Searching \ for '[EE]:Oscilloscope' in subject line. ()
Make payments with PayPal - it's fast, free and secure! Help us get a faster server
FAQ page: techref.massmind.org/techref/index.htm?key=oscilloscope
Search entire site for: 'Oscilloscope'.

Exact match. Not showing close matches.
PICList Thread
'[EE]:Oscilloscope'
2002\02\03@225226 by Gary Russell

flavicon
face
I am just a home hobbyist (no corporate $$ to help out).

I have a background in software and have just started to experiment with
microcontroller application development.

Do people consider an oscilloscope a "must-have"? A logic probe just doesn't
cut-it for rapidly changing pins. Does simulation using MPLAB completley
eliminate the need for real circuit checking? (I'd be surprised).

I have read very interesting .pdf from Tektronix which really pushes $$$
DPOs, but I do not have a multi $k budget for my (new) hobby.

Can anyone recommend an entry-level 'scope for use in developing PIC
circuits/applications.

My budget is not without limits, but I want to get something that will be
useful. Is spending, say, < $500 a fruitless exercise?

TIA.

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2002\02\03@235244 by Dale Botkin

flavicon
face
On Sun, 3 Feb 2002, Gary Russell wrote:

> I am just a home hobbyist (no corporate $$ to help out).
>
> I have a background in software and have just started to experiment with
> microcontroller application development.
>
> Do people consider an oscilloscope a "must-have"? A logic probe just doesn't
> cut-it for rapidly changing pins. Does simulation using MPLAB completley
> eliminate the need for real circuit checking? (I'd be surprised).

A 'scope is really nice to have, but I personally very rarely have to drag
it out.

> I have read very interesting .pdf from Tektronix which really pushes $$$
> DPOs, but I do not have a multi $k budget for my (new) hobby.

Of course -- they make a LOT of money pushing new, super-whizbang scopes.
If you're designing new 2GHz motherboards or UHF transceivers, you need a
high end scope.  If you're playing with 10 or 20MHz PICs, you don't need
anywhere near that kind of hardware.

> Can anyone recommend an entry-level 'scope for use in developing PIC
> circuits/applications.
>
> My budget is not without limits, but I want to get something that will be
> useful. Is spending, say, < $500 a fruitless exercise?

Not at all.  I have an old low-end Hitachi V-212 20MHz 'scope you could
probably pick up used for well under a hundred bucks, it's quite
sufficient for anything I've worked on lately.  You don't need a lot, but
at least a dual-channel with triggered sweep is good.  For a lot of years
I worked as a mainframe field engineer working on IBM gear.  We always
carried Tektronix 475 'scopes, which I have seen selling at under $200 on
eBay...  this floors me, these things are super nice.  If you can find one
with a DM44, so much the better - it's a piggyback digital multimeter.

Dale

--
http://www.piclist.com hint: The PICList is archived three different
ways.  See http://www.piclist.com/#archives for details.


2002\02\04@001936 by David Koski

flavicon
face
On Sun, 3 Feb 2002 22:41:29 -0500
Gary Russell <spam_OUTgary-russellTakeThisOuTspamPSUALUM.COM> wrote:

> I am just a home hobbyist (no corporate $$ to help out).
>
> I have a background in software and have just started to experiment with
> microcontroller application development.
>
> Do people consider an oscilloscope a "must-have"? A logic probe just doesn't
> cut-it for rapidly changing pins. Does simulation using MPLAB completley
> eliminate the need for real circuit checking? (I'd be surprised).

For a hobby, maybe it is not necessary to have a 'scope.  But I can think of a
times when a storage scope was worth its weight in gold.  Debugging I2C and SPI
drivers, finding compiler interrupt handler bugs, and presenting an oscillograph
to a memory manfuacterer showing their product is not to spec are a few.

> I have read very interesting .pdf from Tektronix which really pushes $$$
> DPOs, but I do not have a multi $k budget for my (new) hobby.
>
> Can anyone recommend an entry-level 'scope for use in developing PIC
> circuits/applications.

For a low cost storage 'scope see:

http://www.linkinstruments.com/oscilloscope21.htm

I think you can get a 100MSa/s for 525USD.

> My budget is not without limits, but I want to get something that will be
> useful. Is spending, say, < $500 a fruitless exercise?
>
> TIA.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@012849 by Aaron K

flavicon
I am kind of in the same boat you are - its a hobby, and I don't want to
spend thousands. I was seriously considering this product:
http://www.bitscope.com You can get either kits or assembled units, and it
uses your computer to display the data it captures (as either a scope or a
logic analyzer). Lots of good info on the site, its actually an open design,
so all the schematics and software are available. I don't own one (yet) so I
can't truly vouch for this product, but it looks really promising.

Aaron

{Original Message removed}

2002\02\04@045635 by Vit

picon face
Gary,

About a month ago I bought a Tektronix 475A Oscilloscope that Dale is
talking about, on eBay.  It cost me $252.45 including shipping.  That thing
is heavy and kind of beat up, but works very well - it's a 200Mhz scope with
two channels and a multimeter.  Once you compare it to RadioShack's 50Mhz
scope for $800, I think you would agree that it is an awesome deal.

I think you can get by without an oscilloscope, but when your circuit
doesn't work, it simplifies troubleshooting by letting you "see" what's
going on.  Logic probe can't do it for you.

Bottom line is, if you spend a lot of time dealing with circuits and don't
care about the instrument's appearance, I would go ahead and buy a used
scope.  Works just as good (perhaps even better) as a new one, but doesn't
cost as much.

Sincerely,

Vitaliy


<SNIP>

>We always
> carried Tektronix 475 'scopes, which I have seen selling at under $200 on
> eBay...  this floors me, these things are super nice.  If you can find one
> with a DM44, so much the better - it's a piggyback digital multimeter.
>
> Dale

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listservspamKILLspammitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@062317 by Dave Dilatush

picon face
Gary Russell wrote...

>Do people consider an oscilloscope a "must-have"?
My own personal opinion, yes.  It's one of those things which you don't
really "need" that frequently, but when you do need it, it has this
magical ability to transform the deeply mysterious into the blatantly
obvious.  An oscilloscope can save a **LOT** of time and frustration.

Unless you're doing a lot of high-speed digital work, though, I don't
think getting a scope with wide bandwidth gets you much added
troubleshooting power.  I'm still using the 20 MHz B&K two-channel scope
I bought for hobby use ten years ago, and am completely satisfied with
it.

Dave

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email .....listservKILLspamspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@063608 by Russell McMahon

picon face
> I am just a home hobbyist (no corporate $$ to help out).
>
> I have a background in software and have just started to experiment with
> microcontroller application development.
>
> Do people consider an oscilloscope a "must-have"? A logic probe just
doesn't
> cut-it for rapidly changing pins. Does simulation using MPLAB completley
> eliminate the need for real circuit checking? (I'd be surprised).

As lots of people are about to tell you, an oscilloscope is the most
indispensable iinstrument in the world. By dint of converting time domain
signals into eye-domain :-) signales it lets your brain input vast
quantities of otherwise unavailable information.

If you are going to deal with analog signals

Even if you are going to deal almost only with purely digital signals the
scope will be very useful.

If you deal with multiple digital channels the scope will be less useful
mainly because it is less than adequate for the task which is better suited
to a logic analyser BUT will still be far far better than alternatives.

Ideally you want dual trace and delayed timebase and as many MHz as possible
BUT a miniumum of a single channel with a good triggered sweep will be very
very useful.
At the very very bottom lvele you get old nasty single beam scopes without
proper triggering. These are extremely frustrating and will put you off
scopes.

Even a 5 MHz scope is useful for many things but 10 MHz is better, and
higher still better again.
A scope will display signals above its rated bandwidth at rapidly decreasing
amplitude but ideally you want a bandwidth at least as high as the maximum
pulse speed you want to observe. Thus you will still see a 20 MHz / 50 nS
single pulse  on a 20 MHz scope even though you are at (or theoretically
beyond) the limits of its ability.

If you can afford digital storage you will not regret having it but it is
not an essential to start with.

An oscilloscope is liable to be your most useful tool.



regards



               Russell McMahon












{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email EraseMElistservspam_OUTspamTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@072207 by Francisco Ares

flavicon
face
You may look in to http://xoscope.sourceforge.net/  and
http://www.bitscope.com/

Francisco


Russell McMahon wrote:

{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email @spam@listservKILLspamspammitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@095751 by John Hansen

picon face
A number of years ago I bought a used 15 MHz analog dual trace scope at the
Dayton Hamvention for $80.  A better $80 has never been spent.  This has
saved hours and hours of debugging time by allowing me to figure out
exactly what is going on rather than making educated guesses.  The MPLAB
simulator is not a complete substitute because it moves rather slowly
through timing loops when the stopwatch is enabled.  When you are dealing
with the timing of signals, the scope is a much more useful tool.   Given
that I was working with PIC's... mostly at 4 MHz... the 15 MHz bandwidth
limitation was never much of a problem

Recently my employer purchased a really nice Agilent mixed signal
scope.  Of course it does a lot that my old $80 scope won't do.   But I
survived quite nicely for several years with a cheap scope... it was well
worth the money.

John Hansen

At 10:41 PM 2/3/2002 -0500, Gary Russell wrote:
{Quote hidden}

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email KILLspamlistservKILLspamspammitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@101806 by Roman Black

flavicon
face
Dave Dilatush wrote:
>
> Gary Russell wrote...
>
> >Do people consider an oscilloscope a "must-have"?
>
> My own personal opinion, yes.  It's one of those things which you don't
> really "need" that frequently, but when you do need it, it has this
> magical ability to transform the deeply mysterious into the blatantly
> obvious.  An oscilloscope can save a **LOT** of time and frustration.
>
> Unless you're doing a lot of high-speed digital work, though, I don't
> think getting a scope with wide bandwidth gets you much added
> troubleshooting power.  I'm still using the 20 MHz B&K two-channel scope
> I bought for hobby use ten years ago, and am completely satisfied with
> it.


I think a decent dual trace cro is very important,
especially for a beginner who will gain a lot
from "seeing" what the electricity is doing.
Even 50MHz duals are cheap secondhand.
-Roman

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email RemoveMElistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@130819 by John Ferrell

flavicon
face
Good Tektronix scopes go begging on EBAY.

The 453 usually goes between $50-$75. It is a 50mhz scope with delayed
sweep. It weighs about 35 pounds, so plan shipping into the overall cost. I
have given away a 535, a 545 and a 514. All DC, greater than 5 mhz vertical
response. They are just too big for my shop. If you can afford a 475A
(250mhz) about $300, You will have to go to a modern scope (digital) to beat
it.

John Ferrell
6241 Phillippi Rd
Julian NC 27283
Phone: (336)685-9606
Dixie Competition Products
NSRCA 479 AMA 4190  W8CCW
"My Competition is Not My Enemy"



{Original Message removed}

2002\02\04@161509 by Dwayne Reid

flavicon
face
At 10:41 PM 2/3/02 -0500, Gary Russell wrote:

>Do people consider an oscilloscope a "must-have"? A logic probe just doesn't
>cut-it for rapidly changing pins. Does simulation using MPLAB completley
>eliminate the need for real circuit checking? (I'd be surprised).

You have a question about something that I feel *VERY* strongly about!

I consider a scope to be *essential* if you are going to be doing any
serious electronics work.  I use a dual trace analog scope (Tek 465) as my
main tool - I use more it than I use any other instrument.  Even more than
a multi-meter or DMM.  I reach for the scope probe whenever I need to
measure a voltage or see just the circuit is doing.

Most of the time, voltage measurements are qualitative and do not need a
lot of accuracy.  Is the supply sitting at about 5V?  The scope tells you:
yes - about 5V - nice and clean - no ripple or noise.  What about that pin
on the processor?  Touch the probe and see.

Spend some money on a used (but working!) analog scope and spend as much or
more money on a couple of used (but working!) Tek X10 scope probes.  Good
scope probes are essential - you will waste much time and frustration
working with cheap probes.  X10 probes are MUCH more useful than X1 but
switchable X1 - X10 Tek probes tend to be expensive - even used.  So stick
with X10 probes if you are on a budget.  eBay or a local hamfest are great
places to buy both scopes and probes.

If you have any budget left after buying the analog scope and probes, head
over to Oricom's site <http://www.oricomtech.com/indexa.htm> and take a
close look at Dan's pocket test bench.  Its a nice little add-on for a PC
or laptop that gives you digital scope capability, as well as logic
analyser, pulse generator, etc.  Dan has done a nice job on the package and
software and sells it for a very reasonable price.  But you won't use it
anywhere near as often as the analog scope.

dwayne


Dwayne Reid   <spamBeGonedwaynerspamBeGonespamplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax

Celebrating 18 years of Engineering Innovation (1984 - 2002)
 .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-
    `-'   `-'   `-'   `-'   `-'   `-'   `-'   `-'   `-'
Do NOT send unsolicited commercial email to this email address.
This message neither grants consent to receive unsolicited
commercial email nor is intended to solicit commercial email.

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email TakeThisOuTlistservEraseMEspamspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@161632 by Colin Constant

flavicon
face
Has anyone tried one of those multimeters that have a PC interface? Worth
having?

Thanks,
Colin

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email RemoveMElistservspamTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@170708 by David Duffy

flavicon
face
At 01:05 PM 04/02/2002 -0800, you wrote:
>Has anyone tried one of those multimeters that have a PC interface? Worth
>having?

I've used the RS232 interface on one of mine to log temperature for some
chicken egg incubators we made. Was handy to see how tight the temp
control was. It's a cheapish Brymen brand one. I also have a Bitscope but
must get around to getting the upgrade & writing some Delphi software to
drive it for custom applications.
Regards...

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listservEraseMEspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@172350 by John Ferrell

flavicon
face
I bought a METEK from Jameco several years ago. I don't recall using the PC
interface cable other than to check it out.
I could not be happier with the multimeter! It outperforms my Fluke 8060 at
a fraction of the cost.

John Ferrell
6241 Phillippi Rd
Julian NC 27283
Phone: (336)685-9606
Dixie Competition Products
NSRCA 479 AMA 4190  W8CCW
"My Competition is Not My Enemy"



{Original Message removed}

2002\02\04@173244 by leandro

picon face
Hi!

I Used the RS232 output from my DMM  (Voltkraft, true RMS autorange)
it's a nice feature, specially because this model has an Optocoupler,
so the measured source is isolated from the computer, I use this one with a
computer program in visual basic to plot the curve discharge/charge
of a battery, very useful when you design a battery charge :-)

But keep in mind that the readout speed is SLOOOOOW, about 1 read every 2
seconds,
but for my requirements are far enough!.
thisone sends a decimal value ever 2 seconds in 2400 baud N81

Oh another thing: Thinking about buy an Oscilloscope???, My humble opinion
is that
if you are a Pic programmer (or any processor) there is nothing more
usefull that a DSO
(Digital storage oscilloscope) I have the Tektronik TDS-220 dual trace 100 mhz
1 Gigasample, great machine, It's a little expensive but it worth every cent.
Sometimes when I can't get a pic program works, and I have no idea of what
is going on,
just program one pin in the PIC so that in a given moment a UP or DOWN
signal ocurrs and connect this to the TRIGGER input, and set the Scope for
single shot.

After that event, the oscilloscope will record all the information from the
triger moment to
ahead (depends on the timebase) later you can simply navigate the signals
to see what
hapened in this moment, this is an amazing capability that is impossible in
any analog
scope!.

hope be helpfull with my comments.

see you.

byby



Some hours ago you wrote:
>Date:    Mon, 4 Feb 2002 13:05:04 -0800
>From:    Colin Constant <EraseMEColin_Constant-NRspamRAYTHEON.COM>
>Subject: Re: [EE]:Oscilloscope
>MIME-Version: 1.0
>Content-Type: text/plain; charset=us-ascii
>
>Has anyone tried one of those multimeters that have a PC interface? Worth
>having?
>
>Thanks,
>Colin


_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com


--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email RemoveMElistservEraseMEspamEraseMEmitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@174458 by Lawrence Lile

flavicon
face
----- Original Message -----
From: "Colin Constant" <RemoveMEColin_Constant-NRspam_OUTspamKILLspamRAYTHEON.COM>
To: <RemoveMEPICLISTTakeThisOuTspamspamMITVMA.MIT.EDU>
Sent: Monday, February 04, 2002 3:05 PM
Subject: Re: [EE]:Oscilloscope
> Has anyone tried one of those multimeters that have a PC interface? Worth
> having?

I have a metek with a PC interface, and I used it a lot.  Didn't like the
software that came with it, so I hacked my own interface with visual basic.

One time I used it to calibrate a wind veloicity meter.  We hacked the wind
velocity meter to a tall pole on top of my pickup truck, tossed a generator
in the back, and my friend rode shotgun with a desktop PC in his lap (having
no laptop) taking data from the wind sensor.  I drove the rig.

We got it all together about midnight one Saturday night, and rode out into
the flats on a long straight road to do the calibration run.  I started out
driving down this highway at 5mph for a few  minutes, then 10 mph for a few
minutes, and so on whilst he operated the datalog program I wrote, jotting
down the speeds and making sure the data was being logged.

It was quite a sight, creeping along at 5mph in the night, with this crazy
sensor pole sticking up 15' high out of the truck bed whizzing away,

Well pretty soon some bright lights come up behind us.  It was a cop.  He
stopped us, and asked if we were drinking, then started examining the crazy
rig, the PC in the lap, and the running 120V generator on the back of the
truck, all inching down the road at a fast walk, with these two guys telling
this cockamamie story.  He was not convinced by our excuses  for a long
time.

When we finally talked our way out of jail, we resumed our slow test, 5mph
at a time.  The sensor blew up when we hit 50MPH, exploding in a flash of
plastic, metal, and duct tape.

It was the most fun I'd had in years.

--Lawrence

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email EraseMElistservspamspamspamBeGonemitvma.mit.edu with SET PICList DIGEST in the body


2002\02\04@190054 by Tim McDonough

flavicon
face
I have a Metex that works well. "Worth having" depends on your
application. I originally bought mine to log the discharge of some
NiCd battery packs and it worked out well.

Tim

> > Has anyone tried one of those multimeters that have a PC
interface? Worth
> > having?

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email RemoveMElistservKILLspamspammitvma.mit.edu with SET PICList DIGEST in the body


2002\02\05@104327 by Lawrence Lile

flavicon
face
> At 10:41 PM 2/3/02 -0500, Gary Russell wrote:
>
> >Do people consider an oscilloscope a "must-have"? A logic probe just
doesn't
> >cut-it for rapidly changing pins. Does simulation using MPLAB completley
> >eliminate the need for real circuit checking? (I'd be surprised).

Scopes are like libraries:

ANY scope is better than no scope.
Any library is better than no library.

A fast scope is better than a slow scope
A two channel (or more) scope is better than a single channel scope
a DSO is better than an enalog scope, in most cases

but if you don't have any scope at all, and have no money, a really cheap
used student model from 1960 will be a great addition to your lab, and won't
set you back much more than a week's worth of  big macs.   90% of what you
use a scope for will be will under 1 mHz, single trace, repetitive waveforms
that won't require DSO.

Another guy in the lab gave his old scope to his kids, who built it into
part of their "submarine control room" consisting of blamkets over cardboard
boxes, a cheap student model scope, some relays and wires and a burned out
audio board.

--Lawrence

--
http://www.piclist.com hint: To leave the PICList
piclist-unsubscribe-requestSTOPspamspamspam_OUTmitvma.mit.edu


2002\02\05@105919 by Josh Koffman

flavicon
face
Also don't discount the (really) cheap approach. There is a program
called DigiTrace out there. Basically it turns your parallel port into a
logic analyzer. You just have to build a cable that hooks your port up
to your project. No circuitry involved...just a cable. It's a great
program, and you get some pretty good results considering the price. It
has saved my butt a couple of times at least. The one thing I'm not
exstatic about is that when you exit the program, I think it turns the
port back to outputs, and if your cable is still connected, you can get
some wierd results. That one freaked me out once :) I tried to contact
the author of the program about adding a small buffer that could be
tristated when the program exits, but I have yet to see a response (~1-2
months). Eventually when I find time, I will try to figure out if when
the program is loaded, it happens to toggle some other bit on the
parallel port, which I could then hook to a buffer. If anyone else has
time to do this first, please share :)

This program is windows based. I've only ever run it on win98. The
timing seems to be fairly accurate, it runs through a self calibration
when you start it. If you play with the value you lose timing accuracy,
but you can see more than one iteration of the waveform. Here is a link
for the page: http://www.xs4all.nl/~jwasys/old/diy2.html . I hope
someone else finds this as useful as I do!

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
       -Douglas Adams

> > I am just a home hobbyist (no corporate $$ to help out).
> >
> > I have a background in software and have just started to experiment with
> > microcontroller application development.
> >
> > Do people consider an oscilloscope a "must-have"? A logic probe just doesn't
> > cut-it for rapidly changing pins. Does simulation using MPLAB completley
> > eliminate the need for real circuit checking? (I'd be surprised).
>

--
http://www.piclist.com hint: To leave the PICList
spamBeGonepiclist-unsubscribe-requestSTOPspamspamEraseMEmitvma.mit.edu


2002\02\05@110523 by Douglas Butler

flavicon
face
My most common use for a scope is for RS232 or RS485 connections that
won't work.  The scope makes it obvious if the baud rate is wrong, if
the signal is inverted, if the signal really goes negative when it
should, how many data bit are there, etc.  For that a 5MHz single
channel would do, but I recommend at least two channels.

If money is short, (as usual) buy used gear locally so you can play with
it before buying.  If you buy used gear by mail you should know the gear
and/or the dealer well.  Don't worry about age as long as it is at least
transistorized.

The age of gear may become a factor in the future.  I have some analog
stuff built in the 60's that I use reguarly.  But if EPROMS are only
good for 10 to 25 years some of the digital stuff built in the 70's and
80's may start crapping out soon!

Sherpa Doug

P.S. If anybody knows of a modern replacement for a HP4800A Vector
Impedance Meter for under US$5000 please let me know.

> {Original Message removed}

2002\02\05@210306 by Russell McMahon
picon face
> ANY scope is better than no scope.

> but if you don't have any scope at all, and have no money, a really cheap
> used student model from 1960 will be a great addition to your lab, and
won't
> set you back much more than a week's worth of  big macs.


I agree with the above

BUT !!!

There really is a minimum level below which you have to work hard to make
your tool help you.
The really cheap 60's model student type instruments (eg some bottom end
Heathkit scopes etc) didn't have a triggered sweep that understood the
meaning of the word trigger, had no time base calibration, no vertical
amplitude calibration and more (or, rather, less).

While such scopes DO have a useful place when there is absolutely nothing
else you really really really should try and rise above this level if you
can. I would venture to suggest that an old valve scope with a decent
timebase and y amplifier with calibration would be more useful than a newer
bottom end largely solid state scope. (I've used both). I suspect you could
often do this for only tens of dollars in the US.

As noted before - more is always better but useful entry level is one
beam/trace, proper triggered sweep, calibrated sweep speeds, multi range
calibrated voltage input, 5 MHz bandwidth. After that a second trace is
pretty useful, more bandwidth is always nice, various sync modes, beam
add/subtract etc. Delayed sweep is very useful but usually comes after quite
a jump in other specs. Storage is nice but dearer. Old analog storage scopes
tend to be very dim, very dead, hard to use and cranky. The tube is a very
very major part of the system and they degrade terminally with age and are
cost far more than the scope is worth to replace. (Note that most scopes
have a single beam which is chopped or alternated to make two traces. True
dual beam scopes are rare - the feature is useful to have but only if
everything else meets your spec).

Probably un-useful thought - a modern PC would make an interesting high
speed scope using eg a Sigma Delta A2D if you could burrow under the
operating system and timers etc. You might be able to get many 10's of MHz
of analog bandwidth using a now entry level Celeron/AMD/xxx 850/1000 MHz cpu
and a parallel port.




       Russell McMahon

--
http://www.piclist.com hint: To leave the PICList
KILLspampiclist-unsubscribe-requestspamBeGonespammitvma.mit.edu


2002\02\06@022655 by Dave Dribin

flavicon
face
On Mon, Feb 04, 2002 at 01:37:59PM -0700, Dwayne Reid wrote:
> I consider a scope to be *essential* if you are going to be doing any
> serious electronics work.  I use a dual trace analog scope (Tek 465) as my
> main tool - I use more it than I use any other instrument.  Even more than
> a multi-meter or DMM.  I reach for the scope probe whenever I need to
> measure a voltage or see just the circuit is doing.

Would an analog scope, like the Tek 465, be useful for a serial
digital signal, like the PS/2 port on a PC?  I guess I'm asking, would
a used Tek 465 or a used TDS 210 be a better buy for a
beginner/hobbyist doing some PC integration projects?  From the looks
of it, a used TDS 210 goes for about 3 times a used Tek 465, but if
it's 3 times as useful, I may consider it.

-Dave

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@052138 by J.Feldhaar

flavicon
face
Hi Dave,

I bought my first 'scope when 13 years old, a Hameg 307, 10 MHz, one
channel, cost me more than half a year of my pocket money, and still my
father added abt 75% of the cost. Last April it celebrated its 20 th
anniversary, and I still use it some, it is still as good as it was 20
years ago.
Of course, I have progressed along the line, and my most recent buy was
a TEK 485 (350 MHz) for 700 Deutschmarks (abt. 300 $US), and I consider
this  one among the best 'scopes for any hobbyist - IF we are talking
analog 'scopes, that is.
I have worked several years as developer at a well-known 'scope
manufacturer in Frankfurt, Germany, they are called HAMEG, in the US
IIRC they are called B+C, this gave me a lot of insights also for
preferring analog 'scopes to digital ones for ALMOST any work.
I have used the TEK TDS220 and the big 300 series, and "I was not
amused"!
Cumbersome menus, knobs responding a lot after "realtime", and - hear,
hear - some nasty software errors, if you knew where to look for them...

My "I wish I had it" instrument is the TEK 2467, a 400 MHz unit with a
super optical amplification unit in front of the CRT. Price for this one
- albeit used - is absolutely prohibitive! But for the lucky guys who
have used it sometime, it is abolutely the best.

Greets
Jochen Feldhaar DH6FAZ
(BTW: I always use my analog 'scopes for looking at serial signals, to
check for baud rates and voltage levels. I even use the 'scope instead
of a multimeter in most instances where I am looking for a fault in some
circuitry)

Dave Dribin schrieb:
{Quote hidden}

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@083504 by Dale Botkin

flavicon
face
Absolutely, an analog scope is fine for digital signals.  IMHO a low end
analog scope would be far more useful than a low end digital scope, but
that's my opinion.  I have not used digital scopes extensively, but from
what I understand a cheaper DSO might nt have a hgh enough sample rate to
catch very short glitches.  You won't see a one-time glitch on an analog
scope either, but you won't miss any detail.

Dale
--
"Curiosity is the very basis of education and if you tell me that
curiosity killed the cat, I say only the cat died nobly."
         - Arnold Edinborough


On Wed, 6 Feb 2002, Dave Dribin wrote:

{Quote hidden}

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@084413 by D Lloyd

flavicon
face
part 1 3057 bytes content-type:text/plain; charset=us-ascii
Hi,

Dale wrote:
Absolutely, an analog scope is fine for digital signals.  IMHO a low end
analog scope would be far more useful than a low end digital scope, but
that's my opinion.  I have not used digital scopes extensively, but from
what I understand a cheaper DSO might nt have a hgh enough sample rate to
catch very short glitches.  You won't see a one-time glitch on an analog
scope either, but you won't miss any detail.

I agree with what Dale says especially with respect to digital signals;
this is where the low-end digital scopes are very useful. We have several
TDS-220s and we find them invaluable especially when debugging serial
comms/bit bash protocols; it is very easy to capture I2C sequences, for
example, which is very difficult using an analog scope. In the end, it
boils down to what you imagine you will use it for most.

I will say that when we introduced one of our contractors to the TDS-220,
he went and purchased his own almost the next day and he uses it day in-day
out.

Dan





(Embedded     Dale Botkin <EraseMEdalespamEraseMEBOTKIN.ORG>spamEraseMEMITVMA.MIT.EDU
image moved   06/02/2002 13:34
to file:
pic22413.pcx)





Please respond to pic microcontroller discussion list
     <@spam@PICLIST@spam@spamspam_OUTMITVMA.MIT.EDU>
Sent by:  pic microcontroller discussion list <spamBeGonePICLISTspamKILLspamMITVMA.MIT.EDU>


To:   .....PICLISTspam_OUTspamMITVMA.MIT.EDU
cc:
Subject:  Re: [EE]:Oscilloscope

Security Level:?         Internal


Absolutely, an analog scope is fine for digital signals.  IMHO a low end
analog scope would be far more useful than a low end digital scope, but
that's my opinion.  I have not used digital scopes extensively, but from
what I understand a cheaper DSO might nt have a hgh enough sample rate to
catch very short glitches.  You won't see a one-time glitch on an analog
scope either, but you won't miss any detail.

Dale
--
"Curiosity is the very basis of education and if you tell me that
curiosity killed the cat, I say only the cat died nobly."
       - Arnold Edinborough


On Wed, 6 Feb 2002, Dave Dribin wrote:

> On Mon, Feb 04, 2002 at 01:37:59PM -0700, Dwayne Reid wrote:
> > I consider a scope to be *essential* if you are going to be doing any
> > serious electronics work.  I use a dual trace analog scope (Tek 465) as
my
> > main tool - I use more it than I use any other instrument.  Even more
than
> > a multi-meter or DMM.  I reach for the scope probe whenever I need to
> > measure a voltage or see just the circuit is doing.
>
> Would an analog scope, like the Tek 465, be useful for a serial
> digital signal, like the PS/2 port on a PC?  I guess I'm asking, would
> a used Tek 465 or a used TDS 210 be a better buy for a
> beginner/hobbyist doing some PC integration projects?  From the looks
> of it, a used TDS 210 goes for about 3 times a used Tek 465, but if
> it's 3 times as useful, I may consider it.

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads






part 2 165 bytes content-type:application/octet-stream; (decode)

part 3 154 bytes
--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@085037 by Mitch Miller

flavicon
face
> Would an analog scope, like the Tek 465, be useful for a serial
> digital signal, like the PS/2 port on a PC?  I guess I'm asking, would
> a used Tek 465 or a used TDS 210 be a better buy for a
> beginner/hobbyist doing some PC integration projects?  From the looks
> of it, a used TDS 210 goes for about 3 times a used Tek 465, but if
> it's 3 times as useful, I may consider it.
>
> -Dave

I've never used an analog scope (well, not technically true, but not for
anything practical!), but do have a TDS-210.  I absolutely love it!  As a
hobbyist, I found it difficult to determine whether a resonator was
resonating, and if my project was not working because of a logic bug, or
because the micro had no clock!  As I moved into IIC communications, and
serial comms., the scope became complete indispensable ... it's amazing
how you can (with the right sweep rate) actually display and read the
digital data of an RS-232 connection running at 115,200 (or such).

I do mostly digital stuff and the digital scope has done me well.  For
someone with a broader analog requirements, an analog scope might be a
better choice.

-- Mitch

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@094324 by Kathy Quinlan

flavicon
face
----- Original Message -----
From: "Mitch Miller" <TakeThisOuTmitch.....spamTakeThisOuTMDMILLER.COM>
> I've never used an analog scope (well, not technically true, but not for
> anything practical!), but do have a TDS-210.  I absolutely love it!  As a
> hobbyist, I found it difficult to determine whether a resonator was
> resonating, and if my project was not working because of a logic bug, or
> because the micro had no clock!  As I moved into IIC communications, and
> serial comms., the scope became complete indispensable ... it's amazing
> how you can (with the right sweep rate) actually display and read the
> digital data of an RS-232 connection running at 115,200 (or such).
>

I would like to add, I have a TDS 220, and I would sell body parts to rasie
money to pay bills before parting with the scope.

I design equipment for DMX 512 stage lighting. The serial RS 485 stream runs
at 250Kbps, and I can get a good trigger and then move to any byte I wish to
observe and watch the bits toggle. (the data stream has 513 bytes (one start
byte and 512 data bytes))

I used to own a Kenwood cs 5165 IIRC triple channel 6 trace analogue scope
(the third channel was useless as it was a fix amplitude) and I would have a
hard job to keep it triggered while trying to watch a byte.

Another partially satisfied tek customer (not satisfied as the supplied
probes keep loosing tips, and the wave star software they give with the fft
comms module is next to useless, the new version costs a bit to upgrade to
:o()

Regards,

Kat.

____________________________________________________________________________
/"\   ASCII Ribbon Campaign  |        K.A.Q. Electronics
\ / - NO HTML/RTF in e-mail | Software and Electronic Engineering
X  - NO Word docs in e-mail  |      Perth Western Australia
/ \                                            |        Ph +61 419 923 731
____________________________________________________________________________

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@100650 by Gary Crum

picon face
Hello everyone,

Love the talk about the scopes, it's been on my mind too.
I think all of you have just modivated me to LUG my huge Tek 45A  from
storage to my shop
my grandpa gave it to me a long time ago, but I never did anything with it.

For those of you unfamilar with the Tek 45A.....  it's HUGE!!!
I'm not sure how old it is, but I'm pretty sure it's a tube scope.  I have a
"little" cart that it sits on
and I think you can rack mount it....  but I don't have a rack for it.

Hopefully it's good enough for what I need it for......   pic6F877 stuff....
20MHz
I'm not sure how fast the scope is.....
------
I'm looking into the OsziFOX  (ProbeScope).... it looks neat....small and
portable
I just got an email back from a sales person
checkout:
www.testequipmentdepot.com/Wittig/ozsifox.htm
they have the OsciFox for $69
   it comes with the Windows Software...... and the cables
for $10 you can get software that will work on the PalmPilot!!!!!!
which is what I was REALLY looking for.......so I think I'm gonna shell out
the bucks for that now.

--you can also find some software on sourceforge.net that will work with it
too.... for linux and other OS's

g



{Original Message removed}

2002\02\06@123907 by Lawrence Lile

flavicon
face
Maybe un-useful, but one I have thought of often.  Here's my thinking:
Forget trying to get high speed analog signals into your PC.  Have an
external box that captures the waveform, scales it, isolates it from your
precious PC's ground and power supply, and also scales it in the time
dinemsion, and wraps a nice ground plane around it..  Jam a bitstream into
whatever port is easy - RS232, parrallel, or USB (if it were a commercial
product USB would be the way to go) and use the PC's megabytes of memory for
the digital storage, use the PC's powqerful graphics for the display, and
use the brain for things like displaying the RMS value as a digital
voltmeter, counting the frequency, counting the pulse width, all the things
that take a lot of squinting or guessing on an old analog scope.  At least 4
channels, plus a few logic channels like an HP mixed signal scope.

Now if we are going to measure signals in the megahertz range, we are out of
the PIC's league.  How do TEK and the other big boys achieve A/D conversion
in a 100 mHz scope?

keep in mind this is just an interesting mental excercise - I'm not planning
on building this anytime soon.  Besides, they already make them.

--Lawrence


> Probably un-useful thought - a modern PC would make an interesting high
> speed scope using eg a Sigma Delta A2D if you could burrow under the
> operating system and timers etc. You might be able to get many 10's of MHz
> of analog bandwidth using a now entry level Celeron/AMD/xxx 850/1000 MHz
cpu
> and a parallel port.
>
>
>
>
>         Russell McMahon
>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@124441 by Dal Wheeler

flavicon
face
----- Original Message -----
From: Dave Dribin <TakeThisOuTdave-mlKILLspamspamspamDRIBIN.ORG>

> Would an analog scope, like the Tek 465, be useful for a serial
> digital signal, like the PS/2 port on a PC?  I guess I'm asking, would
> a used Tek 465 or a used TDS 210 be a better buy for a
> beginner/hobbyist doing some PC integration projects?  From the looks
> of it, a used TDS 210 goes for about 3 times a used Tek 465, but if
> it's 3 times as useful, I may consider it.

Well, I'd say yes.  For doing embedded work digital scopes are a huge help.
I got a used TDS 320 off of Ebay a while back for $350; it's in rough shape,
but very usable --nice to have a "real" digital scope at home.  We've got
TDS-420's at work that we use all the time.  We also have a TEK 465, but use
the TDS's more often, however there are times when you can't see whats
really going on with older digital scopes like we have.  The digital
phosphor scopes are nicer, but are still going for $$$.  These seem to do
the trick for now.

Before that, at home I used a RadioShack Probescope (aka OzziFox) that I got
when RS was closing them out ~$28.  --Its a little cumbersome, but you could
use it when a proper scope wasen't available.  Also, the thing is darn
portable.  These are offered up all the time on Ebay.

Anyway, if you're just tinkering at home, and can wait, maybe you could shop
around and see whats available.  If you get paid to tinker, I doubt you'd go
wrong going for the TDS210.  My old instructor used to say something like
"You never regret having the proper tools, but you can often regret not
having them."   :')

-Dal

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@130402 by Dave Dribin

flavicon
face
On Wed, Feb 06, 2002 at 07:34:19AM -0600, Dale Botkin wrote:
> Absolutely, an analog scope is fine for digital signals.  IMHO a low end
> analog scope would be far more useful than a low end digital scope, but
> that's my opinion.

Well, I like that opinion (probably because it's cheaper :).  As long
as an analog scope is "good enough" for my limited home use, I'd
rather save the few hundred dollars on PCB manufacturing or something.

BTW, are there any "buyer beware" questions I should ask and signs I
should look out for while buying a used analog scope?  Are there
certain parts that always break?  How important is calibration for
non-critical measurements?

Are there certain models that should be avoided due to notriously poor
quality?  Are there certain models that are notriously high quality?

Thanks again for all the good input so far, guys!

-Dave

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@132135 by Dave Dribin

flavicon
face
On Wed, Feb 06, 2002 at 10:42:03AM -0700, Dal Wheeler wrote:
> ----- Original Message -----
> From: Dave Dribin <.....dave-mlspamRemoveMEDRIBIN.ORG>
>
> > Would an analog scope, like the Tek 465, be useful for a serial
> > digital signal, like the PS/2 port on a PC?  I guess I'm asking, would
> > a used Tek 465 or a used TDS 210 be a better buy for a
> > beginner/hobbyist doing some PC integration projects?
>
> Anyway, if you're just tinkering at home, and can wait, maybe you could shop
> around and see whats available.  If you get paid to tinker, I doubt you'd go
> wrong going for the TDS210.  My old instructor used to say something like
> "You never regret having the proper tools, but you can often regret not
> having them."   :')

Yeah, I totally agree about having the proper tools.  I'm just trying
to find the minimum I can skirt by with.  If I got paid to tinker
(i.e.  price really wasn't a limiting factor), I'd definitely go with
a new DSO.  But if I can monitor signals like I2C and PS/2 with a used
analog scope, I'll probably go that direction.

-Dave

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@133211 by Martin Peach

flavicon
face
The commonest gotcha with a digital scope is aliasing caused by the sampling
frequency being too slow. If you want to look at a 20MHz square wave you
need to sample at >100MHz to have even an idea of what it looks like. I was
snagged for a while looking at what was supposed to be a 4MHz PIC oscillator
(using a Tek THS720) and seeing a perfect sine wave of several kHz, thinking
something was very wrong but finally just changing the timebase clarified
the situation. I would not have had the problem using my ancient Heathkit
20MHz single-trace scope that I had to throw out after a filter cap broke
down and burned out a transformer winding: impossible to get parts.
/\/\/\/*=Martin

{Original Message removed}

2002\02\06@142711 by Tim McDonough

flavicon
face
> Yeah, I totally agree about having the proper tools.  I'm just
trying
> to find the minimum I can skirt by with.  If I got paid to tinker
> (i.e.  price really wasn't a limiting factor), I'd definitely go
with
> a new DSO.  But if I can monitor signals like I2C and PS/2 with a
used
> analog scope, I'll probably go that direction.

There is always a market for working, used test equipment. You can
probably grow your capability pretty painlessly as your needs and
budget grow. If you purchase a used scope (analog or digital) at a
fair price and take care of it you'll get a lot of your money back
when you trade up some day.

My first scope at home was a 20MHz Dual Trace Hitachi. I bought it at
a Hamfest for $90USD, used it for about 5 years and sold it for
$75USD. Pretty low cost of ownership considering all of the projects
it worked on.

Tim

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@143546 by Dwayne Reid

flavicon
face
At 11:55 AM 2/6/02 -0600, Dave Dribin wrote:
>On Wed, Feb 06, 2002 at 07:34:19AM -0600, Dale Botkin wrote:
> > Absolutely, an analog scope is fine for digital signals.  IMHO a low end
> > analog scope would be far more useful than a low end digital scope, but
> > that's my opinion.
>
>Well, I like that opinion (probably because it's cheaper :).  As long
>as an analog scope is "good enough" for my limited home use, I'd
>rather save the few hundred dollars on PCB manufacturing or something.

I use both analog (Tek 465) and digital (Tek THS-720P) scopes and find I
use the analog scope FAR more often than the digital.  I agree with Dale -
if you have a limited budget, spend it on an analog scope.  But like I
mentioned earlier, buy decent scope probes too.  If you buy a used scope
off eBay, expect to spend as much on probes as you paid for the scope.  I
really can't emphasize enough just how important good probes are.  Stick
with Tek X10 probes unless you get a great deal on Tek X1-X10
probes.  Avoid the cheap import X1-X10 probes - they break easily and just
don't work well.

>BTW, are there any "buyer beware" questions I should ask and signs I
>should look out for while buying a used analog scope?  Are there
>certain parts that always break?  How important is calibration for
>non-critical measurements?

Make sure the trace is bright and focused over the entire screen.  Wiggle
(side to side as well as up & down) all the controls and rotate them over
the whole range - you are looking for noise or bad connections.  Feed a
variable frequency square wave signal into the vertical inputs (DC coupled)
and see just how square it looks.

>Are there certain models that should be avoided due to notriously poor
>quality?

No idea.

>  Are there certain models that are notriously high quality?

Tektronix!  Just excellent!

dwayne


Dwayne Reid   <RemoveMEdwaynerspamspamBeGoneplanet.eon.net>
Trinity Electronics Systems Ltd    Edmonton, AB, CANADA
(780) 489-3199 voice          (780) 487-6397 fax

Celebrating 18 years of Engineering Innovation (1984 - 2002)
 .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-.   .-
    `-'   `-'   `-'   `-'   `-'   `-'   `-'   `-'   `-'
Do NOT send unsolicited commercial email to this email address.
This message neither grants consent to receive unsolicited
commercial email nor is intended to solicit commercial email.

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@145209 by Lawrence Lile

flavicon
face
I knew somebody had done it.

BTW, the link you sent was really interesting, but didn't seem to have much
to do with a scope.
--Lawrence

{Original Message removed}

2002\02\06@154454 by Dal Wheeler

flavicon
face
----- Original Message -----
From: Lawrence Lile <spamBeGonellile@spam@spamspam_OUTTOASTMASTER.COM>
To: <TakeThisOuTPICLISTspamspamMITVMA.MIT.EDU>
Sent: Wednesday, February 06, 2002 12:51 PM
Subject: Re: [EE]:Oscilloscope


> I knew somebody had done it.
>
> BTW, the link you sent was really interesting, but didn't seem to have
much
> to do with a scope.
> --Lawrence

Well, no, but the fundamental components are there.  You mentioned that a
pic probably wasen't up to it previously, but it really doesn't need to be
part of the actual aquisition circuit using the techniques shown in the
video digitizer.  Fill up the FIFO using a HS clock, use the pic to poll the
ram and send it serially; like the bitscope...  Actually he does have a
20MHz generic sampler somewhere on that site...

PS sorry responding directly to you, I hit reply and didn't send to the
list...
>
> ----- Original Message -----
> From: "Dal Wheeler" <dwheelerEraseMEspaminsightek.net>

> > Doesn't this sound like the Bitoscope project?
> >
> > I thought about rolling my own someday too though...
> > Something roughly like this: (only faster)
> > http://www.techmind.org/vd/mk1/vdescrpt.html
> > Slap a different trigger on it; higher clock and smaller buffer,
multiple
> > similtaneous channels, 8 fast comparitors into an extra FIFO,No fpga on
> > it...?

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@154517 by Roman Black

flavicon
face
> >BTW, are there any "buyer beware" questions I should ask and signs I
> >should look out for while buying a used analog scope?  Are there
> >certain parts that always break?  How important is calibration for
> >non-critical measurements?

Calibration is normally good on more "modern"
cros, generally anything 20MHz dual trace or 50MHz
dual trace will have ok calibration, even the cheap
asian brands. I've owned a few.

As they age the electro caps can get ESR faults,
these change performance over time and heat. Most
typically the symptoms are that the timebase or
vertical amp will change over time, so a 10v dc
input may start ok reading 10v than read 10.5v
when the cro is hot. (or freq change) This only
takes 10 mins to test. Also check with a hard
to trigger signal and adjust the triggering so
it JUST triggers, then wait for it to get hot and
see if the triggering circuit goes iffy.
A good signal for this is a composite video from
an AV plug on a VCR etc.

The MOST COMMON fault is "scratchy" pots, like
an audio pot they "crackle" when moved and will
cause movement or jumping of the trace. Watch the
trace while you wiggle and slowly turn the pots.
Sometimes that can be fixed by spraying with
pot cleaner, but likely they will never be perfect
again.

Also look for any burnt-in lines across the screen
showing the cro has seen long hours of use.
:o)
-Roman

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@165605 by Josh Koffman

flavicon
face
I really want one of these: http://www.jwardell.com/about/seniorproj/ .
Seems ideal for me for so many applications. Also begging to be open
sourced...a $25 scope would help so many people out (ok, ok I know you
gotta pay for the Palm too). Unfortunately every time I check with one
of the guys who designed it, he tells me that Syracuse University is
still pulling an intellectual property thing, and that he can't give me
any more information bout it. Now since all the guys have graduated, he
says the project is pretty much dead. Does anyone know how to get around
intellectual property crap like this? Seems like the university is
limiting education, not helping it along. Any ideas? Did I mention I
really really want one? :)

Josh

--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
       -Douglas Adams

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@165817 by leandro

picon face
Hi Dave

The 465 is a nice Scope! however, not a DSO at all, and I think that
Digital storage is a requirement for capture data from Rs232, It would be
useful to see if the voltage changes are right, but to see
what data is going on, how many bits, and stuff like that, you need a
digital storage.

You need Digital Storage for that, I have at home the TDS 220 and is a
amazing machine, I can see almost everything, and I think that it worth
every cent I spend on it, but , I buy it because I work at home.  if you
intend to use it for hobby maybe it's a little expensive for that :-)

I think that If you want an Oscilloscope for digital use, and hobby only,
you can use a
computer based scope, they are far more cheaper (yet not as good as a
TDS-210) and
is good for digital signals.

an even cheaper way for digital analisys are parallel port "software" logic
analyzer.

There is one at: http://www.xs4all.nl/~jwasys/old/diy2.html

the program is called : digitrace_win95.zip

I downloaded the software (the only necessary thing), but don't tested yet,
it uses the
parallel port directly as digital inputs directly.
Does not have too much storage 32K samples only, but It can be enough for
Rs232 capture.

see you

Leandro


At 01:18 06/02/2002 -0600, you wrote:
>Would an analog scope, like the Tek 465, be useful for a serial
>digital signal, like the PS/2 port on a PC?  I guess I'm asking, would
>a used Tek 465 or a used TDS 210 be a better buy for a
>beginner/hobbyist doing some PC integration projects?  From the looks
>of it, a used TDS 210 goes for about 3 times a used Tek 465, but if
>it's 3 times as useful, I may consider it.
>
>-Dave


_________________________________________________________
Do You Yahoo!?
Get your free @yahoo.com address at http://mail.yahoo.com


--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@175252 by Bob Barr

flavicon
face
On Wed, 6 Feb 2002 18:58:30 -0300, leandro wrote:

>Hi Dave
>
>The 465 is a nice Scope! however, not a DSO at all, and I think that
>Digital storage is a requirement for capture data from Rs232, It would be
>useful to see if the voltage changes are right, but to see
>what data is going on, how many bits, and stuff like that, you need a
>digital storage.
>

Sorry to disagree but a DSO is not really a *requirement* to scope
RS232 data. Folks were scoping RS232 data long before DSO's came into
existence (or at least commonly available).

With proper  triggering, sweep rate, and a repeating data pattern,
RS232 data can be quite easily seen on an analog scope. The ability to
'de-calibrate' also allows you to set the sweep for one division per
bit time. Very handy.

This isn't to say that DSO's aren't very good tools; they are. Analog
scopes, though, are a good alternative in many cases.


Regards, Bob

<snip>

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@200009 by Dale Botkin

flavicon
face
On Wed, 6 Feb 2002, Bob Barr wrote:

> Sorry to disagree but a DSO is not really a *requirement* to scope
> RS232 data. Folks were scoping RS232 data long before DSO's came into
> existence (or at least commonly available).

Amen!  I'm one of them.  Of course the last time I did it, 19200 was
considered pretty fast ;) but of course the speed doesn't matter, until
you get really sloooow, when phosphor starts to fade between bits...

I've occasionally wished for a DSO when looking at hard to reproduce
one-shot events, but since I already have a CRO I seriously doubt I'll
ever need one badly enough to actually shell out cash for one.

Dale

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@212030 by John Ferrell

flavicon
face
Also beware of dim traces. Short pulses in long time intervals will get too
faint to be usable.
John Ferrell
6241 Phillippi Rd
Julian NC 27283
Phone: (336)685-9606
Dixie Competition Products
NSRCA 479 AMA 4190  W8CCW
"My Competition is Not My Enemy"



{Original Message removed}

2002\02\06@214838 by Spehro Pefhany

picon face
At 11:55 AM 2/6/02 -0600, you wrote:

>Are there certain models that should be avoided due to notriously poor
>quality?  Are there certain models that are notriously high quality?

Some of the Tek models use hybrids in the deflection circuits. They
are not repairable except by cannibalizing another 'scope as the
hybrids were proprietary/in-house and Tek has gotten rid of their
hybrid facility but kept the design secret. "U401"  ;-)

Best regards,


Spehro Pefhany --"it's the network..."            "The Journey is the reward"
RemoveMEspeffEraseMEspamspam_OUTinterlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
9/11 United we Stand

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@224824 by Kevin Fisk

flavicon
face
Spehro, or anyone else for that matter: any chance you can share the
"models"?

> At 11:55 AM 2/6/02 -0600, you wrote:
>
>> Are there certain models that should be avoided due to notriously poor
>> quality?  Are there certain models that are notriously high quality?
>
>
> Some of the Tek models use hybrids in the deflection circuits. They
> are not repairable except by cannibalizing another 'scope as the
> hybrids were proprietary/in-house and Tek has gotten rid of their
> hybrid facility but kept the design secret. "U401"  ;-)

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@225525 by Scott Newell

flavicon
face
>> Some of the Tek models use hybrids in the deflection circuits. They
>> are not repairable except by cannibalizing another 'scope as the
>> hybrids were proprietary/in-house and Tek has gotten rid of their
>> hybrid facility but kept the design secret. "U401"  ;-)

>Spehro, or anyone else for that matter: any chance you can share the
>"models"?

I've got a 7934 with hard-to-get hybrids in it; the same devices are also
used in some of the 7104, 7103, and maybe 7904A units as well.  The 2465
series is notorious for parts made of unobtanium.


newell

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\06@232621 by Spehro Pefhany

picon face
At 07:22 PM 2/6/02 -0800, you wrote:
>Spehro, or anyone else for that matter: any chance you can share the
>"models"?

The 2445/65, according to the info I have. Tek sold off their hybrid
division to Maxim, who decided Tek wasn't buying enough and they'd
discontinue the chips (Horizontal output), so Tek did a last time
buy. The parts from the last time buy had an abnormally high
failure rate. This, from a Tek insider at the time (not me).
Tek also has closed their repair department and subs it to 3rd
party cal/repair, BTW.

I have no way of verifying it, but it seems plausible.

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
@spam@speffRemoveMEspamEraseMEinterlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
9/11 United we Stand

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


2002\02\07@041423 by Michael Rigby-Jones

flavicon
face
Not really what the OP was after, but a couple of us at work built the
GameBoy DSO and I have found it very usefull for relatively low frequency
jobs where power is a problem e.g. checking igntion/injector waveforms on
car enignes.  Only real downer is the author signed a deal with Elektor so
he can't open the source code.

http://www.semis.demon.co.uk/Gameboy/DsoDemo/DsoDemo.htm

Regards

Mike

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\02\07@042158 by Alan B. Pearce

face picon face
>Are there certain parts that always break?

Yes, probes. Always have some cheap probes available that you normally use,
and keep the expensive wide band/high quality ones in a draw for when you
need them. Probe leads always manage to get tangled where you least need
them and get pulled so that the inner core of the coax breaks or goes
intermittent. If you can find cheap probes with a replaceable lead, they may
be worth investigating.

You will find that cheap probes will generally be designed for 50 or 100Mhz
bandwidth, so with most scopes will not be too limiting. It is only when you
go to a 200+MHz scope that the differences really become apparent.

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\02\07@042721 by Alan B. Pearce

face picon face
>>  Are there certain models that are notriously high quality?

>Tektronix!  Just excellent!

Or Hewlett Packard/Agilent. Either Tek or HP are really the best when it
comes to 'scopes.

The biggest problem you will have with trying to look at serial transmission
(I2C, SPI, RS232) with an analogue scope is that it is hard to "read" the
data unless you have a reliable trigger point and a repetitive wave form
(identical data going across each time). This is where the digital scope
scores because you can do single shot displays. If it is more a case of
looking for marginal levels, then an analogue unit will be OK.

However there is always the possibility of building a digital storage unit
to use with an analogue scope if you need to look at serial data. This may
be useful as you can then set the amount of storage available :)

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\02\07@090020 by Spehro Pefhany

picon face
At 09:08 AM 2/7/02 +0000, you wrote:
> >>  Are there certain models that are notriously high quality?
>
> >Tektronix!  Just excellent!
>
>Or Hewlett Packard/Agilent. Either Tek or HP are really the best when it
>comes to 'scopes.

Everyone seems to believe that, with the consequence that other brands
can be cheaper to buy for the same functions. I have a compact 20MHz one
that I keep on my office mini-bench that does 90% of what is needed and
leaves room for everything else. Cost? Maybe $140 US including the 'scope,
reprinted service manual, and two nice new generic probes. The Tek gets
used when its needed, but often most of the work is in the software, the
analog stuff just needs a quick test or two). I picked up a cute little
Tenma (Taiwan made)  3" scope (needs a new cap in the power supply) for
$10 that will live in a  semi-permanent test fixture for one product
line.

The only ones I'd absolutely avoid are the old vacuum tube Eico and
Heathkit ones unless you absolutely can't afford anything more than
$15-$25- even a 1MHz scope is sometimes better than nothing! There are
still even a few Tek vacuum tube scopes that are still worth having if you
have more room than money. Also, take care on ebay, there are stories of
known bad stuff being sold, so do watch feedback ratings and so on.
Watch out when there is no return policy and the seller claims not to
know anything. For example, there is a  problem on the 4xx series with
attenuator contacts, IIRC, and those can be hard to fix, I understand.

But, used test equipment dealers are so expensive that you could buy a
couple from ebay and still come out ahead.

P.S. I've heard Frys (SW USofA) sometimes has good prices on some of the
little Tek TDS portable digital LCD scopes.

http://www.tek.com/Measurement/cgi-bin/framed.pl?Document=/Measurement/scopes/index/prodindex_handheld.html&FrameSet=oscilloscopes

(of course they are more than $500, but $900+tax might be within reach).

Best regards,

Spehro Pefhany --"it's the network..."            "The Journey is the reward"
EraseMEspeffspam@spam@interlog.com             Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog  Info for designers:  http://www.speff.com
9/11 United we Stand

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\02\07@103813 by Al Williams

flavicon
face
Somehow I wound up replying directly on this, so here it is again...
(Sorry Lawrence)

The bitscope project is nice. Velleman has some assembled PC scopes at
about the same price point (with plusses and minuses over bitscope).
I've been spoiled to have Tek and HP analog and storage scopes over my
entire career, but I've often thought that for the hobbyist, a scope is
a big investment. The PC soundcards scopes are probably better than
nothing but not accurate for quantitative measurements. I've often
wondered what you could do to make a cheap hobby scope. I've thought
about an A/D, a counter, a memory system, and a CPU, but then you have
bitscope and you probably can't do it for much less money. $200-$300
will buy a pretty nice used scope so there isn't as much incentive.

Some of my wilder ideas:

It sure seems like you could make a multisync monitor into a bizzare
scope with just a little hassle. 15" monitors are cheap as can be these
days. Drive the horizontal at the sweep frequency. You can convert the
signal to 8 bits using an A/D and feed the green (mono) input. Count
lines to skip a little bit between "traces" and use a counter to
generate a vertical sync. So you wind up with a 3D scope where the
amplitude is the brightness of the "trace" and you get a bunch of traces
on the screen at once. Probably not very practical.

We've all see the propeller clocks and the little LED "metronomes" that
display messages in the air. Wouldn't a scope like that be cool? An
LM3909 (bar graph driver, right?), and LED bar, and a motor spinning at
the horizontal sweep frequency. Blank it between pi and 2pi.  I wonder
if you could have one blade of the propeller do channel 1 and the other
blade channel 2? While one is blank, you drive the other one (chop only,
no alt).

I remember seeing plans years ago for driving an old TV's sweep circuits
to make a scope. That's always been an interesting idea to me but it
seems too hard to go find the right spots. Easier to display on a PC.

A while back I did a "stamp project of the month" where we took our
APP-II (basically a PIC16F873) converted analog samples and drove a VB
program to make a kind of scope. Not especially fast but sort of cool.

Anyway, just random musings....

Al Williams
AWC
* Floating point A/D
http://www.al-williams.com/awce/pak9.htm



> {Original Message removed}

2002\02\07@120101 by Josh Koffman

flavicon
face
The other thing I heard is that the magazine isn't going to be supplying
ROMs for much longer (they might have stopped already), which means that
again, the information is out there, but you can't get access to it. The
author can't distribute it, and the magazine won't.

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
       -Douglas Adams

Michael Rigby-Jones wrote:
{Quote hidden}

--
http://www.piclist.com hint: The list server can filter out subtopics
(like ads or off topics) for you. See http://www.piclist.com/#topics


2002\02\09@005135 by Josh Koffman

flavicon
face
I think this is somewhat appropriate :)
http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1072240233

Josh
--
A common mistake that people make when trying to design something
completely foolproof is to underestimate the ingenuity of complete
fools.
       -Douglas Adams

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email @spam@listservspam_OUTspam.....mitvma.mit.edu with SET PICList DIGEST in the body


2002\02\11@032533 by Michael Rigby-Jones

flavicon
face
> -----Original Message-----
> From: Josh Koffman [SMTP:spamBeGonelistsjoshEraseMEspam3MTMP.COM]
> Sent: Thursday, February 07, 2002 5:17 PM
> To:   PICLISTspamBeGonespamMITVMA.MIT.EDU
> Subject:      Re: [EE]:Oscilloscope
>
> The other thing I heard is that the magazine isn't going to be supplying
> ROMs for much longer (they might have stopped already), which means that
> again, the information is out there, but you can't get access to it. The
> author can't distribute it, and the magazine won't.
>
> Josh
>
Just checked on the Elektor web site, and they have 30 complete (ready
built) cartridges left at the 'special' sale price of $135 (76.50ukp).  That
doesn't seem very special compared to the Oszifox which has a 20MS/s sample
rate, and has a built in LCD.  The gameboy cartridge is two channel though,
and I have found it usefull.  But then, a couple of us in work built them
and we only had a buy a few components (ROM, PCB and a couple of op-amps),
the rest we "found" in our lab :o)

The site is also showing the PCB for $16.50 and the EPROM for $28.00.  If it
ever gets to the state when neither Elektor nor the author will supply the
EPROM/hex file then I may be able to help (but not until/if that situation
arises).

Mike

--
http://www.piclist.com hint: PICList Posts must start with ONE topic:
[PIC]:,[SX]:,[AVR]: ->uP ONLY! [EE]:,[OT]: ->Other [BUY]:,[AD]: ->Ads


More... (looser matching)
- Last day of these posts
- In 2002 , 2003 only
- Today
- New search...