Audio Transformer

[akillian]

I am playing around with

[audioguru]

Hi Akillian,
You don't need a big expensive audio transformer to make a simple AM Tx and Rx. Transistors and resistors will work instead.
Audio transformers have poor low frequency and poor high frequency response. So when fed a square wave, the output will look rounded and tilted on an oscilloscope. There also might be some ringing immediately following each transition of the wave.
Little transformers saturate when fed a DC voltage along with some signal.