Being relatively new to ham radio, I am considering some form of
oscilloscope. I am intrigued by PC-based systems (eg., BitScope Pocket
Analyzer)

I've read a few NG posts about used HP scopes and a few negative remarks
about PC scopes.

My question:

Given my neophyte status and the likelihood that I would use a scope for
anything more the basic / with learning, moderate/ complexity,
.... is the PC-based scope a good choice for me?
Cost is under $400, not incl. a $40 analog probe.

John
AB8O

Geez I bought an almost new 50 MHz Tektronics 2225 for $35 and that was with
probes. You can get a decent bench scope for not much money.

--
Brian Denley
http://home.comcast.net/~b.denley/index.html

"jawod" wrote in message
...
Being relatively new to ham radio, I am considering some form of
oscilloscope. I am intrigued by PC-based systems (eg., BitScope Pocket
Analyzer)

I've read a few NG posts about used HP scopes and a few negative remarks
about PC scopes.

My question:

Given my neophyte status and the likelihood that I would use a scope for
anything more the basic / with learning, moderate/ complexity,
... is the PC-based scope a good choice for me?
Cost is under $400, not incl. a $40 analog probe.

John
AB8O

jawod wrote:
Being relatively new to ham radio, I am considering some form of
oscilloscope. I am intrigued by PC-based systems (eg., BitScope Pocket
Analyzer)

I've read a few NG posts about used HP scopes and a few negative remarks
about PC scopes.

My question:

Given my neophyte status and the likelihood that I would use a scope for
anything more the basic / with learning, moderate/ complexity,
... is the PC-based scope a good choice for me?
Cost is under $400, not incl. a $40 analog probe.

You don't say what you want to measure with a scope, and it is very
important with a digital storage scope.

Nyquist's theorem says that if you are sampling at 2x the highest
frequency present, you can determine that frequency. My experience with
digital storage scopes is that you want at least 5x the sample rate and
10x is better to look at a waveform. As a result, a 20 MSample/sec scope
is useful up to 2 - 4MHz of input bandwidth. Beware, some of the digital
storage scopes specify a "repetitive sweep" bandwidth that is equal to
the Nyquist rate. If you are looking at a repetitive signal, you
actually can approach this rate. If you are looking at a one-time or
rare event, the usable bandwidth is much lower. Exceeding the bandwidth
of an analog scope gives you a distorted view of the amplitude and
possibly the waveshape. Exceeding the Nyquist rate on a digital scope
becomes outright deceptive in amplitude, waveshape and frequency.

Unless you need a DSO, I would suggest you look for a good used analog
scope. Tektronix made some really nice analog scopes and the 465 is one
of the best. HP's analog scopes were always a disappointment to me, but
their digital scopes are first rate. As a solid scope, for learning and
genearal utility, analog scopes offer a lot more bang for the buck.

Good Luck,
Bob

jawod wrote:
Being relatively new to ham radio, I am considering some form of
oscilloscope. I am intrigued by PC-based systems (eg., BitScope Pocket
Analyzer)

I've read a few NG posts about used HP scopes and a few negative remarks
about PC scopes.

My question:

Given my neophyte status and the likelihood that I would use a scope for
anything more the basic / with learning, moderate/ complexity,
... is the PC-based scope a good choice for me?
Cost is under $400, not incl. a $40 analog probe.

John
AB8O
Download one of the programs that turns your sound card into a low
frequrncy scope. You can do audio stuff, spectrum analysis, etc.
You can learn a lot without spending any money.

If you have a specific application and know what you're doing,
a card that plugs into a PC can be useful. For most of us,
it's not a viable option. It's a real PITA to go find the mouse
and click a bunch of menus when you could have changed the gain
on your standalone scope with the turn of one switch.

Next, join your local ham radio club or get friendly with the folks
on a local repeater. Ask your question there. Most hams are helpful.
We also have more scopes than we'll ever use and can often be talked
into loaning them out. Try to borrow something like a TEK 453 or 465.
They're plentiful and won't give you a hernia carrying them out to your car.

If you work in electronics, go convince the service manager that it
would be a company benefit to loan you an old scope. About 15 years
ago, ISO9000 made it a requirement that every piece of equipment on the
production line have a current cal sticker. That got so expensive
that management had all the little-used stuff pulled and sold or put
in storage. I'll bet there's tons of scopes in storage that will never
be used again. Shine up that silver tongue and see what you can unleash.

Rule number one...don't get in a hurry to buy something.
Good deals come along. Visit some ham radio swapmeets, club meetings
etc. I've been able to snag 2GS/S 4 channel DSOs for free. Be patient.
A silver tongue and brown nose will take you far ;-)
Try to get probes with the scope. Typically, probes will cost you more
than the scope did. Ditto for manuals.

I'd recommend a limit of $20 for your first scope. That $400 scope
will still be there later when you're experienced enough to decide if
you can use it.

If you get some experienced help evaluating the possibilities, a scope
that's not fully working can be a great deal. Just be aware that some
types of problems are more difficult/impossible to fix than others.
Older scopes are fixable...newer ones, not so much...you just can't get
the parts.
That's where the experienced help comes in.

ALWAYS assume a used scope is busted. I've never bought one that was
fully functional...and the seller anways assured me it all
worked...right!! If you buy it at a busted price, you won't be
disappointed. I just bought a TEK 7K scope with plugins. "Sure it
works.." Well, I beg to disagree. Looks like they took a busted
mainframe and filled it with busted plugins. Busted price and I can fix
it, no foul...
Get help.

I don't like EBAY for scopes. Surely there are many good deals to be
had. I just haven't figgered out how to tell which ones. Beware of
anything that says, "no way to test it." I once had an interchange with
an ebay seller on that subject. He slipped up and replied from the
corporate email of the largest refurbished equipment dealer in the
world. When I challenged his inability to test it, he vanished.
Hmmmm...wonder if it was repairable?

Unless you can get a real deal, stay away from a digital scope for your
first one.
For most of us, a DSO is a VERY useful tool in a VERY limited number of
situations. I find it mostly confusing. I use mine mostly for
troubleshooting because it gives me a digital readout of the DC voltage.
Most of us don't need a $20K low resolution digital voltmeter.
But a free low resolution digital voltmeter ain't so bad.
If I don't see the waveform I expect, I always dig out the analog scope.
I've been confused more times than I like to admit. For most GP
applications, you should get a DSO with WAY more bandwith than you think
you'll need. That often puts it into the "can't afford" category.

mike