1) Go to youtube canal that you want follow.
2) Search in HTML code the string: channel-external-id
i.e
data-channel-external-id="UClX7lyXmscb7W7iLql_vZtA"
3) Concatenate the string found with the following:
https://www.youtube.com/feeds/videos.xml?channel_id=
i.e.
https://www.youtube.com/feeds/videos.xml?channel_id=UClX7lyXmscb7W7iLql_vZtA
or
http://www.youtube.com/feeds/videos.xml?channel_id=UClX7lyXmscb7W7iLql_vZtA
4) Now you can enter the URL newly generated in any RSS feed reader
