I had some MPS2222 transistors and built up a quick LZ1AQ and swept it, with the sweeps and picture of the ugly-build added to the Photos. This is only for comparing? with Caaarlo's build and sweeps (thanks, Caaarlo, you did a nice job building yours). His nanovna sweep didn't include gain sweep. I used the DG8SAQ VNWA with the same two frequency sweeps, and with calibrated-out 1:1 input transformer (unbalanced to balanced) which shows both input impedance and gain on the same sweep. I used -30 dBm input level to ensure the loop amp is not overloaded. I'm not sure what transformer and turns Caaarlo used; I used a BN73-302 binocular core with 8/8:6 turns which is what I use with a nominal 50 ohm coax cable output. (Same as what Everett Sharp N4CY's LZ1AQ PCB uses.) The transistors run out of gain-bandwidth product at 30 MHz as you can see from the sweep (the gain is rolling off). Caaarlo's loop amp should have similar gain since both used the same transistors.
/g/loopantennas/album?id=296351??? If that doesn't work, search Photos for "Steve LZ1AQ Sweep".
