开云体育

maybe you can find some cheap chinese 10x probes that wili compensate to a 50 pf input
maybe deane kidd has some older tek probes that have that much range
you might be able to build a simple 10 x probe that would be good up to 5 or 10 mhz
"heathkit sold probe kits for their early scopes like that"

I'm in need of help with my HP Agilent 54110D 1GHz scope … No Video
but can see a brief flash as High Voltage enters CRT and when turning
off. LED on first power supply board is lit but no other voltages
present on any other test points. Have no service manual ….any help
would be greatly appreciated.

Thanks Pat

you have a spare 8620a manual to sell me?

Traitors.

Thats what gets my goat, companies or individuals that sabotage, they
should be
treated as commercial and environment traitors and they should face
prospect of
jail !

This is not a new thing. In the 1970s, Data General introduced a Nova 2

mini with a potted power fail module that PURPOSELY caused random

memory

failures if you did not use DG memory, then spread rumors that second
source memory was no good. I eventually unpotted one of the modules.
They CLEARLY engineered it in. There was no other POSSIBLE use for the
circuit.

-John

It got quite a bit of notice. See, for example:



-John

On Thu, 4 Jan 2007, Geoff Blake wrote:

On Thu, 4 Jan 2007, Rainer wrote:

Hi,

can someone help me with Service manuals for HP8620C
and HP8621B in electronic form - preferred PDF ?

Hi Rainer,

I can probably help with the 8621 and some modules in .pdf, but
not until the weekend at the earliest I am afraid. I am in the
process of sorting the computer room/shack and I will have to
search for the CD.

Rainer,

Sorry, I was mistaken, I thought I had the .pdf's you need, but
they were for single band plug-in's, like the 86245A.

If you are really stuck, I probably have paper copies.

73

Geoff
--
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Traitors.

Thats what gets my goat, companies or individuals that sabotage, they should be
treated as commercial and environment traitors and they should face prospect of
jail !

I am certain that a 47pF Silver Mica capacitor would do, I think
that the effort of making a surface mount version would be
overkill, just string the components across a BNC male/female pair
in a small screened box and that will do.

These boxes were available in a wide range of capacitances and
were used to 'standardize' the input capacitance to enable probes
to be switched between 'scopes (of the same input capacitance).

Geoff



Tek just uses an off the shelf ITT Pomona cast box, roughly 1" x 1" x
2", with M and F chassis mount BNCs on the ends and wired the R & C
from center conductor to center conductor. Trivial.

-John

Geoff Blake wrote:

[snip]

I find it strange that any successful non-microsoft product, like
Opera, Word Perfect, Samba, etc. is strangely broken by an
'improvement' to Windows....

Geoff



This is not a new thing. In the 1970s, Data General introduced a Nova 2
mini with a potted power fail module that PURPOSELY caused random memory
failures if you did not use DG memory, then spread rumors that second
source memory was no good. I eventually unpotted one of the modules.
They CLEARLY engineered it in. There was no other POSSIBLE use for the
circuit.

-John

On Fri, 5 Jan 2007, Jerry Massengale wrote:

Greetings,
My thanks to all for the very instructive replies. At the
moment SC501's are my immediate concern. I wonder if it might
be reasonable to just use 47pf mica cap as the SC501
adjustment instructions call for 47pf with 1 megohm. Surface
mount parts would be neat.

I will build another with the trimmer for my other scopes. I
have some Le Croy 9400's that have such a high input
capacity(50pf) that none of my newer probes work with them.
Newer probes like the lecroy PP001 and PP002 cause a display
with severe leading edge roll-off.

I am sure that you will have seen Craigs post (and mine) pointing
out my error.

I am certain that a 47pF Silver Mica capacitor would do, I think
that the effort of making a surface mount version would be
overkill, just string the components across a BNC male/female pair
in a small screened box and that will do.

These boxes were available in a wide range of capacitances and
were used to 'standardize' the input capacitance to enable probes
to be switched between 'scopes (of the same input capacitance).

Geoff

--
Geoff Blake G8GNZ located near Chelmsford, Essex, U.K.
Please reply to: geoff (at) palaemon (dot) co (dot) uk
Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms

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The IT people at one of my employers have stated "DO NOT INSTALL IE7 ON ANY COMPANY OWNED EQUIPMENT!" in big red letters on the intranet home page...

On Fri, 5 Jan 2007, Geoff Blake wrote:

The input normaliser is a series 1M ohm / 47pF capacitor placed in
series with the scope input. It should be as close to the input as
possible. There should be no coax between the input and the
compensator. The 47pF is normally something like a 39pF plus a
trimmer capacitor to set exactly to 47pF. The Tektronix devices
use a chassis mounted male BNC with the C/R soldered to the pin.

It acts as a potential divider and the input capacitance of the
scope is adjusted on an input squarewave, just like compensating a
scope probe.

CORRECTION The series element comprises a 1.0 Mohm and 47pF in
parallel, not as I wrote. I wrote that at work and was interrupted
by about a dozen telephone queries as I wrote.

It is thus:
47pF
|-----||-----|
generator o---| |---o to scope o----|---|-->
|---/&#92;/&#92;/&#92;---| | &#92; input
1M | / circuit
= &#92; of
| / 'scope
| &#92;
o--------------------o o----|---|-->

Sorry for the error.

Geoff

--
Geoff Blake G8GNZ located near Chelmsford, Essex, U.K.
Please reply to: geoff (at) palaemon (dot) co (dot) uk
Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms

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Greetings,

My thanks to all for the very instructive replies. At the moment SC501's are my immediate concern. I wonder if it might be reasonable to just use 47pf mica cap as the SC501 adjustment instructions call for 47pf with 1 megohm. Surface mount parts would be neat.

I will build another with the trimmer for my other scopes. I have some Le Croy 9400's that have such a high input capacity(50pf) that none of my newer probes work with them. Newer probes like the lecroy PP001 and PP002 cause a display with severe leading edge roll-off.

Jerry

--- In hp_agilent_equipment@..., Geoff Blake <geoff@...>
wrote:

Just to go a little bit further, there is also Opera, which IMO,
hase advantages over the others mentioned.
Opera and Firefox also run natively on most UNIXs including Linux.

I use Opera since the early versions. It is great!
The early versions didn't like some sites with Microsoft-specific
content, but the present version can read just about anything. I only
open IE on rare cases. The user interface is far superior to IE and
once you become accustomed to it, it's hard to go back to IE.

I find it interesting that the same version of Opera running on
Linux is vastly more stable than when running under XP. It seems
like that the display engine that Microsoft uses causes Opera to
crash regularly.

I run Opera on Win98 and it is quite stable. And if anything go wrong
and you are forced to exit, on return, a dialog box asks if you want
to reload the pages where you were in the first place or a blank one.
Nice!

I find it strange that any successful non-Microsoft product, like
Opera, Word Perfect, Samba, etc. is strangely broken by an
'improvement' to Windows....
Geoff

This is precisely the notorious Microsoft's interpretation of the
word "improvement" ...

Regards to all,

The input normaliser is a series 1M ohm / 47pF

No! It is a *parallel* 1M/47pF in *series* with the input.

You knew that of course!

Craig

On Fri, 5 Jan 2007, Jerry Massengale wrote:

Greetings,

I am in need of an input rc normalizer for adjustments on Tektronix SC501,etc. It is described as a time constant, 1 Mohm x 47pf, part number 067-0541-00. Is this something I can build? Is there a schematic for it?

Jerry

The input normaliser is a series 1M ohm / 47pF capacitor placed in
series with the scope input. It should be as close to the input as
possible. There should be no coax between the input and the
compensator. The 47pF is normally something like a 39pF plus a
trimmer capacitor to set exactly to 47pF. The Tektronix devices
use a chassis mounted male BNC with the C/R soldered to the pin.

It acts as a potential divider and the input capacitance of the
scope is adjusted on an input squarewave, just like compensating a
scope probe.

HTH

Geoff
--
Geoff Blake G8GNZ located near Chelmsford, Essex, U.K.
Please reply to: geoff (at) palaemon (dot) co (dot) uk
Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms

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See <>
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On Fri, 5 Jan 2007, Chuck Harris wrote:

Matt wrote:

About 3 months ago, I downloaded the Beta Version of IE7 from the
Microsoft site. After encountering compatability problems with some
websites, I decided to fall back to the IE6 release. BIG MISTAKE!
The uninstall program for the Beta IE7 left my computer in an
unbootable condition. I had to go through great pains to get rid of
the various IE7-related files on the computer and get everything
working as before. Now, I'm a little apprehensive about upgrading
to the IE7 Release Version.

And yet you keep coming back to Microsoft! Amazing! Go check out
Mozilla's Firefox, or Seamonkey. Either will run rings around IE.

For the odd few sites that refuse to work with non IE browsers, you
can install a plugin that makes your browser identify itself as being
IE.

Just to go a little bit further, there is also Opera, which IMO,
hase advantages over the others mentioned.

Opera and Firefox also run natively on most UNIXs including Linux.

I find it interesting that the same version of Opera running on
Linux is vastly more stable than when running under XP. It seems
like that the display engine that Microsoft uses causes Opera to
crash regularly.

I find it strange that any successful non-microsoft product, like
Opera, Word Perfect, Samba, etc. is strangely broken by an
'improvement' to Windows....

Geoff
--
Geoff Blake G8GNZ located near Chelmsford, Essex, U.K.
Please reply to: geoff (at) palaemon (dot) co (dot) uk
Using Linux on Intel & Linux or NetBSD on Sun Sparc platforms

Please avoid sending me Word or PowerPoint attachments.
See <>
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and the sender by return and permanently delete the message.

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attachments to any third party without the prior consent of the
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------------------------------------------------------------------------------

Greetings,

I am in need of an input rc normalizer for adjustments on Tektronix SC501,etc. It is described as a time constant, 1 Mohm x 47pf, part number 067-0541-00. Is this something I can build? Is there a schematic for it?

Jerry

-Chuck Harris

Richard W. Solomon wrote:

Where do you find that plug-in ??
Thanks, Dick, W1KSZ
-----Original Message-----

...

For the odd few sites that refuse to work with non IE browsers, you
can install a plugin that makes your browser identify itself as being
IE.

-Chuck Harris

And yet you keep coming back to Microsoft! Amazing! Go check out
Mozilla's Firefox, or Seamonkey. Either will run rings around IE.

Hmm. I stuck Firefox on my (previous) machine, and later uninstalled it.
Ever after, IE identified itself externally as Mozilla Firefox. Never did
manange to get to the bottom of that (there are too few hours in the day).

But having experienced the dreaded "certificate error" when trying to access
long-used https sites I am seriously considering going back to IE6. There
is a whole thread on Microsloth's own forum of users bemoaning this
"feature" and tearing IE7 off their machines. The security features in IE7
cannot be turned off, it would appear - part of their philosophy of a
"sandbox" into which anything that does not conform precisely with what
u-soft thinks it should is dumped.

Craig

Where do you find that plug-in ??

Thanks, Dick, W1KSZ