I got to thinking about other approaches to this problem. I took another look at a design that I use when I go car camping(my version of a caravan). It uses a couple of bent, folded dipole antennas, made out of 1/2" copper plumbing pipe and soldered joints, connected together with a couple of balun, equal length coax, and a splitter/combiner. I know that my actual gain will be at least .5db below what the model shows, because of the combiner and cable. I just assume that my losses will be about 1db. The two loops are held on a PVC frame, that comes apart and allows me to carry them in the car. I leave the cables attached, so it's easy to assemble and put up. I've modeled a version with reflectors, that greatly improves the HiVHF band, but haven't added the reflectors to my setup. I just use the two loops. AGT adjustment is close enough, for HiVHF and UHF, that you can get pretty good results displaying both band together. The design works very well in the US Repack band, but displays a bit of excessive SWR and Impedance mismatch above 675mhz. Maybe a little more work, and that can be resolved. Otherwise, your going to see some issues on those last few upper UHF channels.
Frame for the reflectors could be left unglued, and fold up as well. This may give you another option. It doesn't have a much gain, as the 2 bay bowtie, but has more gain than your 1bay, and the parts fold up and store pretty easy. Photos are my antenna, without reflectors. You can remove the reflectors, from the model, and recalculate, to get results.
Let me know if you have any questions.
CM Design began with HiVHF+UHF, VEE Stick Dipole, Variable ANGLE, 4nec2 by holl_ands, 27Jul2014 CM Stacked 2 elements CM Adjusted for Australian band HiVHF 174-230mhz UHF 526-694mhz CM Combine with 4:1 balun and equal length coax connected to 75ohm splitter/combiner (Expect about 1/2db additional loss due to combiner). CM All elements 5/8-in Copper (1/2" plumbing tubing and joints) CM Folded forward 45 degrees (use 90 degree elbow) CM Sides are 90 degree elbows and tee. CM ALL MEASUREMENTS IN INCHES. CM Char. Impedance = 300-ohm. AGT=1.0 CM Modeled without autoseg. CM Folding forward 45 degrees gives better UHF results and Reflectors improve Hi-VHF results CE SY Rsrc=0.319 'Simulated SOURCE Wire Radius, Adjust for AGT=1.0: UHF(610)=0.310, HiVHF(202)=0.328 SY Scale=1.0 SY sc=Scale SY Relem=0.3125 'Radius of Elements (1/2" copper tubing actual diameter is 5/8") SY Rrefl=0.125 'Radius of Reflector (1/4" rods) SY DipoleHeight=3.1875 'Distance between Folded Dipole Elements SY dh=DipoleHeight 'Distance between Folded Dipole Elements SY gap=3.0 'Center Gap Size between Elements SY Rlen0=52.0 'Center Reflector length SY Rlen1=33.25 'Inner Reflector length SY Rback0=15.0 'Outer Reflector back from element SY Rback1=11.0 'Inner Reflector back from element SY Rseperation=20.0 'Reflector Seperation betweet outer reflectors SY Rsep=Rseperation/2 'Reflector Seperation SY len=14.6875 'Total Length of Folded Dipole Element: 15.1875" for US Repack band SY Angle=90 'Sweep Angle between element legs (For Straight Dipole set Angle=0.0): SY ang2=Angle/2 'Swept Forward Angle away from Y-Axis (For Straight Dipole set Angle=0.0): SY wingDx=len*sin(ang2) 'Wing end location X axis SY wingDy=len*cos(ang2) 'Wing end location Y axis SY gapDy=gap/2 'Gap end location Y axis SY gapDx=gapDy*tan(ang2) 'Gap end location X axis SY Eseperation=24.0 'Seperation of element Feed Point 25.875 25.0 SY Esep=Eseperation/2 'Seperation of element Feed Point from center SY Hseperation=88.0 'Seperation of element Feed Point 88.0 SY hsep=Hseperation/2 'Seperation of element Feed Point from center GW 2 5 gapDx*sc gapDy*sc Esep*sc wingDx*sc wingDy*sc Esep*sc Relem GW 3 5 gapDx*sc -gapDy*sc Esep*sc wingDx*sc -wingDy*sc Esep*sc Relem GW 4 5 gapDx*sc gapDy*sc (Esep+dh)*sc wingDx*sc wingDy*sc (Esep+dh)*sc Relem GW 45 1 gapDx*sc gapDy*sc (Esep+dh)*sc 0 0 (Esep+dh)*sc Relem GW 5 5 gapDx*sc -gapDy*sc (Esep+dh)*sc wingDx*sc -wingDy*sc (Esep+dh)*sc Relem GW 55 1 gapDx*sc -gapDy*sc (Esep+dh)*sc 0 0 (Esep+dh)*sc Relem GW 6 1 wingDx*sc wingDy*sc Esep*sc wingDx*sc wingDy*sc (Esep+dh)*sc Relem GW 7 1 wingDx*sc -wingDy*sc Esep*sc wingDx*sc -wingDy*sc (Esep+dh)*sc Relem GW 23 19 -Rback1*sc -Rlen1/2*sc (Esep+(dh/2))*sc -Rback1*sc Rlen1/2*sc (Esep+(dh/2))*sc Rrefl GX 800 001 GW 41 19 -Rback0*sc -Rlen0/2*sc 0 -Rback0*sc Rlen0/2*sc 0 Rrefl GW 990 3 gapDx*sc -gapDy*sc Esep*sc gapDx*sc gapDy*sc Esep*sc Rsrc 'SOURCE GW 991 3 gapDx*sc -gapDy*sc -Esep*sc gapDx*sc gapDy*sc -Esep*sc Rsrc 'SOURCE GS 0 0 0.0254 GE 0 LD 5 0 0 0 58000000 'Copper Elements GN -1 EK EX 0 990 2 0 1 0 0 EX 0 991 2 0 1 0 0 FR 0 45 0 0 174 12 RP 0 1 73 1510 90 0 1 5 0 0 EN
Let me know if you have any questions.