[Elecraft] Oscilloscopes

[Carl Clawson]

> 
> What is the rating of my Techtronics 475?
> We used them at work for required adjustments to tolerances 
> of 2/10 nanoseconds.
> 
> Thanks es 73, de Jim KG0KP

For any common model you can easily find info on the web if you aren't sure.
Bandwidth for scopes is like horsepower for a performance car. It'll be the
first spec that's mentioned.

A handy rule of thumb for the 10% to 90% rise time is ln(9)/(2*pi*bandwidth)
= 0.35/bandwidth. So a 200 MHz scope has an inherent rise time of a bit less
than 2 ns. The 485 comes in at an even 1.0 ns and I always suspected that's
why they targeted 350 MHz for its bandwidth spec.

Exercise for the reader: derive this formula assuming a single pole filter
response.

73 and thanks for listening
Carl WS7L
K3 #486