[Hackrf-dev] HackRF-dev Digest, Vol 42, Issue 10

Cinaed Simson cinaed.simson at gmail.com
Sat Apr 16 02:19:34 EDT 2016


On 04/15/2016 06:15 AM, McDonald, J Douglas wrote:
> 
> In my opinion the HackRF receive is fairly poor because of the conflation
> of two things:
> 
> only 8 bits
> 
> inadequately steep frequency skirt filters
> 

The HackRF doesn't have a front-end. Either buy a band pass filter or
construct one using gnuradio.

It's highly recommend to use an external band pass filter with an
external amplifier.

Also, you didn't indicate which software package you were using - the
bandwidth or sampling rate.

> This means there are spurious responses all over the place. 
> These are really really a nuisance.
> 
> Also, the connections to the box are not well done: any serious RF device needs 
> a full metal shield with all connections bonded to the box, not sticking
> through holes. 

See Michael Ossmann's tutorial on the HackRF

  https://greatscottgadgets.com/sdr/

> 
> On the short wave bands I can get a usable signal from my amplified 
> outside antenna by touching the shield of the RG6 coax to the input connector,
> and the actual differential mode signal (center conductor versus shield) does not
> fully swamp that. 

Isn't RG6 75 ohm cable? The HackRF unlike the RTL-SDR dongle is a 50 ohm
device. It's not a big deal provided you already have a good impedance
match with the antenna. If you reflect roughly 10 mW of power back at
the HackRF, you'll smoke the RF amplifier on the HackRF - see the link
above.

Regarding the antenna problem, did you try a different antenna -
preferably one which sees the same ground as your computer?

In any case, nothing you described above has anything to do with the 8
bit ADC.

> 
> 
> Doug McDonald
> 
> -----Original Message-----
> Today's Topics:
> 
>    1. RTL-SDR For Hobbyist Comments About HackRF (O.T. Powell)
>   >
>> ?In the hard copy that I have of this book, it says that the HackRF RX
>> capabilities aren't as good as the SDR Play or the BladeRF.  Is this
>> because it only has a 8bit ADC??  Or is this information provided by the
>> writer of the book perhaps incorrect or just an opinion?
>>
> 
> _______________________________________________
> HackRF-dev mailing list
> HackRF-dev at greatscottgadgets.com
> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
> 



More information about the HackRF-dev mailing list