Closed mk1blacklimited closed 2 years ago
I can see you are just about getting a signal (the vertical dark stripes on the spectrogram are the clue). But its very weak. To compare i have pushed an 'average' quality one from a pass here this morning:
So its a simple solution i think: The gains are defaulted to 'auto' which essentially doesnt really work.
in settings.yml : noaa_15_gain: 0
etc
Set the gains in each satellite's settings up to around 38 or 42
Note @colinluthier : I think we should probably lift the default gains right up to around 40 in a future update to the repo since quite a few folks come round with this issue.
Thanks for replying! :)
I think I mentioned (among all the other text...:D) I've tried adjusting the gain, both at 2/3 and to max. I did however try what you recommended(-ish), and set the gain to 40.2. This is what I got now, and while it looks a little better in the middle of the picture, it's still not quite what I'd like to see:
This is the spectrogram:
What type of antenna are you using?
The rabbits ear antenna that came with the RTL-SDR dongle.
Sorry for the delay in the response, Work decided that I needed to do stuff.
Each leg of the rabbit ear needs to be 21.02 inches (53.4cm). In a v at 120 degrees. The center of the V should point North. The V be laid flat (Both legs should be parallel to ground. I found 44.3 gain to work about the best for me. But I ended up altering some code and I use Auto gain with a turnstile antenna.
No worries, work trumps hobby. :)
The antenna is configured as you describe, except the v is pointing south - I've read it doesn't matter if it's pointing north or south?
I've moved the antenna to the top of my roof since my last posting, and increased the gain to 40.2, and the images have improved:
I've just changed the gain to 44.5 (closest I got to what rtl_test presents as available), so exited to see if that helps even more. :)
I actually got an image from METEOR as well, that's a first:
Max gain now, getting there:
I guess I could turn the antenna so the v is facing north, but not sure if it would make reception better?
A QFH antenna would probably be the next thing? I really shouldn't be using so much time on this (but hey, it's fun!), so I really could use some advice about buying an antenna instead of making one - recommendations?
I went looking for a prebuilt antenna, about 2 months ago, Never really found one that I could not make for WAY less than what they would cost. Ended up with a turn-style antenna, Mainly for the ease of building. I used 1/2 inch (12mm) copper pipe, and RG6 tv antenna (satellite/cable) wiring. With this setup I get pretty consistent images
I do have a dead spot, But I also have a large tv antenna that is mounted higher on the roof. So I know that it is giving me the week spots. If the pass is to the west of me, I dont have that issue.
That's interesting, the QFH-antenna build seems a bit daunting to me. :)
With my V-style antenna I'm now quite happy with these images (one of the better ones):
I have maxed out the gain, but should I try to lower it some to further improve the image, or is that no point?
Did you build your antenna from a guide? Link if you have one :)
I Used this image, as my guide. Elements and phasing cable are 534mm long. I did not use a matching cable.
A properly made QFH will be a very good solution for noise free picture. I use one and works great even decoding Meteor images
Looks like 'team RN2' got you sorted! Closing now, but good to see the success!
Describe the bug Probably not a bug. :)
Screenshots and/or logs All my images are very noisy, this is the best I've captured so far.![image](https://user-images.githubusercontent.com/45683539/117928532-fb71b280-b2fb-11eb-9a37-d22f6bf8a697.png)
Spectrogram:![image](https://user-images.githubusercontent.com/45683539/117929812-84d5b480-b2fd-11eb-88cc-aef8739eb829.png)
settings:
output.log
Support Output
Server information (please complete the following information):
Additional context Just started this, and I've reinstalled the SD-card twice. Seems very much like this https://github.com/jekhokie/raspberry-noaa-v2/issues/96 but a reinstall didn't help. I've tried adjusting the gain from 2/3 to max, now it's at auto. I do get lots of files in /srv/*, e.g. ls -l /srv/audio/noaa/ total 88868 -rw-r--r-- 1 pi pi 2628262 May 11 18:18 NOAA-15-20210511-181637.wav -rw-r--r-- 1 pi pi 2628262 May 11 19:57 NOAA-15-20210511-195550.wav -rw-r--r-- 1 pi pi 21195938 May 11 12:27 NOAA-18-20210511-120415.wav -rw-r--r-- 1 pi pi 22011800 May 11 22:15 NOAA-18-20210511-215956.wav -rw-r--r-- 1 pi pi 20711238 May 11 17:54 NOAA-19-20210511-173928.wav -rw-r--r-- 1 pi pi 21814562 May 11 19:35 NOAA-19-20210511-191938.wav
I've only got a rabbits ear antenna, so that might explain it all? I've tried tuning it to FM reception just to make sure it actually is ok, and FM radio reception works.