A Rybakov antenna on the bench?

In the garage I have a virtually unused SRC X80 end-fed vertical antenna. This was very briefly erected in about 2011 and has remained unused for years. I took it down as reports said it blew around in high winds and at the time my interest was mainly on 10m for which I had a suitable antenna at that time.

The X80 is a sort of Rybakov antenna. These are end fed antennas fed via a unun transformer so the very high end impedance is transformed into a VSWR less than 3:1 that can usually be matched via the auto-ATUs in most modern HF rigs.

As an experiment, I tried loading up the coax to my 2m big-wheel via this Rybakov transformer. I can get quite a good match on a couple of HF bands (at least) but on some bands the VWSR was so bad that the rig just turned off!

By ear, I think my small indoor magnetic loop is as good!