Hey guys,
I did build from leftover shit sewer pipes an QFH antenna:
For weathersat reception of NOAA/Meteor* on the 137 MHz band with the cheap ass RTL-SDR 820 USB DVB-T sticks.
*Howto -> http://www.rtl-sdr.c...images-rtl-sdr/
Gallery https://dl.dropboxus...teor/index.html
Antenna http://sdrformariner...s-antennas.html
Anyway, during weathersat reception of NOAA/Meteor on the 137 MHz band i did see quite often unidentified interrupting signals.
After a bit of Googling around I learned that these were Dead Satellite’s that still are broadcasting given the right sunlight conditions, the signal strength is sufficient to show up in SDRSharp (
http://sdrsharp.com ), not all signals are very strong some very weak and needed a good close up zoom in SDRSharp.
There are many shutdown Satellite’s who apparently having a life of their own varying from Military, Navigation, Experimental, Weather, and also Amateur ones.
Although these satellite’s batteries have long been expired, because of some sort of chemical reaction due to thousands of failed recharge cycles the batteries begin to conduct over time and allow the satellite to be powered directly from the solar panels thus activating the transmitter.
Most are not transmitting any usable telemetry or weather images but they still use the original frequencies to sent out a unmodulated carrier, which interferes with the current operational Satellite’s in the 136/138 MHz band.
Normally when a satellite goes out of service and runs almost out of fuel the last reserve is used to shift it in a graveyard orbit which resides above the normal operation orbit, it will be switched off and left on their own.
But this will not always goes as planned, sometimes due solar radiation or other technical failures it will not respond again to the ground station commands, which leaves the Satellite in its current orbit.
Some have a timer onboard which will be activated at end of life scheduled to end/shortcut the power feed to the transmitter so it will not broadcast again, also this can fail.
Until some day they might not work at all anymore..
But that can take a while one of the oldest satellite still broadcasting are:
Others are just a spooky hauling sound like LES-1, NOAA’s etc due the Voltage fluctuation from the solar panels.
Updated once a week.
You can use it in your favorite tracker, i prefer Gpredict for this (
http://sourceforge.n...ojects/gpredict ) course of the unstable frequency and Doppler effects Orbitron will not always suite on this birds.
I also provided a frequency database for SDR# containing the frequencies of all the dead satellites.
So lessen your mothers shame and pull out the dvb-t stick at the back of your Satellite receiver and enter a new world of fun
Kind regards Happysat and blame it on the drivers offcourse