Satdump software & wxsat reception

[pontiend]

The next M2-3 pass here is at 20.31 pm.N18 may be in the way it looks like getting disabled.It will probably not help much but it keeps me busy.

 

[Terryl]

un-scheduling the offending satellite does nothing, it's still transmitting on the same frequency (or close to it) as the one your looking at, you can't mix two RF transmitting channels on the same frequency, it gobbles up the signals for both.

 

[Terryl]

This is a screen shot of the Meteor 2-3 with NOAA-18 right next door to it.

You can see that both are affecting each other, M2-3 at 137.9 MHZ (center of display) and NOAA-18 right next door at 137.9125 MHz. (to the right of center)

 

[pontiend]

If Satdump starts scanning NOAA 18,I have no chance of getting anything from M2-3 anyway.

 

[pontiend]

un-scheduling the offending satellite does nothing, it's still transmitting on the same frequency (or close to it) as the one your looking at, you can't mix two RF transmitting channels on the same frequency, it gobbles up the signals for both.

Thanks Terryl I had forgotten how close those frequency's are.
Another bright idea is scuppered.

 

[Analoguesat]

19/4/24 NOAA19 2050utc
avhrr 3 rgb mcir
Thats a long way east for me

 

[Terryl]

I'm having some funny noise problems here, discovered by using the new LNA with the 137 MHz band-pass filter, the noise spikes come and go, sometimes they are right on top of some of the satellites down link, as an experiment I'm setting everything up on a different computer to see if that's the problem, it's an old windows 7 laptop, so it's going to take some doing as some of the DLL files are missing that are needed to run satdump, downloading updates for that, going to be a bit.

 

[Analoguesat]

Met M2-4 is using 80k atm so satdump users need to change change the decode pipe.

20/4/24 1610 utc msu mr rgb 221

 

[pontiend]

After not getting much from M2-3 recently.I got a good scan this mornings 11.29 am pass.

 

[pontiend]

There were three M2-4 passes in the night .I changed the settings to 80 K and left the computer on overnight ,maybe I would get something Nope I just got black images

 

[Analoguesat]

There were three M2-4 passes in the night .I changed the settings to 80 K and left the computer on overnight ,maybe I would get something Nope I just got black images

Its something to do with the channels the software is decoding. I think its set for just the visible light channels. There has to be a way of changing it to process the IR channels instead? (Assuming M2-4 is transmitting IR atm)

 

[Terryl]

I'm still getting zip on the meteor satellites, again I wounder if they are turning them off when they go over North America.

Great pass but no downlink audio.

 

[pontiend]

I was not sure about this one.It looks like I got an image from M2-4 pass at 15.06. meteor-m2_x_lrpt_80k
I also got a broken image from the 16.46 pass
The frequency is right.

 

[Terryl]

OK, my new SAW/LNA filter for 137 MHz died in service last night, didn't get anything on any satellite because of that, returning it to Amazon for replacement.

 

[Terryl]

After removing the dead unit and just using the SDR dongle by it's self, I'm getting beautiful signals on NOAA-18. I guess that filter was junk.

 

[Terryl]

OK, after many many tweaking's of the settings I got something from Meteor 2-4 on the last pass, but it looks like I do need an LNA as the signal was very weak, will see what goes on when I get the new one (replacement) from Amazon.

This is all I got.

 

[pontiend]

I got two decent
scans from M2-3 this morning.10.44 and 12.22.The second one is farther north than I usually get.It looks like it maybe Iceland in the clear.

 

[Terryl]

WOW I almost got a full pass on M2-3 this morning.

Still have noise problems.

 

[Analoguesat]

I got two decent
scans from M2-3 this morning.10.44 and 12.22.The second one is farther north than I usually get.It looks like it maybe Iceland in the clear.

Yup thats Iceland

 

[Terryl]

I wish there was a SatDump forum to post possible bugs in the program, I have some strange noise problems that show up when running satdump, the spikes are only there when using that program, using SDR console or SDR++ they are not there.

For troubleshooting info one of the engineers at Nooelec (one of my SDR dongles) said to try a program called GQRX, it's has a very clean noise floor and is free of the nasty spikes I see in satdump.

I don't think is direct harmonic radiation from the PC as the antenna is 10 meters away from the PC and the coax is double shielded, I have even put the dongles in a double shielded box, no help, I even tried a second source dongle from RTL-SDR, same problem.

I'm stumped, if I can get rid of these spikes I can get good passes on the Meteor satellites.

I think I see these spikes because my noise floor is very low, it's around -75 dBm, so everything shows up, what are some of you guys noise floors at?

Don't know whats going on as I'm not a software guy...