In the future, installing updates will be a little bit easier.
Next complete image will be running also on new Raspberry Pi 4.
SAT Controller SDR Nano
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You don't have to adjust a signal all the time manually.
The LNB LO frequency of GQRX will be corrected automatically by the drift correction function of "SAT Controller SDR Nano" software. And thats all we need. Then the system is stable and there is no more (significant) drift in the demodulated audio.
The displayed RX frequency will not change. But the "real" RX frequency (IF of SDR stick) changes automatically depending on changing LNB LO frequency.
Only during warm up time of the SDR sticks there will be a little drift. But after that time (5-10min) your RX signal will be stable.
Hello Frank,
Again i will try to explain my problem with SAT-Controller V0.2.
SAT-Controller is locked to Master beacon.
CW beacon signal is on the marked position "CW" in GQRX.
SAT-Controller corrects the"LNB LO" according the drift of the LNB.
So far everything is fine.
But now when LNB drifts also the signal from "CW beacon" drifts also from marked position "CW".
This means the "LNB LO" is corrected but the tuned frequency for the signal "CW beacon (10.489.548.500 Hz)" does not follow or is not corrected.
What can be the problem and how to fix it?
73, DH2VH
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1. Do you use a PLL LNB?
2. Do your SDR sticks both have 0.5ppm TCXO or better?
3. Do you have run GQRX and SatControl 10-15min for warming up?
4. Is "Drift correction" button switched on?
5. Do you see a low drifting value in field "RX ERR"?
Then all should be ok. The displayed RX frequency will be fixed on 10.489.548.500 but there should be no more significant drift in demodulated audio.
1. Unmodified LNB GM-201
2. Yes NEWGEN.RTL2832SDR, TCXO 0,5ppm
3. Yes warm up for 1 hour and more
4. Yes "Drift correction" switched on
5. Yes i see drifting in "RX ERR"
But there is a significant drift in demodulated audio in value of drift.
This is my problem.
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Correct. "LNB LO" is corrected but demodulated audio does not follow.
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I know. That is the reason for "Drift correction".
btw: In V0.1 it works on my system
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Other idea: Do you have locked your system to beacon of Es'hail 1 (see below) or an other reference signal? Es'hail 1 beacon works very fine.
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Image is latest i can get. Pi3B+ i am using.
Locked on Es`hail 1.
But if "LNB LO" follows drift the beacon should be ok.
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Or there is a bug in the latest version Gqrx. Nothing is impossible.
Don`t worry. It`s just hobby.
I`m sure you will solve the problem.
73 DH2VH
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Next complete image will be running also on new Raspberry Pi 4.
Beta version of new image for Raspberry Pi 4B now is running for first tests on my mini satellite station (described here).
Many small improvements were made and on Raspberry Pi 4B all filters (like CW narrow etc.) from GQRX works well and without audio drops.
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Image for Raspberry Pi 4B comes with new desktop wallpaper ...
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Question: Which Version of the RPi 4B do you prefer ?
tnx info
herbert
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For fast PTT detection the signal TX GND from ACC socket can be connected to CTS input of the USB/serial adapter (because via serial CAT command there will be some delay):
If the SCU-17 sound card interface is used for CAT then there is a small modification of the CT-62 (RS232/CAT) cable required. For this cut the track on PCB between RTS and CTS pins and solder the emitter of a PNP transistor to the RTS pin and the collector to the CTS pin. Connect the base via a 4k7 resistor to TX GND signal of ACC socket:
Remark: The original cable can not be used for this because there is no wire connected to TX GND. It has to be replaced.
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Hi Frank,
thank you for that lovely project
Could you please explain with a few words why you are using two RTL sticks and not just one?
Is that neccessary for the beacon correction only?
I am using almost a GPSDO stabilized LNB.
When can we expect the image for the PI4 ?
73, Mike
DK1ML