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The 1740A & 1741A 'scopes provides 100MHz capability in a smaller package
with better triggering.

Would a 1742A be a better option than 180series then? I've got the
opportunity to purchase one from a non-ebay source for $400AU without
probes or manuals. Does that sound like a reasonable .au price?

cheers
Paul

On 22/01/2007, at 1:13 PM, Mike wrote:

At 10:23 AM 22/01/07, you wrote:

The 1740A & 1741A 'scopes provides 100MHz capability in a smaller
package
with better triggering.

Had a 1742A for some 15 years bought from new, though first one I
got from HP
had a bad bow in the trace, they tried to tell me it was within
spec and that +-1.0 mm
is acceptable, suffice it to say I wouldnt accept it and told the
finance co at the
time the delivery was being rejected but HP had already rang the
finance co to report
it was ok without my signature !! I was really angry and
threatened to publish a
photo of the trace in the local paper. Within 4 hours got a ph call
from HP
apologising profusely and another unit with perfect straight line
trace turned up
about 2 weeks later from USA with freight at their expense,
<chuckle>

Dont think this was indicative of HP - more of the local management
and fact
that often in Australia we get the dregs of stuff made in Singapore
under HP's
trade name which doesnt pass Singapore tests, so its not shipped to
USA but
dumped here, happens more often than it should from other stories I
have
heard.

After that the 1742a performed almost flawlessly for 15 years and
sold it locally to
a "cash converters' store for AUD$500 after it was repaired, still
see some models
on ebay in Oz from time to time,

And yes I kept the service manual with the equipment and used it
twice to
look at a burned out resistor on the input stage as I recall and
rewind/swap
a transformer for the grid supply,

Cheers

I think I'd prefer to stay clear of hybrid components. They don't do
much for long term maintainability. I take it the 180's are better in
that respect?

If I can get the 1742A for closer to $300 I'll go and take a look.
The scope is in Melbourne, so perhaps reasonably unlikely that it is
your unit?

cheers
Paul

On 22/01/2007, at 1:33 PM, Mike wrote:

At 11:08 AM 22/01/07, you wrote:

Would a 1742A be a better option than 180series then? I've got the
opportunity to purchase one from a non-ebay source for $400AU without
probes or manuals. Does that sound like a reasonable .au price?

<cough> if its the one I sold, I'd say no as I recall the hybrid
for the
vertical deflection was on the verge of getting erratic, that was
the other
reason for selling... Other than that it was a great scope as I also
had the top multimeter option :) Which state are u in btw ? and is
the
service manual in a red 3 ring binder ? *grin*

The original probes were quite good but didnt like to be kinked, the
single nickel steel wire was prone to breaking in older cro probes and
new probes are quite cheap now. If the vertical deflection on the
cro is close to calibrated dial settings then sure its worth it, I'd
probably make an offer (if it was in perth) but closer to $300 on
basis that the hybrids are not replaceable any more etc.

Let us know the serial number if you get it :)

Rgds

Mike

cheers
Paul

On 22/01/2007, at 1:13 PM, Mike wrote:

At 10:23 AM 22/01/07, you wrote:

The 1740A & 1741A 'scopes provides 100MHz capability in a smaller
package
with better triggering.

Had a 1742A for some 15 years bought from new, though first one I
got from HP
had a bad bow in the trace, they tried to tell me it was within
spec and that +-1.0 mm
is acceptable, suffice it to say I wouldnt accept it and told the
finance co at the
time the delivery was being rejected but HP had already rang the
finance co to report
it was ok without my signature !! I was really angry and
threatened to publish a
photo of the trace in the local paper. Within 4 hours got a ph call
from HP
apologising profusely and another unit with perfect straight line
trace turned up
about 2 weeks later from USA with freight at their expense,
<chuckle>

Dont think this was indicative of HP - more of the local management
and fact
that often in Australia we get the dregs of stuff made in Singapore
under HP's
trade name which doesnt pass Singapore tests, so its not shipped to
USA but
dumped here, happens more often than it should from other stories I
have
heard.

After that the 1742a performed almost flawlessly for 15 years and
sold it locally to
a "cash converters' store for AUD$500 after it was repaired, still
see some models
on ebay in Oz from time to time,

And yes I kept the service manual with the equipment and used it
twice to
look at a burned out resistor on the input stage as I recall and
rewind/swap
a transformer for the grid supply,

Cheers

Regards

Mike

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In complete contrast to the discussion on the nature
of scientific
knowledge, I have a couple of fairly prosaic
questions.

I'm new to the list, and to scopes in general and
I'm currently
looking at buying a 180 series scope for doing basic
audio work, with
some digital. Digital would primarily be checking
alignment of 16Mhz
clock signals in an audio DAC.

Will a 180 mainframe with 50Mhz plugins be up to
this kind of work?

Can someone give an idea of what the pro's & con's
of the 180A, 180C
and 184A mainframes are?


thanks
Paul

I've been advised to replace all the tantalum caps on units of this
age. Is that reasonable advice?

cheers
Paul

On 22/01/2007, at 3:15 PM, Thomas Hejl wrote:

Paul,

The 180 series of scopes will do just fine for your
basic audio applications. It is the "some digital"
that you mentioned that has me offering a suggestion
or two.
If you wish to just analyze the timing of the DAC
signals, than the 180 series will do. If you wish
however to see any relationship of that timing to
other aspects of your digital signal, than another
option might be considered.
Most scopes will give you a voltage indication, which
is vertical, in reference to a particular time period
base (or frequency), which is horizontal. These
voltages may be analog (as in a sine wave audio
signal) or digital (with a constant pulse of one,
stepped pulses or no change from base - zero). If you
wish to analyze the digital signal (a series of ones &
zeros) to a series of timed events that may be in
constant change, or a one time event that might too
quick or fast to notice, than you might get the
feeling that something is missing.
If you ever wish to more in depth analyzing of digital
signals then consider a unit that does both. Two such
are the HP1631D (primarily a Logic analyzer with a 2
channel scope included) or a HP54201D (a digitizing
scope with a logic analyzer included). These will give
you logic (digital) analyzing that can have timing and
signal inputs for comparisons. They have the ability
to stop recording waveforms (since they are digital,
they use RAM to store info) on a glitch (or digital
noise).
As for your application, the 180 series should do
well. The 181 (50MHz)& 184 (100MHz) have screens with
persistence (a type of screen hold to freeze your
display). Some of the vertical plug-ins are the 1801A
(50MHz), 1805A (100MHz), 1808A (75MHz), (which are all
2 vertical channels) and the 50MHz 1804A (which has 4
vertical input channels). Be sure to use X10
oscilloscope probes as to not load your signal under
test and therefore you will get truer readings.
Some of the pros: Other available options for the 180
series are spectrum analyzer plug-ins (to analyze band
pass and/or harmonics). They are inexpensive compared
to more modern equipment. Since they are modular, if a
plug-in does fail, purchase another and replace.
Some of the cons: The units are getting on in age. The
CRTs are going to get harder to find if needed to be
replaced. Finding a repair facility might be difficult
as well. (Some places will try to sell a newer unit
altogether.)
As what might be your first oscilloscope, you could do
worse than a 180 series unit. For a beginner who might
be on a buget, a 180 series should do you well.

Good Luck,
Tom

--- Paul Jacobson <<mailto:pj%40cutlerco.com.au>pj@...> wrote:

In complete contrast to the discussion on the nature
of scientific
knowledge, I have a couple of fairly prosaic
questions.

I'm new to the list, and to scopes in general and
I'm currently
looking at buying a 180 series scope for doing basic
audio work, with
some digital. Digital would primarily be checking
alignment of 16Mhz
clock signals in an audio DAC.

Will a 180 mainframe with 50Mhz plugins be up to
this kind of work?

Can someone give an idea of what the pro's & con's
of the 180A, 180C
and 184A mainframes are?


thanks
Paul

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Tom,

thanks so much for such an informative response.
in regards to the digital what i *think* i need is
to be able to view
two clock pulses simultaneously to ensure their
timing alignment with
each other is correct. so if I understand right the
180's with 50mhz
vert/horizontal plugins would be sufficient.

what is available is:
180A with 1801A, 1821A (approx $280AU)
180C with 1801A, 1821A (approx $320AU)
184C with 1805A, 1825A (approx $480AU)
all of these units come with 10008A passive voltage
probes, so I
think i'd need to factor in buying x10 probes?

The 184C is pushing the boundaries $ wise. The 180C
looks be in the
better condition cosmetically of the 180's as the
plugins on the 180A
don't appear to align quite right in the mainframe.

Checking the 180C service manual d/l'd from BAMA, it
appears to be
all discrete componentry, which is a bit reassuring
if something does
break.

I've been advised to replace all the tantalum caps
on units of this
age. Is that reasonable advice?


cheers
Paul

So changing capacitors (in the power supply at least)
is a wise thing to do. Whether they are tantalum's or
electrolytic's it might save aggravation in the
future. As for changing ALL the tants I counted about
20 per plug-in on the ones I have in my shop. It is
going to be a task, so weigh your time, effort and
cost vs. probability of their failure.

dipped epoxy tants normally are good or measure close to a dead short
i use an esr meter + multimeter to check caps
"i also have a sprague to6 2 megohmeters and capacitance meters + bridges
leakage can be checked in circuit normally.

(I could not find specs.
right away on the HP10008A).