SDR under Linux or Windows?

    • Official Post

    Just wanted to try GQRX under Windows and installed the bundled GQRX with Pothosware (latest release) and followed the instructions on:

    When I start GQRX.EXE, nothing happens.. no error message, no logfile, nothing.. :(

    When I try to run PothosFlow I get this error:

    The only tool which runs without problems is CubeSDR :)

    Someone having an idea?

    pe1chl The first computer I played with was an MITS Altair8800 computer which my brother got for little money from someone in Hamburg who bought it from the US as a kit, but never got it working. My brother found the short in the power supply and other bugs quickly.. Just looking like in this youtube video:

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    Since you had to enter the program using the switches on the front panel, you learned to write short Intel 8080 assembler code.

    My next computer I designed and build myself, with Motorola MC6802 CPU in it and the first static CMOS RAMs. I remember I pay a hell of money for the chips, never told my parents how much. Everything was build using this manual wiring technique (Fädeldraht) which became very popular at that time. I used the computer to write code for my first self designed and build VDU controller which was connected via RS232 and had a video controller and 6802 in it. Everything was Assembler indeed. Than I found and bought an BASIC interpreter from US, the same which Bill Gates used in his garage, but he was more clever than me. I got it on tape cassette or I had to type-in the whole code from the book by hand and than store it on tape.. don't remember anymore. Later I had an ATARI 1020ST with GEMDOS and all of that. Than I had several ATARI400/800 because I became involved in AMSAT-DL and Karl Meinzer DJ4ZC developed all the IPS software for the on-board computer from P3-A, OSCAR-10 and so on with these computers. They were originally for gaming, but the hardware architecture was brilliant and Karl put his IPS software developing environment on it. The ATARI800 were used also for the ground and command stations to control and operate the P3 satellites. Well, this is still the best part of the history.. later I also needed to have a PC running MSDOS, first Windows 3.1 (because during my university study I was developing software for a big company, which is actually my employee now). I also worked with Linux, because I did'nt like Windows so much.. Netwinder 275 the first ARM based computer from Canada. But I also could not avoid Windows and never completely switched to Linux.. But I have at least a few Raspberry PI's running Linux ;)

  • hallo agn...

    if you want get more information about the microwave SDR - concept

    ...look at german hamradio magazine

    FUNKAMATEUR 12/2018

    additional downloads about my work can be found here…

    and here can be more information found for the USRP users..…tion-dubus-vol-47-4-2018/

    have fun... and be relaxed.... it is HAMRADIO (dont forget)

    73 :)

  • Those were the days :)

    I left out my 8-bit times, but this was a little after that Altair system.

    I played with a couple of 6802 and 6502 evaluation boards, the kind of A4-sized PCB with a hex keyboard and 7-segment display and a monitor program in ROM, e.g. during internship at the TELEX exchange at our telecom company and at Philips, but my first own 8-bitter was a 4KB TRS-80 model 1 that I extensively upgraded and modified with homebrew boards using the same techniques :)

    It was built up with 64K RAM, a SD/DD 5"/8" floppy controller (I had 3 surplus 8" floppy drives and two 5" drives I bought new), graphics, and in the end even a 5MB harddisk with SASI controller. It could run CP/M 80 2.2 besides the standard TRS-80 OS.

    Like you I spent thousands of guilders (~DM) on that :)

    I programmed it mainly in Z80 assembler (as that was the only way to get some performance out of it), e.g. wrote a monitor program, the BIOS and even a command processor extension for CP/M that used overlays just like the original TRS-80 OS.

    With the Atari ST the fun was also in the homebrewing, I also built a harddisk interface for that (before Atari had it available in the shops) and then the Z8530 SCC interface for packet radio that I also used with the PACSATs and UoSATs (with G3RUH 9k6 and PSK 1k2 modem).

    (I wrote my own software for the PACSAT broadcast and file transfer protocols and automated my entire station to do all the tracking, uploading and downloading without me having to touch anything, much to the dismay of some users of the "official" software who always found me connected even at 02:00 before they could press their connect button...)

    This software was used for some time by the BBS systems that forwarded their bulletins via the satellite.

    But I did also an implementation of NET/ROM (after TheNET of course) on the Atari ST as part of KA9Q NET. All that software I could cross-compile for MS-DOS so others with a PC clone could use it as well, and a local amateur PA0HZP developed a Z8530 card for ISA bus and sold a lot of kits. Some others made similar cards. Most packet nodes and BBSes here used this setup.

    Those were fun times, but for me the computing really became interesting when I got my Linux system running and suddenly it was not a 1-program-at-a-time thing anymore. Before that, I had two Atari ST systems at home, one for running the amateur radio system (with a TRS-80 mini color computer, later an EPSON PX-8 alongside to run the W3IWI tracking program) and another one to do development. With Linux this was no longer required and everything, packet, tracking, BBS, and development, by then also internet browsing/mail etc, ran on one single system. But not so much homebrewing anymore, just standard PC hardware with some oddities attached via serial ports. E.g. the rotator via an AMSAT-DL tracking interface controlled via RTS and DTR of a serial port :)

    The other systems more and more became relics that I never discarded because they had cost so much money, but are no longer in use. I still have most of it in storage boxes...

    • Official Post

    pe1chl haha.. sounds very similiar and familiar :) I used my first 6802 homebrew computer to decode the telemetry from UoSAT-1 OSCAR-9 after the launch and sent it to Martin G3YJO. Every weekend they put up the famous UoSAT Bulletin with news about satellites. Meanwhile my brother DD2OJ re-build his Altair8800 and build a new CPU board with Z80, video terminal, floppy disk and so on to run CP/M operating system. It was when OSCAR-10 was launched, he build a hardware demodulator for the 400 Bit/s BPSK telemetry and wrote all the software to decode the signal and telemetry. It was DK2ZF who heard this from my friend Heinz, DL1CF and he knew Karl DJ4ZC. Karl put a special message on OSCAR-10 which was saying "The station in Hannover who can read this... please call me under phone number xxx" - believe it or not, we both were disappointed and thought that there is another station in Hannover capable to read that telemetry from OSCAR-10. But after some more days we finally called Karl and there was nobody else indeed. He invited us to Marburg. Well, not long after that I became command station for OSCAR-10 and got involved in P3-C project and so on.. ;)

    There is much more, but nowadays I wonder where did I found all the time to do such things ;) Endless nights I guess...

    Somewhere I should have some photos too.. if I find them on my backup, from the backup, from the backup... hahaha

  • Ah that is a very interesting story to read Peter! Now we know how you became involved with AMSAT-DL :)

    At that time I did not have a 400bps decoder, I only listened to the characteristic sound of the telemetry to align the antennas etc. And of course I was QRV on Oscar 10 a lot.

    I have only very few photos from that time, and they are all on negative and paper. I should scan them sometime, let's dig through the old photo boxes. But my shack looked similar to what I0LYL posted :)

    (with other types of equipment)

    My involvement with satellites came mainly through knowing some people in Eindhoven who were also active in a local information roundtable led by Nico PA0DLO. So I became interested in that and we went to the colloquium etc.

    Nico is still very active in determination of object numbers of newly launched satellites, and he still has this roundtable on 2 meters but I no longer have the suitable antennas to be able to receive and join it.

    (that was possible with my AZ/EL rotated 2m and 70cm crossed yagi pair, but now I have only an omni)

  • floppy disks came later. At first the programs were loaded with the cassette recorder and like Peter, I also copied this famous basic program line by line and then converted it into other languages.

    Actually it was my wife who copied and typed the whole program. I debugged the beating errors that were inevitable.

    It seems like yesterday... :(

  • Yes indeed, as I mentioned I also used the W3IWI "BASIC Orbits" program and modified it a lot, mainly to change it from a "prediction" type program into a "continuous tracking" program. I have made a version that showed the position of 9 satellites on screen simultaneously and then could track any one of them. Even automatically, so I could track a number of packet satellites using a priority list.

    Indeed a lot of typing from listings was going on back then, although I think I have not typed this particular program but received it on cassette from Eindhoven.

    I bought my TRS-80 in 1980 (easy to remember) but after initially starting with cassette tape (I even wrote an alternative loader that used a higher baudrate) I soon used floppies. My friends at the local club had systems with floppies and it was so much more convenient. Luckily I had another friend who had surplus floppy drives and diskettes and the only problem was they were 8". So I made a floppy controller that could support 8" (double the clock of 5") and used them. As I also needed a 5" drive to be able to swap programs with friends, I bought one Teac FD-55B. I still have the bill. Over 1000 guilders (or about 475 euro) in that time. But ready made drives with powersupply and enclosure from Tandy were about 1700 guilders. and those were single-sided while mine was double-sided. Well :)

    • Official Post

    Just received my two additional 0.5ppm NEWGEN RTL-SDR dongles from China.. I want to use them on my RPI 3B+ server and connect via Win10...

    I have re-installed the whole Pothos package with GQRX on Win10.. but still no luck... :(

  • Those dongles are fine, I received 2 as well up to now (ordered 3 at different shops, 1 still in the mail).

    I tried it on Es'hail-2 although there are intended for extra bands in our WebSDR

    (now we have 430-434 1296-1297 2320-2321 5760-5761 and 24048-24049 MHz already QRV)

    I can't help you with Windows 10, the sticks work OK in Linux (and should work in Windows as well I hear from others)

  • Heh, I addressed Peter, but to catch up your last sentences: same here with Windows! I started Windows as it was called Win286 ;)

    I would never have grown to an open source contributor if I had stayed in the (very) limited Windows world. I still use it when really absolutely neccessary in very few cases nowadays. :)

    Best regards,


    Edit: But let's not start a flamewar here - let's focus on more important stuff like building a GS system ;)

    Edit2: typo :P

    • Official Post

    I got GQRX with RTL-SDR dongle running under a virtual machine with Ubuntu under Windows10. Surprisingly it did work and I watched the Es'hail-2 beacons, but indeed the resources are limited and I will not continue this idea..

    I think I will install a second disk and boot from Linux, makes all more sense indeed.. :)

    Or I buy another RPi 3B+ and use VNC... I don't want to have a 4th monitor here ;)

  • Hi Peter,

    that's the right choice! :) I have run here on my RPi 3B+ GQRX under VLC watching on my WIN10 computer, the utilization of the processor including VLC is around 38%. Power consumption 6.5 watts when decoding ...

    • Official Post

    That sounds very good Robert! I'm already using an RPi 3B+ running Fox 1 Telemetry Analysis with my Funcube Pro+ Dongle (Serial 00000002) and it's between 55% and 60%.

    I was not sure if the 3B+ will be sufficient for GQRX, GnuRadio and all of that.. Will get another one dedicated to P4-A ;)

  • I have been working on my satellite station. I currently have receive working quite well with a 60cm offset dish using an unmodified Octagon OTLSO with an V3 dongle.

    For the software I am using my own linHPSDR Linux software, which was originally written to work with the HPSDR/Apache Labs Radios, which I have been adding support for SoapySDR so I can use it with the RTL-SDR dongle and devices which it supports. I am also working on getting my LimeSDR working which I intend using for transmit.

    Next steps are to build a dual feed and also to get a 2.4GHz PA.