[Amps] About LP100A

[Manfred Mornhinweg]

Bill,

> As a technician who used to work at Tektronix, I can assure you that
 > digital scopes can do everything that analog van do

Can a digital scope do Lissajous figures?

The ones I have used cannot. They simply don't have a horizontal input!


My own work with both analog and digital scopes makes me think that they 
complement each other very well.

Very slow signals are essentially impossible to visualize on an analog 
scope. Instead on a storage scope it's child's play. But analog storage 
scopes are not the most common thing in the world, so it's here where 
digital scopes come in, as almost all of them work as storage scopes.

What I have found hard to do with a digital scope is hunting for 
problems. When I know beforehand what signal I have, and just need to 
measure it, digital scopes work fine. Instead if I don't know what I 
have, it takes a lot of effort to discover all details of a signal with 
a digital scope. Instead analog scopes don't "lie": They always show you 
all detail a signal has. The only thing you do is scale the image, 
horizontally and vertically, to see the parts that interest you. That 
makes it easy to discover spikes, transients, high frequency 
self-oscillations riding on the desired low frequency ones, and so on.

By the way, my 40 year old Tektronix D755 is asking for retirement. Too 
many totally worn potentiometers, contacts, etc, all of which are 
Tektronix special parts. Can you, or anyone, recommend a good scope 
available for a decent price? Are any of the Chinese ones good? I would 
love one that gets well beyond 100MHz. Just two channels is fine.

Manfred

========================
Visit my hobby homepage!
http://ludens.cl
========================