Trying to Listen to RS-44 Linear Satellite on VU3ZNG OpenWebRX

 I have been hearing a lot about RS-44 satellite which is very popular among LEO satellite operators. Being a linear satellite with a bandwidth of 60 kHz, multiple simultaneous QSOs are possible. As it is located at a higher altitude with perigee of 1182.5 km and apogee of 1516.8 km, it has a much larger footprint than the FM satellites which I am able to access with my IC 2730 FM radio. Many of my friends have reported working a lot of DX on RS-44, while I have been able to work very few DX with my FM only radio. Though I am not planning to upgrade to an all mode radio in near future, I thought of listening to RS-44 on VU3ZNG OpenWebRX, which covers UHF band as well. RS-44 is a V/U satellite with uplink from 145.935-145.995 MHz and downlink from 435.670-435.610 MHz. It has an inverting transponder, meaning that uplink is on LSB and downlink on USB.


I have to figure out how to use the WebSDR for listening to RS-44 as I have only tried to listen to FM satellites so far with it. Being relatively bigger than the usual amateur radio CubeSats and having 5W output, it should be possible to hear it on the WebSDR, provided someone is using it at the time in range of the WebSDR. Even otherwise, I think it should be possible to hear the CW beacon on 435.605 MHz, identifying as RS44. I started a live stream of 435.605 MHz with mode selected as CW as you can see in the link (http://125.99.242.56:8073/#freq=435605000,mod=cw,sql=-150), so that I can listen it later. During the passf at 5.49 am, which had a maximum elevation of 56 degrees at the location of VU3ZNG OpenWebRX and it was an Eastern pass, I tuned in to RS-44 on UHF 70CM-2 SAT band which has the downlink frequencies at its lower end.

It was interesting to note that the basic sound in the browser was quite different from the hissing noise of open squelch which I was familiar with while working FM satellites. The sound resembled the noise I hear in my HF radio on CW mode. When I switched over to USB mode, the sound was a bit more different. Though I tried listening for the full pass, I could not hear any beacon or stations. Stations might not have been there as it was an early morning pass and there are very few linear satellite operators in this region. Why I could not hear the beacon may be because the OpenWebRX uses omnidirectional antenna, though one of my friends has been able to work RS-44 with an omnidirectional atennna on a high rise building. My friends who work RS-44 used to say that they use preamplifiers. I am not sure whether there is an LNA at the VU3ZNG OpenWebRX for the UHF band. Here is a short video recording of both CW and USB modes.

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