[sdiy] Pocket oscilloscope

[gordonjcp at gjcp.net]

On Sat, Sep 13, 2014 at 01:20:18PM +0200, Andre Majorel wrote:
> On 2014-09-13 07:42 +0100, gordonjcp at gjcp.net wrote:
> 
> > If you're looking for an oscilloscope at a budget-sensitive
> > price, pick up a nice old dual-trace analogue 'scope from
> > someone near you.  Look on eBay, search "nearest first" and
> > when you find one ask if they'll show you how to use it if you
> > don't know how it works or if they'll let you try it out if
> > you do know.
> > 
> > It'll cost about as much as a decent Chinese takeaway for a
> > perfectly adequate 25MHz-ish 'scope that'll do everything you
> > could possibly need.
> 
> Except deal with slow signals. How do you look at an LFO or EG
> shape on an analogue scope ?

Not something I do very often.  About the only time I use a digital 'scope is for extremely slow or extremely fast signals (catching quick pulses) and I usually use my Thurlby DSA524 for that.

> For me, the choice between a cheap analogue scope and a cheap
> digital scope is far from being a no-brainer as it seems to be
> for you.
> 
> > My HP quad-trace 100MHz DSO sits with a thick layer of dust on
> > top and my Iwatsu 20MHz analogue is pretty much never switched
> > off, even working on RF stuff...
> 
> I'm curious. In what ways is the HP worse than the Iwatsu ?

Like all digital 'scopes it cannot display analogue signals.  Good luck making any sense of the aliased pixelly mess.

-- 
Gordonjcp MM0YEQ