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Hello Tek Heads -
I made a bunch of extenders, thank you to those that purchased through my Amazon page or through this group. I hope everyone that bought one is happy with them.
I am out of PC boards, and I'm trying to decide whether to make another batch. I sort of feel like the market for these is like 100 people and everyone that wants one (or two) has already bought them.
If you think you might want one, or if you have an opinion about the total available market for these please let me know.
I guess at the same time, if anyone that bought a set has any ideas for improvements please let me know that, too. If I do happen to make more I'll improve them if I can.
One thing I did was make the SMT parts larger (the resistors are 1206 and the diodes are SMA size, and the LEDs are T-1 through-hole parts). This is for the people that just wanted to buy a kit of parts, so you can more easily solder the parts yourself, rather than me doing it.
I was thinking about this because I had two module that I fixed this weekend. Reminded how handy these things are!
Thanks -
Dan

Here's a link showing the extenders:

I am out of PC boards, and I'm trying to decide whether to make another batch. I sort of feel like
the
market for these is like 100 people and everyone that wants one (or two) has already bought them.
If you think you might want one

I didn't at the time, but I'd be in for two if you are doing another batch

Craig

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Raymond
Domp Frank
Sent: Monday, May 14, 2018 5:25 PM
To: [email protected]
Subject: Re: [TekScopes] 7T11 sampling timebase - how does it behave?

Hi Dennis,
I'm getting the impression that you haven't seen my contribution earlier
today. I commented your post and added info about today's measurements. For
ease of reference, I'm repeating it in full below:

*** QUOTE
Hi Dennis,
I took a few photographs with current equipment and my previous
measurements were largely confirmed. Please refer to the added photographs
in the album. Their names indicate what's shown, as opposed to the older
photographs which only carry their image number.
I apologise for the disappointing quality of the "rush job".
I used two 'scopes and two S-52's:
- A 7854 with 7T11A, 7S11/S-52 and 7S11/S-4
- A 7904 with 7S12, S-52 and S-6, terminated

You seem to have 30pSec risetime and I would like to know how you do
that since the S4 has a 25pS rise time. That would
mean you were using a 13pS pulse.

I'd say slightly more: 36 to almost 40 ps, ignoring the influence of
overshoot. The sampling outfits are separate. I've never attempted to
adjust the time bases and adjusted the horizontal sensitivity of the
mainframes using a Calibration Fixture (067-0587-01), calibrated against a
second unit so I'm tempted to trust the measurements. ISTR that Tek
specified minimum ("at least") specs for the samplers and pulse generators.
I also STR that it was not easy to measure the performance of these heads
at the time (state of the art technology) so specs may have been very
conservative. You're definitely far more knowledgeable on this than I.

The 2nd photo must have been on a 7854 since the time jitter at 20ps is
almost 0ps.

Surprise! I used the High Resolution setting of the 7S12 in the 7603. I
repeated it today in the 7904. Please refer to today's picture.

You didn't say what your signal source was in any of these photos. Was
it the S-52: If so how did you get it to trigger.
I was aware that the 2nd pulse was taller and I tried to trigger on it
but I could only trigger on both simultaneously which
made for a very confusing waveform and a lot of knob twiddling to no
avail.

I used two different S-52's, please refer to the new photographs. In the
7T11A setup, I used internal triggering. Only with the trigger amp. on X1 I
was able to filter out the one waveform, strangely enough. I remember the
same thing from my previous experiments.

Please let me know if you can't derive a setting from the new images in the
album.

Raymond
*** UNQUOTE

Also, I can't find your following post online; I only received it by email.
Below, I'm commenting it inline.

The most likely explanation is that his 7T11 sweep speed is about 10% out

of cal.

If you read my post earlier today, you'll see that I don't think that's
likely. My references certainly are significantly better than 10%
(horizontal sensitivity of mainframes) and I haven't tried to adjust the
7T11A nor the 7S12's time bases ever. They are from different sources. Both
the 7S12- and 7T11A- time bases show faster rise times than you find
likely. I just found out that the 7S12 I used in 2012 isn't the same that I
used today so really, no, a significant time base error isn't likely.
Assuming that the edges suffer overshoot (at least part of it is visible),
I think 5 ps extra or a bit more isn't unlikely. I used a terminated S-6
(actually, 2) and an S-4.
Also, I've seen other people report times in the range I saw, like Albert
Otten, as he reported earlier today.

IMG_0349.JPG looks like 32pS but just pressing the smooth button will not

result in such a smooth trace.

So something else was done to smooth this pulse. What was it.

I agree, see today's post, it wasn't smoothing that did the trick.

As far as I know only a 7854 set to acquire 100 traces will do this.

You'll see in my report today, where I reported my repeated experiments
that the High Resolution option on the 7S12 was used.

Unfortunately it seems Raymond didn't document the photos he took so I
may never be able to duplicate the results for myself and find out why

his trouble free experience with the 7S11/7T11 is so different from my
experience.

Again, please refer to today's report and the exchange between Albert O.
and me.

Dennis Tillman W7PF
*** UNQUOTE

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Raymond
Domp Frank
Sent: Monday, May 14, 2018 5:25 PM
To: [email protected]
Subject: Re: [TekScopes] 7T11 sampling timebase - how does it behave?

Hi Dennis,
I'm getting the impression that you haven't seen my contribution earlier
today. I commented your post and added info about today's measurements. For
ease of reference, I'm repeating it in full below:

*** QUOTE
Hi Dennis,
I took a few photographs with current equipment and my previous
measurements were largely confirmed. Please refer to the added photographs
in the album. Their names indicate what's shown, as opposed to the older
photographs which only carry their image number.
I apologise for the disappointing quality of the "rush job".
I used two 'scopes and two S-52's:
- A 7854 with 7T11A, 7S11/S-52 and 7S11/S-4
- A 7904 with 7S12, S-52 and S-6, terminated

You seem to have 30pSec risetime and I would like to know how you do
that since the S4 has a 25pS rise time. That would
mean you were using a 13pS pulse.

I'd say slightly more: 36 to almost 40 ps, ignoring the influence of
overshoot. The sampling outfits are separate. I've never attempted to
adjust the time bases and adjusted the horizontal sensitivity of the
mainframes using a Calibration Fixture (067-0587-01), calibrated against a
second unit so I'm tempted to trust the measurements. ISTR that Tek
specified minimum ("at least") specs for the samplers and pulse generators.
I also STR that it was not easy to measure the performance of these heads
at the time (state of the art technology) so specs may have been very
conservative. You're definitely far more knowledgeable on this than I.

The 2nd photo must have been on a 7854 since the time jitter at 20ps is
almost 0ps.

Surprise! I used the High Resolution setting of the 7S12 in the 7603. I
repeated it today in the 7904. Please refer to today's picture.

You didn't say what your signal source was in any of these photos. Was
it the S-52: If so how did you get it to trigger.
I was aware that the 2nd pulse was taller and I tried to trigger on it
but I could only trigger on both simultaneously which
made for a very confusing waveform and a lot of knob twiddling to no
avail.

I used two different S-52's, please refer to the new photographs. In the
7T11A setup, I used internal triggering. Only with the trigger amp. on X1 I
was able to filter out the one waveform, strangely enough. I remember the
same thing from my previous experiments.

Please let me know if you can't derive a setting from the new images in the
album.

Raymond
*** UNQUOTE

Also, I can't find your following post online; I only received it by email.
Below, I'm commenting it inline.

The most likely explanation is that his 7T11 sweep speed is about 10% out

of cal.

If you read my post earlier today, you'll see that I don't think that's
likely. My references certainly are significantly better than 10%
(horizontal sensitivity of mainframes) and I haven't tried to adjust the
7T11A nor the 7S12's time bases ever. They are from different sources. Both
the 7S12- and 7T11A- time bases show faster rise times than you find
likely. I just found out that the 7S12 I used in 2012 isn't the same that I
used today so really, no, a significant time base error isn't likely.
Assuming that the edges suffer overshoot (at least part of it is visible),
I think 5 ps extra or a bit more isn't unlikely. I used a terminated S-6
(actually, 2) and an S-4.
Also, I've seen other people report times in the range I saw, like Albert
Otten, as he reported earlier today.

IMG_0349.JPG looks like 32pS but just pressing the smooth button will not

result in such a smooth trace.

So something else was done to smooth this pulse. What was it.

I agree, see today's post, it wasn't smoothing that did the trick.

As far as I know only a 7854 set to acquire 100 traces will do this.

You'll see in my report today, where I reported my repeated experiments
that the High Resolution option on the 7S12 was used.

Unfortunately it seems Raymond didn't document the photos he took so I
may never be able to duplicate the results for myself and find out why

his trouble free experience with the 7S11/7T11 is so different from my
experience.

Again, please refer to today's report and the exchange between Albert O.
and me.

Dennis Tillman W7PF
*** UNQUOTE

I find this to be easy...
I receive each post as an individual email, not a daily digest.
I use an email client (Thunderbird or Seamonkey) that displays messages in
their
threads, as a tree based on their subject. Thus assuming all these messages
have
the same subject and each digit implies which post is a reply to which other
post
1
-1.1
-1.2
--1.2.1

Hi all,

1. There are several Topics on this Site that I wish to follow closely. Is

there a way for me to identify these Topics so that I don't miss any posts,
even when I go away for a few weeks?? I know that I could write down the
Topic name and do a Search ... but surely there is a better way??
Specifically, Topic "7633 readout drift" by Lop pol .... as my 7603 Scope
has the same symptoms.

-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Ed
Breya via Groups.Io
Sent: Monday, May 14, 2018 11:49 AM
To: [email protected]
Subject: Re: [TekScopes] 7T11 sampling timebase - how does it behave?

I'd say the 36-40 pSec tr displayed result is in the right ballpark. If the
tr of the pulse and the the sampler are both 25 pSec, then the net would be
about 35. If they are both 30 pSec, then it would net about 42.

Ed
-----Original Message-----
From: Dennis Tillman W7PF, Sent: Sunday, May 13, 2018 4:45 PM

Hi Raymond,
I looked at the pix. You seem to have 30pSec risetime and I would like to
know how you do that since the S4 has a 25pS rise time. That would mean you
were using a 13pS pulse.

The 2nd photo must have been on a 7854 since the time jitter at 20ps is
almost 0ps.

Your time jitter is about the same as mine and within spec.

You didn't say what your signal source was in any of these photos. Was it
the S-52: If so how did you get it to trigger. I was aware that the 2nd
pulse was taller and I tried to trigger on it but I could only trigger on
both simultaneously which made for a very confusing waveform and a lot of
knob twiddling to no avail. I will try it again. I didn't think of using a
2nd 7S11 to power the S-52. Maybe that will work better. Since you powered
the S-52 from the 7S11 can you use that 7S11 to provide the triggering for
the 7T11/7T11A internally through that 7S11. I see you had no external
trigger from the pretrigger output of the S-52 to the external input of the
7T11/7T11A. I was applying the pretrigger from the S-52 to the external
trigger of the 7T11/7T11A

Dennis Tillman W7PF

-----Original Message-----
From: Raymond Domp Frank, Sent: Sunday, May 13, 2018 9:23 AM

Please have a look at the screen shots from 2012 and 2015:
/g/TekScopes/album?id=49077
You'll see the scope and plugins I used. I see no more than 15 - 20 ps
jitter p-p, unfiltered. I have several sets of all equipment, which should
explain the big difference between the first two images (2012) and the
rest, which is from 2015 (!). The early traces look much better, except for
the large overshoot. No idea about that, I took them 6 months after I
started collecting Tek equipment.

Raymond