Bought my RH-770 years ago, have used it countless times!
Today it was my go to horizontal antenna when in a rush!
Held the 817 flat and worked my friend Craig!! I have also modded the HF antenna centre to have a BNC coupler on it, so that the HF coax can be connected to it and then add the RH-770 to the top of the pole!!
Crude, but quite effective
Here it is taped on, have since put that chassis mount BNC into the dipole centre!!
I simply can drop the mast, switch the coax and it’s a 2m vertical at 6m agl, I suppose the best and easiest way to improve it would be a 19inch pigtail on the earth side