Re: Sample Rate & Hardware Considerations Tutorial: GNURadio.org

[Barry Duggan]

James,

Thank you for your comments on our documentation! I started working on 
the docs last year including adding flowgraphs to the block docs and 
updating the tutorials to rel 3.8. The 
https://wiki.gnuradio.org/index.php/Guided_Tutorial_Hardware_Considerations 
is one which has been updated recently, but I didn't have the hardware 
to test it. (I will next week).

So, for question 1: that tutorial was written several years ago. I don't 
know why that sample rate was chosen, but some older computers have 
trouble with high sample rates. Actually the broadcast FM signal in the 
US is 200kHz with all the SCA, etc. but the minimum for stereo is less. 
If you look at the flowgraph for 
https://wiki.gnuradio.org/index.php/WBFM_Receive I use 192kHz because 
that is the rate for a FunCube Pro+.

For question 2: In the tutorial 
https://wiki.gnuradio.org/index.php/Guided_Tutorial_Hardware_Considerations#A_Working_Software_Radio_Broadcast_FM_Receiver 
there is no multiplier, so I am guessing that you are looking at 
https://wiki.gnuradio.org/index.php/WBFM_Receive where the multiply 
block is the volume control.

You said "In your (Barry Duggan's) example the multiplier helped to 
remove his static". Can you tell me which of my examples you are 
referring to?

Best regards,
--
Barry Duggan KV4FV