When demodulating a real-world signal, you have the problem that there's
other signals too - there's the other station 4kHz down that you want to
remove. So yes, you can say the signal of interest is an analytic
signal, but then there's everybody else too. True, you can demodulate
the signal
On 4/19/20 1:21 PM, Michael Carosino wrote:
The Hilbert block in gnuradio is specifically for taking a real input
and creating it's analytic signal. As noted above, this means the
output is complex with real(out) = delayed(in), imag(out) =
hilbert_filtered(in). This is the same as how it is
It seems to me that there is a fundamental design flaw in how the UI
elements of GnuRadio Companion work.
Several modules, like the Qt Frequency blocks, can output messages when
you click them, to inform *somebody* as to where you clicked. This would
be great for setting a new frequency,
I noticed that the version of GnuRadio that is released in Ubuntu 20.04
has a real-in/Complex out Hilbert block, which is great for modulating
SSB. But it lacks a complex-in/complex-out Hilbert for doing the
demodulation side. Is there any package with the complex/complex form of
the Hilbert?
I was trying to use the PLL carrier tracking block, and found that it
doesn't seem to work at all. I have a simple flow graph demonstrating
this - what would be the best way to share it?
It's pretty easy to demonstrate: take a signal generator generating a
complex sinusoid at some frequency
I applied your correction of multiplying by 2pi, and while it locks now,
it also doesn't seem to be very clean - there's a lot of noise on the
signal, and the phase compared to the reference still is running through
the unit circle. I've tried increasing and decreasing the loop
bandwidth, and
I'm trying to find any documentation on the gr-rds modules -
specifically, what do they expect to be fed with? It doesn't look like
they accept IF, nor demodulated FM - it looks like they expect some
other block between them and the FM discriminator. I've not found any
docs on the WIKI, nor
On 10/4/20 11:26 AM, Barry Duggan wrote:
> Hi,
>
> Yes, there are blocks to implement SSB transmit and receive using
> either the phasing method or filters.
I don't thing OP was referring to Upper Side Band...
> There must be a way to implement one of the most common means of
> communication
On 10/28/20 2:53 PM, hel...@relix.de wrote:
Hi all,
Good news, dear Kristoff!
My question to all of you: Does any of your national Amateur Radio Examination
Authorities foresee exam questions on SDR?
The US exams for amateur licenses have a few questions on SDR for all 3
levels (Tech,
The main difference between sampling with reals ('floats') and i/q
sampling with complex numbers, is that the latter does not only
provide the instantaneous value (voltage) of a signal at a certain
point of time, but also includes phase information (i.e. the slope of
the signal at that
I am sorrowful that you have decided you are going to stick with an
explanation that is fundamentally incorrect. I know how direct
conversion systems work - I design the software for them for a living.
What you are basing your mental model on is an optimization for the case
where the system is
Like I said previously:
Think of the spinning dancer illusion. It works because you only see
from one vantage point. If you saw a real doll spinning, and assuming
you have two eyes and normal binocular vision, you will have parallax,
and that will allow you to determine in reality which way
Now, unless I am completely wrong, the model you use captures both the
I and the Q samples at the same time. This means that there is no
element of 'time'.
In electronics, this works fine, due to the nature of mixing and a
difference of phase of the two Local-Oscillators.
But that's not how
On 11/4/20 6:26 PM, david vanhorn wrote:
"Twice the bandwidth" but that doesn't account for the 0 Hz "hole"
where the incoming signal is exactly at the sampling rate.
Or am I missing something?
What "hole" are you referring to? There is the "zero bang", which occurs
because most systems
Thanks! That solved most of my problems, now it's just that the LimeSDR
stuff isn't working under 3.9, but that's for another list.
On 4/11/21 8:45 PM, Jeff Long wrote:
If you haven't already, try removing ~/.cache/grc_gnuradio/cache.json
and restarting GRC. Then do the reselect if it still
Has there been a release of GRC3.9 that fixes the errors in some of the
blocks that comes from the swig to pybind change? e.g. I have a flow
with the signal source, and it has this error:
Param - Waveform(waveform):
Expression gr_waveform_t.GR_COS_WAVE is invalid for type 'int'.
Just
Do you know the frequency(ies) of the beep you are looking for? Perhaps
a bank of IIR filters at the beep frequencies would be cheaper than an
FFT, and is more of a continuous processing so it won't have edge
conditions? Or maybe just a simple energy detection, and then do the FFT
when you see
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