Regarding Observation 4523202 …
The signal looks good but the data is very poor - producing an almost unintelligible result.
I do not believe there is any external interference here causing the problem, and it was an overhead pass, so are there any comments and suggestions, please?
Hello, is your Nooelec LNA and saw filter getting power from USB or bias-t? Maybe run a few manual passes to verify all is running properly power wise. To help with interference you could use fared beads on the network Cable and usb, if using that for LNA/saw power. Amazon had a good multi pack.
It seems on your setup that you should be getting good data from the Sats … Is the LNA/SAW close to the antenna(s) ? You have 2 antennas listed but one station, do you run a splitter, switcher or plexer for this? These are all just thoughts and not necessary to answer to myself, you may be ahead of all I mentioned. Just figured I’d have a go at the mystery … Keep it up and enjoy your hobby!
Instructions for installing RTL-SDR.com Bias-T Software Switch can be found here if you haven’t already done so.
Software Defined Radio - SatNOGS Wiki
Hello, and many thanks for your reply. As you will have probably deduced, I am a relative newbie to SatNOGS, but wishing to make good progress and enhance my station.
So far I have been running the recently acquired Nooelec LNA and saw filter from an independent plug-top power source, to see how it performed, as the setup is on my worktable. I have thought about placing all the items (LNA/ST, RTL-SDR, and RasPi4) in a weatherproof box on the antenna mast. However, I have read that providing power with PoE causes interference, and there are two power levels required: 5V and 12V. Your comments on this would be appreciated? And is using Bias-T any better than independent power?
I have already ordered the ferrite bead clamps to help reduce interference.
I run two antennas (QFH on 2M, and Turnstile on 70cms), but without a splitter/combiner as I set up the band observations independent of each other and change the antenna inputs. I am unsure as to whether good results can be obtained by using a splitter/combiner. Perhaps I should run two stations?
My thanks again for your advice and comments, and I shall always welcome additional input, should you or others wish to comment further.
Hello, I’m new at all this as well and it’s been pretty good here with the community. I’ll input on some of your response just to get ideas flowing.
- I have thought about placing all the items (LNA/ST, RTL-SDR, and RasPi4) in a weatherproof box on the antenna mast.
*I have not done this myself and am coming out with some good passes, not saying that placing all devices there wouldn’t help. I have read that because the LNA and saw are able to be powered via Bias-t that doing so at the mast is a good idea and easily achieved. This is my next step.
2)However, I have read that providing power with PoE causes interference, and there are two power levels required: 5V and 12V. Your comments on this would be appreciated? And is using Bias-T any better than independent power?
*Yes I have read that myself about the PoE power at the mast. I’m using a power supply for my Rpi3b+ and bias-t for the LNA, seems pretty clean and I would definitely try it.
- I run two antennas (QFH on 2M, and Turnstile on 70cms), but without a splitter/combiner as I set up the band observations independent of each other and change the antenna inputs.
*Switching antennas is okay, the saw has a specific band filters so make sure you leave it in for the proper antenna application. Adding a FM filter wouldn’t hurt as well, though the saw filter may have a FM stop incorporated. Running 2 stations is a good way to go as well. I’ve set up a station just for NOAA passes and decoding. The 137mhz antenna has arrived and will be on the roof shortly.
In any case we are all having a great time learning and maybe someone will also add some input on the right direction. Enjoy the SatNOGS
Hello, and good to hear from you again.
Its been a busy weekend: relocating antenna feeds, adding ferrite clamps, replacing RTL-SDR-V3 with an AirSpy R2 with Bias-T to the LNA, and setting up remote access to the station in the hope of reducing interference/noise by eliminating other equipment. But have not, as yet, installed the SatNOGS items in a weatherproof box on the antenna mast. That’s a job for next weekend.
There have been some improvements in the waterfalls and data but still nothing exciting. See observation #4543718, which I’ve queried.
I’m coming to the conclusion that the immediate terrain (hills and trees) is blocking lower angles of the passes, as well as the antennas not being sufficiently high. However, I cannot change the terrain but I can attempt to increase the antenna heights by acquiring a higher mast - which would have to be a lightweight lattice design for stability (probably expensive).
Also I’m going to try a diplexer to allow both VHF and UHF passes. I already have a 2m/70cms one by Diamond. [And, of course, a stearable dish would make further improvements🤔 Even more expense].
Yes, you are quite correct: SatNOGS is becoming more and more interesting - if not addictive🙄
Enjoy, and let’s keep in touch👍