On 3/30/2012 7:38 AM, Johan H. Bodin wrote:
I am thinking about a front end using something like your old I/Q sampling PIC
with a preamp and a BPF. Fs should be close to 4*9=36kHz for near-DC IF but not
too close in order to avoid 1/f noise from the preamp. If the sampling MCU is
clocked with a precision frequency and connected to a simple serial port, we
could say goodbye to soundcard jitter and jumps and other unexplainable
phenomena! Not a "soundCard" really, but a "dreamCard"...
Hi Johan,
may I suggest you to give a look at the dsPIC from Microchip ?
It has a 12-bit ADC and a couple of DACs on board, together with
an instruction set rich of
instructions tailored to DSP processing, like MAC, ring buffer
support, etc. etc.
I used it for an SSB generator, using a modified Weaver method,
and found it perfectly
adequate for this kind of tasks. I bet that with a single dsPIC
chip, you can digitize
the 8.9 kHz band signals, process them and playback them through
the DACs, no PC
whatsoever needed....
73 Alberto I2PHD
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