Urgent Call: All Power To The ISS!

Update Feb 5th 2019, 16:36 UTC: Feedback is overwhelming, will try to update this page as good as possible! Note that we will only receive signal strength value for 435-438 MHz, we will not be able to decode the data.

Update Feb 6th 2019, 08:49 UTC: Thanks for all the transmissions! For today, please look at the “reserved” spots below and try to find another frequency if you are in the same location/ area, as these guys might use the frequencies again. We might not be able to update the list below today, so please use the comment section to indicate planned use instead of sending emails. Good luck & have fun!

Update Feb 7th 2019, 19:17 UTC: Amazing work everyone! Experiment ends today at midnight (UTC), since the device is only recording until then. From tomorrow morning 9/10 UTC we record again, but we do not know yet if and when we can download the data.


We were just informed that it is likely that MarconISSta will be deinstalled on February 9th 2019. This is about three weeks earlier than expected, so we quickly have to finish any outstanding activities. Therefore: All Power To The ISS!

We want to invite everybody who owns a UHF antenna, preferably with an e.i.r.p. of more than 30 dBW (we did successful tests with 50W transmit power and 15 dBi antenna gain), to do transmissions to the ISS. These transmissions will be recorded by MarconISSta and we will publish the results here. This experiment is a nice way for you to test your antennas, while it is great for us and ARISS to evaluate the ARISS VHF/UHF antenna pattern.

Transmission Details:

  • Trasmission time: Whenever you see the ISS between now and February 9th. Next time that we will downlink data is on February 8th, so if you want to make sure that you get the results early, transmit before February 8th.
  • Frequency: 435-438 MHz. Please avoid 435.95 MHz in Europe (our reference frequency) and 436.5 MHz (center frequency of receiver)
  • Power: Continuous transmission of carrier, we recommend  an e.i.r.p. of more than 30 dBW. The reason for this is that MarconISSta integrates the transmissions, short bursts might get lost.
  • Please do not use Doppler correction. We want to see the Doppler shift, it might help us to localize your transmission from this

Results will be published over the weekend.

Please let us know about your transmissions in the comments!

EDIT: To prevent overlap, we will post intended transmissions below:

435.050 MHz: KM39gc (Greece), SV8QG
435.163 MHZ: G3VZV, IO92QA
435.250 MHz: FF46ro, CE3RY
435.300 MHz: Europe
435.325 MHz: FF46QI, CE3QC
435.350 MHz: 05 Feb 19, 19:24 UTC, IV3RYQ
435.350 MHz: EB1ASA
435.375 MHz: 06 Feb 19, several passes over Europe, IN87KM
435.435 MHz: 06 Feb 19, 12.03 and at 19.30 utc (JN65qt), IV3RYQ
435.440  MHz: 05 Feb 19, 17:45 -17:55 UTC, HB9WDF
435.500 MHz: Europe, MX0MXO
435.550 MHz: Europe, ON7UX, ON4ISS
435.580 MHz: 05 Feb 19, 19:21 UTC, SQ6PNV
435.950 MHz: Europe
435.600 MHz: Italy
436.100 MHz: DM91SK, AA5PK
436.500 MHz: Do not use Worldwide – Center frequency (DC Offset)
436.625/.635 MHz: 05 Feb 19, 14:33-14:42 UTC, 16:09 UTC, OH2FQV
436.700 MHz: JO82II, SQ3DHO
436.800 MHz: 06 Feb 19, 01:44-01:52 UTC, PV8DX
437.000 MHz: 05 Feb 19, 19:06-19:09
437.280 MHz: 06 Feb 19, 01:33-01:44 UTC, K4KDR
437.333 MHz: 05 Feb 19 19:20 UTC, JO54DI
437.485 MHz: Italy
437.700 MHz: 06 Feb 19 01:40 UTC, 08:29 UTC, EM90eg, KB4PML

FYI: Yesterday (Feb 5th 2019) we had more visits (2468) on this blog than on any other day! Thanks for all the good work!


126 thoughts on “Urgent Call: All Power To The ISS!

  1. If I understand the request, you want us to just tx a carrier. Obviously we have to include an ID. Is that how you would find our particular signal?


  2. I am a licensed amateur and would love to assist in any way that I can. Can you provide more clear instructions here, or link me to a place that does? Thanks. -B


  3. It might be good to use FM carrier and give the station call sign every 30 or 60 seconds.
    16:09UTC pass, I was on 436.635MHz as web page said .625, what I use previous pass today – just to avoid overlapping with someone else.

    Liked by 1 person

  4. for the record..
    G3VZV IO92QA was transmitting a plain carrier on 435.163 during the following periods yesterday 5th Feb:
    35 dBW with occasional breaks due to temperature alarms!


  5. Leo OK2UUJ, loc JN89ON with IC910 (about 75W ) to horizontal Yagi.
    06.02.2019 UTC 12:04 to 12:14 on 435.255MHz
    06.02.2019 UTC 13:40 to 13:51 on 437.100MHz


  6. I want to let you know that I will do my best to send a signal to ISS at 437.015 MHz during all day time ISS passes 50 watts wide FM.


  7. EI4ESB TX on 435.825 1 degree above horizon at 6th Feb 19 at12:06, same again 15:20 max elevation 45 degrees from 1063VJ


  8. If I read it correctly, I’ll transmit a carrier on the ISS passes and ID only once at the end of 10 min, as the FCC mandates. I hope this gets you guys what you are looking for and hopefully decode my location.


  9. Transmitted on 435.435 from 18.30 every 18.39 utc 05 feb max elevation iss 34° About 80 watts
    on Yagi 12 elements 15 dBi. At the next for tomorrow ‘ 73.


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