DVR records are 1/4 of your screen size by default.
Settings > DVR and turn off Request Best Output Size and set your requested output width and height.
Please read the tooltips on the Request Best Output Size and the width and height that explain the pros and cons of doing this.
Is there a way to download Premium Plus subscription videos from Funiation in Full HD?
I tried with the DVR but that is only HD quality.
Using the converter option to Full HD makes the quality even worse.