HADES-D: New FM Satellite for Amateur Radio

HADES-D: New FM Satellite for Amateur Radio

Yesterday I was a bit disappointed when I could not hear anything on a high elevation pass of Amateur Radio on International Space Station. Checked the AMSAT Live OSCAR Satellite Status Page and found that others globally have also not been able to receive it. Then came the good news that a new amateur radio FM voice transponder has been opened for the public! HADES-D repeater has been opened to the public on 16 December 2023 by AMSAT-EA.

SatNOGS has mentioned that it has a NORAD ID 58567 and an alternate name as HYDRA-1. N2YO website lists NORAD ID 58567 as OBJECT CY and tracks it as well as gives two line elements or TLE, also known as Keplerian elements or keps among amateur radio satellite enthusiasts.

My favourite webpage for tracking satellite passes, Argentinian Amsat webpage has also listed it, which will enable manual Doppler tuning. AMSAT-EA has given uplink frequency as 145.875 MHz and downlink frequency as 436.663.5 MHz. SatNOGS reports show a downlink frequency of 436.666 MHz. No CTCSS tone is required for access.

The repeater of HADES-D is on FM/FSK mode and AMSAT-EA has further suggested that modulation is more appropriate by narrowing the bandwidth. Hence they have recommended NFM. I presume it is narrow band FM, which I have seen in the settings of my IC 2730 radio as well. HADES-D is the first satellite with FM repeater mounted on a PocketQube platform.

Wikipedia tells me that PocketQube is a miniaturized satellite for space research that usually has a size of a cube with 5 cm sides and hence one eigth the volume of a CubeSat. HADES-D has a 1.5P PocketQube form factor  and a mass of 0.2 kg, as per Gunter’s Space Page.

PocketQubes have a mass of just 250 gm and typically uses commercially off the shelf components for its electronics. You may note that even one CubeSat unit has 10 x 10 x 10 cm sides and is quite bigger than the PocketQube! So the panel size and size of battery are much smaller for HADES-D compared to other amateur radio FM satellites, most of those currently active are CubeSats. Naturally you can expect weaker signals and need for better antenna and radio setup to work HADES-D. But that is the challenge in amateur radio satellite operations and in amateur radio at large!

AMSAT-EA mentions that HADES-D is a satellite QRP and cautions that you should not call at the satellite entrance if you do not have the capacity to receive your signals on the way down! As I had read a version of the website translated from Spanish, I presume that this would mean that you should not use the HADES-D transponder if you are unable to hear your own signals on the downlink, which is a usual rule in amateur radio satellite operations.

Practically this would mean that you need either a full duplex radio which can monitor your downlink while you are transmitting or two radios, one for the uplink and another for monitoring the downlink simultaneously. Downlink monitoring radio will need appropriate front end filters to prevent your uplink signal from overloading its front end. Two antennas with adequate physical seperation are also needed. While connecting two anntennas to a full duplex radio, a diplexer of appropriate rating is needed, for the same reason.

AMSAT Live OSCAR Satellite Status Page has also added HADES-D to its list of satellites. I could see several reports of both uplink and downlink being active, from different regions of the globe. Of course there are also some reports of ‘not heard’, ‘telemetry only active’ and ‘conflicting reprts’. That is quite expected for a new QRP satellite as radio amateurs are getting ready for HADES-D! Next pass of HADES-D in my region is due in a few hours and has a maximum elevation of 25 degrees and is an Eastern pass. I am not sure whether my very basic setup will be enough to hear it. Still, I wish to try this very first PocketQube amateur radio FM transponder! Links to all pages discussed in the video are available on my blog page listed in the decription box of the video.

Udate: HADES-D is designated as SO-121 on Amsat Live Oscar Satellite page.