All the info is very interesting. Thanks folks.

Just want to make two 50-ohm 1/4-wave section lengths to transform the
impedance of two linear-loaded 40 meter verticals (spaced 1/4 wave) from
around 32 ohms to about 75 ohms, and then extend the cable from the
"director" vertical element with another 1/4-wave with 75 ohm coax for the
90/90 phasing. Then I just "tee" the two feedpoints together to get one
common feed point that's close to 50 ohms. Have done this previously with
good results, and had a much better than expected match to the 50-ohm
transmitter feedline. The last time I did this, I used fence wire that was
staked into some flat farmland turf for the ground system. This time I will
have to create an artificial ground plane or counterpoise, as the present
mountain terrain does not lend itself well for creating a good low-loss
real-ground system. Still have my old RG-11 matching section for the one
75-ohm coax 1/4-wave extension cable, but the two RG-8 sections are no
longer around. So, thought I would use the smaller and cheaper RG8X this
time. Maybe I won't. HI
AK