🚀 go-pugleaf

I built the Heath scope for my lab here at work.  I built the
fancier model with the pushbuttons on the fron that can operate in
standalone mode without the computer, if desisred.

The unit is best as an audio bandwidth storage oscilloscope.  The
inputs are sampled through an 8 bit ADC.  They traces are displayed
on a cheap slave oscilloscope via a 10 bit DAC so that there is
some lattitude to move the display around on the screen.  The
number of samples per channel is fixed at 512.  Two current and two
stored traces are possible.

Data is shipped back to the host computer via a standard RS 232
port with jumper selected baud rates from 300 to 9600.  The
communications protocol is quite simple and easy to program in
basic or c.  The software included is written in microsoft basic
with a couple of routines written in 8088 masm.  They also give you
a .exe version compiled with the microsoft basic compiler.

Sweep rates above about 50 uS per division are sampled in
"equivalent time", meaning that the display is useless unless you
are looking at a steady-state waveform.  There is no delay line, so
the triggering event is lost at high sweep rates-- generally, this
isn't a problem since only repetative steady-state signals can be
viewed at high sweep rates anyway.

All in all, the heath digital scope is pretty good, as long as you
understand its limitations.  I needed to look at some very slow
signals, and I didn't have a storage scope, so this was perfect for
me.  I have a tektronix 2445 that I have to look at higher speed
stuff and use as a slave scope for the heath unit.

If you don't have a scope to begin with I think that the B&K model
2520 20 MHz digital storage scope would be a pretty good choice.
The 2520 features dual trace and a very flexible timebase and
triggering modes.  It costs about $1800.  We recently replaced a
raft of 8 year old Tek 912s in our student labs with the B&Ks.  We
find that the B&Ks are much nicer instruments, especially for
storage.  Students can also make hard copy plots on an X-Y
recorder with the B&K.

It seems that for scopes, the rule of you get what you pay for
pretty much applies.

Bill Mayhew Electrical Engineering
Division of Basic Medical Sciences
Northeastern Ohio Universities' College of Medicine
Rootstown, OH  44272-9989  USA    phone:  216-325-2511
(wtm@neoucom.UUCP   ...!cbosgd!neoucom!wtm)