That's correct.... another possibility is to use the inexpensive Discovery board from STM, as shown in this page : http://saq.weaksignals.com

Just a guess, not knowing the internals of the Airspy : the cause could be the so-called processing gain, which you obtain when you do a downsampling of a digital signal. Given that the output on the

I don't subscribe to QST, so cannot check that article, but, how is implemented the T/R switch ? If it uses a mechanical relay, IMHO it is too slow to protect the receiver. If instead it uses PIN diod

@Joanne, don't know if you were addressing me in your message. Just to clarify things, I did not build that low pass filter for the Airspy HF+, which I know that has a very good dynamic range. It was

SAQ started its message (after the VVV and CQ SAQ sequence) more or less at the time announced, i.e. at 17:00 UTC, and the message duration was a bit less than 8 minutes.

That would be true had the Airspy HF+ actually a 50 ohm input impedance. But the 100nF capacitor alone at 17.2 kHz has a (purely reactive) impedance of more than 92.5 ohm. Add to this the complex impe

Stephen, well, in my experience a receiver rarely has actually the nominal input impedance... usually it is higher than the nominal 50 ohm, and not purely resistive, but with some reactance... not hav

Very good reception of the today (Oct. 24th, 2018) transmission of the SAQ station, using the Airspy HF+. All the details here : http://www.sdradio.eu/SAQ_2018_10_24.html

Hi Leif, thanks for your answer. It looks like it is doable. I will scrutiny those lines of code. TNX

#airspyhfplus #bestpractice

Very interesting video Leif... do you perhaps have a description of the I/Q balancing algorithm ? I know that the source code of Linrad is open source, bur reconstructing an algorithm by just perusing

#airspyhfplus #bestpractice

Same here. Just after dinner, my laptop asked me the permission to perform a restart, in order to install V.1803 of Windows 10. I had no need to use it for a while, so I said "Go ahead". It took not a

Sure, but I bet that all those who have had good reception of SAQ have performed the R3 modification...

Nothing here... but I haven't performed (yet) the R3 mod, so I guess the sensitivity at 17.2 kHz is rather low. I will be ready for the next SAQ transmission, on July 1st. The antenna was an active lo

Just a small note based on my personal experience. At first, shorting the two "Erase" pads as shown in the photo did not work... Then I realized that maybe the pads could have been covered by a transp

Andrea, it looks like you have an outdated link on that page...

#airspyhfplus

Not to my knowledge... I don't even know if the format of the SDR# I/Q wav files is documented... maybe not.

Tom, I don't know your code (nor Spyserver for that matter), as I don't have an Airspy HF+, so the only thing that I can tell you is what you can gain by sampling at an high rate, then downsampling (i

#airspyhfplus

I am afraid it cannot be done, as the code has to run under Raspbian on the Raspberry Pi 3B...

#airspyhfplus

Stepan, I don't know the internals of SDR#, but for a generic SDR program, for example HDSDR which I know rather well, the decimation happens in two distinct points. The first is the visualization of

#airspyhfplus

Interesting. Is that source code available ? Maybe under a NDA ? I could maybe use it in my (not commercial) project.

#airspyhfplus