Neglected Groundstations

Hi, my 2 ground-station, ID-568 and ID-724 have recently been finally updated to bullseye and client 1.8.1
They have been running without getting much attention for years due to other commitments.
VKFF & WWFF.
I would appreciate if some of those, who are better acquainted with the SatNOGS system, would schedule some observations and post comments on the results.
My stations have been off-line for long periods and probably been off the radar for many for too long.
I have forgotten a lot and have to slowly bring myself up to speed again.
Iā€™m acquiring some 23cm gear and wondering if there are any satellites near 1296MHz.
Thank you for taking the time to respond.
73 Bob vk2byf

2 Likes

Hi Bob,

I will run a couple of satnogs-schedular jobs and see how the system is able to decode successful.

All the best.

1 Like

Bob,

I had similar problems to yours when I first set up my SatNOGS stations (ID-1936 & ID-1946). I got around the low count of scheduled passes by adding an extra RPi with a scheduler. I now get about 150-200 passes per day and in about 20 months of operation am up to 65k+ captured passes. I only added it to schedule my UHF but will probably add it to do the the VHF sooner or later. It is pretty east to do.

The reliability I got around by adding a timer to the AC power supply that turns the system off and back on at midnight. I still get occasional lockup but that is generally solved at midnight. I did have a scheduler RPi failure and had to rebuild that so it is not fool proof.

My SatNOGs station has a pic that shows the setup and has a short description. Hope this helps.

John - VK4JBE

2 Likes

Thanks, John for your ideas. I had plenty of users until I had problems with the failing upgrades. Turns out the SD cards had bad blocks and I had to start from scratch. In this application, they just wear out. Too many read write cycles in 3 years + of 24/7 operation.
I went the other way. Making sure the power came from Solar/battery power with an old analog 3 terminal regulator to provide the 5.1V without the switching noise of ordinary regulators.
There is a script to test if the RPi is running, if not, it does a reboot. If that doesnā€™t work, I get an email telling me, Iā€™m off line. I just unplug and replug the power plug.
73 Bob vk2byf

Thanks, Iā€™ll look out for your report.
Bob

Bob,

Sounds like you have a pretty good solution. One other option that my mate Mike runs on the station YMCF - 2108 is to use one of the internet connected remote switch. His site is out at a remote airfield near Dalby in Queensland. Great site from a noise floor/interference point of view but a 3-4hr drive awayā€¦so the internet connected switch is perfect.

The seperate scheduler is great if you really want to ramp up the numbers.

John - VK4JBE

Hi Bob,
Re frequencies: you can see the downlink frequencies used by all the satellites in the SatNOGS database at SatNOGS DB - Transmitters (click on the ā€˜Listā€™ button and then the ā€˜Downlinkā€™ column header to sort down or up). As far as I can see though, thereā€™s only Hilat using 1238.084 MHz - everything else is either above or below. Time to make yourself a new antenna!
Regards, David.

Found it, thanks. A handy table to use. The transverter is only good for 1240 - 1300 MHz and only 2W.
I have built a couple of helical antennas for receiving Inmarsat which worked well once pointed in the right direction. 6 1/2 turns are enough.
73 Bob

The VHF station seems to be fine, UHF isnā€™t receiving, even satellites where we know they have a strong signal like GRIFEX.

OK thanks PEOSAT. That was very helpful. I have examined the wiring to the UHF QFH antenna and I suspect power was not getting to the LNA. Iā€™m not sure if I fixed it, but it looks OK electrically.
I will continue to monitor and have scheduled some observations on ID-724 UHF, to see if I fixed the problem.
I may have to bring down the antenna mast for a closer inspection.
Both the UHF and VHF antennas are home-brew QFH antennas with LNA4ALL preamps on the same mast. The UHF one may have issues, although they are both pulling the same Current.
We shall see.
Thanks, Bob vk2byf

I donā€™t know what kind of setup you are using on UHF, maybe you can share the support information.

Run sudo satnogs-setup and select Advanced and then Support copy and past the output.
If you use the option ā€œ</>ā€ preformatted text it will keep its format.

My VHF & UHF setups are identical. QFH antenna with LNA4ALL preamp at the antenna. Raspberry Pi and RTL-SDR. Not the clone. Has been working for 3 1/2 years, just recently upgraded to bullseye and SatNOGS Client 1.8.1
Putty wonā€™t let me cut and paste the support info. I would have posted it by now.
I found I get a better result by increasing the RF gain setting from 30 to 35 on my ID-568 VHF station.
My ID-724 UHF is on 35 as well now after the upgrade.
Thanks, Bob

Thanks for the reply, the support info would be very useful.

My own system 431 has RTL-SDR and NOOLEC LNA and a 3 element yagi point up 90 degrees.

The Client has the following settings:

SATNOGS_SOAPY_RX_DEVICE="driver=rtlsdr"
SATNOGS_RX_SAMP_RATE="2.048e6"
SATNOGS_RF_GAIN="28.0"
SATNOGS_ANTENNA="RX"
SATNOGS_DEV_ARGS="biastee=true"

I think I have found my problem with my ID-724 UHF ground station.
We have a saying down under. If itā€™s not broken, donā€™t fix it.
After updating & upgrading my ID-568 & ID-724 ground stations, I decided to replace some cables from the SDR to a switch & power box with some nice brand-new Chinese SMA-BNC cables to tidy up my setup.
One of these new cables had a dead short, hence the UHF SDR could not receive anything. Not even noise. Please feel free to schedule some observations to test my fix.
Thanks, Bob, vk2byf

2 Likes

I am familiar with that saying, but the opposite is also true.

Good to see you found it and I will create a couple of observations.

All the best Jan PE0SAT

The only satellite I know of is FOX-1D (I think) which has an experimental L-band uplink, but unfortunately no downlinkā€¦

Thanks, jubitersaturn09, Iā€™ll look into it further
Bob