Posts by s-band

Still going but it's hard to tell how long for.

The 2 plots used different settings, One with 0.4Hz RBW, no averaging and the other with 0.7Hz RBW and 4x averaging. The Doppler was -0.69Hz/sec.

1.2m dish, 0.8dB NF LNA, 6.8GHz LO, B210 clone SDR

Now 1.6Mkm away at L2.

1.2m dish, 0.8dB NF LNA, 6.8GHz LO, USRP B210 clone SDR

I installed SDRAngel on the same PC but I struggled to get anything useful done with SDRAngel but probably due lack of familiarity. Sometimes I thought I could get it running easier if I loaded the FPGA using uhd_usrp_probe first. It did produce a spectrum which looked OK at 61.4Ms but I lost patience with the interface. I don't think having used Zadig broke SDRAngel, I think is just painful to use for me. I ran it on Linux and it seemed better on that but still not useful.

I have no problems running Satdump on the same PC. I'm using the latest NI/Ettus firmware.

Testing a re-built down-converter with the USRP B210 clone SDR, here's IMAP at 1.39Mkm. 1.2m dish, 0.8dB NF LNA, 6.8GHz LO.

VMA & impulse0879 I'm using the ExtIO from here on a basic PC with an 8th gen i7 and 32G RAM. The driver will not allow anything higher than 32MHz sampling. It runs without overflows or 'short reads' as long as there's nothing else running on the PC.

HDSDR was set up to show 32MHz span in the lower window with 48ks/s for the audio window which was zoomed in to show the frequency wobble on IMAP.

I think that your 5925 has the STV091x chip set which will tune below 950MHz. If you change these settings in the streamreader.ini file for CrazyScan, you could try it:

;IFStart=250
;IFStop=2350

If you just want to power the LNB, then use anything that will give you 13/18V & no tone/22kHz. Use a splitter that has one DC path for the supply and one path that does not pass DC for the SDR.

This post includes a link to using the software on the Amsat-DL forum which does work but is not the most friendly in use. The rest of VMA's thread includes other useful information on setting a system up with an SDR.

It looks like you are almost there with SDR Angel but you have the sample rate set quite low which would be OK for some of the narrow signals but the beacon needs a much wider setting. You will also need to set the sample rate correctly. Have a look at VMA's settings. The BATC web RX will give you setting to use for transmissions at the time you look. I don't use SDR Angel but maybe someone else can help with more detail.

Thank you, that;s very interesting. I've been using a B210 clone for a while but haven't tried any DVB with it. I chose this one as it is 100% compatible with Ettus firmware. It was about 300GBP delivered.

B210 AD9361 RF 70MHz-6GHz Software Defined Radio USB3.0 Compatible with Original Official B210

Features:1. Fully compatible with the official ecosystem, no need to replace any files.2. Introduced GPIO port for easy installation of expansion board.3.…

opensourcesdrlab.com

My observations:

It's very nicely made and in a milled clam-shell style case. However, that's a disaster due to the size of the case and it's waveguide properties. Noise from the USB (at the opposite end of the board to the RF section) propagates to the RF input. In addition, the case is anodised so the 2 halves do not make contact with each other, the PCB or the connectors. The noise levels from about 1-3GHz peak at around -80dB relative to full scale.

I ground the edges of the case, soldered the USB socket shell to the the PCB ground, filled the lid of the case with abosorber and made spring connections to make sure that the SMAs were connected to the case. This improved things by about 20-30dB. Sometime I will put a shield over the AD9361 and the input circuitry.

Since I use it mainly for DSN, I needed it to be locked to an external reference. It would not lock. It appears that either a defective VCTCXO was fitted or it was a TCXO (i.e. no voltage control). Changing this to a proper VCTCXO, it locked to an external reference.

I first tried it on Linux with GnuRadio command line utilities but they are a pain to use. SDR Angel is not ideal for DSN work but a quick test on Linux had it running. I have been using it on Win 10 with HDSDR and Satdump since. Here's an example of using it for FM demodulation.

On an 8th gen i7, the maximum rate it will run on HDSDR is 32Ms/s and on an 8the gen i5 laptop it will run at 16Ms/s without dropping samples. The HDSDR driver is limited to 32MHz/s. Satdump will run up to about 50Ms/s on the i7 but not with processing enabled. When I get time, I'll try it with DVB and write a better review.

This appears to be CB like chatter. The transcript and a translation into English are attached. There are several different transmissions with slightly different frequencies and levels. There also appear to be some weak signals underneath, the strongest wins. This has been going on for a long time https://www.google.com/search?q=russian+pirates+on+skynet

Link to ITU database for Skynet 5D

The frequency is correct on this one. If you look closely at the waterfall, you can see a few different carriers in the gap between the strong stations' transmissions:

Not data but there's no section for SCPC audio! I was looking for Spainsat NG II but this was nearby at the time. Amongst some narrow signals I found 3 narrow band FM audio sources (there may be more). They appear to carry Russian language religious programming. AI transcriptions and translations are below. The audio files are attached.

Edit: I forgot to connect the SDR reference so all frequencies are shown about 50kHz low. However, I think that the transmissions are all from pirates so the frequencies may change.

1.2m dish, DSN feed (poor performance on Milsat), 1dB NF LNA, 5.5GHz LO down-conversion, USRP B210 clone SDR, Rb reference locked.

I think that this is Türksat 4B see this

I don't think that there are any GS signals present, all seem to be BPSK or other narrow band data modes. The constellations in the posts above look like BPSK or carriers.

Thoughts?

I have convinced myself that this is Türksat 4B based on better calibration of the tracker and this from ITU Space Explorer As always with the ITU system, the names of craft don't always match the common names.

The system was set up for DSN with RHCP however there is little cross polarisation rejection when used below 7.75GHz. Can someone check the polarisation, please? I can see 2 active transponders. The lower one had no signals when I first saw it hence mis-identifying it as a wide band signal in my first post. Both transponders have a number of narrow band BPSK signals some of which are pulsed. They can be seen on a pedestal of TP noise. Wide spectra:

Here's a CS scan where it was just possible to catch a BPSK constellation. The SDR plot shows the BPSK below a pulsed BPSK signal.

Here are some other examples

1.2m dish, 1dB NF LNA, 6.5GHz LO downconverter, B210 USRP clone SDR

It's been a long time since I had a go at S band. The noise and interference here is even worse now. This plot shows the level of interference in the lower window. It's hard to find the wanted signal.

1.2m dish, ZHA-1724LN LNA, USRP B210 clone SDR

Different settings on the plot today. This craft might be a useful beacon for testing systems.

1.2m dish, 0.6dB NF Amplitech LNA, multiple down-conversions and an RX888 SDR.

Interstellar Mapping and Acceleration Probe

Interstellar Mapping and Acceleration Probe (IMAP)

The Interstellar Mapping and Acceleration Probe, or IMAP, will explore and map the very boundaries of our heliosphere — a huge bubble created by the Sun's

science.nasa.gov

From JPL Horizons:

The "Interstellar Mapping and Acceleration Probe" (IMAP) will study the
energization of charged particles and interaction of the solar wind with
that of other stars and material in our galaxy. IMAP is the fifth mission
in NASA's Solar Terrestrial Probes (STP) Program.

It was launched Sep. 24, 2025 @ 11:30 UTC from Launch Complex 39A (LC-39A)
at Kennedy Space Center, USA, on a Falcon 9 booster.

From a halo-orbit at the Earth-Sun L1 Lagrange Point, ~1.6 million km
closer to the Sun than Earth and free from planetary magnetic influences,
IMAP will spin once every 15 seconds while using 10 instruments to scan
the heliosphere.

At 1.5Mkm today. The 15 second rate frequency variation, due to craft rotation, is easily seen. The amplitude level is reasonably constant. It's not strong enough to detect any modulation

1.2m dish, SMW LNB with 6.8GHz LO, B210 USRP clone SDR

This plot was from 19th November when the craft were at 0.7Mkm.

Now that they are at L2, at around 1.5Mkm, I can no longer see the modulation sidebands.

522,000km today and here are both craft:

This is what they would looked like soon after launch on a 20m dish

A view today using similar SDR hardware & software on the 1.2m dish (the spike in the middle is spurious):

EscaPADE Blue & Gold

ESCAPADE - NASA Science

ESCAPADE will use two identical spacecraft to investigate how the solar wind interacts with Mars’ magnetic environment.

science.nasa.gov

Gold down link 8423.148147 MHz

Blue down link 8417.165797 MHz

I only found 'Gold' today it was at about 390000km after launch on 13th November. Using a 1.2m dish and an SMW LNB (6.8GHz LO)

The viasat ODUs are very difficult to use as they have a complex control signal. I don't know of anyone who has managed to repurpose one. They are highly integrated whereas the Gilats have a normal LNB inside and can be used without mods, just ignore the tx part.

I've no experience of it but it looks like a good PLL band B model. I don't know how easy they are to obtain in Oz but in Europe, Gilat AN8002 outdoor units (TX/RX) are sometimes on Ebay. They have good performance and include a polariser and feed. The AN8004 is band D but less common. Try a search here and on SatsUK to see how they have been used. In UK they are often around 20-50GBP but weigh around 2kg so shipping can be expensive.

Feedhorn I didn't manage to find a cheap route to registration. If you go through the process and find one, let us know. However, the free access is useful but it's hard to work out how some satellite names translate to commonly used names. Here's a screenshot of an Asiasat wild card search limited to 122E. Click on 'Open dashboard for detail' for the frequency bands (Link it Asiasat-AAA).

Maybe the Ka bands were approved but never activated. You need more detail of the craft itself.

jaes Keep an eye on it, I have been caught out by Elektro-L 2 which has a very strong carrier on 7500 when the modulation is off. My 1.2m may have worse side lobes than your 2.2 but I see the 7500 signal in a few places far removed from 14.5W. Check if there's any correlation between the 2.