Sunday, October 19, W6MRR-35 was launched. This was the third battery powered version, in an attempt to extend transmissions past solar generation “sunset”. The payload was very similar to the previous -33 flight. After a full week of successful testing, immediately after launch, only a few transmissions were heard, and they were very weak. We are hoping it will come to life in the near future.
Kazu’s analysis of today’s balloon failure:
– I have successfully captured the APRS signal with my FT5D APRS HT right before the launch (at 09:30:20am PDT)
– Our launch was around 09:32am PDT
– I have 4 WSPR reports total (see below), one with W6MRR and others Q?6??? (2nd frame with special call sign)
– I have no APRS reports (W6MRR-11) on aprs.fi
on wsprnet.org:
Call: W6MRR
Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az Mode
2025-10-19 18:02 W6MRR 14.097005 -26 0 CM87uv 0.001 KB7GF DN06ta 959 18 W-2
Call: Q_6*
Timestamp Call MHz SNR Drift Grid Pwr Reporter RGrid km az Mode
2025-10-19 16:44 QY6FUU 14.097023 -22 0 CM87 0.001 W6EXT CM87wi 82 99 W-2
2025-10-19 16:34 QY6FUU 14.097012 -29 0 CM87 0.001 KD7EFG-1 DN31uo 1029 60 W-2
2025-10-19 16:34 QY6FUU 14.097012 -29 0 CM87 0.001 KD7EFG DN31uo 1029 60 W-2
I assume that Martin hasn’t transmit WSPR from his home this morning, and all above 4 reports were from W6MRR-34.
– At 16:34, 16:44 UTC (09:34, 09:44 PDT 2min and 12min after launch)
– balloon altitude was less than 60m (Pwr field in the 2nd frame is 0.001W = less than 60m)
– the grid was CM87uu (same grid as Berkeley Marina)
– battery voltage was 3.7V (still good)
– At 18:02 UTC (11:02 PDT, 90min after launch)
– the balloon altitude is still less than 1000m (Pwr field is 0.001W = less than 1000m)
– the grid was CM87 (CM87uv is incorrect since the wsprnet.org automatically put the last heard 6 digit grid to same 4 digit grid, Martin must has transmit WSPR TYPE2 message with 6 digits grid before from his home QTH)
Since other WSPR reporter stations in bay area never received W6MRR-34 signals, my guess is:
– Transmission power on both 20m and 2m somehow really low
– May damage the antenna during launch?
But, I still don’t understand why the altitude was still less than 1000m even after 90min from the launch.
Anyway, we now know the balloon isn’t completely dead, and may wake up soon or later.
Kazu. AG6NS
SF-HAB 