Date   

Re: 495P problem

Dave Emery
 

On Sun, Jul 28, 2013 at 06:04:02PM -0700, John Miles wrote:
John what is the general era in question ? What years ?



It seems they started using those caps in the late 1980s-early 1990s
timeframe. They continued to be a problem until at least the mid-to-late
1990s, after which I haven't heard that many horror stories (possibly
because there is less interest in surplus gear from that era.)
What about 2710/11/12 instruments ? Same time frames ?

--
Dave Emery N1PRE/AE, die@dieconsulting.com DIE Consulting, Weston, Mass 02493
"An empty zombie mind with a forlorn barely readable weatherbeaten
'For Rent' sign still vainly flapping outside on the weed encrusted pole - in
celebration of what could have been, but wasn't and is not to be now either."


Re: 495P problem

John Miles
 

 

 

From: TekScopes@... [mailto:TekScopes@...] On Behalf Of David I. Emery
Sent: Sunday, July 28, 2013 2:24 AM
To: TekScopes@...
Subject: Re: [TekScopes] 495P problem

 

 

On Sat, Jul 27, 2013 at 01:22:37PM -0700, John Miles wrote:
> No prob. I recently picked up a 2784 from the same production era, so that
> annoying smell is going to become all too familiar around here. :(
>
> You might pull the cover off of the log amplifier assembly and check it as
> well. Depending on the production date there may be quite a few of them in
> there.

John what is the general era in question ? What years ?

It seems they started using those caps in the late 1980s-early 1990s timeframe.  They continued to be a problem until at least the mid-to-late 1990s, after which I haven't heard that many horror stories (possibly because there is less interest in surplus gear from that era.)

The late-model 495/P, 494A/P, and 497/P units were built around 1990, just when the engineers at Tek were getting really enthusiastic about the endless exciting possibilities of surface-mount Al electrolytics.  This is also when the 278x models were being designed, so they have the same problem.

OTOH the 492A/P, 494/P and earlier 492/496 models used few if any SMT parts at all.  Peak reliability for Tek spectrum analyzers seems to be associated with the 492A/494 era in the mid-to-late 1980s.  It was a bit worse before then, and was definitely worse afterward. 

 

-- john, KE5FX


Re: Readable schematics for the 2710

Dave / NR1DX
 

Fred


I have both a high resolution scan as well as an original OEM paper manual contact me off list for details

Dave
ArtekManuals
On 7/28/2013 6:18 PM, fred wrote:
 

I'm still struggeling with my 2710. The biggest problem is the schematics. I found a service manual ( and uploaded it to bama and KO3BB because it is hard to find. But the schematics are very hard to read. It is not a great copy, but better as nothing.

Does someone has a good manual or readable schematics. Or better a real paper manual for sale. ( I have a 2712 too, that is working great but probably needs some new caps too soon)

I replaced all caps, a lot were bad. I changed a dozen 1 uF tantaliums, they were leaking around 10-20 uA,, lost some capacitance (10-40 %) and D was 0.4 to over 1.5. I'm out of stock so I have to order new ones. In the mean time I'm tracking the problems. No readable readout, a raster of spots on the graticule and no response to signals, not even the internal reference. It reacts on all buttons, seems to pass the selftest ( it beebs like the 2712 when done but I can not read if that is thru.

It looks at this moment the problem is in the storage display board or microprocessor (commands not reaching the other parts of the SA) board. A lot of work. I have no extenders so i must solder short wires to the IC pins to clip a probe or pod to. Look for truth tables of the 74 logic and look if the gates all work. And guess about the PLS things ( a friend helps with that) And work my way from PLS and gates through the board.

And if it turns out to be a PLS, eprom or other digital thing i may have a problem ( but that friend maybe can do things in that area, he is ( in my analog eyes) a real digital wizzard )

Fred pa4tim


-- 
Dave Henderson
Manuals@...
www.Artekmanuals.com
PO Box 175
Welch,MN 55089
651-269-4265


Re: MCP and CRT Readout

Don Black <donald_black@...>
 

I don't have experience with MCPs but their glass channel wear out sounds similar to the problems with Image Orthicon camera tube targets. These are thin glass discs that have an electron image built up on the lmage side which has to leak through the glass between scans to form a charge on the scanned side. The original targets were made of doped glass that was slightly "ionic"conductive and they only had a life of a few hundred hours before they wore out as their resistance increased. A different type of glass was introduced (by EEV I think) called Elcon (electron Conduction) that used a resistive mode and that increased tube life ten fold plus was much less prone to "sticking" (image retention) than the old type. I guess similar developments were made to the glass channels in MCPs.

Don Black.


I mean later MCP CRTs which are still used in some specialized
applications. I base this on the links posted here in a MCP
discussion thread some time ago which discussed MCP lifetime and
wearout mechanisms. I suspect the MCPs Tektronix used had unusually
short rated lifetimes but maybe they wear out quickly because of how
they are applied.




Readable schematics for the 2710

PA4TIM
 

I'm still struggeling with my 2710. The biggest problem is the schematics. I found a service manual ( and uploaded it to bama and KO3BB because it is hard to find. But the schematics are very hard to read. It is not a great copy, but better as nothing.

Does someone has a good manual or readable schematics. Or better a real paper manual for sale. ( I have a 2712 too, that is working great but probably needs some new caps too soon)

I replaced all caps, a lot were bad. I changed a dozen 1 uF tantaliums, they were leaking around 10-20 uA,, lost some capacitance (10-40 %) and D was 0.4 to over 1.5. I'm out of stock so I have to order new ones. In the mean time I'm tracking the problems. No readable readout, a raster of spots on the graticule and no response to signals, not even the internal reference. It reacts on all buttons, seems to pass the selftest ( it beebs like the 2712 when done but I can not read if that is thru.

It looks at this moment the problem is in the storage display board or microprocessor (commands not reaching the other parts of the SA) board. A lot of work. I have no extenders so i must solder short wires to the IC pins to clip a probe or pod to. Look for truth tables of the 74 logic and look if the gates all work. And guess about the PLS things ( a friend helps with that) And work my way from PLS and gates through the board.

And if it turns out to be a PLS, eprom or other digital thing i may have a problem ( but that friend maybe can do things in that area, he is ( in my analog eyes) a real digital wizzard )

Fred pa4tim


Re: McMaster-Carr

Peter Gottlieb <hpnpilot@...>
 

Oh, I didn't know they were prized! We had them all over the place at the last place I worked. It's up to their field sales staff to distribute them and they only print them periodically and they run out in between printings. When I left I took one but could have just as easily taken a dozen. If you know someone in the plant maintenance or mechanical shop or engineering at a decent sized company have them contact the rep for you and you'll get one at the next printing.

Peter

On 7/28/2013 5:17 PM, Paul Amaranth wrote:

There's sort of a grey market on old McMaster-Carr paper catalogs;
they're highly prized among the mechanical bent. I don't know if
they're still printing paper catalogs, but they were difficult to
obtain when they were. I have a '98 copy and most of the part numbers
are still good, although the pricing is not.

MSC used to send out their bible to anyone who wanted one which
made them easier to order from and they generally had excellent
customer service.

On Sun, Jul 28, 2013 at 09:10:59PM -0000, iglesia_cristiana_arpas_eternas wrote:


--- In TekScopes@yahoogroups.com <mailto:TekScopes%40yahoogroups.com>, Peter
Gottlieb <hpnpilot@...> wrote:

What an amazing place. Yesterday afternoon near 5 I ordered some hardware
from
them. The bell just rand and fedex ground delivered it. They must have
regional distribution locations but regardless, amazing!

No association other than being a happy customer.

Peter
What really astonished me about http://www.mcmaster.com ,is that the server
is located in my country .. Argentine .. according to what Mozzila browser shows !
Gabriel.

--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@AuroraGrp.Com <mailto:paul%40AuroraGrp.Com> | Unix & Windows

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

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Re: McMaster-Carr

Paul Amaranth
 

There's sort of a grey market on old McMaster-Carr paper catalogs;
they're highly prized among the mechanical bent. I don't know if
they're still printing paper catalogs, but they were difficult to
obtain when they were. I have a '98 copy and most of the part numbers
are still good, although the pricing is not.

MSC used to send out their bible to anyone who wanted one which
made them easier to order from and they generally had excellent
customer service.

On Sun, Jul 28, 2013 at 09:10:59PM -0000, iglesia_cristiana_arpas_eternas wrote:


--- In TekScopes@yahoogroups.com, Peter Gottlieb <hpnpilot@...> wrote:

What an amazing place. Yesterday afternoon near 5 I ordered some hardware from
them. The bell just rand and fedex ground delivered it. They must have
regional distribution locations but regardless, amazing!

No association other than being a happy customer.

Peter
What really astonished me about http://www.mcmaster.com ,is that the server is located in my country .. Argentine .. according to what Mozzila browser shows !
Gabriel.

--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@AuroraGrp.Com | Unix & Windows


Re: McMaster-Carr

iglesia_cristiana_arpas_eternas
 

--- In TekScopes@yahoogroups.com, Peter Gottlieb <hpnpilot@...> wrote:

What an amazing place. Yesterday afternoon near 5 I ordered some hardware from
them. The bell just rand and fedex ground delivered it. They must have
regional distribution locations but regardless, amazing!

No association other than being a happy customer.

Peter
What really astonished me about http://www.mcmaster.com ,is that the server is located in my country .. Argentine .. according to what Mozzila browser shows !
Gabriel.


Re: MCP and CRT Readout

 

On Sun, 28 Jul 2013 21:23:22 +0200, "cheater00 ."
<cheater00@gmail.com> wrote:

On 28 Jul 2013 20:55, "David" <davidwhess@gmail.com> wrote:

On Sun, 28 Jul 2013 20:34:35 +0200, "cheater00 ."
<cheater00@gmail.com> wrote:

On 28 Jul 2013 20:13, "David" <davidwhess@gmail.com> wrote:

The 7L5, 7L14 and 7L18 spectrum analyzer plug-ins have storage so they
should not be used. In general *any* plug-in which generates a slow
continuous sweep or vector graphics should not be used which would
include the 7L13 spectrum analyzer which does not have storage.

The readout is vector generated but considered a necessary evil and
only affects the top and bottom border area of the CRT.
Thanks, makes sense. What if one modulated the signal e.g. with a sine
wave... might not be so damaging then?

Given readout is fully digital. I'm surprised no one came up with an LCD
readout mod ... 20 years ago.
My understanding is that the MCP cells just have a finite limit to the
number of electrons they can amplify so damage is cummulative with the
gain in each cell diminishing over time. In a continuous tone
application like a low light image amplifier tube, this is not as
serious a limitation because the whole MCP will tend to wear evenly
but with an oscilloscope, wear is limited to very sharply defined
areas where the CRT beam scans.

I think later MCPs were a lot tougher than the 7104 MCP.
Does this mean the 11302 and 2467, or were there even later MCP CRTs?
I mean later MCP CRTs which are still used in some specialized
applications. I base this on the links posted here in a MCP
discussion thread some time ago which discussed MCP lifetime and
wearout mechanisms. I suspect the MCPs Tektronix used had unusually
short rated lifetimes but maybe they wear out quickly because of how
they are applied.


I have a few 012-0747-00 probe leads available.

Paul Amaranth
 

I ended up with a few surplus 012-0747-00 probe leads. No grabbers,
unfortunately.

$10 postpaid US or Canada, three bucks more if you want Priority Mail.

--
Paul Amaranth, GCIH | Rochester MI, USA
Aurora Group, Inc. | Security, Systems & Software
paul@AuroraGrp.Com | Unix & Windows


Re: 7854 glitches with TDR

sander.slang
 

Hi David, Albert,

Today I did some measurements on the rear BNC connectors of the 7854. I used my TDS3202B to check the TDR waveform via this output. I did not see any glitches and the signal looks clean on these outputs.

After that I hooked the oscilloscope 10 Meg Ohm probes to the frontpanel 2mm connectors from the TDR. On the Vertical output connector I saw the same signal but now with noise and short glitches (I estimate 100 glitches per visible single acquire waveform). It is a sort of noise I can easily filter out with 20MHz oscilloscope filter and 4 times avg on the TDS3202B. I have the feeling the rear panel BNC output is the same signal but with a filter.

My goal with this 7854 and 7S12 is only TDR and TDT measurements that I need to transfer to PC and postprocess with LabVIEW. I now have an idea that I want to use the 7S12 stand-alone connected to my TDS3202B.
So I can make the system compact and future prove (I already have some issues with the 7854).

I did a quick check in the manual and I have the feeling the 7S12 can run stand alone when I hook up a DIY powersupply unit (+-50, 15 and 5V). Can someone comment on this and tell me what more I need to hookup to the TDR in stand-alone mode?


Sander

--- In TekScopes@yahoogroups.com, "Albert" <aodiversen@...> wrote:

(continued)
The change in numbering Q690/Q694 seems to be an error in schematic 7 of my manual, schematic rev sept 1982. I will use number Q690 now for the rightmost transistor.
I have reason to suspect line A16.
When Right Vert and A Hor are selected to display the 7S12 output on the CRT, then line B7 is HI (about 1.1 V) and A16 is LO. Line B7 is OK.
In the 7704A line A16 is switched either to GND or to +5V, depending on the ADD button. So A16 is hard zero in our case, and the 7S12 works fine in a 7704A. In the 7854 line A16 is driven in a much more complicated way involving the ADD button, IC outputs and emitter follower output. The level appears to be negative with lots of "noise". For the moment I don't have time to investigate this further.

Albert


Re: Readout Signals and Decoding

 


On 28 Jul 2013 21:10, "David" <davidwhess@...> wrote:
>
> On Sun, 28 Jul 2013 20:34:35 +0200, "cheater00 ."
> <cheater00@...> wrote:
>
> >Given readout is fully digital. I'm surprised no one came up with an LCD
> >readout mod ... 20 years ago.
>
> This would not be difficult to do now.  The readout signals for each
> of the 8 discrete CRT readout locations consist of two lines of serial
> thermometer code.  A low performance microcontroller with a two
> channel 8 bit ADC could grab it pretty easily.  The actual code is
> 1-of-10 thermometer code so an 8 bit ADC is overkill but the excess
> resolution can be used for automatic calibration.  Generating the code
> from a microcontroller is just as easy.

That's great info for the posterity. Thanks.

> I suspect the largest problem would be synchronizing with the 10
> readout strobe pulses because without external decoding or
> asynchronous operation, that will absorb 10 microcontroller I/O lines
> all by itself.  The readout encoders and decoders have dedicated ICs
> just to handle these signals.

Lickily, modern uCs have 100s of pins. The real question is if one could find an uC to route the strobes directly to it or if glue chips are needed.

Cheers,
D.


Re: MCP and CRT Readout

 


On 28 Jul 2013 20:55, "David" <davidwhess@...> wrote:
>
> On Sun, 28 Jul 2013 20:34:35 +0200, "cheater00 ."
> <cheater00@...> wrote:
>
> >On 28 Jul 2013 20:13, "David" <davidwhess@...> wrote:
> >>
> >> The 7L5, 7L14 and 7L18 spectrum analyzer plug-ins have storage so they
> >> should not be used.  In general *any* plug-in which generates a slow
> >> continuous sweep or vector graphics should not be used which would
> >> include the 7L13 spectrum analyzer which does not have storage.
> >>
> >> The readout is vector generated but considered a necessary evil and
> >> only affects the top and bottom border area of the CRT.
> >
> >Thanks, makes sense.  What if one modulated the signal e.g. with a sine
> >wave... might not be so damaging then?
> >
> >Given readout is fully digital. I'm surprised no one came up with an LCD
> >readout mod ... 20 years ago.
>
> My understanding is that the MCP cells just have a finite limit to the
> number of electrons they can amplify so damage is cummulative with the
> gain in each cell diminishing over time.  In a continuous tone
> application like a low light image amplifier tube, this is not as
> serious a limitation because the whole MCP will tend to wear evenly
> but with an oscilloscope, wear is limited to very sharply defined
> areas where the CRT beam scans.
>
> I think later MCPs were a lot tougher than the 7104 MCP.

Does this mean the 11302 and 2467, or were there even later MCP CRTs?

> Philips used dedicated LCDs for the readout information but displaying
> the readout on the CRT has the advantage of allowing complete
> documentation via a camera attachment.  Tektronix even made a 7000
> plug-in, the 7M13, to take advantage of this by generating custom
> readouts in one slot.

I have the 7M13, but certainly a camera could take a photo of both CCD and LCD. Setting backlight intensity could take practice.

Thanks,
D.


Readout Signals and Decoding

 

On Sun, 28 Jul 2013 20:34:35 +0200, "cheater00 ."
<cheater00@gmail.com> wrote:

Given readout is fully digital. I'm surprised no one came up with an LCD
readout mod ... 20 years ago.
This would not be difficult to do now. The readout signals for each
of the 8 discrete CRT readout locations consist of two lines of serial
thermometer code. A low performance microcontroller with a two
channel 8 bit ADC could grab it pretty easily. The actual code is
1-of-10 thermometer code so an 8 bit ADC is overkill but the excess
resolution can be used for automatic calibration. Generating the code
from a microcontroller is just as easy.

I suspect the largest problem would be synchronizing with the 10
readout strobe pulses because without external decoding or
asynchronous operation, that will absorb 10 microcontroller I/O lines
all by itself. The readout encoders and decoders have dedicated ICs
just to handle these signals.


Re: MCP and CRT Readout

 

On Sun, 28 Jul 2013 20:34:35 +0200, "cheater00 ."
<cheater00@gmail.com> wrote:

On 28 Jul 2013 20:13, "David" <davidwhess@gmail.com> wrote:

The 7L5, 7L14 and 7L18 spectrum analyzer plug-ins have storage so they
should not be used. In general *any* plug-in which generates a slow
continuous sweep or vector graphics should not be used which would
include the 7L13 spectrum analyzer which does not have storage.

The readout is vector generated but considered a necessary evil and
only affects the top and bottom border area of the CRT.
Thanks, makes sense. What if one modulated the signal e.g. with a sine
wave... might not be so damaging then?

Given readout is fully digital. I'm surprised no one came up with an LCD
readout mod ... 20 years ago.
My understanding is that the MCP cells just have a finite limit to the
number of electrons they can amplify so damage is cummulative with the
gain in each cell diminishing over time. In a continuous tone
application like a low light image amplifier tube, this is not as
serious a limitation because the whole MCP will tend to wear evenly
but with an oscilloscope, wear is limited to very sharply defined
areas where the CRT beam scans.

I think later MCPs were a lot tougher than the 7104 MCP.

Philips used dedicated LCDs for the readout information but displaying
the readout on the CRT has the advantage of allowing complete
documentation via a camera attachment. Tektronix even made a 7000
plug-in, the 7M13, to take advantage of this by generating custom
readouts in one slot.


Re: 11A33 - what are possible problems, gotchas, and revisions?

 

On 28 Jul 2013 20:13, "David" <davidwhess@...> wrote:
>
> On Sun, 28 Jul 2013 19:54:04 +0200, "cheater00 ."
> <cheater00@...> wrote:
>
> >On 28 Jul 2013 19:29, "David" <davidwhess@...> wrote:
> >>
> >> On Sun, 28 Jul 2013 12:17:01 -0500, David <davidwhess@...>
> >> wrote:
> >>
> >> >On Sun, 28 Jul 2013 18:49:38 +0200, "cheater00 ."
> >> ><cheater00@...> wrote:
> >> >
> >> >>I guess if 7104 is not allowed, neither should 11k, but those are
> >sampling
> >> >>scopes too. I believe the 11302 which is not sampling has an MCP. But do
> >> >>the sampling ones? Why would a sampling plugin damage an MCP - is it
> >some
> >> >>sort of burnout in the phosphor?
> >> >
> >> >Sampling plug-ins have a long dwell time, about  at each location
> >> >which would easily overdrive and damage the MCP.
> >>
> >> Sorry.  Sampling plug-ins can dwell for almost 20 microseconds on each
> >> point which would easily overdrive and damage a MCP.
> >>
> >> For the same reasons, plug-ins which generate a vector display like
> >> the 7D01, 7D20, or any storage plug-ins should not be used with a MCP
> >> CRT.
> >
> >Oh! That is REALLY good to know. I'm sure I would have ended up burning out
> >an MCP one day if I hadn't been warned. Thanks a LOT.
> >
> >What other plugins have "vector display"? I guess only the storage ones?
> >What about readout, doesn't that count as vector?
> >
> >Thanks,
> >Damian
>
> The 7L5, 7L14 and 7L18 spectrum analyzer plug-ins have storage so they
> should not be used.  In general *any* plug-in which generates a slow
> continuous sweep or vector graphics should not be used which would
> include the 7L13 spectrum analyzer which does not have storage.
>
> The readout is vector generated but considered a necessary evil and
> only affects the top and bottom border area of the CRT.

Thanks, makes sense.  What if one modulated the signal e.g. with a sine wave... might not be so damaging then?

Given readout is fully digital. I'm surprised no one came up with an LCD readout mod ... 20 years ago.

> The MCP does not fail so much as just continuously and cumulatively
> wear out in areas where the CRT beam strikes even at low intensity.
> Since a normally generated trace is shifts position, the wear in the
> vertical center of the CRT is relatively even but using a plug-in that
> generates a vector display defeats that safety.

Thanks.

D.


Re: 11A33 - what are possible problems, gotchas, and revisions?

 

On Sun, 28 Jul 2013 19:54:04 +0200, "cheater00 ."
<cheater00@gmail.com> wrote:

On 28 Jul 2013 19:29, "David" <davidwhess@gmail.com> wrote:

On Sun, 28 Jul 2013 12:17:01 -0500, David <davidwhess@gmail.com>
wrote:

On Sun, 28 Jul 2013 18:49:38 +0200, "cheater00 ."
<cheater00@gmail.com> wrote:

I guess if 7104 is not allowed, neither should 11k, but those are
sampling
scopes too. I believe the 11302 which is not sampling has an MCP. But do
the sampling ones? Why would a sampling plugin damage an MCP - is it
some
sort of burnout in the phosphor?
Sampling plug-ins have a long dwell time, about at each location
which would easily overdrive and damage the MCP.
Sorry. Sampling plug-ins can dwell for almost 20 microseconds on each
point which would easily overdrive and damage a MCP.

For the same reasons, plug-ins which generate a vector display like
the 7D01, 7D20, or any storage plug-ins should not be used with a MCP
CRT.
Oh! That is REALLY good to know. I'm sure I would have ended up burning out
an MCP one day if I hadn't been warned. Thanks a LOT.

What other plugins have "vector display"? I guess only the storage ones?
What about readout, doesn't that count as vector?

Thanks,
Damian
The 7L5, 7L14 and 7L18 spectrum analyzer plug-ins have storage so they
should not be used. In general *any* plug-in which generates a slow
continuous sweep or vector graphics should not be used which would
include the 7L13 spectrum analyzer which does not have storage.

The readout is vector generated but considered a necessary evil and
only affects the top and bottom border area of the CRT.

The MCP does not fail so much as just continuously and cumulatively
wear out in areas where the CRT beam strikes even at low intensity.
Since a normally generated trace is shifts position, the wear in the
vertical center of the CRT is relatively even but using a plug-in that
generates a vector display defeats that safety.


Re: 11A33 - what are possible problems, gotchas, and revisions?

fjh001
 

On 28.07.2013 19:54, cheater00 . wrote:
Oh! That is REALLY good to know. I'm sure I would have ended up burning out an MCP one day if I hadn't been warned. Thanks a LOT.

What other plugins have "vector display"? I guess only the storage ones? What about readout, doesn't that count as vector?

Thanks,
Damian
Readout is generated by the 7k mainframes. The plugins only provide to the mainframe a set of switched resistors that tells the mainframe what to display. The 11k mainframes completely ignores this, when you plug a 7A22 or similar on an 11k mainframe, you have no readout from it (only an L, C or R depending on the slot). The 11k mainframe is not aware of any setting you've in the plug-in. The DSA display the units as 'U' and does not know (nor cares) if you've it set to 5mV/div or 1V/div.Sometimes is tricky to get the channel displayed, since the 11k firmware basically thinks that you've absolutely no plug-in at that location.You must navigate through the menu to get that, since the 7k plug-ins does not have the CH button that 11k plugins have to enable/disable a channel.

Regards,

Javier


Re: 11A33 - what are possible problems, gotchas, and revisions?

 

On 28 Jul 2013 19:29, "David" <davidwhess@...> wrote:
>
> On Sun, 28 Jul 2013 12:17:01 -0500, David <davidwhess@...>
> wrote:
>
> >On Sun, 28 Jul 2013 18:49:38 +0200, "cheater00 ."
> ><cheater00@...> wrote:
> >
> >>I guess if 7104 is not allowed, neither should 11k, but those are sampling
> >>scopes too. I believe the 11302 which is not sampling has an MCP. But do
> >>the sampling ones? Why would a sampling plugin damage an MCP - is it some
> >>sort of burnout in the phosphor?
> >
> >Sampling plug-ins have a long dwell time, about  at each location
> >which would easily overdrive and damage the MCP.
>
> Sorry.  Sampling plug-ins can dwell for almost 20 microseconds on each
> point which would easily overdrive and damage a MCP.
>
> For the same reasons, plug-ins which generate a vector display like
> the 7D01, 7D20, or any storage plug-ins should not be used with a MCP
> CRT.

Oh! That is REALLY good to know. I'm sure I would have ended up burning out an MCP one day if I hadn't been warned. Thanks a LOT.

What other plugins have "vector display"? I guess only the storage ones? What about readout, doesn't that count as vector?

Thanks,
Damian


Re: 11A33 - what are possible problems, gotchas, and revisions?

fjh001
 

On 28.07.2013 19:19, David wrote:

On Sun, 28 Jul 2013 19:00:05 +0200, Javier Herrero
<jherrero@hvsistemas.es <mailto:jherrero%40hvsistemas.es>> wrote:

Hi,

On 28.07.2013 18:49, cheater00 . wrote:

I guess if 7104 is not allowed, neither should 11k, but those are
sampling scopes too. I believe the 11302 which is not sampling has an
MCP. But do the sampling ones? Why would a sampling plugin damage an
MCP - is it some sort of burnout in the phosphor?
The 11301/11302 are conventional analog oscilloscopes, the 11302 with
MCP CRT, the 11301 with conventional CRT.
I thought I remembered the 11301 but my 1990 produce catalog does not
list it.

_
Probably shorted-lived than the 11302/A. It was 400MHz (vs 500MHz in the 11302) and with a larger CRT, otherwise more or less the same. Easy to find pictures of it around the web :)

Regards,

Javier

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