[sdiy] Old 20Mhz scope high on LSD!!

[karl dalen]

 --- Paul Perry <pfperry at melbpc.org.au> skrev: 
> 
> ----- Original Message -----
> From: "karl dalen" >
> > Lets say a DC 100-150Mhz total Bw without changing to much
> > of the internal circuit would be possible! That would not be
> > baad for an old farty 20Mhz scope!
> >
> It's pretty well impossible.
> At 200MHz, all the stray capacitances and inductances of wiring are part of
> the 'circuit'.

Why use long wires, i have the schemos of my scope
so one could take out everything and make it smd.
 
> If it was easy, we'd have cheap 200MHz scopes coming from China.

My friend have designed a 700Mhz active probe it was designed for 1Ghz
but he i made a error, still it works fine, he use it as a HF sniffer.
He uses a simple RF to IF down converter to display on his scope.
So i dont se the impossibility in upgrade a 20Mhz scope!
Think RF!

> I have a series of books on Scope design published by Tektronix.
> They would freeze your blood!! even making a damned probe with lead is
> hi-tech.

I would love to have a peek into them!

Reg
KD