Introduction
During the past two years I have been able to successfully receive CubeSats CANVAS, ENSO, Veronika and EIRSAT-1 (Ref.1/4). Recently a new Canadian 3U CubeSat MARMOTsat was launched by SpaceX Transporter 17 on July 7th 2026 (Ref.5). MARMOTSat has 3 transmitters in the 10m/2m/70cm bands. Technical details are given in Ref.6/7.
Equipment Setup
Figure 1 shows the equipment setup. I first tried receiving the HF CW transmitter on 10m 29.410MHz. The first attempt I used an open wire antenna down at the Toronto harbour front. The second attempt I used an AlexLoop hf loop antenna from my home QTH. On both occasions I did not receive a recognizable CW signal. Keep in mind that the antennas did not have any appreciable gain. I next tried receiving the VHF CW transmitter on 2m 145.875MHz. As in previous attempts I used SDR# tuned 10KHz below the rx frequency to allow for Dopper Shift and sampled at 250Ksps. I used Gpredict/SatNogsDB to track the satellite and saved the rx signal when the coverage spot entered my QTH. Initially I was looking for a sinx/x type of signal and ignored the small pulsing carrier. Later on when I played the signal back I could clearly hear Morse code and then decoding in FLDIGI I received text that this was the MARMOTsat cubesat.
Signal Capture Sept18th_2026
Figure 2 shows SDR# playing back the saved BB IQ file. The file was approx 6min long and the CW carrier makes its appearance at about 2min in. In order to get a good decode on FLDIGI, you have to continually adjust the frequency to compensate for the Dopper shift. Figure 3 shows the FLDIGI decode with key words “MARMOTSAT”…”DIPOLE”…”VA7UVS”…”2 WATT”. Figure 4 shows using the visual SDR# waterfall display along with the rx audio to decode the CW.
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References
#1. – “CubeSat CANVAS on GNURadio”
https://jeremyclark.ca/wp/telecom/cubesat-canvas-on-gnuradio/
#2. – “CubeSat ENSO on GNURadio”
https://jeremyclark.ca/wp/telecom/cubesat-enso-on-gnuradio/
#3. – “CubeSat Veronika on GNURadio”
https://jeremyclark.ca/wp/telecom/cubesat-veronika-on-gnuradio/
#4. – “CubeSat 437MHz on GNURadio”
https://jeremyclark.ca/wp/telecom/cubesat-437mhz-on-gnuradio/
#5. – “MARMOTsat”
https://www.marmotsat.ca/
#6. – “SatNOGS Data Base MARMOTSat”
https://db.satnogs.org/satellite/HPYK-4830-8894-4849-3491
#7. – “UVic Propagation Lab”
https://www.propagationlab.ca/satellite/
