— On Thu, 4/2/09, John G. firstname.lastname@example.org wrote:
There’s another chance to get kids into radio…
If a high volume kids’ laptop had stereo “HD audio” ports available
(24-bit 192 kHz converters, 95 db input and 100 db output), how cheap
and small a circuit could you build onto that motherboard to provide
useful LW/AM radio reception?
Here is my 2 cents:
AM signals known to be strong, RF Gain may not be required.
Undersampling can be used to downconvert/digitize AM signals.
RF Tunning is the problem. We have to think for away to use the
voltage from one of the audio output ports to control a bandpass filter
center frequency (voltage controlled filter).