Connecting the lead in wire to the middle of the antenna creates a
dipole antenna which is very good for transmitting - and I suspect,
equally good for receiving. However, lots of folks use what is called
a long wire antenna and they, so far as I know, all connect at the end.
So, I think you will get improved reception with either one. Perhaps
someone else will clarify this somewhat. You didn't state what radio
you'll be using it with. Some cheaper receivers have a tendency to
overload fairly easily with good external antennas.

There are antennas which use multiple length radials (i.e. the discone
(? one or two s's)) to give improved reception on multiple frequencies.
I suspect the DX sloper works very similarly. Therefore, I suspect
you could place it well off center to give improved reception on the low
end and the high end of a frequency range. You'd need to consult a
formula to determine the optimum length wire for a given frequency.

Pierre Vachon wrote:
Can the lead in wire connect to the wire antenna in the middle or does it
have to be on the end. This is a receiving antenna.

Thanks
Pierre