Eugen_E
Joined: 29 Nov 2004
Posts: 273
Helped: 23
|
 07 Jan 2008 16:13 A simple sampling product detector for SDR |
|
|
|
I've finished building the control board and frequency synthesis board for an HF SDR receiver (3 - 4MHz). The synthesis drives an I/Q sampling detector, producing an AF signal, which is amplified and applied to a PC soundcard for software demodulation. For testing, I built a sampling detector with the 74HC4053 switch, and an AF amplifier (+30dB) with the LM833 opamp.
The problem is, the noise level on the AF output it's very high, about 30mV peak, even without the antenna.
If you know a low noise configuration with 74HC4053 or 74HC4066 as sampling detector, please post it.
|
|
