Issue on Debian Buster 10 using Gnome on Laptop

[xtranerd]

Hi - I was very pleased to see a Linux QO-100 application. I have used Sdrangel on linux to transmit and receive on QO-100 which worked - but in the end I ended up using SDRConsole on Windows as it supported beacon tracking easily.

I installed QO100_Transceiver on a Debian 10 Buster install on an I3 laptop and the install went OK - I had to apt install a missing gtk theme but that was the only issue.

The first problem is that I cant resize (or reduce/expand) the program window and there is only a "X" to close option on the applications window - this means I can't see the bottom row with all buttons on it - I got around this by using ALT+F7 and dragging the window and ten resizing it but this is really inconvenient as bits of the profgramme view are "chopped off"

The other issus are -

The configuration after initial setup and calibration is not saved for the next time the programme is run

I'm using a ADALM-PLUTO (with original firmware) over etherent and receive works- but I can't transmit (I know it works fine with Sdrangel in linux and SDRConsole in Windows. Audio and rf loopback both work fine. I think I can just about hear my signal on the downlink but I think the output rf level from the pluto is far too low . I understand other programmers have had this issue, I have a portable station with 1.8 W and a 60 cm dish so I need as much rf output from the pluto as possible. On SDRConsole the output level is set at about 88% to ensure I don't overdrive the next rf amplifier.

If these issues could be fixed and perhaps some frquency correction for lnb frequency drift (perhaps tracking the beacons) and a signal meter for alignment this would be a great option for portable QO-100 operation.

Thanks again for all your hard work on this project

James G1PVZ

[dj0abr]

Hi James,

I have tried to fix all your issues. The version 1.63 is ready for download.

There are two new settings in the SETUP window:

1. Pluto TX power (the output power can be set up to pluto's maximum now)
2. Screen resolution

and a new small circular button right of the bandplan line to change the contents of this line.

The screen layout is quite complex, so I cannot make it freely sizeable. But I have made the most important screen resolutions used by small SBC computers, even down to 480x350, see the setup menu. (The Setup window needs at least 800x480px).

"I had to apt install a missing gtk theme". Please tell me what you installed, maybe I should add it to the installation script.

Kurt, DJ0ABR

[xtranerd]

Hi Kurt,

Thanks for the quick reply and the update - 1.63 has fixed a lot but I still can't get it to produce a sufficient trasmit output from my Pluto to drive my rf preamp.

I'll details the issues -

1, Screen resolution - my laptop screen resolution is 1366x768 (16:9). The best usable option I can choose from your screen size menu is 1280x480 (see screen shot). If I select 1024x768 the width is OK but the buttons are still not visible as the top bar takes up the space. - would it be possible to add say 1280 × 720 to the list if resizing is not an option (as I think this my just fit the screen) ? That would provide some more vertical space for the signals. Your click on Rx to reset to 640x480 has been really useful !

2, Reception of signals from QO-100 has been easy but I still can't transmit - I know the system works fine on SDRConsole (Windows) and SDRAngel (Linux) using exactly the same laptop and QO-100 hardware. Both the Audio and RF loopback tests work. I've tried multiple settings of TX power but I still cannot hear myself on the downlink. I think there still issues with the power setting on the Pluto - when I have some more time I will take some rf measurements to see what the Pluto output really is with the different software. Obviously this is the number one problem I am experiencing.

3. I had to apt install libcanberra-gtk-module during the first install.

Again many thanks for all your work !

James G1PVZ

[xtranerd]

Hi Kurt just tried 1.64 for the screen resolution update.

Unfortunately the changes now mean I can't select or change resolutions.

If I click the new screen icon I get the button (see screenshot) but all I can do now is close.

The previous option of click on RX to reset to 720x480 with the screen sizes set in the setup menu was better !

Thanks again !

James G1PVZ

[dj0abr]

Hi James, fixing the screen issues is easy, I will do it later today.

regarding output power: I can measure peak max values of 0dBm at the TX connector of pluto. I will test the same with sdr console and see what the TX level is.

vy 73 Kurt

[dj0abr]

James, thank you for testing and reporting these issues. I really appreciate it to get comments.

I have just uploaded V1.65.

the AGC is totally new. It raises the level to the maximum allowed level for the pluto. In a direct comparison with SDR console the signal is now even louder. In my first test-QSO is triggered Laila and had to reduce the TX level, hi.

My settings are: AGC on, Mute on, Comp off, TXbass off. I got very good modulation reports from the other stations.

I have modified the screen size, you can now select 1280x720 which hopefully fits your screen. Also the screen-size selection menu should be visible now. Window-Scaling is sometimes a problem between different Linux boxes, so if you find a window which is not correctly scaled, please tell me.

vy 73 Kurt, DJ0ABR

[xtranerd]

Hi Kurt,

Just some quick feedback the 1280x720 works well and I can select it from the screen-size selection menu.

Unfortunately still no tx - I can hear the impact of the AGC on the rf loop back but still no signal from me is heard on the QO-100 downlink.

Rx is fine.

Over the weekend I will take some measurements of the Pluto rf output on SDRConsole and with your software to see if I can provide any more feedback. I must admit I'm a little confused why the Pluto appears not to be providing a good Tx signal.

Thanks,

James G1PVZ

[dj0abr]

Thanks for the feedback James,

for your reference some measurements I did today.

TXqrg: 2400.25 MHz same USB sound card for both measurements, connected a 1kHz source to the MIC input .

SDR-Console: Power: 100%, Level: to the beginning of the red area. Measured output -1dBm, if I overdrive the sound input it shows +1dBm. my usual setting with sdr-console is 80% power, which makes -7dBm at the TX connector.

Linux-TRX: Power-setting: 0, AGC on. Measured output -4dBm. (It is possible to get 0dBm but I want to have some reserve to avoid clipping at short loud voice passages). With this setting I'm triggering Laila, so a power setting of -6 is used normally.

I am very curious why no RF comes out with your Pluto.

Maybe some misunderstanding with TX frequency calculation? What is your station-setup and which TX frequency did you enter in the setup?

vy 73,Kurt, DJ0ABR

[xtranerd]

Hi Kurt,

I done some more experimenting.

The Station setup is Pluto, then Analog Devices CN0417 followed by a Chinese Wifi Amplifier which provides an output of 34.6 dBM to a homemade POTY feed and a 60cm offset dish.

I have found a couple of issues - I had selected 2400.00 as the TX value when I believe it should have been 2400.25. I changed it to 2400.25 and I could hear myself on tyhe downlink ! The signal was poorer in quality and signal than I experienced with SDRConsole a few moments later.

I have just completed some rf measurements tests

SDRConsole USB sppech processing on (5Db) 100% drive Tx Bandwidth 2.8 kHz Pluto output 2.9 dBm ( I normally drive the CN0417 at 88% 2.8 dBm)

DJ0ABR USB 0 drive AGC ON Compression High Tx Bandwidth 2.2 kHz Pluto output 1.7dBm

I dont think the 1.2 dB difference is the full problem as even after calibating both Tx and Rx using the CAL script I have quite a few kHz offset between Tx and Rx (and the the XIT doesnt track I make when I tune to a different RX frequency) - an option to have a fixed offset which remains active when you change receive frequency would be very useful.

I'm sure there must be something relatively simple that is prventing me from transmitting a clean and adequate uplink signal.

If there are any more tests you like meto make plaese let know.

Thanks,

James G1PVZ

[dj0abr]

Hi James, so the initial problem is solved by entering the 2400,25 MHz. Regarding the sound quality please switch off the compressor or maximum to "low". In the next version I will remove the mid and high settings. The new AGC makes the compressor almost unnecessary.

To fix RIT and XIT is a good idea. I will implement it this way. vy 73, Kurt

[xtranerd]

Thanks Kurt,

I could still do with some more rf drive/output from the Pluto if that is possible.

Thanks again,

James G1PVZ

[dj0abr]

Hi, the current version 1.66 drives the pluto with full possible amplitude if the AGC is switched on. Also the compressor high-settings has been removed because the modulation was bad. The RX and TX buttons had been modified to fit to touch screens. Its now much easier to tune by finger. And the RX/TX offset is now permanently stored as you requested before. vy 73 Kurt

[xtranerd]

Dear Kurt,

My QO-100 dish is being repaired - but I hope to have it fixed very soon. When it is back up and operational I will install 1.66 and report back !

73,

James

[xtranerd]

Hi Kurt,

I managed a have a short QSO using your software and the receving station said I was just above the noise of the transponder. I then rebooted in to Windows 10 and SDR Console - the same station reported me 5 and 9. I made no other changes

I'm a little confused why my power outpot is so much lowwer with your linux software. I'm happy to contine testing for you if that helps.

Regards, James G1PVZ