[Hackrf-dev] Fwd: Low pass filter lesson 1

[Dominic Spill]

On 9 May 2018 at 01:29, Matteo Terzi <matteo.terzi97 at gmail.com> wrote:
>
> Hi Chuck,
> could you explain me better?
> Sorry but I don't understand why I should mix the signal. I'm a newcomer
with GNU Radio.
> If you can, give me a website where I can find something more.

Some of these concepts are explained in later videos in Mike's series, so
they may offer the explanation that you're looking for.

> 2018-05-09 0:22 GMT+02:00 Chuck McManis <chuck.mcmanis at gmail.com>:
>>
>> Hi Matteo,
>>
>> It is the difference between "baseband" and "RF". If you take an RF
signal that is at 100Mhz and has a bandwidth of 2.5Khz,  you can mix it
with another signal at 100Mhz and that will produce two outputs, one at
200Mhz, and one at 0Mhz. It will still have a 2.5Khz bandwidth so on the
low end it will be between 0 and 2.5kHz so a low pass filter is needed.
>>
>> This is the fundamental principle behind radios.
>>
>> --Chuck
>>
>>
>> On Tue, May 8, 2018 at 5:59 AM, Matteo Terzi <matteo.terzi97 at gmail.com>
wrote:
>>>
>>> Hi all,
>>> I'd like to know why does Micheal Ossmann use a Low Pass Filter in the
Lesson 1 (https://greatscottgadgets.com/sdr/1/ --> minute 22:00).
>>> He says that in that way just frequencies near to the zero Hz can pass
but it doesn't make sense....how radio frequencies can pass if they have a
value of MHz??
>>> Thanks
>>>
>>> Matteo
>>>
>>> --
>>> Matteo TERZI
>>> Google Gmail Member
>>>
>>> _______________________________________________
>>> HackRF-dev mailing list
>>> HackRF-dev at greatscottgadgets.com
>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
>>>
>>
>
>
>
> --
> Matteo TERZI
> Google Gmail Member
>
>
>
> --
> Matteo TERZI
> Google Gmail Member
>
> _______________________________________________
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> HackRF-dev at greatscottgadgets.com
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>
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