Search found 23 matches

by Stromeko
Sat Mar 28, 2020 12:28 pm
Forum: RTL-SDR Discussion
Topic: RTL-SDR for airplane tracking
Replies: 4
Views: 1819

Re: RTL-SDR for airplane tracking

I am new to this too. I have installed SDR# on a windows 10 machine and built a small antenna called a "quarter wave monopole ground plane" build to this design: https://ketil.com/la2dna/antenner/PMR446_ground_plane_antenna.htm . You do realize that this antenna is for an entirely different frequen...
by Stromeko
Tue Mar 17, 2020 5:57 am
Forum: KerberosSDR
Topic: 4x dump1090 on KerberosSDR
Replies: 6
Views: 5191

Re: 4x dump1090 on KerberosSDR

Note to self: I've likely fallen prey to the default dithering here… I need to find an IQ recorder that allows me to switch off dithering or compile my own rtl_sdr with that option patched in. Done that and it looks much better as long as I only look at the magnitude of the four signals (or alterna...
by Stromeko
Sun Mar 15, 2020 8:34 pm
Forum: KerberosSDR
Topic: 4x dump1090 on KerberosSDR
Replies: 6
Views: 5191

Re: 4x dump1090 on KerberosSDR

Looking at certain points in the data it seems that the magnitude signal on the four channels shifts around one or two samples depending on which message I look at. I have not yet tried to combine the data in magnitude space and the synthesize it back to IQ for dump1090, that might actually work be...
by Stromeko
Sat Mar 14, 2020 12:11 pm
Forum: KerberosSDR
Topic: 4x dump1090 on KerberosSDR
Replies: 6
Views: 5191

Re: 4x dump1090 on KerberosSDR

I can now play around with the IQ files a bit before coding it up as an RT program. So I ran out of memory a few times while doing that… :lol: I can correlate the four data records to a stable alignment that looks correct when checking various signals. Remember that I work off a 1:4 passive splitte...
by Stromeko
Sat Mar 14, 2020 11:59 am
Forum: KerberosSDR
Topic: 4x dump1090 on KerberosSDR
Replies: 6
Views: 5191

Re: 4x dump1090 on KerberosSDR

hjj9777 wrote:
Sat Mar 07, 2020 4:35 am
Curious to know your thoughts on combining dump1090 data with passive radar capability of the KerberosSDR […] Any thoughts?
In a sense that is what MLAT already does, so I'm not sure what I'd gain (except more data to increase the confidence level or precision).
by Stromeko
Sun Mar 01, 2020 9:51 am
Forum: KerberosSDR
Topic: Feedback on possible KerberosSDR V2 Hardware
Replies: 38
Views: 13867

Re: Feedback on possible KerberosSDR V2 Hardware

Just commenting on these four points: Redesigned calibration network with low phase distortion switches added to the board - no more need to disconnect antennas when returning and recalibrating. As long as your antennas and cables are identical, there should be no phase distortion. SMA out's arrange...
by Stromeko
Sun Mar 01, 2020 9:08 am
Forum: KerberosSDR
Topic: Interfacing KSDR in C/C++
Replies: 6
Views: 2688

Re: Interfacing KSDR in C/C++

One of the questions I have is if you need to re-sync after each control change? I would appreciate if I could get an answer to that question. To re-state, once the data coming from the four channels is aligned, can I control them -- specifically, changing the gain -- and expect the alignment to st...
by Stromeko
Sun Mar 01, 2020 9:04 am
Forum: KerberosSDR
Topic: 4x dump1090 on KerberosSDR
Replies: 6
Views: 5191

Re: 4x dump1090 on KerberosSDR

So this took way longer than I've had hoped for various reasons, but yesterday I've recorded ADS-B in parallel on all four channels into an IQ dump file and then used GNU Octave to align the samples. That actually worked as expected, so I can now play around with the IQ files a bit before coding it ...
by Stromeko
Wed Jul 17, 2019 6:39 pm
Forum: KerberosSDR
Topic: Power connection question
Replies: 25
Views: 6924

Re: Power connection question

You might take solace in the fact that not even the RaspberryPi folks got USB-C power delivery right and then didn't catch it in pre-manufacturing testing either:

https://hackaday.com/2019/07/16/explori ... -in-depth/

:roll:
by Stromeko
Tue Jul 16, 2019 5:50 pm
Forum: KerberosSDR
Topic: Strange USB problems
Replies: 4
Views: 1801

Re: Strange USB problems

If you power the unit via USB-C, then there shouldn't be any appreciable voltage drop on the USB connection to the PC. If you specifically bought a "long USB cable with low voltage drop", then chances are it's meant for charging only and has never been tested with actual high-speed USB communication...