Repairing the HackRF One

Testing the RX

Looking at GSM downlinks from BTS is an easy way to check if your receiver works fine, there should always be something on the GSM downlink frequency range (935-960).

echo $arfcn

osmocom_fft --help
osmocom_fft --args=hackrf=0 --center-freq=`arfcncalc -a $arfcn -d` --samp-rate=2e6 --averaging --peak-hold
#-v
#--waterfall

PERSISTENCE
IF=32
BB=32

Validate the RX amplifier

RF=0 vs RF=14

You can also have a look around 433Mhz

osmocom_fft --args=hackrf=0 --center-freq=433e6 --samp-rate=2e6 --averaging --peak-hold

PERSISTENCE
IF=32
BB=32

Testing the TX

Listening with an RTL device on 433e6

osmocom_fft --args=rtl=0 --center-freq=433e6 --samp-rate=2e6 --averaging --peak-hold

LNA=41.5?
IF=34

With and w/o amplifier

hackrf_transfer -h
hackrf_transfer -a0      -f 433e6 -t /dev/urandom
hackrf_transfer -a1      -f 433e6 -t /dev/urandom
hackrf_transfer -a0 -x47 -f 433e6 -t /dev/urandom
hackrf_transfer -a1 -x47 -f 433e6 -t /dev/urandom
#-c 127

==> there is no diff between the last two. why?

Donno how to use this

#osmocom_siggen --help
#osmocom_siggen --args=hackrf --tx-freq=433e6 --sine
#osmocom_siggen --args=hackrf --tx-freq=100e6 --sweep -x 2M -y 1 -c34
#osmocom_siggen_nogui --args=hackrf --tx-freq=433e6 --sweep -x 2e6 -y 10 -v

Components

TX Power Amplifier / U25 / Avago MGA-81563 at the top
TX RF switch / U12 / Sky13317

RX Low Noise Amplifier / U13 / Avago MGA-81563 at the bottom
RX RF switch / U14 / Sky13317

Resources

https://www.onesdr.com/2020/04/09/how-to-fix-a-broken-hackrf/

https://github.com/mossmann/hackrf/issues/178

https://www.reddit.com/r/hackrf/comments/gegfiw/how_can_i_enable_antenna_pre_amp_for_receiving/

HW Repairs

https://github.com/mossmann/hackrf/tree/master/doc/hardware https://github.com/mossmann/hackrf/blob/master/doc/hardware/hackrf-one-schematic.pdf http://www.t4f.org/articles/repairing-the-hackrf/ https://dmyt.ru/forum/viewtopic.php?t=1663 http://hackrf-dev.greatscottgadgets.narkive.com/l3GVPhsh/i-lost-the-pre-amp-on-the-hackrf-how-to-get-it-back http://hackrf-dev.greatscottgadgets.narkive.com/cgFRO1eq/amp-on-or-off http://www.cqdx.ru/ham/new-equipment/hackrf-one-sdr-10-6000-mhz/

RX Testing

HackRF TX amplifier test, RF, IF, BB Gain to very high values https://www.reddit.com/r/hackrf/comments/8g0uh6/hackrf_tx_amplifier_test_rf_if_bb_gain_to_very/

http://osmocom.org/projects/sdr/wiki/GrOsmoSDR#Spectrum-Browser https://wiki.gnuradio.org/index.php/HowToUse https://wiki.gnuradio.org/index.php/Guided_Tutorial_GRC https://wiki.gnuradio.org/index.php/Guided_Tutorial_Introduction