"bpnjensen" wrote

the impedance for this type of antenna is about 100 ohms.

At what frequency?

A large horizontal loop of about 40 feet or larger circumference will
exhibit different impedance across the bands as will any single wire antenna
or dipole. Except that a large horizontal loop will exhibit a significantly
less impedence variation.

would suggest that, if this type of antenna is used, for best match it
be mated to the low-Z input of the radio (50 ohms rather than 500),
although an appropriate transformer could easily resolve this (probably
minor) problem regardless of the input.

I wouldn't be too concerned about the impedance for receiving purposes. The
broadband nature of a large horizontal loop will offset any loss from
impedance mismatch compared to any other type of single wire antenna or
dipole at the same height.

As a once famous person said, "It's all relative." Or better, "If you build
it 'RF' will come."
Just do it and experiment.