Now, I could understand if the frequency received may vary around its nominal value a little bit (the signal also needs to pass through the atmosphere, or other factors), but if I expect 137.1 MHz and I get the signal (also in the right time window!) on another frequency (137.9 MHz), the cases for me are the following: either the website is somehow wrong (and in that case I ask to you if there's one better), or I don't know yet something quite important, and in that case, what? I received barely nothing, but I saw that in the while a signal was coming from another frequency, in specific 137.9 MHz (which, from what I understood, is NOAA 18 frequency, which in that moment was on the other part of the world, according to the tracking website above). In any case, by the time the first available satellite was above my horizon with a good elevation (in this case I wanted to listen to NOAA 19 signal, frequency 137.1 MHz), I tuned on the expected frequency and waited for a signal. Two days ago I tried to receive one of the NOAA satellites for the second time (the first one was a test in order to check if the antenna worked fine for the job), and I kept open the tracking on this website: NOTE: I already knew the frequency range of the NOAA satellites is from 137 to 138 MHz, but the first time I didn't check the exact frequency I was listening to and which satellite I was listening. I'm a newbie with the RTL2382, so hope the question is not that stupid and the flair on the question is correct.

Hope this is the right subreddit where to submit the question (probably can fit also on r/amateursatellites).

Noaa 19 downlink frequency