Date   

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.


Re: TG501 enigma :)

 

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?


Re: 7A22 relay adapter

 

On Thu, 24 Dec 2015 23:21:36 +0000, you wrote:

On 24/12/15 22:39, David davidwhess@... [TekScopes] wrote:

On Thu, 24 Dec 2015 16:49:49 +0000, you wrote:

On 24/12/2015 16:22, David davidwhess@... [TekScopes] wrote:
These types of relay were used in the 5030, 5031, 5L4, 7A11, 7A12,
7A13, 7A14, 7A16, 7B70, 7B71, and 7J20.
Thanks. I'll keep my eyes open. I'm in the UK so these things aren't
quite as abundant as they are over there.

I have a pulse generator with a 30ns rise which should give me some idea
if there's a significant performance issue. I'll post back once I've got
some results.

Cheers

Gordon
30 nanoseconds is not nearly fast enough. The output from an AC
(Advanced CMOS) type of gate like a 74AC00 would be though.
74LVC1G14 is around 650ps, judging the frequency spectrum of its output.
Some of the lower voltage CMOS gates are even faster. I like the AC
series because it can still operate at 5 volts. I did not keep my
notes but I think AHC and AS were almost as good.

It is worth noting that on these gates, the transition time only has
to support the propagation delay and while the propagation delay is
specified, the transition time often is not and it is often slower
than you would expect. They go to some effort to use as slow a
transition time as possible because edges which are faster than
necessary can cause problems.

I finally found the video I was going to link. W2AEW used the AC
series for this also:

https://www.youtube.com/watch?v=9cP6w2odGUc


Re: Advice for a sick DC505a

 

On 24 Dec 2015 02:20:48 -0800, you wrote:

Ok, I scoped the PNP drives of the common anode digits. For sure the edge most LED is intermittent cuz touching the transistor (with a probe) or my finger gets the Digit to light up.
Have a look at the annotated scope images here for each digit with the Reset button depressed (all supposed to show 8's)
file:///C:/users/user/appdata/local/temp/dbxlrixsxf.html#
The emitter and collector currents from these transistors are pretty
high at about 20 milliamps per segment so maybe 140 milliamps maximum
and your finger is not going to have any effect on that. Do to the 1k
shunt resistors which make sure that the transistors turn off, the
base current needs to be about 600 microamps before conduction even
starts and that is also more than just a finger touch will provide.

The actual base drive from U755 through the resistors to the
transistors is about 10 milliamps so they are driven pretty hard.

I am not sure where my DC505 is but if touching something allow them
to work, then I suspect an open socket connection and I think these
transistors are socketted using those Berg insert things.

These transistors can be replaced by 2N2907s or 2N4403s if necessary.

So I suppose somehow the transistor collector drive isn't getting to the digit common anode.
Any dismantling advice on this....'exercise'
I'll look at the odd triggering once I can get the Digits to work , else there's no point.
Like I said for the odd triggering, check the laminated ribbon cable
which connects the two boards at the rear of the plug-in. Mine had
delaminated and the traces touching each other caused all kinds of
weird behavior.


Re: TG501 enigma :)

Sergey Kubushyn
 

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

I will offer those here first al lower price. As of now it is 2 x SG503, one
PG506, 2 x TG501. I will offer them right after New Year, probably January
1st because the proceeds should go into my next financial year.

There is a lot more in the works but it won't be ready by January 1st.

Will us Tek members get a discount on any of those plugins?
---
******************************************************************
* KSI@home KOI8 Net < > The impossible we do immediately. *
* Las Vegas NV, USA < > Miracles require 24-hour notice. *
******************************************************************


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

mosaicmerc
 

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.

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.

Having figured out the Tek plugin 'pull'-release gizmo, I can now laser cut a replacement for the 'broken' one on my PS503A. I had drilled the plastic stub and added a 'wire' loop to do the pull.

If anyone needs those replaced maybe we can do a group batch. I'd say $3 plus postage, snail mail.


Re: 314/335 Volts/Div Knob

John Clark
 

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











.


Re: P6055 Manual

Dave / NR1DX
 

We have the P6055 manual ...IT is not listed on our WEB site for some
reason , so I will get it up there tomorrow. I may even have an original
manual buried in the shop it will take several days to find that ( if it
is there at all), as I just moved and only began unpacking the
electronics lab this week

Dave
ArtekManuals.com

On 12/24/2015 8:13 PM, tubesnthings tubesnthings@... [TekScopes] wrote:

Treasure trove, indeed. Many thanks.
Now, if I could only find the docs for the P6055 differential
probe...unobtainium, it seems?

Sent from TypeMail

On Dec 24, 2015, 7:19 AM, at 7:19 AM, "'Craig Sawyers'
c.sawyers@... [TekScopes]" <TekScopes@...>
wrote:
Guys'n'gals



Just discovered a real Christmas Present -
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/publikacje/



Among a whole saucerfull of gems there is a complete set of all the
Service Scopes, and a shed load
more.



Enjoy!



Craig



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


--
Dave
Manuals@...
www.ArtekManuals.com


Re: Tek 2215 Power supply Fixes

Tothwolf
 

On Thu, 24 Dec 2015, stever1k@... [TekScopes] wrote:

Is there any reason I can not remove the pre regulator board from the chassis by using 4 wores to extend it and then start up the scope to read the voltages...That should work shouldnt it??
When I was rebuilding one of my preregulator boards, I reinstalled it with only the primary side connected and connected my meter to the secondary side with hook clips on my probes. I didn't have any trouble gaining access to anything for testing in my scopes with the preregulator boards in place.


Re: Massive document depository

tubesnthings <tubesnthings@...>
 

Treasure trove, indeed. Many thanks.
Now, if I could only find the docs for the P6055 differential probe...unobtainium, it seems?

Sent from TypeMail

On Dec 24, 2015, 7:19 AM, at 7:19 AM, "'Craig Sawyers' c.sawyers@... [TekScopes]" <TekScopes@...> wrote:
Guys'n'gals



Just discovered a real Christmas Present -
http://bee.mif.pg.gda.pl/ciasteczkowypotwor/Tek/publikacje/



Among a whole saucerfull of gems there is a complete set of all the
Service Scopes, and a shed load
more.



Enjoy!



Craig




Re: 314/335 Volts/Div Knob

Tothwolf
 

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

Sorry Raymond, you're correct. The Ch 2 is, in fact, the light colored knob. Tek calls the light color "gray" and the darker one "charcoal gray." Whatever colors they are now I'm sure aren't what they were when they were new.

Anyhow, the parts diagram shows it all as one knob assembly, but like you, I decided not to try and remove it even from my non-working unit as it's not worth the trouble. It does look like if you could get the knobs off you could probably push a small diameter rod through the hole from the back side and push out the cap. I just don't know what would be gained by getting access inside the cap. I'm pretty sure it could be glued on with no future adverse affects. I've never done the solvent welding with plastic so I'll have to read up a bit on that. There's no real reason to do anything with the small crack on the knob as I can't even close it up by squeezing it together.
Unfortunately, if the surfaces won't fit together without a gap, solvent welding isn't going to be possible. For gap filling of broken plastics, you would need a compatible plastic to use as filler which could be either solvent or thermally welded in place.

If the cap is just a cosmetic part, gluing it in place with rubber cement probably is going to be the best route. I've also had some success using "Goop" to glue such things in place, however I've had problems with the solvents in Goop attacking some styrene and pvc plastics, so you have to be careful with what you use it on.


Re: TG501 enigma :)

mosaicmerc
 

Will us Tek members get a discount on any of those plugins?


Re: 2236 Counter timer board swap

chipbee40
 

You can swap the CTM boards, no problem. When you say you can't zero the CH1 volts, does it read any DC levels? If not you may have the shielded connector (P2900) to the CH1 attenuator board reversed. I've seen this several times and as the CH1 connection is pretty much straight through to the ctm circuit and assuming the side sockets read volts ok I would say the ctm board is fine. Most faults with these scopes are dirty or broken mulitpole switches on the ctm board, or high resistance leakage in the ctm relays.


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

Hi all,

I've got two 2236 scopes. One works fine as a scope but the voltage display
of channel 1 is off on the VFD display. I've gone through the calibration
portion relating to that function but I cannot zero out the display even at
the end of the pot travel. The second 2236 is a parts mule with several
problems but has a seemingly functional CTM board. Is there any reason not
to swap the CTM board from the mule to the first 2236. I've gone through
the service manual and I don't think I'll screw up the scope portion or
loose calibration. But maybe I'm missing something.

Any ideas on where to start on a CTM troubleshoot? I've checked all supply
rails and all are within spec. according to the manual.


TG501 enigma :)

Sergey Kubushyn
 

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: 7A22 relay adapter

Tom Gardner
 

On 24/12/15 22:39, David davidwhess@... [TekScopes] wrote:

On Thu, 24 Dec 2015 16:49:49 +0000, you wrote:

On 24/12/2015 16:22, David davidwhess@... [TekScopes] wrote:
These types of relay were used in the 5030, 5031, 5L4, 7A11, 7A12,
7A13, 7A14, 7A16, 7B70, 7B71, and 7J20.
Thanks. I'll keep my eyes open. I'm in the UK so these things aren't
quite as abundant as they are over there.

I have a pulse generator with a 30ns rise which should give me some idea
if there's a significant performance issue. I'll post back once I've got
some results.

Cheers

Gordon
30 nanoseconds is not nearly fast enough. The output from an AC
(Advanced CMOS) type of gate like a 74AC00 would be though.
74LVC1G14 is around 650ps, judging the frequency spectrum of its output.

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