Re: [Discuss-gnuradio] Frequency modulation in GRC

[Marcus Müller]

You still seem to have no real grasp on what the frequency_modulator
block does.
Read my reply, and the documentation to that block again:

>> The frequency mod is but an input amplitude controlled complex sine.
>> It outputs a signal, which has a momentary phase increase that is
>> proportional to sensitivity and input amplitude; see the doxygen
>> documentation for the frequency_modulator block.

Greetings,
Marcus

On 25.05.2014 20:01, jason sam wrote:
> But if it is doing FM then there should be some min and max
> frequencies between which the signal will be switching?
>
> On 5/24/14, jason sam <address@hidden> wrote:
>> thnx i will see that.
>>
>> On 5/24/14, Marcus Müller <address@hidden> wrote:
>>> Ali,
>>>
>>> again: there is no center frequency in a baseband simulation. Your
>>> sawtooth-repeat combination will give you a step signal, where the
>>> amplitude is constant for 500 items. All frequencies that you set are
>>> only used to calculate what will happen in one sample.
>>>
>>> The frequency mod is but an input amplitude controlled complex sine.
>>> It outputs a signal, which has a momentary phase increase that is
>>> proportional to sensitivity and input amplitude; see the doxygen
>>> documentation for the frequency_modulator block.
>>>
>>> Greetings,
>>> Marcus
>>>
>>> On 24.05.2014 09:47, jason sam wrote:
>>>> Correction not 50 Hz but whatever the rate is after interpolation
>>>>
>>>>
>>>> On Sat, May 24, 2014 at 12:23 PM, jason sam <address@hidden> wrote:
>>>>
>>>>> Another question related to my flowgraph  that when i use the'
>>>>> Frequency
>>>>> Mod' block...then it will take the center frequency as 50Hz(the freq of
>>>>> the
>>>>> signal coming in)??
>>>>>
>>>>>
>>>>> On Fri, May 23, 2014 at 1:28 PM, Ron Economos <address@hidden> wrote:
>>>>>
>>>>>> I was experimenting with this the other day. I used
>>>>>> the wide band FM modulator instead, since the
>>>>>> deviation can be set. Here's the flow graph.
>>>>>>
>>>>>> http://www.w6rz.net/fmtest.grc
>>>>>>
>>>>>> The test audio files. sine01.wav is 0.1 Hz and
>>>>>> sine15k.wav is 15000 Hz.
>>>>>>
>>>>>> http://www.w6rz.net/sine01.wav
>>>>>>
>>>>>> http://www.w6rz.net/sine15k.wav
>>>>>>
>>>>>> Some C code to generate audio files at other frequencies.
>>>>>>
>>>>>> http://www.w6rz.net/sine.c
>>>>>>
>>>>>> Ron
>>>>>>
>>>>>>
>>>>>>
>>>>>> On 5/22/2014 9:26 PM, jason sam wrote:
>>>>>>
>>>>>>> Hi,
>>>>>>> I have made the flowgraph as attached..It is showing the modulation
>>>>>>> in
>>>>>>> scope but in fft block it's continuously changing  so I am still
>>>>>>> unable
>>>>>>> to
>>>>>>> find out that what are the max and min frequencies??I know how to
>>>>>>> find
>>>>>>> that
>>>>>>> in theory but i want to prove it from my results..
>>>>>>>
>>>>>>>
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