If the message returned says Good signature and that it was signed by ThomasV with a pubkey 7F9470E6, then the software is authentic.
NOTE: do NOT be concerned if you see a warning that the key is "not certified":
gpg: WARNING: This key is not certified with a trusted signature!
This simply means that YOU have not personally trusted ThomasV's key.
As long as you see "Good Signature" and ThomasV's information, you can be sure it is OK:
gpg: Signature made Thu 19 Apr 2018 03:10:44 AM STD using RSA key ID 7F9470E6
gpg: Good signature from "Thomas Voegtlin (https://electrum.org) "
gpg: aka "ThomasV "
gpg: aka "Thomas Voegtlin "