@Kellenjb I got one of those scopes, the cooling fan sounds like a hair dryer it's so loud! However it works very well and is a bargain at twice the price :) I'm very pleased with it

@Kortuk I guess it depends on what work you're doing with the scope, I've used mine mostly for examining audio signals, so the bandwidth has never bothered me

@Jim interesting.

@Kortuk I wouldn't suggest using it for RF work ;)

@Jim Am radio!

I'm using it right now with an analogue sine wave oscillator

it's a one of those quadrature resonant ones

what's really interesting is when you shout at the capacitors

the microphonic effect kills the resonance!

@Majenko was looking at some info on ceramic caps and he discovered they are microphonic

so i decided to shout at my circuit to see if it would effect the frequency

I had no idea it would be enough to kill the oscillation all together

crazyness!

@Jim awesome

@Jim very. I did not realize that either

Even electrons have feelings.

Did any of you here ever have electret microphones pick up 2.4 GHz interference?

@AndrejaKo what do you mean pick up interference?

Hello. I have an Arduino Mega, and a separate +12v power supply. How can I safely control the +12v with the Arduino through a transistor?

would it be safe to connect the two grounds together?

or should I use the Arduino ground? or the power supply ground?

(I'm trying to drive a stepper motor)

@MicronXD The two grounds should be connected together. What type of transistor do you want to use? MOSFET would be easiest, since you'd just connect the gate to a output pin of the ATmega.

@MicronXD You could also connect a relatively high resistor (say 10k) between the gate and ground. It should allow the MOSFET to turn of faster.

@MicronXD If you have a bi-polar junction transistor, you'd have to connect the pin in series with a resistor which will limit the current going into the transistor. Use the datasheet to calculate the maximum base current and set the appropriate resistor on the line going from microcontroller to the base. If you want the transistor to turn off more quickly, then again put a large resistor between the base and the ground.