Mosquito Sound

[Chaos Master]

John Woodgate writes within:

There's a bit more to it. My pseudocode produces an extreme outlier
result, which the user really ought to pick up. It does NOT produce an
error message that stops the program. Of course it can be extended to
produce a *warning*. Stopping the program for a recoverable error is,
IMHO, really rather stupid.

IF DIVISOR = 0 THEN PRINT "Division by 0!" ELSE RESULT = DIVIDEND/DIVISOR


[]s
--
Chaos MasterŽ, posting from Brazil.
"Two of the most famous products of Berkeley are LSD and Unix. I don't think
that this is a coincidence." -- Anonymous
"I'd rather be hated for who I am, than loved for who I am not" - Kurt Cobain
"F*** you, pal. " -- Amy Lee

"STATUS: ELF and ORC signals detected on Tolkien (sp?) Ring network!"

The Evanescen(t/ce) HP: http://marreka.no-ip.com

 

[John Woodgate]

I read in sci.electronics.design that Chaos Master <spammers.fuck@spam.c
om.INVALID> wrote (in <MPG.1bc0c555d40b9c8398973d@news.individual.net&gt
about 'ELF detector', on Sun, 26 Sep 2004:

John Woodgate writes within:


There's a bit more to it. My pseudocode produces an extreme outlier
result, which the user really ought to pick up. It does NOT produce an
error message that stops the program. Of course it can be extended to
produce a *warning*. Stopping the program for a recoverable error is,
IMHO, really rather stupid.

IF DIVISOR = 0 THEN PRINT "Division by 0!" ELSE RESULT =
DIVIDEND/DIVISOR

But that overflows the column in a table of results, and is liable to
scramble the whole rest of the print-out. I speak from experience! (8-O(
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

 

[w_tom]

A wide variety of good responses and outright myths. Some
just post answers without even providing a single reasons
why. Those posters are particularly insidious and typically
respond with insults.

Turning something off will not help. Destructive surges
were not stopped or absorbed by 3 miles of air. Why then will
millimeters inside a switch do what miles of air could not?

In the early days of ham radio, equipment would suffer
lightning damage. Antenna lead was disconnected and even put
inside a mason jar. Damage finally stopped when the antenna
lead was connected to earth ground. They only rediscovered
what Ben Franklin demonstrated in 1752. Lightning seeks earth
ground. If not earthed before entering a building, then
lightning will seek earth ground, destructively through
appliances.

Some will claim that a plug-in protector would help. Again,
plug-in protector will stop or block what miles of air could
not? So very quietly, those plug-in manufacturers forget to
mention they don't even claim to protect from that destructive
type of surge. Obviously. No dedicated earth ground. They
just let others assume all surges are the same type.

Industry professionals demonstrate how protection is
installed as it was proven before WWII on the Empire State
Building.

http://www.erico.com/public/library/fep/technotes/tncr002.pdf
Two structures each with their own single point earth ground.
Any wire entering each structure first makes a connection to
that earth ground. Connection either by a hardwire or via a
surge protector. Notice what an effective surge protector
does. Makes a temporary and short connection to earth ground
during a surge.

Also notice the buried phone wire in that figure. Even
underground wires must first connect to that single point
earth ground. Yes even underground wires will carry
destructive surges inside a building.

So what can you do? Protection is a building wide
solution. However if your circuit breaker box is 'earthed'
(connected) to building steel, then it already has an
excellent single point ground. Breaker box then gets a 'whole
house' protector so that surges entering on AC mains are
immediately earthed long before they can get to your
computer. Most destructive surges - especially to modems and
portable phone base stations - are incoming on AC electric.

Same applies to phone line. But phone line already has an
effective protector provided free by the telco because 'whole
house' protectors are so effective and so inexpensive. Cable
company is also required to bond to earth ground where cable
enters the building. Cable requires no surge protector
because cable can make a direct (hardwired) connection to
earth ground.

All electronics contains internal protection. Anything that
is effective on an appliance power cord would already be
inside the appliance. But that internal protection assumes
destructive transients are earthed before entering a
building. Earthed transients will not overwhelm protection
already installed in appliances. Again, protection that has
been proven repeated in virtually every town for so many
decades. Protection that does not use plug-in protectors.

Do not fall for urban myths that a UPS or power strip will
filter or stop surges. Again, a 1 inch component will stop
what miles of sky could not? Of course not. A UPS will stop
or filter a surge? Franklin did not stop or absorb
lightning. He shunted (diverted, connected) an electrical
transient to earth so that it did not seek earth ground via a
church steeple. Effective protection inside telephone
switching centers, 911 emergency response centers, and even in
grocery stores do same.

A telephone switching center connected to overhead wires
everywhere in town does not unplug during thunderstorms. And
yet that is what your are being told. They simply connect
every incoming wire to single point earth ground where wires
enter the building. Protection that is best located 50 meters
from computers.

The plug-in protector does not even claim to protect from
the destructive type of surge. It claims to protect from
surges that don't typically exist. Myth purveyors then assume
protector protects from all kinds of surges - not knowing that
different types of surges exist.

Plug-in manufacturer encourages others to play word games as
if it was technical fact. Surge protector and surge
protection are same? No. All protection 'systems' require
surge protection - earth ground. Only some incoming utilities
require a surge protector to connect to surge protection. A
surge protector is only as effective as its earth ground.
Plug-in protector manufacturers even avoid discussing earth
ground. Telling the 'whole truth' would only hurt profits.
Effective protection is a 'whole house' protector. Therefore
internal appliance protection will not be overwhelmed. A
surge protector is only as effective as its earth ground.

Recommended is a 'whole house' protector at AC mains
electric box. That is effective protection for about $1 per
protected appliance.

nospam256K wrote:

Here in New York City (Manhattan) where I live, I usually use a laptop
computer running on an AC adapter, and get online via a dial-up modem
(phone line plugged into computer's built-in modem).

When it's merely raining outside, it's usually of no concern to me.
But when there's lightning or thunder, I quickly get offline, turn off
the computer, and literally unplug the AC adapter from the outlet, and
unplug the phone line from the computer.

This is done to avoid the possibility of the AC adapter or the modem
suffering damage from a voltage spike carried through either the AC
power line or the phone line (because of a lightning strike).

Does all this sound sensible to you, or am I being
overly/unneccesarily cautious?

 

[Rich Grise]

On Sunday 26 September 2004 12:23 am, John Woodgate did deign to grace us
with the following:

I read in sci.electronics.design that Ken Smith
kensmith@green.rahul.net> wrote (in <cj4o62$g7l$8@blue.rahul.net&gt
about 'ELF detector', on Sat, 25 Sep 2004:

I doubt software can do it. You need to divide by zero. Most
programmers have a hard time writing code that does that successfully.

IF DIVISOR = 0, THEN RESULT = 1E+38 ELSE RESULT = DIVIDEND/DIVISOR

It's the order in which you write it that matters. (;-)
--

Gee, John, do you still punch your Fortran onto Hollerith cards?

;-)
Rich

 

[Charles W. Johson Jr.]

"John Woodgate" <jmw@jmwa.demon.contraspam.yuk> wrote in message
news:SFdBncC3znVBFwEZ@jmwa.demon.co.uk...

I read in sci.electronics.design that Robert Baer
robertbaer@earthlink.net> wrote (in <4156705F.31F860EE@earthlink.net&gt
about 'ELF detector', on Sun, 26 Sep 2004:
John Woodgate wrote:

I read in sci.electronics.design that Ken Smith
kensmith@green.rahul.net> wrote (in <cj4o62$g7l$8@blue.rahul.net&gt
about 'ELF detector', on Sat, 25 Sep 2004:

I doubt software can do it. You need to divide by zero. Most
programmers have a hard time writing code that does that successfully.

IF DIVISOR = 0, THEN RESULT = 1E+38 ELSE RESULT = DIVIDEND/DIVISOR

It's the order in which you write it that matters. (;-)
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

ORDER??????????
What is *that*??

Ask your friendly local Marine sergeant.
--
Regards, John Woodgate, OOO - Own Opinions Only.
The good news is that nothing is compulsory.
The bad news is that everything is prohibited.
http://www.jmwa.demon.co.uk Also see http://www.isce.org.uk

Friendly?

Charles

 

[Roger Johansson]

w_tom <w_tom1@hotmail.com> wrote:

Some will claim that a plug-in protector would help. Again,
plug-in protector will stop or block what miles of air could
not? So very quietly, those plug-in manufacturers forget to
mention they don't even claim to protect from that destructive
type of surge. Obviously. No dedicated earth ground. They
just let others assume all surges are the same type.

A good surge protector contains one or more of these components:

A spark gap device, also called ComGap, which allows overvoltage, charge,
to jump to the earth connection.

A VDR which is slower than the Comgap, but it lowers the voltage to zero,
which protects the Comgap, this is needed if we are talking about a mains
wire, because mains delivers current until the mains cycle reaches the
zero crossing, and this current hurts the Comgap device.

A Comgap needs to be used in series with a resistor, a big mass type
resistor, value 20 Ohm or so. The VDR is used in parallell with this
Comgap-resistor combination.

To make the protection better one can use small coils in the signal/mains
way, after the comgap. The coils stop fast voltage changes and make the
comgaps take the charge instead.

The comgaps and the VDR:s need to have the right voltage, 450Volt for a
240Volt mains wire, a 140Volt for the phone line.

It doesn't hurt the computer and other devices if the voltage is raised a
thousand volts for a short moment, as long as all connections to it are
raised together. So the surge protector only has to keep all connections
at fairly the same voltage, even if they all are raised momentarily. What
really hurts the equipment is if one of the connections moves far away
from the other connections, because then there is a surge inside that
piece of equipment, burning some component to pieces.

That is why the extension with outlets protected by a surge protector
works. It creates a subsystem which is kept together at virtually the
same potential for all connections to that subsystem.

When a modem is hurt by the lightning it is because the mains connection
to it and the phone connection to it are pulled apart by thousands of
volts, and that creates a damaging surge inside the modem.

If both the mains and phone line connections to the modem first have to
pass through a protector box, where they are prevented from moving apart
too much, voltage-wise, the modem is protected.


--
Roger J.

 

[Shawn Hearn]

In article <24a23015.0409201837.1b40dbcd@posting.google.com>,
nospam256k@yahoo.com (nospam256K) wrote:

Here in New York City (Manhattan) where I live, I usually use a laptop
computer running on an AC adapter, and get online via a dial-up modem
(phone line plugged into computer's built-in modem).

When it's merely raining outside, it's usually of no concern to me.
But when there's lightning or thunder, I quickly get offline, turn off
the computer, and literally unplug the AC adapter from the outlet, and
unplug the phone line from the computer.

This is done to avoid the possibility of the AC adapter or the modem
suffering damage from a voltage spike carried through either the AC
power line or the phone line (because of a lightning strike).

Does all this sound sensible to you, or am I being
overly/unneccesarily cautious?

The odds of a lightning strike doing any damage in a densely populated
region such as Manhattan are astronomically slim. If I lived in that
area I wouldn't worry about it. There are so many tall buildings in
Manhattan to attract lightning and the majority of them probably have
lightning rods on them.

The situation in a rural area is different. I once had some electronic
equipment fried by a nearby lightning strike a few years ago in a
suburban Philadelphia home.

 

[Ken Smith]

In article <4156700E.AD098E76@earthlink.net>,
Robert Baer <robertbaer@earthlink.net> wrote:

Ken Smith wrote:

[...]
You didn't give enough details. How big does the loop have to be to do
the "0-" part of the range?

--
--
kensmith@rahul.net forging knowledge

Depends on the sensitivity you want.
Obviously, you cannot make a loop any where near 1/4 wavelength...

When you go to normalize the gain of the induction loop at zero Hz, you
have to write some very tricky software. You have to divide by zero to
get any sensitivity you want. Most programmers would have trouble
designing a divide by zero routine that is accurate to more than 1 bit.


You could use a GMR or other magnetoresistive device.



--
--
kensmith@rahul.net forging knowledge

 

[Roger Johansson]

w_tom <w_tom1@hotmail.com> wrote:

Your example of an adjacent power strip protector works IF
destructive surges are normal mode. Destructive surges are
longitudinal mode. That means a surge shunted by the power
strip will seek many paths back to earth ground -

Damage you demonstrate inside a modem is classic of a surge
that enters on AC electric. Remember primary school science.
First electricity must flow through everything in that
circuit. Only later does something fail.

protection - Polyphaser. Polyphaser application notes are
legendary. Polyphaser makes a protector that has no
connection to earth ground. Distance to earth ground is so
critical that the Polyphaser protector sits directly ON earth
ground. That is zero feet to earth ground.

I feel like I am discussing loudspeaker cables with an audio hi fidelity
enthusiast.

You obviously do not understand what I am saying, but you have a lot to
say about special modes, earth connections and special brands, which
doesn't make sense from a scientific point of view.

You do not have an education in electronics, but you have a brain filled
with blurb from advertisements.


--
Roger J.

 

[Roger Johansson]

w_tom <w_tom1@hotmail.com> wrote:

http://www.polyphaser.com/ppc_technical.asp

Or maybe the National Institute of Science and Technology
might help. They are not advertising. Their figure is used
to demonstrate how a fax machine is protected or may be
damaged. Again 'whole house' protector and the all so
critical single point earth ground:
http://www.epri-peac.com/tutorials/sol01tut.html

A lot of useful information in these links, but you still need an
education in electronics to fully understand that information.

Like Henri Poincare said: Facts are just the building blocks of science,
you need to know how to build them together, you need models and
theories, that is real science.

Yes, you made a good case for normal mode protection. But
that is not the type of surge that typically damages
electronics. How many industry professional citations need I
provide? A surge protector is only as effective as its earth
ground. A fact well proven even before WWII.

"Ground Potential Rise (GPR)", is used a lot on the Polyphaser web site.
If you understood what it means you would not write about "sitting ON
earth", as you did in your earlier message, because no point can be
exactly "on earth" during a thunder storm. All points are moving
voltage-wise, so you have to choose a suitable moving point and use it in
a proper way.

As I stated earlier, the important thing is not to keep everything
exactly at earth potential, because that is impossible, read about GPR,
the important thing is to prevent different parts of the system from
moving too far apart voltage-wise.
And that is what we use spark gaps and other devices for.
This can be done for a whole building or for subsystems within a building.



--
Roger J.

 

[Kent Wills]

I was just walking down the street, when someone handed me a piece of
paper. I thought it was something for a free meal at Popeye's
Chicken. Instead, I found that on 20 Sep 2004 19:37:36 -0700,
nospam256k@yahoo.com (nospam256K) wrote:

Here in New York City (Manhattan) where I live, I usually use a laptop
computer running on an AC adapter, and get online via a dial-up modem
(phone line plugged into computer's built-in modem).

When it's merely raining outside, it's usually of no concern to me.
But when there's lightning or thunder, I quickly get offline, turn off
the computer, and literally unplug the AC adapter from the outlet, and
unplug the phone line from the computer.

This is done to avoid the possibility of the AC adapter or the modem
suffering damage from a voltage spike carried through either the AC
power line or the phone line (because of a lightning strike).

Does all this sound sensible to you, or am I being
overly/unneccesarily cautious?

Odds are you would be safe, but it's certainly not dumb to
disconnect. It's far better to KNOW your computer is safe than to
take the risk and learn it's not.

Kent
--
Nie'se schlect sim'wa

 

[Ken Smith]

In article <jjFtuWAUgxVBFwAS@jmwa.demon.co.uk>,
John Woodgate <noone@yuk.yuk> wrote:

I read in sci.electronics.design that Ken Smith
[...]
There is a trick you can use in C++ to do it. C++ allows all operators to
be overloaded. Thus in C++ you can make up you own rules about ADD,
SUBTRACT, MULTIPLY and DIVIDE to that 1/0 is perfectly legal.

In C++ you can make the main part of your program:

int main(void){ return 1/0; }


Is that essentially different from my pre-emptive *redefinition* of N/0
as '= 1E38'?

A few differences:

(1)
What you showed could be figured out by the maintainers. The C++ version
can easily be written so that no-one can understand it.

(B)
The version you did is discontinuous near zero. In C++ you can redefine
the divide so that X/Y <==> cos(X/Y) yelding a nice smooth curve near
zero.

(iii)
The 1E38 is machine dependant.

(d)
C++ is coded in lower case.

--
--
kensmith@rahul.net forging knowledge

 

[Jim Adney]

On 25 Sep 2004 05:34:33 -0700 larwe@larwe.com (Lewin A.R.W. Edwards)
wrote:

Anyway, I'm having trouble finding a probe that will match this scope
properly. Here's what the calibrator output looks like:
http://www.larwe.com/dsc00461.jpg>. That's the best I can adjust it
to using the trimcap on the probes available to me (mostly x1/x10
switchable units of post-1998 vintage at oldest). If I just hook a
piece of wire to the cal output, the trace looks nice and square. So
it's a probe capacitance issue.

The scope will have an input resistance and capacitance. On Tek scopes
this is marked on the front panel. What does the NIC scope say?

What characteristics should I look for in a probe for such an ancient
scope?

You need to use a probe which has a compensation range that includes
the input capacitance of your scope.

-
-----------------------------------------------
Jim Adney jadney@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

 

[Robert Baer]

Ken Smith wrote:

In article <jjFtuWAUgxVBFwAS@jmwa.demon.co.uk>,
John Woodgate <noone@yuk.yuk> wrote:
I read in sci.electronics.design that Ken Smith
[...]
There is a trick you can use in C++ to do it. C++ allows all operators to
be overloaded. Thus in C++ you can make up you own rules about ADD,
SUBTRACT, MULTIPLY and DIVIDE to that 1/0 is perfectly legal.

In C++ you can make the main part of your program:

int main(void){ return 1/0; }


Is that essentially different from my pre-emptive *redefinition* of N/0
as '= 1E38'?

A few differences:

(1)
What you showed could be figured out by the maintainers. The C++ version
can easily be written so that no-one can understand it.

(B)
The version you did is discontinuous near zero. In C++ you can redefine
the divide so that X/Y <==> cos(X/Y) yelding a nice smooth curve near
zero.

(iii)
The 1E38 is machine dependant.

(d)
C++ is coded in lower case.

--
--
kensmith@rahul.net forging knowledge

Reply to option (d): That is because the programmers are too damn lazy
to use mixed case.

 

[Mike Monett]

Ken Smith wrote:

[...]

(B) The version you did is discontinuous near zero. In C++ you can
redefine the divide so that X/Y <==> cos(X/Y) yelding a nice
smooth curve near zero.

kensmith@rahul.net forging knowledge

Ken, my math is shaky at best, especially near infinity. Wouldn't
cos(X/Y) give an infinite number of zero crossings as X<>0 and Y-->0?

Best Wishes,

Mike Monett

 

[BFoelsch]

I have a Tek TDS2012 I purchased for home use and will offer the following.

The TDS2012 is basically the digital equivalent of a 100 MHz analog scope,
and Tek markets it as such. Aside from the storage feature (and the FFT
function), there is really no functionality to it that cannot be had from a
GOOD analog scope. The criticism of the sample record length is valid. The
1/4 VGA screen resolution puts visible "stair steps" in many waveforms. An
additional criticicsm is the dynamic range, you are pretty much limited to
observing signals one screen-height in amplitude. The math functions are
performed on the screen data and not the input data, so if you do an A-B on
an off-screen signal you are in for a surprise!

Having said that, however, I would never go back to a comparable analog
scope. The compactness and storage features, combined with the readouts and
preset capabilities are addicting.

To sum up, the TDS 2000 series is, to my mind, fine for fooling around,
fixing radios and televisions, audio and ham radio work, power supplies, and
slow digital stuff, which is the bulk of my use of it. However, it is not
even close to state of the art as far as digital work is concerned.

"David L. Jones" <altzone@gmail.com> wrote in message
news:459b0886.0409262351.7abe7ee@posting.google.com...

joble_5@hotmail.com (joble) wrote in message
news:<97db3e03.0409210718.2b861c1f@posting.google.com>...
Hi,

I'm looking to buy a new scope, but I'm still doubting which...

It has to be used in a wide range of applications: design of switched
supplies, simple analog circuits, and microprocessor circuits.

I've had a demonstration of the 3000 and I like it very much. The 2000
I have not seen yet.

Has anyone experiences with those scopes? Is there a large difference
between a DPO and a DSO scope?

Greets!

Most general DSO applications don't really benefit from the DPO
technology, don't waste your money. What you'll most likely find much
more usful and practical in everyday use is a large sample memory. The
2000 and 3000 Tek scopes are both *very poor* in this area with only a
10KB on the 3000 series and a pathetic 2.5KB on the 2000 series. This
is terrible and actually makes the scope next to useless for lots of
digital applications. You need to go to the 5000 series scope to get
more than 10KB.
When you have megabytes of sample memory you can zoom in on packets of
data and this is incredibly useful, you won't turn back once you have
it.

We have a 3000 series Tek and a Agilent 546210A in our lab and the Tek
just gathers dust because the Agilent is a) more user friendly and b)
has 2MB of sample memory which makes the DSO functionality incredibly
useful.

If you buy your DSO based on sample memory legth you can't go wrong.
Forget wanky technology like DPO unless you are 100% certain you have
a specific need for it.

For my money the Agilent 54600 series is the best value, most user
friendly, and most practical medium range DSO on the market. The mixed
signal version with its 16 channel logic analyser is invaluable for
digital work. The sample rate isn't all that high on the 54600 series
though, so it's not that great for high frequency work.

Dave

 

[Ken Smith]

In article <4157C48D.7E82@spam.com>, Mike Monett <no@spam.com> wrote:

Ken Smith wrote:

[...]

(B) The version you did is discontinuous near zero. In C++ you can
redefine the divide so that X/Y <==> cos(X/Y) yelding a nice
smooth curve near zero.

kensmith@rahul.net forging knowledge

Ken, my math is shaky at best, especially near infinity. Wouldn't
cos(X/Y) give an infinite number of zero crossings as X<>0 and Y-->0?

Your seems to be better than mine were at that moment in time. Yes I
messed up on that one.

--
--
kensmith@rahul.net forging knowledge

 

[Jamie]

just need a fraction byte


Ken Smith wrote:

In article <4156700E.AD098E76@earthlink.net>,
Robert Baer <robertbaer@earthlink.net> wrote:

Ken Smith wrote:

[...]

You didn't give enough details. How big does the loop have to be to do
the "0-" part of the range?

--
--
kensmith@rahul.net forging knowledge

Depends on the sensitivity you want.
Obviously, you cannot make a loop any where near 1/4 wavelength...


When you go to normalize the gain of the induction loop at zero Hz, you
have to write some very tricky software. You have to divide by zero to
get any sensitivity you want. Most programmers would have trouble
designing a divide by zero routine that is accurate to more than 1 bit.


You could use a GMR or other magnetoresistive device.

 

[Jim Yanik]

and7@bigfoot.com (TekMan) wrote in
news:6a624601.0409262333.1bb8b871@posting.google.com:

Jim Yanik <jyanik@abuse.gov> wrote in message
news:<Xns957089733DC52jyanikkuanet@204.117.192.21>...
bobd426@yahoo.com (Scibuff) wrote in
news:6fa04d1c.0409251726.6f1d16c@posting.google.com:

It looks like my faithful 2235 has bit ths dust! When powered on,
the power LED only pulses on/off about every second and the CRT has
no light. Using the Service manual, I got as far as restoring the
power LED operation by disconnecting the lead from T948-p23 to
U975, which I assume is the HV multplier, but have no details on
it. The 2 5.1K resistors off U975-p4 are good and disconnecting
C975 and C976 one at a time does not allow the Power LED to come on
steady.

Help please!



The HV multiplier has a red lead that goes to the front of the CRT.
The multipliers do fail occasionally.
You will NOT be able to order one from TEK,they consider this model
obsolete.A parts scope will be your only source,I believe.

The HV mult develops the -2960 cathode V from the pin that feeds the
5.1K resistors,the anode V comes from the pin that the red HV lead to
the CRT is connected to.


Are your low voltages proper when you disconnect the HV mult.?

The HV multiplier is a x6 type. Do as Jim proposed and try to get a
parts scope.

It is possible to build the the HV multiplier from discrete parts
(diodes, caps, etc), but is really a tedious task and requires HV
expereince. I did it a couple of times, but would recommend this only
to someone with a lot of repair experience. The HV is nasty, so
careful soldering and isolation technique is a must.

And you have to build it to fit into the available space and not arc to
something else.

you're better of with a commercial build multiplier from a parts
scope.

hth,
Andreas

I believe the multiplier is a X-FOUR,not six. My 2215 schematic shows X4.
I also believe he could adapt a HV mult from a 1700 series TEK waveform
monitor,they're about the same size,but don't have the internal cathode
supply diode,no big deal. 152-0900-00,and probably still available from
TEK.

--
Jim Yanik
jyanik-at-kua.net

 

[Lewin A.R.W. Edwards]

Jim Adney wrote:

Hi,

The scope will have an input resistance and capacitance. On Tek scopes
this is marked on the front panel. What does the NIC scope say?

It's not characterized on the front panel. I think it's probably in the
range ~150pF, at a guess, and my probes are designed for ~13-15pF input
capacitance. I'll look closer at the instructions (they are filed now..
didn't think I would be needing them immediately).

At the moment the scope is running a ten-day data acquisition operation,
I'll play when that's over (it has an ultra-low sample rate, down to 1
sample per 200 seconds, and a 4096-point memory).