How can I display images at /feed/ and /atom/

Hi:
The image that I add with each post I publish is displayed in my blog pdm.com.co with no problems.
But it is not displayed at pdm.com.co/feed/ nor pdm.com.co/feed/atom/
I would like that those images appear there.

I add these images using Add Objet when I edit each post.

Because they do not displayed as I want, decided to use the Featured image option and the plugin SB-RSS_feed-plus, this way those images are displayed at pdm.com.co/feed/ and pdm.com.co/feed/atom/. It works ok, as you can see at this moment.

But, to the Featured Image I can not assign a web link, as the normal images added with Add an Object.

For this reason, I do not want to use Featured Images anymore, and return to the normal images added to a post, but that they do appear at /feed/ and /feed/atom/ too.

How can I do this?

Thank you in advance.
Regards,

Luis