I came across the following article for a rx terminated loop
This uses about 100ft (~33m) of wire which is similar to yours if you used a "ground" wire joining the 2 ends instead of ground spikes. The VE3DO loop has the whole antenna floating above ground by 150 to 600mm , selected for directivity. This loop is "centre fed" rather than "end fed" if you can call it that and it also requires a 9:1 *isolation* transformer as opposed to just a 9:1 balun.
I bought the CCW combination which I think can be massaged into a VE3DO simply by fitting a good choke on the tx side of the balun. I haven't modeled it, but I am hopeful that the loss due to the termination load might be offset by the directivity. I didn't say "gain" because this is a small antenna compared to a dipole on the low bands where it will be most use to avoid noise sources.
Looks like I'm going to be busy playing with more aerials this year.