[Discuss-gnuradio] Just wondering why?

[Adrian Hodgson]

Quite new to this so perhaps a dumb question.

I have the following flowchart Narrow_band_QT.grc and screenshot attached,  
just something I have been playing with.

There are a few variables I use one is band_width.  Now the strange thing is 
if I start with a default of 100KHz band width when running I can scroll down 
to 10 KHz bandwidth and then go back up again, but if I start with the default 
set to 10 KHz bandwidth it will not scroll up to 100KHz.
It is more noticeable when looking at the bandwidth tab which is directly 
after the rational resampler. one can see the pass-band chance width as i 
change the bandwidth.

I am using it with hackrf one, to which I will have several questions about 
but will leave that to a later post.
I am lucky in that I have things like a spectrum analyzer and radio test set 
to work things through with.  I am slowly working through the tutorials and a 
book called Practical Signal processing, perhaps my age but finding it hard 
going especially when it comes to Python, cmake, and some of the mathematics!

Anyway if anyone can let me know why I get the results I do I would appreciate 
it.
OS is SUSE Leap 42.3, GNU radio is 3.7.11, just in case that makes a 
difference.
Cheers
Adrian

Narrow_band_QT.grc.png
Description: PNG image

Narrow_band_QT.grc
Description: application/xml