O-scope question...

S

sbrehler

Guest
Hi all,

Please accept my applogies if this isn't the correct group in which to post
this question...

I am looking to purchase a entry/mid-level O-scope and have been eyeing a BK
precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w

I have tried to find some reviews on the web (and other newsgroups), but to
no avail. All I find are retailer descriptions and specifications. It seems
like a good piece of equipment for the price. I was wondering if any of you
have any experience with this box and would be will to share your
experiences with it...good or bad. If I'm going down the wrong road on this,
would you recommend another path?

As an aside...

I will also be looking into a soldering/desoldering station at some point
soon. I am rather confused as to what would be a good mid-level system. I do
conventional board work, but hope to venture into the SMT arena. Something
in the $250 +/- range. Any thoughts?

Thank you for any help you can provide...

Scott
 
On Mon, 3 Nov 2008 14:51:43 -0500, "sbrehler" <sbrehler@mndspring.com>
wrote:

Hi all,

Please accept my applogies if this isn't the correct group in which to post
this question...

I am looking to purchase a entry/mid-level O-scope and have been eyeing a BK
precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w

I have tried to find some reviews on the web (and other newsgroups), but to
no avail. All I find are retailer descriptions and specifications. It seems
like a good piece of equipment for the price. I was wondering if any of you
have any experience with this box and would be will to share your
experiences with it...good or bad. If I'm going down the wrong road on this,
would you recommend another path?
Click to expand...
well, I have an ancestor of that from around 1980, a 30 MHz B&K 1474,
which is still alive and working. If you're going for a new analog
scope, that one is a reasonable choice.

As an aside...

I will also be looking into a soldering/desoldering station at some point
soon. I am rather confused as to what would be a good mid-level system. I do
conventional board work, but hope to venture into the SMT arena. Something
in the $250 +/- range. Any thoughts?
Click to expand...
Web-tronics has several "no name" systems that look suspiciously like
Xytronic and Aoyue. Probably all made in the same factory ...

Howard Electronics has name brand stuff Xytronic and Edsyn.

For occasional surface mount rework, or just an added tool in your kit,
also look at Chip Quik.

http://webtronics.stores.yahoo.net/sore.html
http://www.howardelectronics.com/index.html
http://www.chipquikinc.com/

--
Rich Webb Norfolk, VA
 
On Mon, 03 Nov 2008 14:51:43 -0500, sbrehler wrote:

Hi all,

Please accept my applogies if this isn't the correct group in which to
post this question...

I am looking to purchase a entry/mid-level O-scope and have been eyeing a
BK precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w
...
It seems like a good piece of equipment for the price.
Click to expand...
It's good equipment, but SIX HUNDRED BUCKS? You could get a used TEK on
ebay for $200-$300.

But, if you like the price, go for it.

(my scope was free - it belonged to some guy in the shop, who quit and
left the scope - the guy who took over his area tossed the scope into
the dumpster! It was circa Halloween, so I told everybody it was a gift
from the Great Pumpkin. ;-) )

I also can't see paying $250 for a soldering iron - if your $15.00 iron
gets too hot, get a lamp dimmer for five or ten bucks. :)

Have Fun!
Rich
 
"sbrehler"
I am looking to purchase a entry/mid-level O-scope and have been eyeing a
BK precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w
Click to expand...

** Looks much like any other, low cost Asian made scope - except for the
inclusion of delayed sweep.

Like all of them I have seen, there is no mention of a magnetic shield
being fitted to the CRT - this means the trace will wobble or shimmer if
ever you bring an AC supply transformer near the unit. Nearly ALL the famous
brand US or European brand scopes have magnetic ( ie Mu Metal ) shields on
the CRT to eliminate this.

Whether this matters to YOU depends on what sort of work you intend doing
and how you like to install the scope on your work bench.

Scopes are very much " horses for courses" and what one user loves another
will just HATE !!

Personally, I cannot bear to use a digital scope.



..... Phil
 
On Tue, 04 Nov 2008 12:50:21 +1100, Phil Allison wrote:

"sbrehler"

I am looking to purchase a entry/mid-level O-scope and have been eyeing
a BK precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?
gclid=CKq61L7h2ZYCFQNvHgodDnLe2w


** Looks much like any other, low cost Asian made scope - except for
the inclusion of delayed sweep.

Like all of them I have seen, there is no mention of a magnetic shield
being fitted to the CRT - this means the trace will wobble or shimmer
if ever you bring an AC supply transformer near the unit. Nearly ALL the
famous brand US or European brand scopes have magnetic ( ie Mu Metal )
shields on the CRT to eliminate this.

Whether this matters to YOU depends on what sort of work you intend
doing and how you like to install the scope on your work bench.

Scopes are very much " horses for courses" and what one user loves
another will just HATE !!

Personally, I cannot bear to use a digital scope.



.... Phil
Click to expand...
My 5MHz Heathkit scope has a mu-metal shield.

Or at least it has a shield of something that _looks_ like mu-metal.

Doesn't work for snot, though -- it wiggles all over in the presence of a
magnetic field. I think they just put something in there so it'd _look_
like it had a shield (either that, or there's something special about the
scope that makes it extra sensitive to mag fields, and it'd be tons worse
without the shield -- that's a scary thought).

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
"Tim Wescott"

My 5MHz Heathkit scope has a mu-metal shield.
Click to expand...
** ?????


Or at least it has a shield of something that _looks_ like mu-metal.

Doesn't work for snot, though -- it wiggles all over in the presence of a
magnetic field.
Click to expand...

** Tin plate shield - shields the sensitive internal circuity from ES
fields from the X and Y plates.

Even cheap Asian scopes will have one of them.

BTW:

There is a very simple and reliable test for the presence of a Mu-Metal
shield - first place the scope so the tube is facing straight up with the
trace line centred.

Then ROTATE the whole scope on its axis.

The line should not deflect more than 0.5mm.



....... Phil
 
"sbrehler" <sbrehler@mndspring.com> wrote in message
news:C9CdnYNH3JLTy5LUnZ2dnUVZ_jCdnZ2d@earthlink.com...
Hi all,

Please accept my applogies if this isn't the correct group in which to
post this question...

I am looking to purchase a entry/mid-level O-scope and have been eyeing a
BK precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w

I have tried to find some reviews on the web (and other newsgroups), but
to no avail. All I find are retailer descriptions and specifications. It
seems like a good piece of equipment for the price. I was wondering if
any of you have any experience with this box and would be will to share
your experiences with it...good or bad. If I'm going down the wrong road
on this, would you recommend another path?

As an aside...

I will also be looking into a soldering/desoldering station at some point
soon. I am rather confused as to what would be a good mid-level system. I
do conventional board work, but hope to venture into the SMT arena.
Something in the $250 +/- range. Any thoughts?

Thank you for any help you can provide...

Scott
Click to expand...
Thanks everyone. I've found one that's only $550 (such a deal). Which isn't

too bad. I was thinking of going Tektronix, buy they tend to be WAY

expensive. I'm not hard core at this point. I just need something that is

reliable and accurate...which you would think they would all be. :>(

I've watched this group for several years now and I value your input.

Thanks again!

Scott
 
Phil Allison wrote:
"Tim Wescott"

My 5MHz Heathkit scope has a mu-metal shield.


** ?????


Or at least it has a shield of something that _looks_ like mu-metal.

Doesn't work for snot, though -- it wiggles all over in the presence of a
magnetic field.


** Tin plate shield - shields the sensitive internal circuity from ES
fields from the X and Y plates.

Even cheap Asian scopes will have one of them.

BTW:

There is a very simple and reliable test for the presence of a Mu-Metal
shield - first place the scope so the tube is facing straight up with the
trace line centred.

Then ROTATE the whole scope on its axis.

The line should not deflect more than 0.5mm.

Ah. I don't think it's mu metal then.
Click to expand...

And it's not a cheap _Asian_ scope. It's a cheap _Oregonian_ scope (and
my first really bad experience with being color blind and doing
electronics -- there was this green wire and this gray wire, one of
which carried +12 and the other +160. Rather than beeping them out
before connection, I just guessed. And guess what happened!)

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
 
On Tue, 4 Nov 2008 12:50:21 +1100, "Phil Allison"
<philallison@tpg.com.au> wrote:

"sbrehler"

I am looking to purchase a entry/mid-level O-scope and have been eyeing a
BK precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w


** Looks much like any other, low cost Asian made scope - except for the
inclusion of delayed sweep.

Like all of them I have seen, there is no mention of a magnetic shield
being fitted to the CRT - this means the trace will wobble or shimmer if
ever you bring an AC supply transformer near the unit. Nearly ALL the famous
brand US or European brand scopes have magnetic ( ie Mu Metal ) shields on
the CRT to eliminate this.

Whether this matters to YOU depends on what sort of work you intend doing
and how you like to install the scope on your work bench.

Scopes are very much " horses for courses" and what one user loves another
will just HATE !!

Personally, I cannot bear to use a digital scope.



.... Phil
Click to expand...
My Tek TDS2012 doesn't have a CRT shield!

John
 
"Tim Wescott" <tim@seemywebsite.com> wrote in message
news:aaadnaBZCuD2H43UnZ2dnUVZ_gqdnZ2d@web-ster.com...
Phil Allison wrote:
"Tim Wescott"

My 5MHz Heathkit scope has a mu-metal shield.


** ?????


Or at least it has a shield of something that _looks_ like mu-metal.

Doesn't work for snot, though -- it wiggles all over in the presence of
a
magnetic field.


** Tin plate shield - shields the sensitive internal circuity from ES
fields from the X and Y plates.

Even cheap Asian scopes will have one of them.

BTW:

There is a very simple and reliable test for the presence of a Mu-Metal
shield - first place the scope so the tube is facing straight up with
the
trace line centred.

Then ROTATE the whole scope on its axis.

The line should not deflect more than 0.5mm.

Ah. I don't think it's mu metal then.

And it's not a cheap _Asian_ scope. It's a cheap _Oregonian_ scope (and
my first really bad experience with being color blind and doing
electronics -- there was this green wire and this gray wire, one of
which carried +12 and the other +160. Rather than beeping them out
before connection, I just guessed. And guess what happened!)

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" gives you just what it says.
See details at http://www.wescottdesign.com/actfes/actfes.html
Click to expand...
My Hitachi V-1065A has a mu-metal screen, yet still jiggles when perched on
top of a Thurlby PSU. Most wobbly bit is the readout characters displayed on
the screen lower edge.
 
"sbrehler" <sbrehler@mndspring.com> wrote in message
news:C9CdnYNH3JLTy5LUnZ2dnUVZ_jCdnZ2d@earthlink.com...
Hi all,

Please accept my applogies if this isn't the correct group in which to
post this question...

I am looking to purchase a entry/mid-level O-scope and have been eyeing a
BK precision 2125A (30Mhz, Dual Trace, Analog).

http://www.testequipmentdepot.com/bk-precision/oscilloscopes/2125a.htm?gclid=CKq61L7h2ZYCFQNvHgodDnLe2w

I have tried to find some reviews on the web (and other newsgroups), but
to no avail. All I find are retailer descriptions and specifications. It
seems like a good piece of equipment for the price. I was wondering if
any of you have any experience with this box and would be will to share
your experiences with it...good or bad. If I'm going down the wrong road
on this, would you recommend another path?
Click to expand...
What kind of stuff will you be working on?
$650 is a bit expensive for a low bandwidth analog scope these days. New
analog scopes are quite poor value for money IMO.
For almost the same money you can get one of the nice little low end digital
storage scopes. Rigol and Instek (goodwill) makes some good value ones. Both
are available from eBay and many other dealers.
A digital scope will likely be MUCH more useful to you for general purpose
work.

As an aside...

I will also be looking into a soldering/desoldering station at some point
soon. I am rather confused as to what would be a good mid-level system. I
do conventional board work, but hope to venture into the SMT arena.
Something in the $250 +/- range. Any thoughts?
Click to expand...
You can't go wrong with an industry standard Hakko 936, I've seen them for
under $100 in the USA shops like Fry's.
A second soldering iron is *very* handy for smd work.
A desoldering station might be overkill for you, get that second iron first.

Dave.
 
"John Larkin Fuckwit "

My Tek TDS2012 doesn't have a CRT shield!
Click to expand...

** Wouldn't do much if it did - would it ??

Fuckhead.



....... Phil
 
snip

What kind of stuff will you be working on?
$650 is a bit expensive for a low bandwidth analog scope these days. New
analog scopes are quite poor value for money IMO.
For almost the same money you can get one of the nice little low end
digital storage scopes. Rigol and Instek (goodwill) makes some good value
ones. Both are available from eBay and many other dealers.
A digital scope will likely be MUCH more useful to you for general purpose
work.

snip
Click to expand...

Dave.
Click to expand...
Dave,

Your reply came just in time. I was about to order the BK analog scope just
before your post! I have checked out the other mfgs. scopes and I do see
that you are absolutely right. I can get a DSO (40Mhz with lots of whistles
and bells) for only a few dollars more. I have a question though.

I'm going to be doing mostly educational work right now (I have a two-year
degree in Electronics, but will be persuing my EE this spring). But I do
like the thought of the DSO's due to the wide range of functions they
posess. One thing that I'm concerned about is "aliasing." I will be working
mostly with discrete components and microcontrollers with relatively low
frequencies/clock speeds; will a DSO present any difficulties along those
lines. From what I'm reading, it appears that a very low "sampling rate" can
cause erroneous measurments. I've heard others mention in the past something
about "real time" issues (perhaps due to the sampling problem?). When would
one want to have a very low sample rate? It would seem to me that the higher
the better. Anyway, I'm a little confused right now...

Thanks,

Scott
 
On Wed, 5 Nov 2008 11:55:30 -0500, "sbrehler" <sbrehler@mndspring.com>
wrote:

snip

What kind of stuff will you be working on?
$650 is a bit expensive for a low bandwidth analog scope these days. New
analog scopes are quite poor value for money IMO.
For almost the same money you can get one of the nice little low end
digital storage scopes. Rigol and Instek (goodwill) makes some good value
ones. Both are available from eBay and many other dealers.
A digital scope will likely be MUCH more useful to you for general purpose
work.

snip

Dave.


Dave,

Your reply came just in time. I was about to order the BK analog scope just
before your post! I have checked out the other mfgs. scopes and I do see
that you are absolutely right. I can get a DSO (40Mhz with lots of whistles
and bells) for only a few dollars more. I have a question though.

I'm going to be doing mostly educational work right now (I have a two-year
degree in Electronics, but will be persuing my EE this spring). But I do
like the thought of the DSO's due to the wide range of functions they
posess. One thing that I'm concerned about is "aliasing." I will be working
mostly with discrete components and microcontrollers with relatively low
frequencies/clock speeds; will a DSO present any difficulties along those
lines. From what I'm reading, it appears that a very low "sampling rate" can
cause erroneous measurments. I've heard others mention in the past something
about "real time" issues (perhaps due to the sampling problem?). When would
one want to have a very low sample rate? It would seem to me that the higher
the better. Anyway, I'm a little confused right now...
Click to expand...
A good thumb rule, which depends on resolution of the A/Ds and the
steepness of the scope's internal anti-aliasing filter but works pretty
well for general purpose digital scopes, is that you'll want the sample
rate to be about 10x the scope's analog bandwidth, and the analog
bandwidth to be 5x the highest frequency component of the measured
signal. So, roughly, a 40 MHz scope would need a real time (NOT
"equivalent time") sampling rate of 400 MHz and you'd be able to resolve
8 MHz square waves well enough to know they're not simple sines.

"Equivalent time" sampling depends on filling in the gaps by sampling
repeating waveforms, which is okay as long as your waveforms are truly
repetitive. For lots of interesting problems, this won't be the case.

WRT low sampling rates, they go together with slow sweep rates. Consider
how much data you'd need to store if the sweep takes an entire second
and then have to display that on a screen only a few hundred pixels
across. However, a slow sample rate does indeed lead to aliasing
problems. The usual cure is to sample at a high rate and store a max and
a min for each time slice to be displayed on the screen; this is usually
termed "glitch detect" or similar.

--
Rich Webb Norfolk, VA
 
On Wed, 5 Nov 2008 09:47:17 +1100, "Phil Allison"
<philallison@tpg.com.au> wrote:

"John Larkin Fuckwit "


My Tek TDS2012 doesn't have a CRT shield!


** Wouldn't do much if it did - would it ??
Click to expand...

Actually, it would. Like most digital scopes, and a lot of spectrum
analyzers, the LCD backlight screams RF leakage. They should go to
LEDs.

Fuckhead.
Click to expand...
Amateur.

John
 
"John Larkin Fuckwit "
My Tek TDS2012 doesn't have a CRT shield!


** Wouldn't do much if it did - would it ??


Actually, it would. Like most digital scopes, and a lot of spectrum
analyzers, the LCD backlight screams RF leakage.
Click to expand...

** Huh ??

There is no FUCKING CRT !!!!

Plus the subject was " Mu-Metal " anti- magnetic shields

you ASININE SEPTIC FUCKHEAD
 
On Thu, 6 Nov 2008 12:03:40 +1100, "Phil Allison"
<philallison@tpg.com.au> wrote:

"John Larkin Fuckwit "


My Tek TDS2012 doesn't have a CRT shield!


** Wouldn't do much if it did - would it ??


Actually, it would. Like most digital scopes, and a lot of spectrum
analyzers, the LCD backlight screams RF leakage.


** Huh ??

There is no FUCKING CRT !!!!

Plus the subject was " Mu-Metal " anti- magnetic shields

you ASININE SEPTIC FUCKHEAD
Click to expand...
Calm down, Phil, and try to get un-confused.

John
 
"John Larkin Fuckwit "
My Tek TDS2012 doesn't have a CRT shield!


** Wouldn't do much if it did - would it ??


Actually, it would. Like most digital scopes, and a lot of spectrum
analyzers, the LCD backlight screams RF leakage.


** Huh ??

There is no FUCKING CRT !!!!

Plus the subject was " Mu-Metal " anti- magnetic shields

you ASININE SEPTIC FUCKHEAD


Calm down, Phil, and try to get un-confused.
Click to expand...
** Well FUCK YOU -

you ridiculous AUTISTIC YANK CUNT





..... Phil
 
On Thu, 6 Nov 2008 14:06:55 +1100, "Phil Allison"
<philallison@tpg.com.au> wrote:

"John Larkin Fuckwit "


My Tek TDS2012 doesn't have a CRT shield!


** Wouldn't do much if it did - would it ??


Actually, it would. Like most digital scopes, and a lot of spectrum
analyzers, the LCD backlight screams RF leakage.


** Huh ??

There is no FUCKING CRT !!!!

Plus the subject was " Mu-Metal " anti- magnetic shields

you ASININE SEPTIC FUCKHEAD


Calm down, Phil, and try to get un-confused.


** Well FUCK YOU -

you ridiculous AUTISTIC YANK CUNT
Click to expand...
Well, group, does that sound calm?

John
 
"sbrehler"
I'm going to be doing mostly educational work right now (I have a two-year
degree in Electronics, but will be persuing my EE this spring). But I do
like the thought of the DSO's due to the wide range of functions they
posess. One thing that I'm concerned about is "aliasing." I will be
working mostly with discrete components and microcontrollers with
relatively low frequencies/clock speeds; will a DSO present any
difficulties along those lines. From what I'm reading, it appears that a
very low "sampling rate" can cause erroneous measurments. I've heard
others mention in the past something about "real time" issues (perhaps due
to the sampling problem?). When would one want to have a very low sample
rate? It would seem to me that the higher the better. Anyway, I'm a little
confused right now...
Click to expand...

** Seeing as you are not familiar with using scopes at all - it would be
VERY wise to make your first scope an analog type.

Analog scopes do not play nasty ( ailiasing) tricks on you like digital ones
do - so are straight forward to use AND produce a MUCH cleaner, more
detailed and informative trace to view.

Plus, once you know how to use one of them, you will find any other analog
scope easy to drive to.

The same is not true of digital sampling types.


...... Phil
 
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