"Mikal" wrote in message
ups.com...
I've simulated a circuit and a little confused... If I have an BPSK
RF signal at 1KHz, and I mix it with an LO of .9KHz, then I should get
100Hz still in BPSK format? PSpice says otherwise. If I filter the IF
for lowpass at 100Hz, it doesnt look like anything I could possible
work with and doesnt sync to anything. If I pass everything below
200Hz, it looks more like a sign wave, that's syncronous with the
modulation.

When mixed down to 100 hz, will there be enough bandwidth at that frequency
for the BPSK to work ? I have no idea but it does take a certain ammount of
bandwidth for a given ammount of data. Also are the components of the
circuit of the correct value to pass frequencies below 100 hz ?