[Hackrf-dev] FM receive difference between HackRF and RTL-SDR

[Mike Jameson]

Some things to try:

1) Make your antenna as small as possible as you may be overloading it.
Broadcast FM stations are strong!
2) Reduce the gain on all three gqrx gain controls (RF,IF & BB).  Try just
raising IF until the signal appears.
3) Set the center frequency to something slightly above or below the target
frequency and click on the wanted frequency.
4) Set the sampling rate to 10e6 (10M)
5) Start GQRX using a fresh config with 'gqrx -r'

Mike

--
Mike Jameson M0MIK BSc MIET
Email: mike at scanoo.com
Web: http://scanoo.com

On Mon, Sep 22, 2014 at 3:18 PM, Mehdi Asgari <mehdi.qbic at gmail.com> wrote:

> Hmmm, I am using the last version of tools (and I don't know how should I
> change the magnitude)
> By the way, why the same setup in Gqrx produces different outputs for
> RTL-SDR and HackRF One?
> Here's a link to two screenshots from Gqrx window which may be helpful.
> HackRF: http://i60.tinypic.com/o7127d.png
> RTL-SDR: http://i57.tinypic.com/10r79lc.jpg
>
> Thanks
> Mehdi
>
> On Mon, Sep 22, 2014 at 4:54 PM, Simon IJskes <simon at ijskes.org> wrote:
>
>> The experience sounds the same as my first attempt, under linux, with the
>> old osmosdr software, where the magnitude of the signal was incorrectly
>> assumed to be unsigned.
>>
>> After fixing this, it all sounded a whole lot better.
>>
>> Maybe this is also the case in your setup?
>>
>> Gr. Simon
>>
>>
>> On 22-09-14 15:08, Mehdi Asgari wrote:
>>
>>> Hi
>>> I am a beginner in SDRs (and DSP)
>>> For the first sample, I'm, trying to build a FM receiver. I've tried
>>> both RTL-SDR and HackRF One (with both GNU Radio and Gqrx)
>>> I can easily get the desired station (on 88.0 MHZ) without noise on
>>> RTL-SDR (using Gqrx or GRC)
>>> But when I use HackRF One (with Gqrx or GRC), I can get the radio, but
>>> it's noisy.
>>> Is is because HackRF's higher sensitivity or does it need more
>>> adjustment to work fine?
>>>
>>> Note 1: I am using GNU Radio Live DVD and HackRF One with firmware
>>> 2014.08.1 and RTL-SDR (RTL2832)
>>> Note 2:
>>> Link for using RTL-SDR with GRC:
>>> http://www.instructables.com/id/RTL-SDR-FM-radio-receiver-
>>> with-GNU-Radio-Companion/?ALLSTEPS
>>> Link for using HackRF with GRC: Mike's lesson 1
>>>
>>>
>>> _______________________________________________
>>> HackRF-dev mailing list
>>> HackRF-dev at greatscottgadgets.com
>>> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
>>>
>>>
>> _______________________________________________
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>>
>
>
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>
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