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Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

Bryce,

Several Tektronix scopes work that way. The portable 2232, 2211, and several others have a STORE/NON-STORE switch that lets you look at the same signal in either mode. The Tek 7854 mainframe also can do this. In all the scopes I listed, the digitizer rate cannot support single-shot captures at full bandwidth.

--John Gord

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first AFAIK.

Then there was the magnificent 7854. IMO, this is the BEST lab 'scope
ever made. It is still my 'scope of choice.

The downfall of both of these units was the relatively slow A/D by modern
standards.

There were also some Transient Data Digitizers that used specialized
double ended CRTs, I think.

-John

=============

Philips/Fluke PM339X Combiscope series are the true analog scope with proper digitiser, very easy to use and it performs well. The catch is it may not be very reliable. According to my experience, it's just running too hot inside possibly due to inadequate thermal design?

Tim
On 31/12/2012, at 9:40 AM, J. Forster wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first AFAIK.

Then there was the magnificent 7854. IMO, this is the BEST lab 'scope
ever made. It is still my 'scope of choice.

The downfall of both of these units was the relatively slow A/D by modern
standards.

There were also some Transient Data Digitizers that used specialized
double ended CRTs, I think.

-John

=============

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that
were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.


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

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

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

30/12/2012 23:27


I am lucky enough to have both the Fluke / Philips Combiscope and a
Tek 7854. The Combiscope is, in my humble opinion, greatly under rated.
It's so easy to use, small and relatively light, and my 2 channel
model has been 100% reliable. If it packed up I'd look for another. It
does look very "full" inside, and it does run very warm, as another
poster commented.

The 7854 is huge, heavy, dims the lights on power up, and I only
understand and use a fraction of it's abilities. The manual is vast,
and quite daunting to a casual user. It's saving grace is awesome
support on the Tek scopes' reflectors. If it does pack up there are
those able to help you fix it. I also like the availability of cheap
plug ins. I bought a sad and ratty looking 7B53A dual time base with
delay for next to nowt off the `Bay, and with the help of the forum
had it fixed up and calibrated inside a few hours. Must have been a
fabulous beast in its day, even now USB scope users see it and go off
wanting a "proper" scope unless they have spent a fortune on something
VERY high end.



--
Best Regards,
Chris Wilson.

The 7854 does take some learning, especially if you want to use the
keyboard functions.

BTW, a 7B53A is not the correct PI as a sweep. It is a sweep for something
like a 7603 or other 100 MHz mainframes.

The 7854 is a 400 MHz mainframe. The proper sweeps for the 7854 are the
7B80 & 7B85 or the 7B92A.

To use the digitizing functions properly, you need the 7B87.

-John

===============

HP 1980B has a digital sampler board used to store a waveform. It has a whole 501 points of resolution. This is an Analog scope with Digital controls. Very nice " AUTO-SCOPE " for it's age.

On Sun, 30 Dec 2012 17:09:00 -0500, you wrote:

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

Look at the Tek 468 scope. It had a digital backpack, capable of
about 10 Mhz bandwidth. The processor was (IIRC) and 8051 style, with
limited memory, etc.

The basic scope was a 465, a 100 Mhz dual channel scope. The
circuitry was an add-on backpack that could take over the display
(without the processor running, the scope won't work). The amount of
digital controls available were minimal, but allowed you to measure
waveform extensions (amplitude) and timing conditions with several
manually adjustable cursors. IIRC there was one memory.

A more modern processor would allow much greater capability, and one
of these days, I might just make a plugin to make that happen.

If you look at the scope, there's a digital backpack with an add-on
hood for the display, and an extension with the processor boards. The
scope was capable of running the HPIB interface as a talker only.

Other scopes, say in the 24xx series for Tektronix, are completely
digital.

Harvey

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

On Sun, 30 Dec 2012 14:40:09 -0800 (PST), you wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first AFAIK.

That would be the Tektronix 7D20 (as a combined timebase/dual channel
scope) which was intended to run at least in the 760x series.

Then there was the magnificent 7854. IMO, this is the BEST lab 'scope
ever made. It is still my 'scope of choice.

and I'd like to have one, but that's still out there, somewhere.....

The downfall of both of these units was the relatively slow A/D by modern
standards.

10 MHz bandwidth for the 468, and about 70 Mhz bandwidth for the 7D20
(IIRC).

There were also some Transient Data Digitizers that used specialized
double ended CRTs, I think.

That would be the 7912, IIRC, which used the 7B16P and 7B90P
programmable plugins as a minimum. Never had one, but it looks like
an interesting possibility to have.

Harvey

-John

=============

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that
were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

Tektronix made a number of oscilloscopes like you describe including
some interesting hybrids. Phillips made some oscilloscopes
contemporary to the Tektronix 2232 series but supporting 4 channels,
200 MHz bandwidths, and with more features. I have avoided them
because of the lack of service information.

Here are the Tektronix analog oscilloscopes that include at least some
form of digital storage roughly in order:

The Tektronix P7001 attaches to a 7704A (200 MHz) between the display
and mainframe:




The Tektronix 7854 (400 MHz) works like a P7001 but is all one unit.
It uses the analog timebase for digital storage which has the side
effect of allowing equivalent time sampling without a clock delay
timer. With a 7B87 timebase, it also supports low speed real time
single shot captures with pretrigger. The user interface and
programming make a great companion to your HP RPN calculator.

The Tektronix 468 is a 465 (100 MHz) with a digitizer module (8 bits
and 25 MS/sec) mounted on top. It apparently supports some type of
equivalent time sampling called "jitter correction" in the manual but
is still limited to a 10 MHz bandwidth in storage mode.

The 2232 (100 MHz 100 MS/sec), 2224 (60 MHz and 100 MS/sec), and 2230
(100 MHz 20 MS/sec) support real time sampling, equivalent time
sampling, and peak detection. The other 22xx series oscilloscopes
operate with real time sampling only and no peak detection. The 2221A
(100 MHz 100 MS/sec) and 2221 (100 MHz 20 MS/sec) are single timebase
versions of the 2232 and 2230.

My 2230 is my go to oscilloscope although if I need to backup
waveforms for later, I use my 2232 instead because my 2230 does not
have the memory backup option.

The Tektronix 2252 is a 2247A (100 MHz 4 channels) with limited
digital storage using sequential sampling.

Some of the above oscilloscopes have much higher storage resolution
than you would expect. The 2252 is 12 bits vertical. The 7854 is 10
bits horizontal and vertical.

Of the above, the 2230 and 2232 are the most common and easiest to
maintain. The 2221 and 2221A are just as easy to maintain because
they are essentially the same as the 2230 and 2232. The 7854 is the
most versatile but lacks real time operation and peak detection.

On Sun, 30 Dec 2012 17:09:00 -0500, Bryce Schroeder
<bryce.schroeder@...> wrote:

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

Thanks for all this information. Certainly there are more options to
consider than I thought there would be if it existed at all.

On Sun, 30 Dec 2012 20:03:41 -0500, Harvey White
<madyn@...> wrote:

On Sun, 30 Dec 2012 14:40:09 -0800 (PST), you wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first AFAIK.

That would be the Tektronix 7D20 (as a combined timebase/dual channel
scope) which was intended to run at least in the 760x series.

I think he means the Tektronix P7001 which attaches to a 7704A between
the display and mainframe:

Then there was the magnificent 7854. IMO, this is the BEST lab 'scope
ever made. It is still my 'scope of choice.

and I'd like to have one, but that's still out there, somewhere.....

The downfall of both of these units was the relatively slow A/D by modern
standards.

10 MHz bandwidth for the 468, and about 70 Mhz bandwidth for the 7D20
(IIRC).

The 7D20 uses a CCD based sampler like the 2430 series of DSOs.

I've looked into the Tek 2230 before and found it's performance and ease of use is nowhere near the Fluke PM3390. It's also very hard to get detailed info of 2230. For Fluke PM3390, you can purchase a service manual for very little but some parts are very hard to get. Then you end up getting a few units and start cannibalise them.


On 31/12/2012, at 12:46 PM, David wrote:

Tektronix made a number of oscilloscopes like you describe including
some interesting hybrids. Phillips made some oscilloscopes
contemporary to the Tektronix 2232 series but supporting 4 channels,
200 MHz bandwidths, and with more features. I have avoided them
because of the lack of service information.

Here are the Tektronix analog oscilloscopes that include at least some
form of digital storage roughly in order:

The Tektronix P7001 attaches to a 7704A (200 MHz) between the display
and mainframe:




The Tektronix 7854 (400 MHz) works like a P7001 but is all one unit.
It uses the analog timebase for digital storage which has the side
effect of allowing equivalent time sampling without a clock delay
timer. With a 7B87 timebase, it also supports low speed real time
single shot captures with pretrigger. The user interface and
programming make a great companion to your HP RPN calculator.

The Tektronix 468 is a 465 (100 MHz) with a digitizer module (8 bits
and 25 MS/sec) mounted on top. It apparently supports some type of
equivalent time sampling called "jitter correction" in the manual but
is still limited to a 10 MHz bandwidth in storage mode.

The 2232 (100 MHz 100 MS/sec), 2224 (60 MHz and 100 MS/sec), and 2230
(100 MHz 20 MS/sec) support real time sampling, equivalent time
sampling, and peak detection. The other 22xx series oscilloscopes
operate with real time sampling only and no peak detection. The 2221A
(100 MHz 100 MS/sec) and 2221 (100 MHz 20 MS/sec) are single timebase
versions of the 2232 and 2230.

My 2230 is my go to oscilloscope although if I need to backup
waveforms for later, I use my 2232 instead because my 2230 does not
have the memory backup option.

The Tektronix 2252 is a 2247A (100 MHz 4 channels) with limited
digital storage using sequential sampling.

Some of the above oscilloscopes have much higher storage resolution
than you would expect. The 2252 is 12 bits vertical. The 7854 is 10
bits horizontal and vertical.

Of the above, the 2230 and 2232 are the most common and easiest to
maintain. The 2221 and 2221A are just as easy to maintain because
they are essentially the same as the 2230 and 2232. The 7854 is the
most versatile but lacks real time operation and peak detection.

On Sun, 30 Dec 2012 17:09:00 -0500, Bryce Schroeder
<bryce.schroeder@...> wrote:

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

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

On Sun, 30 Dec 2012 19:57:46 -0600, you wrote:

On Sun, 30 Dec 2012 20:03:41 -0500, Harvey White
<madyn@...> wrote:

On Sun, 30 Dec 2012 14:40:09 -0800 (PST), you wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first AFAIK.

That would be the Tektronix 7D20 (as a combined timebase/dual channel
scope) which was intended to run at least in the 760x series.

I think he means the Tektronix P7001 which attaches to a 7704A between
the display and mainframe:

That's a new one on me.

Then there was the magnificent 7854. IMO, this is the BEST lab 'scope
ever made. It is still my 'scope of choice.

and I'd like to have one, but that's still out there, somewhere.....

The downfall of both of these units was the relatively slow A/D by modern
standards.

10 MHz bandwidth for the 468, and about 70 Mhz bandwidth for the 7D20
(IIRC).

The 7D20 uses a CCD based sampler like the 2430 series of DSOs.

Yep, and they do mention that the CCD has absolutely no static
immunity.

Harvey

Back in the mid 80's I remember using the Tek 7D20 digitizer plug-in. It only had a 20MHz sampling rate with an over sampling bandwidth of 70MHz. It was OK for sampling in the audio range but not go at TTL rates.

I will admit that there is not a complete and free 2230 service manual
available online but ArtekManuals and others have scanned service
manuals available inexpensively. Maintenance is made easier since the
2230 shares so many parts with the ubiquitous 2232, 2235A, 2221, and
others in that series.

The 2232 is easier to use and repair than the 2230 but generally at
least twice as expensive.

On Mon, 31 Dec 2012 13:20:51 +1100, Yuting Wan
<ywan03@...> wrote:

I've looked into the Tek 2230 before and found it's performance and ease of use is nowhere near the Fluke PM3390. It's also very hard to get detailed info of 2230. For Fluke PM3390, you can purchase a service manual for very little but some parts are very hard to get. Then you end up getting a few units and start cannibalise them.


On 31/12/2012, at 12:46 PM, David wrote:

Tektronix made a number of oscilloscopes like you describe including
some interesting hybrids. Phillips made some oscilloscopes
contemporary to the Tektronix 2232 series but supporting 4 channels,
200 MHz bandwidths, and with more features. I have avoided them
because of the lack of service information.

Here are the Tektronix analog oscilloscopes that include at least some
form of digital storage roughly in order:

The Tektronix P7001 attaches to a 7704A (200 MHz) between the display
and mainframe:




The Tektronix 7854 (400 MHz) works like a P7001 but is all one unit.
It uses the analog timebase for digital storage which has the side
effect of allowing equivalent time sampling without a clock delay
timer. With a 7B87 timebase, it also supports low speed real time
single shot captures with pretrigger. The user interface and
programming make a great companion to your HP RPN calculator.

The Tektronix 468 is a 465 (100 MHz) with a digitizer module (8 bits
and 25 MS/sec) mounted on top. It apparently supports some type of
equivalent time sampling called "jitter correction" in the manual but
is still limited to a 10 MHz bandwidth in storage mode.

The 2232 (100 MHz 100 MS/sec), 2224 (60 MHz and 100 MS/sec), and 2230
(100 MHz 20 MS/sec) support real time sampling, equivalent time
sampling, and peak detection. The other 22xx series oscilloscopes
operate with real time sampling only and no peak detection. The 2221A
(100 MHz 100 MS/sec) and 2221 (100 MHz 20 MS/sec) are single timebase
versions of the 2232 and 2230.

My 2230 is my go to oscilloscope although if I need to backup
waveforms for later, I use my 2232 instead because my 2230 does not
have the memory backup option.

The Tektronix 2252 is a 2247A (100 MHz 4 channels) with limited
digital storage using sequential sampling.

Some of the above oscilloscopes have much higher storage resolution
than you would expect. The 2252 is 12 bits vertical. The 7854 is 10
bits horizontal and vertical.

Of the above, the 2230 and 2232 are the most common and easiest to
maintain. The 2221 and 2221A are just as easy to maintain because
they are essentially the same as the 2230 and 2232. The 7854 is the
most versatile but lacks real time operation and peak detection.

On Sun, 30 Dec 2012 17:09:00 -0500, Bryce Schroeder
<bryce.schroeder@...> wrote:

Did HP (or Tek, or anyone for that matter) make any oscilloscopes that were
basically analog scopes, but with the ability to digitize what is seen on
the display (at some lesser resolution than what you might be able to see
on the actual display, presumably)? As I understand it - which may
admittedly be incorrect - some of the older spectrum analyzers are sort of
like this.

So, this hypothetical oscilloscope type would basically have the analog
display "in parallel" with an ADC, such that you could look at the screen
and see the waveform displayed like an analog scope, or use the ADC to see
a digital approximation. (Presumably the digital stuff could also be used
to capture and store one-shot things like a regular digital oscilloscope.)
This would be opposed to a purely digital oscilloscope where the ADC and
memory is always between the signal and the display.

The reason for doing this, of course, would be that the analog display
would be "higher resolution" than the ability of the ADC, but the digital
stuff would enable automation and storage ability. This would stop being
important once digital was high-enough resolution to look more or less
indistinguishable to humans.

Did such "hybrid" oscilloscopes ever exist? If so, what are some model
numbers?

Thanks for your time - sorry if that was a bit lengthy.

------------------------------------

Yahoo! Groups Links

On Sun, 30 Dec 2012 21:34:36 -0500, Harvey White
<madyn@...> wrote:

On Sun, 30 Dec 2012 19:57:46 -0600, you wrote:

On Sun, 30 Dec 2012 20:03:41 -0500, Harvey White
<madyn@...> wrote:

On Sun, 30 Dec 2012 14:40:09 -0800 (PST), you wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first AFAIK.

That would be the Tektronix 7D20 (as a combined timebase/dual channel
scope) which was intended to run at least in the 760x series.

I think he means the Tektronix P7001 which attaches to a 7704A between
the display and mainframe:

That's a new one on me.

The P7001 is not as common as the 7854 which is the same basic design.
I have seen one or two in the past couple of years for sale but would
prefer the 7854 if only because it is relatively common.

Then there was the magnificent 7854. IMO, this is the BEST lab 'scope
ever made. It is still my 'scope of choice.

and I'd like to have one, but that's still out there, somewhere.....

The downfall of both of these units was the relatively slow A/D by modern
standards.

10 MHz bandwidth for the 468, and about 70 Mhz bandwidth for the 7D20
(IIRC).

The 7D20 uses a CCD based sampler like the 2430 series of DSOs.

Yep, and they do mention that the CCD has absolutely no static
immunity.

Those CCD sampling DSOs occupy a weird place in history. Since
Tektronix had access to 100 MS/sec 8 bit ADCs like those used in the
2232, I am not sure why they used them for as long as they did. My
guess is that the CCDs were easier to interleave then the digital side
of the fast ADCs. The 2232 is limited to 50 MS/sec in chop mode
because of that.

I have a Phillips PM3375 out in the workshop, and I'm using an HP54601A in the radio shack to monitor transmitter RF; with accurate directional couplers, I can calibrate watt meters. Not far away, on a very heavy-duty turntable, sits a 141T with 8552B and 8554B plugins. I don't actually use that very much, mainly to check harmonics.

I was using a Leader 15 MHz analog scope with a cracked graticule (now at our radio club) which served almost as well,at least letting me know if the sound card output has reset itself to 100 percent again, but the digitizer lets me capture peaks and know what I have.

The 141T has an analog storage CRT, writing to a charged grid then flooding the CRT with electrons. It's finicky, and the display is perishable, so my "digital" storage is a digital camera on a tripod.
Couldn't afford Polaroid film now even if I had the camera.


Cortland
KA5S

On Sun, 30 Dec 2012 14:40:09 -0800 (PST), you wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first
AFAIK.

That would be the Tektronix 7D20 (as a combined timebase/dual channel
scope) which was intended to run at least in the 760x series.

No. The DPO uses an LSI-11 as a 'puter. I have one.

The 7D20 is much later. The DPO separated thye PI and display sections of
the scope with a digitizer unit, maybe the d7001.

10 MHz bandwidth for the 468, and about 70 Mhz bandwidth for the 7D20
(IIRC).

Are you sure about the 70 MHz on the 7D20. I doubt that it was that good
one shot.

There were also some Transient Data Digitizers that used specialized
double ended CRTs, I think.

That would be the 7912, IIRC, which used the 7B16P and 7B90P
programmable plugins as a minimum. Never had one, but it looks like
an interesting possibility to have.

There were actually several different ones.

-John

==============

Harvey

On Sun, 30 Dec 2012 20:10:34 -0800 (PST), "J. Forster"
<jfor@...> wrote:

On Sun, 30 Dec 2012 14:40:09 -0800 (PST), you wrote:

Yes.

The Tek DPO, based on the 7704 (or possibly the 7704A) was the first
AFAIK.

That would be the Tektronix 7D20 (as a combined timebase/dual channel
scope) which was intended to run at least in the 760x series.

No. The DPO uses an LSI-11 as a 'puter. I have one.

The 7D20 is much later. The DPO separated thye PI and display sections of
the scope with a digitizer unit, maybe the d7001.

10 MHz bandwidth for the 468, and about 70 Mhz bandwidth for the 7D20
(IIRC).

Are you sure about the 70 MHz on the 7D20. I doubt that it was that good
one shot.

The specifications say 70 MHz bandwidth and simultaneous sampling of
40 MS/sec on each channel. I have heard that the bandwidth could be
significantly higher on some units.