It is a truth universally acknowledged, that a
single ham in possession of a good fortune, must be in want of a oscilloscope. At Hamvention, I bought slightly more of an oscilloscope than I needed, a Rigol DS1102E.
After calibrating the probes, I cast around for something to measure. Aha! There lay anÂ Atari Punk Console (previously) ready to show the world what its waveforms look like.
Surprsingly clean output here.
Ahh, the notorious APC “squelch-fart” noise. The poor little speaker hasn’t a chance of reproducing this, so it collapses into spasms.
A noisier high frequency signal from the APC.
The Rigol is pretty easy to use. These images were captured via its USB screen dump feature; no need for an oscilloscope camera here!
I just built my first Atari Punk Console, a simple LM556-based noisemaker beloved of the circuit-bending crowd (and pretty much avoided by everyone else). Jimmie P Rodgers sells a nice board (or kit), and I bought a few boards a while back, and only just built one up now.
The board’s a nicely finished little thing:
… and yes, it really only needs three resistors, three capacitors, and the 556, plus the control pots, power, speaker and all-important on/off button. The APC sounds a little like a drunken, flatulent bee banging around in a lager can, so you really want to be able to turn this thing off.
Jimmie designed this to fit in an Altoids tin, but Catherine had discarded a LUSH Massage Bar Tin which looked just about the right size. The tin is made of butter-soft aluminium, so it’s easy to start holes in it with the awl on my Dutch Army knife. It’s bigger than an Altoids tin, so you don’t have to fight to get things in. Lastly, the LUSH tin is nicely curved, and fits in your hands well.
Wit the lid closed, it looks like this:
And the sound? Well …