800 (PST), you wrote:

On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@... [TekScopes] wrote:

You seem to underestimate the sheer size of that treasure trove...

I'm running "wget -r" on it since the announcement first appeared and it is
already 49Gbytes downloading Tek/2215a.pdf right now. I estimate it will
reach 100Gbytes fully mirrored...

Many manuals there are in greyscale (that is very good) that makes them over
100Mbytes each (that is not good :))

It can easily take 25-30 DVDs to archive and a lot of work to split the
entire thing into separate DVDs. A hard drive would be much better suited
for storing the collection that big.

It would be very helpful if someone would put it all into a single massive
file so it could be downloaded just once and put on a DVD.

Gary


Re: 2236 Counter timer board swap

Dave Ahrendt
 

chipbee40,

Thanks for the info. The display does read DC level but is reading too high. The calibration step is to set the CH1 Volts/Div to 50 Mv & GND the input and then set the zeroing pot on the CTM to zero on the display. I can only get down to about .007 or so at the pot limit. At this point when I use the scope at 5 volts/Div the display is about .7 volts too high. At higher range it’s 7 volts high.

I’ll have to check if the side socket input is also too high.


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

 

ESR in the output capacitors will matter for decoupling the logic but
not the large input capacitors. For them, the loss of capacitance
over time will eventually allow the input voltage to the regulators to
sag far enough between power line cycles that the regulators' output
is affected. I can easily see that as being a problem in some
mainframes but not others.

I found my DC505 (not DC505A) and all of its transistors are socketted
with those little Berg minisert thingies.

My DC505 currently locks up after reaching operating temperature in my
TM504 and I am going to have to add checking the input capacitors to
my list of things to do. I only recently acquired a pair of TM503s
which I can use to test it.

I have made other changes (improvements!) to my DC505 so I am not
surprised that it has some issues. I have just been working slowly on
it so I can savor the experience. That is my story and I am sticking
to it.

On 25 Dec 2015 03:04:28 -0800, you wrote:

It might be that the capacitors in the TM503 have degraded over time and their ESR can't support all the dozens of logic switching (70s' TTL) IC currents.

I'll have to pull it down and have a look see. Could be they are getting leaky.
The two big caps in the DC505A are easily inspected and they seem fine visually, being radially mounted. Since it works in the TM501 I don't think the prob. is with the DC505A


Re: Horizontal Sweep Problem

 

The count looks right for a 100kHz waveform at 10us/div so I think the
sweep is good but I noticed something else; when you used the
horizontal position control, the point where the sweep "piled up" on
the left and right was visible on the CRT.

That is suppose to happen beyond the viewing area of the CRT where you
cannot see it and it can be caused by either low CRT deflection in
general which would be caused by high CRT acceleration voltage or low
gain in the horizontal CRT amplifier.

Is the vertical deflection accurate? If so that rules out a problem
with the CRT acceleration voltage.

If the problem is not the CRT acceleration voltage, then I think you
will find it on schematic 7 which is the horizontal CRT amplifier.

Those traces you displayed at the end were the outputs from the
horizontal CRT amplifier, right? They looked symmetrical which is
good.

R762 and R752 in series control the gain of both sides of the
horizontal amplifier. Make sure neither is open.

I did not see any horizontal nonlinearity so I think we are looking
for a gain problem instead of a biasing problem.

On Fri, 25 Dec 2015 06:07:02 -0500, you wrote:

Here is a link showing the problem...

100khz input displayed with 10 us / division selected.

http://1drv.ms/1J7OQ67

the horizontal deflection signals
(left and right) to the crt and then
the output of the horizontal oscillator
that goes to the horizontal preamp..

the deflection signals sure look poor to me but
i am just out of my league trying to figure out what is wrong.

thanks..


Re: 7A22 relay adapter

 

On Fri, 25 Dec 2015 09:54:34 +0000, you wrote:

On 24/12/2015 22:39, David davidwhess@... [TekScopes] wrote:

30 nanoseconds is not nearly fast enough. The output from an AC
(Advanced CMOS) type of gate like a 74AC00 would be though.
Thanks all. If I'd thought about it for more than a few seconds I'd have
realized it wasn't fast enough. To me, anything with an n after it is
fast, I live in the slow lane. I don't have much logic lying around so
it'll be a while before I've any results.

Enjoy the day:)

Gordon
This is one of the reasons I like to think of oscilloscope performance
in transition time rather than bandwidth. Even "slow" logic has rise
and fall times faster than 10ns and most is faster than 5ns no matter
what the clock rate is and that is where trouble starts.

Typical switching circuits using discrete general purpose transistors
like the 2N2222 and 2N3904 are in the 10s of nanoseconds range.


Re: Plug-ins that use the high power slot in TM500/5000

Mark Wendt
 

On 12/24/2015 11:14 AM, David davidwhess@... [TekScopes] wrote:

Well, hopefully it'll be another 40 years before you have to visit one
again. Get well quick!

Mark
Thanks for the kind words.

I narrowly missed spending Christmas in the hospital.

I am feeling better by the hour and at this point can sit up in my
computer chair without pain if I do not move around to reach things.
David,

That's great news! I've always enjoyed your posts here on the list, and I really appreciate all the help you gave me on that one plugin that had me pulling out my remaining hairs while troubleshooting. You should be a teacher. You'd make a great one.

Mark


Re: 314/335 Volts/Div Knob

John Clark
 

Yeah, I'm not sure what happened to it. The set screws won't back out very far because they back out into the inside of the plastic part of knob so the knob itself has moved on it's housing. I'm unable to move it back and don't see any reason to try very hard since everything works just as it's supposed to. I don't see any way to repair the crack, either. I just want to reattach the cover in some way. The crack ends at the set screw hole so unless the knob gets bumped pretty hard I don't see it getting any worse. The transfer adhesive might be just the ticket if I can find some very thin stuff.

John



To: TekScopes@...
From: TekScopes@...
Date: Fri, 25 Dec 2015 02:25:27 -0600
Subject: RE: [TekScopes] Re: 314/335 Volts/Div Knob


























On Thu, 24 Dec 2015, John Clark johnclark05@... [TekScopes] wrote:



A picture is worth a thousand words. You can see the hairline crack at
the top of the knob. Gluing the cap back in should be a pretty simple
process. I just want to make sure it's the right plan, and get the
group recommendations, before I do it.
https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/2145227623/lightbox/784615181?orderBy=ordinal&sortOrder=asc&photoFilter=ALL


I see. I thought the cap itself was cracked. I wouldn't call that crack in

the knob a hairline. It looks like a stress fracture from the hole in the

middle of the knob being too small for the shaft and/or from too much

radial torque. It cracked at the weakest point -- at the setscrew hole.



If the knob can be removed (are they using a 1/8" to 1/4" shaft adapter?)

to remove internal stress on the knob to allow the crack will close up,

that part could be solvent welded. If not, probably the only option is

going to be to leave that crack alone and just use rubber cement or

similar to glue the cap in place.



Actually, another option you might consider is 3M transfer adhesive. It

could be cut the same diameter as the cap and would stick to the ledge

just inside the knob. Scraps and small sections of various types can be

found very cheaply on eBay. I used a transfer adhesive to reinstall the

overlay on one of my scopes after I replaced the front bezel.

















[Non-text portions of this message have been removed]


Massive document depository

magnustoelle
 

Good Day,
thank you, Craig - that is a very useful collection indeed.
Merry Christmas and have great holidays, all.
Cheers,
Magnus


Re: Horizontal Sweep Problem

A_Hall <bofulforever@...>
 

Here is a link showing the problem...

100khz input displayed with 10 us / division selected.

http://1drv.ms/1J7OQ67

the horizontal deflection signals
(left and right) to the crt and then
the output of the horizontal oscillator
that goes to the horizontal preamp..

the deflection signals sure look poor to me but
i am just out of my league trying to figure out what is wrong.

thanks..


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

mosaicmerc
 

It might be that the capacitors in the TM503 have degraded over time and their ESR can't support all the dozens of logic switching (70s' TTL) IC currents.

I'll have to pull it down and have a look see. Could be they are getting leaky.
The two big caps in the DC505A are easily inspected and they seem fine visually, being radially mounted. Since it works in the TM501 I don't think the prob. is with the DC505A


Re: 7A22 relay adapter

Gordon <tekscopes@...>
 

On 24/12/2015 22:39, David davidwhess@... [TekScopes] wrote:
30 nanoseconds is not nearly fast enough. The output from an AC
(Advanced CMOS) type of gate like a 74AC00 would be though.
Thanks all. If I'd thought about it for more than a few seconds I'd have realized it wasn't fast enough. To me, anything with an n after it is fast, I live in the slow lane. I don't have much logic lying around so it'll be a while before I've any results.

Enjoy the day:)

Gordon


Re: Massive document depository

Craig Sawyers <c.sawyers@...>
 

Treasure trove, indeed. Many thanks.
Now, if I could only find the docs for the P6055 differential probe...unobtainium, it seems?
The pdf is available on line - or are you after the paper documents?

Craig


Re: 3B3 Delayed time base

Martin Mehlhose
 

turn them full left first, there must be a click, snapping in to the start Position.

At front is a transparent plastic ring displaying the Position of the frontside part of the rotating Switches.

When you pull, it will rotate only the delay time Switches behind the coupler with the pin.


The Time Base Position is to read by the transparent plastic ring, the delay time (pull) by the White Point on the knob.


greetings

Martin






Gesendet von Windows Mail





Von: TekScopes@...
Gesendet: ‎Samstag‎, ‎19‎. ‎Dezember‎ ‎2015 ‎15‎:‎51
An: TekScopes@...








Hello everybody

On my 561A scope with 3b3 sweep unit, the delayed time base knob can be pulled and rotated left and right, but the inside switches are not rotated according to the knob rotation.

I can't manage to desassemble the front knob to fix this. Does somebody known how this knob works?

Thank in advance for help.

Pascal


Re: 314/335 Volts/Div Knob

Tothwolf
 

On Thu, 24 Dec 2015, John Clark johnclark05@... [TekScopes] wrote:

A picture is worth a thousand words. You can see the hairline crack at the top of the knob. Gluing the cap back in should be a pretty simple process. I just want to make sure it's the right plan, and get the group recommendations, before I do it.

https://groups.yahoo.com/neo/groups/TekScopes/photos/albums/2145227623/lightbox/784615181?orderBy=ordinal&sortOrder=asc&photoFilter=ALL
I see. I thought the cap itself was cracked. I wouldn't call that crack in the knob a hairline. It looks like a stress fracture from the hole in the middle of the knob being too small for the shaft and/or from too much radial torque. It cracked at the weakest point -- at the setscrew hole.

If the knob can be removed (are they using a 1/8" to 1/4" shaft adapter?) to remove internal stress on the knob to allow the crack will close up, that part could be solvent welded. If not, probably the only option is going to be to leave that crack alone and just use rubber cement or similar to glue the cap in place.

Actually, another option you might consider is 3M transfer adhesive. It could be cut the same diameter as the cap and would stick to the ledge just inside the knob. Scraps and small sections of various types can be found very cheaply on eBay. I used a transfer adhesive to reinstall the overlay on one of my scopes after I replaced the front bezel.


Re: Massive document depository

Sergey Kubushyn
 

On Thu, 24 Dec 2015, Gary Robert Bosworth grbosworth@... [TekScopes] wrote:

You seem to underestimate the sheer size of that treasure trove...

I'm running "wget -r" on it since the announcement first appeared and it is
already 49Gbytes downloading Tek/2215a.pdf right now. I estimate it will
reach 100Gbytes fully mirrored...

Many manuals there are in greyscale (that is very good) that makes them over
100Mbytes each (that is not good :))

It can easily take 25-30 DVDs to archive and a lot of work to split the
entire thing into separate DVDs. A hard drive would be much better suited
for storing the collection that big.

It would be very helpful if someone would put it all into a single massive
file so it could be downloaded just once and put on a DVD.

Gary


On Thu, Dec 24, 2015 at 8:43 PM, 'John Miles' john@... [TekScopes] <
TekScopes@...> wrote:



Good find! wget snagged 13 GB from the Tek directory alone.

There are a lot of documents that look like internal training manuals and
lecture notes, some of them incredibly detailed:


http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/publikacje/556_Lecture_Notes
.pdf

-- john, KE5FX

From: TekScopes@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
Subject: Re: [TekScopes] Massive document depository

A great Christmas present, indeed!! One of the first files I downloaded
(tek_made_sm.pdf) describes the internals of many of the
Tektronix-manufactured ICs for which, I'm sure, no other documentation
exists.
There are lots of other documents on analog theory circuit design. A bit
dated, perhaps, but the theory still applies.
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


Re: Massive document depository

Gary Robert Bosworth
 

It would be very helpful if someone would put it all into a single massive
file so it could be downloaded just once and put on a DVD.

Gary


On Thu, Dec 24, 2015 at 8:43 PM, 'John Miles' john@... [TekScopes] <
TekScopes@...> wrote:



Good find! wget snagged 13 GB from the Tek directory alone.

There are a lot of documents that look like internal training manuals and
lecture notes, some of them incredibly detailed:


http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/publikacje/556_Lecture_Notes
.pdf

-- john, KE5FX

From: TekScopes@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
Subject: Re: [TekScopes] Massive document depository

A great Christmas present, indeed!! One of the first files I downloaded
(tek_made_sm.pdf) describes the internals of many of the
Tektronix-manufactured ICs for which, I'm sure, no other documentation
exists.
There are lots of other documents on analog theory circuit design. A bit
dated, perhaps, but the theory still applies.

[Non-text portions of this message have been removed]




--
Gary Robert Bosworth
grbosworth@...
Tel: 310-317-2247


[Non-text portions of this message have been removed]


Re: TG501 enigma :)

Sergey Kubushyn
 

On Thu, 24 Dec 2015, David davidwhess@... [TekScopes] wrote:

How can you align 20ns period pulses with 50ns ones? They are different
frequencies not even evenly divisible by each other.

You have a "SET" (or reset that makes no difference) signal every 50ns. This
is applied to a pulse train with 20ns period. That means that reset signal
comes after 2 20ns pulses, 10 ns after the second pulse. What you have in
result is a constant stream of 20-20-10ns pulse sequences that is hardly
something that could've been called 20ns time mark signal... You can clearly
see it with a scope. And this is _ONLY_ present on 20ns range; none of the
others have this weirdness.

TG501 generates a _CONSTANT_ pulse train, not some sequences so it makes no
difference when each particular pulse train started.

Then, there is a switch that selects which of many available frequencies is
connected to the output. Only one can be selected at a time, all others are
just not connected to anything.

All pulse trains are derived from the same 100MHz VCO so they are all
synchronized to that base frequency but that is just a consequence of
deriving everything from the same base signal that has no practical purpose.
Those signals can synchronized or not -- that doesn't matter. Only one of
those signals is used at a time so it doesn't matter what other signals are
and if they exist at all.

100MHz VCO can be either locked to a _SEPARATE_ reference clock (coming from
a separate reference crystal oscillator, either a simple or ovenized one
depending on Option 1 presence) when in "calibrated" state or free-running
with a frequency changed by a voltage from a potentiometer when in
"variable" state. It allows for something like +/-8% tuning from the center
100MHz frequency. All subdivided pulse trains are changed the same
percentage because they are just a VCO signal divided by a constant.

Faster signals (5-2-1ns) are also derived from the VCO signal using a snap
diode for frequency multiplication followed by tuned bandpass filters. As
those are tuned variable frequency can not be implemented so the VCO is
forced locked to the reference when in 5-2-1 range i.e. variable timing is
disabled.

I cut that trace on all 3 TG501s and now they all make perfect regular time
marks on all ranges. I'm still puzzled what was the original intent on
crippling that particular 20ns range pulse train.

I looked at it quickly and I think it was done to keep 20ns divided
output phase aligned with the 50ns divided output. The other outputs
are also phase aligned to the 50ns output through Q330.

Otherwise depending on the state of the divider for the 50ns divider,
the 20ns output could be misaligned with the trigger.

On Thu, 24 Dec 2015 16:13:39 -0800 (PST), you wrote:

Hi everyone!

I'm cleaning up my collection of PG506 and multiple TG501 and SG503s
keeping one each for myself and readying the remainder for selling on EPay
(don't want to sell those in "as-is, don't know if it works" state so
checking/fixing/calibrating everything to offer them as "guaranteed working
and calibrated".)

While working on TG501 I found something strange that I have no explanation
for. _ALL_ of my 3 TG501s were giving crappy output at 20ns range (multiple
overlapped pulses on a scope) so I decided to investigate and fix it. And
here is where something weird showed up.

10/20/50ns range pulses come from 100MHz VCO. It is fed straight to output
for 10ns and through /5 and /2 dividers for 50ns and 20ns ranges. 10ns and
50ns ranges are clean and nice so VCO works fine. It is only 20ns that is
crappy so the trick is definitely in that /2 divider. And it is indeed :)

If you look at schematic sheet 2 you will see that /5 divider at the left
top is nothing special, made of 3 ECL flip-flops (U310 and half of U315) and
it works just fine.

If you look at the /2 divider below the /5 one you would notice something
very weird. A /2 divider is just a flip-flop so it should've been
straightforward. And indeed it is a flip-flop made of the remaining half of
U315. However there is very strange fragment made of U290A and U290B parts
attached to it. It generates a short pulse using a propagation delay in
U290A every 50ns and that pulse is used to forcefully set the U315B
flip-flop every 50ns. 50ns is not an even multiple of 20ns so that is why
U315B output is not a series of pulses with 20ns period.

And that is not something that just happened or had been overlooked; it is
done _DELIBERATELY_ by design. Furthermore, it had been modified in newer
instruments so there are 2 versions of U290A connection on the schematic,
one for S/N below B036900 another for S/N B036900 and above. For later units
it is even crappier because it adds /10 output to the mix...

Cutting a trace at U315 pin 12 predictably makes 20ns pulses nice and clean
like all other ranges. That trace is on the LF board solder side so it is
easily accesible without taking the entire thing apart thus making it an
easy fix.

The question still remains -- what was an intended purpose for crippling
that particular 20ns range pulse train? It is 100% sure that had been done
deliberately and even "enhanced" in later versions of TG501 plugins.

Does anyone has some idea why?
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


Re: Massive document depository

John Miles
 

Good find! wget snagged 13 GB from the Tek directory alone.



There are a lot of documents that look like internal training manuals and
lecture notes, some of them incredibly detailed:

http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/publikacje/556_Lecture_Notes
.pdf



-- john, KE5FX





From: TekScopes@... [mailto:TekScopes@...]
Sent: Thursday, December 24, 2015 8:12 AM
To: TekScopes@...
Subject: Re: [TekScopes] Massive document depository





A great Christmas present, indeed!! One of the first files I downloaded
(tek_made_sm.pdf) describes the internals of many of the
Tektronix-manufactured ICs for which, I'm sure, no other documentation
exists.
There are lots of other documents on analog theory circuit design. A bit
dated, perhaps, but the theory still applies.


Re: Replacing tantalum capacitors with ceramic capacitors

vdonisa
 

TDK makes them in C0G up to .22uF in their reasonably priced FK series, available both from Mouser and Digikey.

---In TekScopes@..., <davidwhess@...> wrote :

Large value NP0/C0G ceramic capacitors are still more expensive than
many alternatives.


Re: Advice for a sick DC505a- discovered a mainframe issue as well.

 

On 24 Dec 2015 18:08:56 -0800, you wrote:

Ok, I got the unit sorted out. Took my time and dismantled it and separated the PCB sandwich, reseated the connector in question, which was quite loose, and did continuity from transistor driver to common anodes.

All digits are ok now.

Upon power up the odd gating and counting had stopped and all digits were stable. This turned out to be an issue with the TM503 vs the TM501 mainframe. It seems the TM503 power rail makes the DC505A unhappy...it counts with no signal. With a signal it counts by about 15% off. I tried it by itself in a TM503...no good. Different slots gave same issue. Yet an SG503 and PS503A have no probs in the TM503.

I note that the DC505A manual (pg 7) mentions a ripple capacitor upgrade (11k to 18Kuf) when used in a low power slot IF there are multiple DC505A units in the mainframe. Well, I just have one.
I will have to remember to take a look at this on mine. It is touchy
after it warms up and I am still working on it. It never occurred to
me that the problem might be related to the power supply mainframe.

DC505A installed in a TM501...all is stable and counts are perfect.

Did some basic tests...with a sig. from the SG503....Frequency counts via Chan A were good and period measures on B are good as well. Trigger level adjustment pots are a bit touchy, but I guess with some use that may clear up.

Can't see how to service those pots with Deoxit.
One problem I had on mine was false counts between the 4th and 5th
digit from the left caused by noise from the display multiplexing
getting into level shifter Q680 shown on schematic 3.

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