I have a full size 1/4 wave vertical that is a great DX antenna. I also have a full size 1 wave length loop antenna for 75 meters. It is very good for local and out to about 300 miles. I wanted an antenna that was a little better for distance on 75 meters so I made a sloper 1/4 that was 65.5 foot long and connected it to the feed point of the 40 meter vertical. The feed is ground level and the other end is 30 foot high connected to the tri-band tower. I have fed 2 antennas with the same piece of coax in the past and it always worked ok. The 40 meter swr changed from 1.2:1 to 1.5:1 and that is fine. The 75 come out 1.1:1 at 3.650 Mhz. I want it at 3.576 so I will lengthen it a foot or so to bring the swr down some at 3.576. I used it last night on both 40 and 75 and the 40 worked the same as always. I managed to contact several DX stations outside the US. The 75 did not get a very good test as not to many stations were using the band. I did switch back and fourth between the loop and the sloper and found little difference on stations out about 300 miles. 75 is a winter band so I'm hoping for a better DX antenna than the loop has been. Time will tell.
P.S. boy was it hot working on the antennas, the temp was 100 degrees !