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Re: [Discuss-gnuradio] Just wondering why?
From: |
Cinaed Simson |
Subject: |
Re: [Discuss-gnuradio] Just wondering why? |
Date: |
Wed, 1 Nov 2017 13:04:57 -0700 |
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Mozilla/5.0 (X11; Linux i686; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 |
On 10/30/2017 04:04 PM, Adrian Hodgson wrote:
> 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.
Note, you should set the RF again to 0 when receiving. There's frontend
on the hackrf and you run risk of smoking the receiving RF amplifier if
there's a strong RF transmission nearby.
Also, the RF gain is either 0 or 1 - on or off.
See the hackrf tutorials greatscottgadgets.com website.
>
> 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.
The bandwidth is equal the sampling rate - in your case - 2M.
Look at with hackrf WBFM tutorial greatscottgadgets.com website.
The channel width of the NBFM is roughly 12-16 kHz - or even 20 kHz
depending on which part of the RF spectrum your working.
The Power Squelch may not work on the hackrf - I tried it awhile back
and I couldn't get it to work. But things have changed since then so
your mileage may vary.
The only parameter you may be able to change reliably using a runtime
slider on the hackrf may be the center and offset frequencies - provided
the offset frequency is within the center frequency +- sampling rate/2.
I did play with sliders on the frequency and sampling rate but I had
trouble - and since I didn't need it - I didn't pursue it. That was a
couple of years ago so thing may have changed. And if I recall correctly
it was changing the runtime sampling rate which gave me trouble.
You should post your hackrf questions on the
address@hidden
>
> 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
>
>
>
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> address@hidden
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>
- Re: [Discuss-gnuradio] Just wondering why?,
Cinaed Simson <=