[geeks] Tektronix TDS 220

[Joshua D Boyd]

On Mon, Jul 15, 2002 at 03:50:49PM -0400, Dave McGuire wrote:
>   It is indeed a digital scope.  The easier to use part doesn't really
> have much to do with it being digital or analog, though.

That is good to know then.  I can stop thinking about digital scopes
and think of cheaper but still usable things.
 
>   Yes the 220 is older than the 2000...but that doesn't make much
> difference here either.  Scopes generally don't go through the "six
> months and it's useless" effect that plagues, for example, PC
> hardware.  There are many, many electronics labs, for example, that
> are using 25-year-old Tektronix 475s.  For most applications, the few
> technological advances that have found their way into oscilloscope
> designs don't really affect much in terms of their operational
> capabilities.  Sure things like weight/power consumption/heat output
> have been reduced, and some ancillary stuff like stored setups and
> remote control...but rarely anything in the "scope functionality"
> area.  Except for the new crop of LCD-based scopes, they haven't even
> gotten any smaller in the past 20-25 years.

Yeah, I know they don't get outdated as fast.  I was just noticing
that some things about the TDS220 looked better than the TDS1000,
which I thought was supposed to be a higher end unit (from the way the
presented the comparisons).  Then I realized that they were replacing
the TDS220.

I know scopes haven't basically changed much.  I'm just trying to
figure out which of the changes are important to me.
 
> > But wait, they don't list a 2200 in the TDS2000 series, so it must be
> > another series I'm looking for.
> 
>   The 2200 isn't a TDS-series scope.  It's simply the "Tektronix
> 22xx"...2215, for example.  No TDS.  You probably won't find marketing
> information pertaining to those scopes on Tek's web site, because
> they're not current.

Doh.
 
> > Now, I don't know how to fix my one good amp (I'm learning more and
> > more about solid state electronics, but it is a tube amp), and I don't
> 
>   If you learn about field-effect transistors, you'll have a good head
> start on tubes.  Just watch out for B+. 8)

I'll have to look that up when I find more spare time.
 
> > But, I also have a number of non working items.  A quick test over
> > with a DMM didn't really turn up anything, so I'm thinking going over
> > them with a scope might help.  If I can make them work, mostly they
> > would be easier to upgrade than starting from scratch would be.
> 
>   A DMM is the single most useful piece of general electronic
> troubleshooting equipment.  A good analog scope (be it ones with
> analog or digital controls, though I strongly prefer the latter) would
> have to be next.

How about an analog multi meter?  I guess they aren't as good as a DMM
for testing caps...  I just realized I typed DMM, but what I really
have is a nice, not particularly cheap analog meter.

>   For your audio stuff, I would have to recommend either a plain analog
> scope or an analog scope with digital controls.  For the stuff you've
> been talking about, I would specifically recommend the Tektronix 2445.
> I have a great deal of personal experience with this scope...they're
> very featureful, built like tanks, have nice on-screen displays,
> voltage and time cursors with on-screen digital delta measurements
> (very VERY handy...in voltage mode for example, two knobs move two
> horizontal lines on the screen and the voltage between them is
> displayed textually atop the screen)...small, easily portable, great
> for general-purpose work, and amazingly reliable.  It should set you
> back maybe $300 or so on eBay, maybe a bit less.  Unless you get into
> *fast* digital stuff or VHF/RF stuff, this might be the only scope
> you'll ever need.  I would recommend it against any of the TDS scopes
> for general work.  Make no mistake, though...this is a high-end scope
> that carried a $6K price tag when new.
> 
>   There's one on eBay, for example, at
> http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1748708659.

I guess I'll try to see if I can find a way to use school scopes for
testing my old stuff, and put a nice Tek 2445 on my wish list in hopes
of a few relatives going together to buy one for me for christmas.

-- 
Joshua D. Boyd