Using .htaccess to virtually rename the file extension of a file

[thedonedeal]

I don't know where I went wrong but I'm generally trying to write a .htaccess file that will redirect all files which end in .tsv to .txt instead. (I don't know why but my extension is insisting on renaming the file back. Which is fine, since it's required by another fetch program.)

Here's my file

Options +FollowSymlinks
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.tsv -f
RewriteRule ^(.*)$ $1.txt

Now the files reside in a directory /googlebase/ and this is the ONLY directory where I need this kind of rename to happen, so I know I don't put this code into the .htaccess file in the / directory but for some reason, my browser is ignoring the .htaccess file in the /googlebase/ directory and insist on redirecting to a 404 page.

Can anyone help? I've seen code like this work when renaming .php to .html and the link so I figured it should work regardless.