[Discuss-gnuradio] Help understanding the role of IF_freq in this snipper of code

[Jonathan Coveney]

http://www.linuxjournal.com/article/7505
This article is a useful one I've studied to understand FM demodulation

In the block of code that implements (albeit I haven't tried to run it because it's not made to run with a USRP, it's more pedagogical), to demodulate two frequencies, it averages them and then centers them around an IF_freq.

My guess is that this is the frequency that serves as a "0" post demodulation. Ie by reading frequency 5.75e6, you are reading the 0 frequency. But I'm not sure.

If this is the case, if I wanted to implement something similar using the USRP and TVRX, is there a similar "center" that I need to use? Is it 5.75e6? or is it simply 0hz?

I've attached the code.

Thanks

7505l3.txt
Description: Text document