I know people have RECEIVED a signal from the ISS on a Baofeng UV-5R, but I'm interested in TRANSMITTING. I'm going to be using a Baofeng UV-5RTP (basically an 8W UV-5R) with a Nagoya NA-771 that seems to be real according to Amazon reviews. Would this be enough for the signal to get through?

  • $\begingroup$ sure. what kind of signal do you want to transmit, and what exactly would you mean when you say "get through"? $\endgroup$ Commented Sep 28, 2022 at 17:34
  • $\begingroup$ (8W is a lot of power if you need little data rate to get through, but not enough for much data, says Shannon's capacity law. So this really depends!) $\endgroup$ Commented Sep 28, 2022 at 17:44

1 Answer 1


Absolutely. In fact, 8W may even be overkill.

VHF/UHF is far more dependant upon line of sight than on transmit power. Since the ISS is a relatively low orbit station, as long as you have a good pass (as close as possible to directly overhead), you should have plenty of time with fairly optimal line of sight.

The amount of transmit power you will require is mostly dependent upon your antenna design. With an omni-directional rubber ducky, you'll need all 5-8 watts and a fair bit of luck but it's not impossible to get a barefoot contact this way. With a handheld yagi or other directional beam, you'll have no issues with 1-2 watts or even less.

Keep in mind that this answer is a bit subjective. It's completely possible to contact the ISS on any standard HT, but picking the right pass and antenna can make this all much easier. Your location, elevation, weather, and noise floor can all influence your results. If you don't succeed right away, keep trying!



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