Date: Wed, 7 Sep 2005 00:28:30 -0500 (CDT)
Subject: the instek isn't nearly as nice as the tektronix
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Here are initial impressions of the Instek 820C DSO (digital storage 
oscilloscope). It's clunky. When I saw the case, my first thought was, "It 
looks like something I would design." That basically means very functional 
but not pretty. At the same time, it doesn't feel that heavy and is still 
a reasonable size even at twice the size of the Tektronix.

The Tektronix...so nice...but so expensive!

There is a loud clack (not click but CLACK) of a relay switching when 
changing the voltage range. A solid state solution is more elegant (the 
Tektronix is completely silent and faster - it must be solid state) but 
poses more challenging engineering.

I am very ignorant of how to use the scope. See the first photo with the 
red wire coming out of the ground port. Of course that is unnecessary. The 
barrel of the probe is already at ground. So the alligator clip is also at 
ground. This is basic electricity stuff.

The buttons on the scope feel like big chicklet keys on a calculator. 
They're not the deep pushbuttons on the Tektronix. Oh for unrequited love! 
But sometimes, we must make practical choices instead of following the 
heart.

Push the Help button and a buzzer sounds. Exit help and it sounds again. 
The on-screen menus don't look cool. They have that old Motif GUI look to 
them. The controls are confusing and not intuitive like they are on the 
Tek.

On the nice side, this scope claims 150 MHz analogue bandwidth. It also 
has both RS-232 and USB. The color screen is nice. And the scope boots 
faster than the Tektronix. The Tek takes an uncomfortably long amount of 
time to start up. But...the Instek only guarantees performance after 30 
minutes warm-up. Maybe the Tek compensates for temperature drift so 
requires no warm up? I'm tempted to take a probe to Fry's and play with 
the scope. But I know that I'd risk being hassled by guys in white shirts.

My overall opinion is that if you are a business or a professional, then 
get the Tektronix, Agilent/HP, etc. unit. At the low end, the Tek units 
aren't priced so high (as much as a small car) as to be unattainable. I 
spent just under $1000 on the Instek. The comparable Tek (still comparing 
apples and oranges here) would be around $500 more.

At the same time, if you derive pride from scrounging and a little 
improvisation, then a good analogue scope or cheap DSO will work. But if I 
were paying an engineer $50/hour to work for me, I'd spend the extra for 
professional grade equipment.

Despite all of my negative comments, I'm happy with my purchase. It's 
about what I expected. Now I have to make it pay for itself.

I have to get busy writing firmware and software now. There's really no 
excuse as the scope gives the ability to see what is going on. So 
debugging firmware should be much easier. A few months ago, I fell into 
the pattern of making a code change, reflashing the microcontroller and 
then looking for any visible change. It was debugging by random 
experiment. This is a horrible way to proceed.

One more thing. I took a stroll down the aisles with girl's robotic doll 
toys. They are extremely primitive right now. But even at the primitive 
state, a dancing Elmo or polar bear that coos and blushes makes a strange 
impression. In a few years, Japanese technology that is in Sony's Qrio 
humanoid robot will be in these toys. They will walk around and plead to 
be purchased and taken home with you. Kids will go nuts over these toys.