hackrf VS rtl-sdr-blog

Another example: the HackRF SDR board was done in KiCAD

https://github.com/greatscottgadgets/hackrf

keep and eye out for this issue: https://github.com/greatscottgadgets/hackrf/issues/668

I have read about this issue on github (have been some reddit posts over the years as well), originally in #541 which has now culminated in an ongoing investigation #974.

HackRF would be my next choice... https://greatscottgadgets.com/hackrf/

However, unlike your sensitivity issues, i dont get any birdies. i have a TCXO though. (https://github.com/greatscottgadgets/hackrf/issues/216). it seems its related to clock drift calibration without one. However this is something most SDR's suffer from, as a cost saving measure. Most RTL_SDR's suffer from this as well ("rtl sdr blog v3" comes with a stable TCXO, resolving the issue.).

I assume this is the case since I found a GitHub issue talking about blown TX: https://github.com/greatscottgadgets/hackrf/issues/1051 And I followed the recommendation of using hackrf_transfer -c with both -a 0 and -a 1. With a separate RTL SDR tuned to the output frequency I can see a very low power CW signal with -a 0. With -a 1 there is no output. This seems to match the results in the issue.

If you're talking about building attachments to work with a phone, you're almost all the way there to a standalone device anyway. You might want to look into HackRF and pwnagotchi for inspiration.

If you get a HackRF there's a utility called hackrf_transfer which can record a block of spectrum and then play it back.

https://www.rtl-sdr.com/ is a good place to start for SDR articles, software and advise. Good luck.

I've reported it here: https://github.com/rtlsdrblog/rtl-sdr-blog/issues/18

Download the https://github.com/rtlsdrblog/rtl-sdr-blog or https://github.com/librtlsdr/librtlsdr version instead. Even try both, since there may be differences.

Take a look at the RTL-SDR, I have a Blog v3 and it's great.

This site has some great examples on what various inexpensive SDR hardware can be used for: https://www.rtl-sdr.com/. Use cases range from receiving weather satellite imagery, to reverse engineering radio protocols (e.g. for remote door openers). Several years ago I used an inexpensive DVB USB dongle containing the RTL2832U chip (which enables SDR), to sniff 2G/GSM broadcast packets.