I have a cophase harness that I made back in my CB days. Since 27.205 Mhz is the middle of the 27 Mhz CB, I guess that is what I had it cut for. I just noticed that both the shared FRS/GMRS and some GMRS channels are almost exactly 17 times the frequency of 27.205 Mhz. That means that a 1/4WL phasing line on 27.205 Mhz is still good (usable) for 462.5 Mhz as a 17/4 WL phasing line and probably even all of the GMRS & FRS freqs even as high as 467.7 Mhz. That is really convenient for me because I still use both of those bands and like some directivity. I find that very convenient and just wanted to share that info in case anyone else in interested in playing around with cophasing both bands like me.
I can get the optimal spacing (2/3WL) for the UHF setup but unfortunately for HF (27 Mhz), I can only get about 1/4 WL spacing on my vehicle although I still get the larger aperture and spacial diversity plus the -3dB quieting off the sides.
Perhaps I should use a "90-90" setup for 27 Mhz using a delay line on the leading antenna for that nice wide cardioid azimuthal shape (similar to a 3 element Yagi-Uda beam) with 3dB additional gain in the favored direction.