On Sat, 01 Oct 2011 16:09:26 -0700, Klaus Kragelund wrote:
> The Tek 7A26S module Joerg spoke of, has a definition of maximum 75
> times overdrive. Quite good, but the overdrive takes 100us to recover
> (worst case specs)
7A13 with attenuator set to 1mV per division recovers to within 2mV in
1us, and 1mV in 100us after a pulse of +/- 10V. (Per published spec)
And it does, too. Better, in fact, with the five I have around the lab,
and have personally calibrated. It's part of the performance check
procedure.
Effective offset range of 10,000 divisions.
I must try the same test with a 7A26. There's one that needs my attention
for unequal trigger delay between channels. Probably another of those
goddamn made-in-Tucson trimmer capacitors again. I'll try when I fix it.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
Reply by Joerg●October 3, 20112011-10-03
Klaus Kragelund wrote:
> On 2 Okt., 01:43, Joerg <inva...@invalid.invalid> wrote:
>> Klaus Kragelund wrote:
[...]
>>> As for the Tek DPO 5000, I dug deeper into it, and found that the
>>> majority of the problem (guess 70%) is actually from the TPP0500
>>> probe. A test with a P6139 probe provided much better results. We are
>>> returning those TPP0500 probes for sure...
>> Strange. How can a passive probe do that?
>>
>> --
>> Regards, Joerg
>>
>> http://www.analogconsultants.com/- Skjul tekst i anf�rselstegn -
>>
>> - Vis tekst i anf�rselstegn -
>
> The datasheet lists it as a passive probe, but it is supplied with
> power, probably for some relays and other gimmicks they have inside
> the probe. When Volt/div is changed clicking can be heard, so its
> probably not a 100% passive probe, only it does not have an amplifier
> per se.....
>
This would probably be the point where I couldn't wait any longer, crack
open the probe enclosures, and get into trouble :-)
There'd have to be some sort of semiconductor involved here. Maybe some
sort of limiter circuit?
--
Regards, Joerg
http://www.analogconsultants.com/
Reply by Klaus Kragelund●October 3, 20112011-10-03
On 2 Okt., 01:43, Joerg <inva...@invalid.invalid> wrote:
> Klaus Kragelund wrote:
> > On 30 Sep., 22:28, Fred Abse <excretatau...@invalid.invalid> wrote:
> >> On Fri, 30 Sep 2011 10:57:08 -0700, Mr.CRC wrote:
> >>> Klaus Bahner wrote:
> >>>> Besides set I only can tell you that I never ran into this problem w=
ith
> >>>> my LeCroy scope and I did that kind of overdrive measurements on an
> >>>> almost daily basis. So, if this is problem is for real, then I dare
> >>>> conclude that not all scopes are affected by it :-)
> >>>> Klaus
> >>> Yes, they are all different. =A0It's too bad that no efforts are made=
to
> >>> specify this behavior in the specs. =A0But admittedly, this would be
> >>> challenging.
> >> Specification of a Tek 7A13 vertical amplifier plugin manages to =A0sp=
ecify
> >> this behavior:
>
> >> Maximum input voltage, (DC direct coupled) at each input attenuator
> >> setting.
>
> >> Not challenging to specify, but they were proud of this particular asp=
ect
> >> of performance, not, as I suspect most modern manufacturers are, asham=
ed
> >> of it.
>
> >> --
> >> "For a successful technology, reality must take precedence
> >> over public relations, for nature cannot be fooled."
> >> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0 =A0(Richard Feynman)
>
> > The Tek 7A26S module Joerg spoke of, has a definition of maximum 75
> > times overdrive. Quite good, but the overdrive takes 100us to recover
> > (worst case specs)
>
> I don't know why they wrote that. Maybe those dreaded lawsuits came up
> in the 70's and they didn't want exposure :-)
>
> So I just tried it out with the 7A26 here. Put a 50MHz square wave in
> it, then cranked it up to over 100x overdrive. No noticeable recovery
> time at all.
>
> > As for the Tek DPO 5000, I dug deeper into it, and found that the
> > majority of the problem (guess 70%) is actually from the TPP0500
> > probe. A test with a P6139 probe provided much better results. We are
> > returning those TPP0500 probes for sure...
>
> Strange. How can a passive probe do that?
>
> --
> Regards, Joerg
>
> http://www.analogconsultants.com/- Skjul tekst i anf=F8rselstegn -
>
> - Vis tekst i anf=F8rselstegn -
The datasheet lists it as a passive probe, but it is supplied with
power, probably for some relays and other gimmicks they have inside
the probe. When Volt/div is changed clicking can be heard, so its
probably not a 100% passive probe, only it does not have an amplifier
per se.....
Regards
Klaus
Reply by Joerg●October 1, 20112011-10-01
Klaus Kragelund wrote:
> On 30 Sep., 22:28, Fred Abse <excretatau...@invalid.invalid> wrote:
>> On Fri, 30 Sep 2011 10:57:08 -0700, Mr.CRC wrote:
>>> Klaus Bahner wrote:
>>>> Besides set I only can tell you that I never ran into this problem with
>>>> my LeCroy scope and I did that kind of overdrive measurements on an
>>>> almost daily basis. So, if this is problem is for real, then I dare
>>>> conclude that not all scopes are affected by it :-)
>>>> Klaus
>>> Yes, they are all different. It's too bad that no efforts are made to
>>> specify this behavior in the specs. But admittedly, this would be
>>> challenging.
>> Specification of a Tek 7A13 vertical amplifier plugin manages to specify
>> this behavior:
>>
>> Maximum input voltage, (DC direct coupled) at each input attenuator
>> setting.
>>
>> Not challenging to specify, but they were proud of this particular aspect
>> of performance, not, as I suspect most modern manufacturers are, ashamed
>> of it.
>>
>> --
>> "For a successful technology, reality must take precedence
>> over public relations, for nature cannot be fooled."
>> (Richard Feynman)
>
> The Tek 7A26S module Joerg spoke of, has a definition of maximum 75
> times overdrive. Quite good, but the overdrive takes 100us to recover
> (worst case specs)
>
I don't know why they wrote that. Maybe those dreaded lawsuits came up
in the 70's and they didn't want exposure :-)
So I just tried it out with the 7A26 here. Put a 50MHz square wave in
it, then cranked it up to over 100x overdrive. No noticeable recovery
time at all.
> As for the Tek DPO 5000, I dug deeper into it, and found that the
> majority of the problem (guess 70%) is actually from the TPP0500
> probe. A test with a P6139 probe provided much better results. We are
> returning those TPP0500 probes for sure...
>
Reply by Klaus Kragelund●October 1, 20112011-10-01
On 30 Sep., 22:28, Fred Abse <excretatau...@invalid.invalid> wrote:
> On Fri, 30 Sep 2011 10:57:08 -0700, Mr.CRC wrote:
> > Klaus Bahner wrote:
> >> Besides set I only can tell you that I never ran into this problem wit=
h
> >> my LeCroy scope and I did that kind of overdrive measurements on an
> >> almost daily basis. So, if this is problem is for real, then I dare
> >> conclude that not all scopes are affected by it :-)
>
> >> Klaus
>
> > Yes, they are all different. =A0It's too bad that no efforts are made t=
o
> > specify this behavior in the specs. =A0But admittedly, this would be
> > challenging.
>
> Specification of a Tek 7A13 vertical amplifier plugin manages to =A0speci=
fy
> this behavior:
>
> Maximum input voltage, (DC direct coupled) at each input attenuator
> setting.
>
> Not challenging to specify, but they were proud of this particular aspect
> of performance, not, as I suspect most modern manufacturers are, ashamed
> of it.
>
> --
> "For a successful technology, reality must take precedence
> over public relations, for nature cannot be fooled."
> =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =A0 =
=A0 =A0(Richard Feynman)
The Tek 7A26S module Joerg spoke of, has a definition of maximum 75
times overdrive. Quite good, but the overdrive takes 100us to recover
(worst case specs)
As for the Tek DPO 5000, I dug deeper into it, and found that the
majority of the problem (guess 70%) is actually from the TPP0500
probe. A test with a P6139 probe provided much better results. We are
returning those TPP0500 probes for sure...
Regards
Klaus
Reply by Fred Abse●September 30, 20112011-09-30
On Fri, 30 Sep 2011 10:57:08 -0700, Mr.CRC wrote:
> Klaus Bahner wrote:
>> Besides set I only can tell you that I never ran into this problem with
>> my LeCroy scope and I did that kind of overdrive measurements on an
>> almost daily basis. So, if this is problem is for real, then I dare
>> conclude that not all scopes are affected by it :-)
>>
>> Klaus
>
>
> Yes, they are all different. It's too bad that no efforts are made to
> specify this behavior in the specs. But admittedly, this would be
> challenging.
Specification of a Tek 7A13 vertical amplifier plugin manages to specify
this behavior:
Maximum input voltage, (DC direct coupled) at each input attenuator
setting.
Not challenging to specify, but they were proud of this particular aspect
of performance, not, as I suspect most modern manufacturers are, ashamed
of it.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
Reply by Mr.CRC●September 30, 20112011-09-30
Klaus Bahner wrote:
> Besides set I only can tell you that I never ran into this problem with
> my LeCroy scope and I did that kind of overdrive measurements on an
> almost daily basis. So, if this is problem is for real, then I dare
> conclude that not all scopes are affected by it :-)
>
> Klaus
Yes, they are all different. It's too bad that no efforts are made to
specify this behavior in the specs. But admittedly, this would be
challenging.
--
_____________________
Mr.CRC
crobcBOGUS@REMOVETHISsbcglobal.net
SuSE 10.3 Linux 2.6.22.17
Reply by Joerg●September 30, 20112011-09-30
Fred Abse wrote:
> On Wed, 28 Sep 2011 19:17:06 -0400, Jamie wrote:
>
>> I have a 20mhz Ab Rigol that just seems to work perfectly. Not bad for
>> chinese junk.
>
> How far will it let you window more than one screen height?
>
> I wouldn't have thought there would be much market for <100MHz 'scopes
> these days.
>
Depends on what you do. For hobby or if you probe around in industrial
control gear all day then it may be all you really need.
--
Regards, Joerg
http://www.analogconsultants.com/
Reply by Fred Abse●September 30, 20112011-09-30
On Thu, 29 Sep 2011 13:07:17 -0700, Rich Grise wrote:
> Fred Abse wrote:
>> On Wed, 28 Sep 2011 10:44:47 -0700, Joerg wrote:
>>
>>> The
>>> software and manual? Full of spelling bugs and stuff
>>
>> Reminds me of a manual written by compatriots of yours that I once read:
>>
>> "Manufactured with a pure technic"
>>
>> WTF does that mean?
>>
> Nothing. The technical term for the above phrasing is "sales jargon"
> or "marketing buzzwords." ;-)
>
> Hope This Helps!
> Rich
> (or marketing jargon, or sales buzzwords - mix and/or match to taste.)
It was in a service manual for some German kit. Translated from the
deutsch by some non=technical minion, probably. This was before the days
of computer translation, and all that jazz,
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)
Reply by Fred Abse●September 30, 20112011-09-30
On Wed, 28 Sep 2011 19:17:06 -0400, Jamie wrote:
> I have a 20mhz Ab Rigol that just seems to work perfectly. Not bad for
> chinese junk.
How far will it let you window more than one screen height?
I wouldn't have thought there would be much market for <100MHz 'scopes
these days.
--
"For a successful technology, reality must take precedence
over public relations, for nature cannot be fooled."
(Richard Feynman)