I understand that, but my radio receiver is a mono type anyway, so I'm
not looking for a stereo version.
But if you don't combine the two channels at the receiver, you'll only
be getting some of the content.
IN order for there to be stereo, there has to be difference between the
channels. How it's arranged can be quite complicated and depends on
what was recorded and how the recording engineer felt things should sound.
If you only have one channel of a stereo signal, you will lose content.
So that trumpet over in the right channel that is only on the right channel
to give a sense of space, will be missing if all you feed into the transmitter
is the left channel. Other things may still be there, but lacking in volume
because the intent was to place it somewhere between the two channels.