HamTV Reception Reports

[nils]

Hi, great to see HAM-TV installed and transmitting again.

Reception report from today, 2025-07-31, 16:39 UTC pass, 44deg EL max, received in JO21ex, Delft, The Netherlands:
2m dish, helix feed, cavity filter, LNA 0.4dB NF/58dB gain, USRP B200, satdump for demod, start 16:39 UTC, end 16:50 UTC, peak SNR 16.3 dB, blank image, on AZ/EL rotator

7 minutes of video was received. Demod was working fine in satdump, signal was weaker/had some multipath during first half of the pass (I guess related to TX antenna geometry/obstruction of TX antenna at ISS). Signal was good and stable during the 2nd half of the pass. Spectrogram of the pass attached below to give an impression of the SNR throughout the pass (start/end @ -1.5deg EL angle).

Best regards, Nils

P.S. FYI satdump seems to lock around 2.3-3.0 dB SNR (for the current DVB-S 2MSym/s 1/2 FEC signal)

[G4IMO-TV]

Just for info:- It is possible to receive pictures using a cheap aliexpress MMDS BT-281 2.2 - 2.4Ghz downconverter. Downconverting to 557Mhz into the Minitiouner. Just remove the dipole, fit an N Socket, and connect directly to the feed. Even with a quoted NF of 2.5 dB I managed MER of 7.4 on a 1M dish.

Nick.

Screenshot (151).JPG (350.37 KiB) Viewed 186 times

[nils]

Reception reports from today, 2025-08-01, from JO21ex, Delft, The Netherlands (tracked all visible passes):

• 11:02 - 11:11 UTC, 13 deg EL max pass, max SNR 5.2 dB, ~30 sec of video decoded, blank image

• 12:37 - 12:48 UTC, 47 deg EL max pass, max SNR 17.8 dB, ~7 min of video decoded, blank image

• 14:14 - 14:24 UTC, 86 deg EL max pass, max SNR 23.1 dB, ~4 min 51 sec of video decoded, blank image

• 15:50 - 16:01 UTC, 57 deg EL max pass, max SNR 19.6 dB, ~7min 12 sec of video decoded, blank image

• 17:27 - 17:37 UTC, 17 deg EL max pass, max SNR 8.4 dB, ~1min 10 sec of video decoded, blank image

• 19:06 - 19:09 UTC, 1 deg EL max pass, no lock, no video decoded

Generally same observed as yesterday; on most passes the first half of the pass has a weaker signal, the 2nd half of the pass has a stronger and more stable signal. Can provide the spectrograms in case there is any interest.

HW/SW: 2m dish, helix feed, cavity filter, LNA 0.4dB NF/58dB gain, USRP B200, satdump for demod, on AZ/EL rotator

Side note: The SpaceX Crew-11 dragon capsule is scheduled to dock to the ISS tomorrow, Aug 2nd, not sure if the ISS attitude was normal today or possibly different due the arriving capsule.

Best regards, Nils