Re: Subject: [Discuss-gnuradio] APCO 25

[Eric Blossom]

On Mon, Jan 20, 2003 at 10:03:17PM +0000, Ian Wraith wrote:
> Hello
> 
> >A great candidate for a gnuradio project. Are you volunteering?
> 
>  Challenge accepted Matt (time allowing of course) for the Tetra
> part anyway as Tetrapol doesn't interest me that much.

Good.

>  Mind you I will have to sort out a soundcard interface. I already
> have a receiver with a 10.7 MHz IF output and have built a small
> quadrature demodulator using a RF2711 IC.

Not familiar with the RF2711.  Who makes it?

> All I need is a 10.7 MHz
> IF amp to get the IF level up to the 1mv needed for the RF2711.

Have you considered just an appropriate bandbass filter centered at
10.7 MHz (if not already suitably band limited), followed by mixing
with 10.7 MHz (or there about) to convert to (or near) baseband,
followed by low pass, then soundcard?  This setup could then be used
to demod pretty much anything that will fit within the bandwidth limits
of the sound card.

We've already got a quadrature demod block:  VrQuadratureDemod

Eric