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

[Matteo Terzi]

---------- Forwarded message ----------
From: Matteo Terzi <matteo.terzi97 at gmail.com>
Date: 2018-05-09 9:28 GMT+02:00
Subject: Re: [Hackrf-dev] Low pass filter lesson 1
To: Chuck McManis <chuck.mcmanis at gmail.com>


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.
Thanks for the support

Matteo


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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