Satdump software & wxsat reception

[ArloG]

Hey. I'm back. I breezed through 20 some pages of tips and hints.
I'd like to grab a few Meteor passes thins evening. Using HDSDR to record.
Pretty sure I need at least 130 kHz FM bandwidth.
I recorded M 2 the other evening but during processing didn't get the 4 quadrature constellation. And received a few errors.
Is it possible to get a few tips for recording settings? Unless i missed something, not finding much baseband recording info. for HDSDR.
Changed a few settings. At first recorded a pass using IF recording.
Don't know I'm missing something.

The last time I used SDR# with an audio file input with the Meteor decoding plugins and the multi steps needed. I did get a nice image.
And I used HDSDR for recording. Guess I'm a bit rusty.

My QFH antenna is working sweet after a bit of dimensional tweaking.

 

[ArloG]

Oops. Forgot this!

 

[Terryl]

ChrOnik, If your thinking of trying for the NOAA 15,18 and 19, 1700 MHz channels with a dish then good luck as the satellites are moving quite fast, you would need a rotor on that dish tracking the satellite as it goes over.

You might have better luck with the GOES satellites as they are in a fixed location.

What brand/type of SDR dongle are you using?

 

[Terryl]

Oops. Forgot this!

View attachment 156247

The Meteor satellites use OQPSK modulation, I don't think the FM modulation setting will work too good.

 

[ArloG]

The Meteor satellites use OQPSK modulation, I don't think the FM modulation setting will work too good.

Terry. FYI. Every SDR radio outputs an I/Q signal on the L-R audio channels that is reconstructed in software to many different formats. In other words, there is no digital RF.
Just like there is no "digital" TV antenna or satellite signal. How it's demodulated in the firmware/hardware/software is what gives it the characteristic. Like DSD+ will input an FM signal with 15 kHz bandwidth and the software decodes it into DMR, P25, etc.

 

[Analoguesat]

Ive had a few of these passes on MetM2-4 in the last couple of days. These seem to be some sort of calibration mode.

 

[Chr0nik]

ChrOnik, If your thinking of trying for the NOAA 15,18 and 19, 1700 MHz channels with a dish then good luck as the satellites are moving quite fast, you would need a rotor on that dish tracking the satellite as it goes over.

You might have better luck with the GOES satellites as they are in a fixed location.

What brand/type of SDR dongle are you using?

Yes, I've seen videos on YouTUbe about the NOAA sats on 1700Mhz and it seems like an imposible task from where I am at. Also, aren't the GOES satellites are only available in North America? I have a couple of RTL-SDR sticks and HackHF (which I'm planning to use for Satcom and a Loop antenna I have)

 

[Terryl]

Yes, I've seen videos on YouTUbe about the NOAA sats on 1700Mhz and it seems like an imposible task from where I am at. Also, aren't the GOES satellites are only available in North America? I have a couple of RTL-SDR sticks and HackHF (which I'm planning to use for Satcom and a Loop antenna I have)

Yah your right about the GOES birds being North/South America only, I forgot that some of you are on the other side of the big pond.

There might be a chance for something on the Meterosat series, Metrosat -10 is on 2101.5 MHz and 1691 MHz.

Info...https://space.oscar.wmo.int/satellites/view/meteosat_10


I've tried for the GOES-18 West satellite (at 137W) but I need a better antenna for that one, I'm thinking of modifying the old "C" band dish to pick it up by adding an antenna for that frequency, but it's a long run from that dish to the radio room, (around 30 meters) so I would had to add an in-line amp.

 

[Terryl]

Ive had a few of these passes on MetM2-4 in the last couple of days. These seem to be some sort of calibration mode.

View attachment 156257

It might have something to do with this....https://www.swpc.noaa.gov/products/goes-proton-flux

A big one

 

[Terryl]

Yah definitely a problem on M2-4 as I'm getting nothing but this on the down link.

 

[Analoguesat]

M2-4 is still in testing & commissioning mode, so interruptions to the imaging is to be expected.

 

[Terryl]

Looks like it's back to normal, a good pass this afternoon on M2-4.


And here is the RGB data, nice one.

 

[pontiend]

I am not getting many decent Meteor passes latley.A nice one of M2-3 though today.9.50 UTC unfortunately NOAA 18 is going over at9.43 UTC.

 

[Chr0nik]

I finally managed to get some clear-ish passes but still having issues with noise. Not much luck with the Meteor sats.

I use Raspberry-NOAA v2 to catch them - there's my web sdr: M7DNU

 

[ArloG]

Back again. How about some recording tips? My gut feeling tells me that I need to record RF using 120 kHz bandwidth.
I've been recording so far with maybe 3.8 MHz and squeezing the IF bandwidth down to 120 kHz in HDSDR.
It has been awhile but using the last SDR# that works with my radio with the Metoer demod plugins. And all of the steps needed to get a final image. I was able to.
And as far as RF gain. I am able to get a "screaming" signal using my proper QFH antenna and the radio preamp on.
NOAA APT sats. are never an issue even approaching the horizon fringes. Overhead and close to passes using wxtoimg always come out sweet.

It's getting the RF levels correct that seem to be an issue in getting a good OQSPK constellation. So far I get just blobs of green scatter in the window.
Is there any leeway or AGC built into sat-take-a-dump that handles not so perfect recorded input files?
Tips? Anyone?

 

[Satspot]

Finally got delivery of the Nooelec v5 USB dongle and installed it in Windows 10. Drivers installed and Satdump. The Nooelec terminates in an SMA female so I got an SMA male to BNC male adapter just to use an old whip antenna I had lying about. All seems to be in working order and Satdump is clearly receiving signal.

My question is, what would be a suitable antenna to use for receiving the 137x MHz band. I’ve seen some off the shelf very simple and inexpensive solutions and some very convoluted and expensive solutions so not really sure what route to take from here. I can cut and solder on the DIY side so that could well be an option. All suggestions welcomed.

 

[pontiend]

To my surprise I got a decent M2-4 pass at 1611.I expected nothing because the EL was only EL21.93.

 

[cirio70]

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My question is, what would be a suitable antenna to use for receiving the 137x MHz band. I’ve seen some off the shelf very simple and inexpensive solutions and some very convoluted and expensive solutions so not really sure what route to take from here. I can cut and solder on the DIY side so that could well be an option. All suggestions welcomed.

A very easy solution is the Turnstile antenna.
I built the one described in THIS POST and i got good result. Since some comment on the picture are in italian, please feel free to ask if you need any information.

 

[Terryl]

I'm using that same antenna and I'm getting good results after a bit of tuning.

The only problem I ran into when assembling the coax matching elements was the fact that most 75 ohm coax has aluminum shielding, trying to connect that to the 50 ohm coax with a copper shield was a puzzle, until I used a couple of standard crimp connectors rated for a AL/CU connection.

And be sure to use some electrical tape or heat shrink to avoid any possible shorts between the center conductors and shielding.

Also instead of using a SO-239 at the end I just soldered directly to my down lead coax, worked for me.

 

[Terryl]

One other thing to note is that some of the passes have both the NOAA satellites and the Meteor satellites in the same orbital time frame, the NOAA birds have a much stronger signal then the meteor's and will wipe them out, also when the NOAA bird are in close orbit to each other you will get zip as far as a usable signal on one or the other.

This photo shows that NOAA-18 is going to wipe out the signals from Meteor M2-3 on the next scheduled pass of both as it is only 12.5 KHz away in frequency.