Hi Mike, I have also contacted you regarding the performance of my HackRF. My former work (some time ago) was test/repair of radio equipment & I still have access to RF test equipment. I have performed RX sensitivity tests on the HackRF extensively on its own, as well as doing performance comparisons with an RTL-SDR 820T and attempts to receive NOAA passes.
The HackRF's RF performance has consistently been inferior to the RTL-SDR 820T - irrespective of configuration / software used. Can I send my HackRF to you for your assessment? Regards, Stephen -----Original Message----- From: HackRF-dev [mailto:[email protected]] On Behalf Of Michael Ossmann Sent: Saturday, 24 January 2015 9:24 AM To: [email protected] Cc: [email protected] Subject: Re: [Hackrf-dev] Sensitivity I apologize for the lack of response. I will get a replacement to you right away. Please reply off-list to confirm your shipping address. Mike On Fri, Jan 23, 2015 at 02:29:05PM -0700, [email protected] wrote: > > Mike, > > When are you going to respond to those of us who received defective > units? I have sent you a number of emails, and posts here as well, > and you have yet to respond. What's the deal? Please respond with > RMA instructions. > > On 1/23/2015 2:24 PM, Michael Ossmann wrote: > > Could you please share the details of your noise figure test method? > > > > Thanks, > > > > Mike > > > > > > On Thu, Jan 22, 2015 at 09:37:10AM +0100, JMG wrote: > >> Sensitivity measurements > >> > >> Test results for the noise figure NF of the HackRF, obtained at a > >> frequency of 435MHz: > >> > >> NF = 22dB LNA=OFF > >> NF = 10.8dB LNA=ON > >> NF = 1.1dB LNA=ON, additional external LNA "LNA4ALL" > >> > >> RTL-SDR, tuner 820T or 820T2 > >> NF = 3.7dB > >> > >> The HackRF really is extremely "deaf" when the internal > >> preamplifier is turned off. Turning it on and installing a good > >> external amplifier brings NF down to a very good value. > >> Applying so much gain at the preamplifiers in front of the mixer > >> will degrade the intermodulation properties. > >> Adding an external LNA will block the transmitter path to the antenna. > >> > >> The noise figure is the fundamental parameter to specify the > >> sensitivity of a receiver. All the other, more common, sensitivity > >> specifications can be derived from it. For example NF=3dB will give > >> an input sensitivity of S=-174dBm+NF+48dB=-123dBm for typical NBFM > >> signal. The factor "48dB" > >> somewhat depends on the test parameters. > >> _______________________________________________ > >> HackRF-dev mailing list > >> [email protected] > >> https://pairlist9.pair.net/mailman/listinfo/hackrf-dev > > _______________________________________________ > > HackRF-dev mailing list > > [email protected] > > https://pairlist9.pair.net/mailman/listinfo/hackrf-dev > > _______________________________________________ HackRF-dev mailing list [email protected] https://pairlist9.pair.net/mailman/listinfo/hackrf-dev _______________________________________________ HackRF-dev mailing list [email protected] https://pairlist9.pair.net/mailman/listinfo/hackrf-dev
