BpnJ,

If the Loop were free standing in open Air; then yes what you say
would be generally true. However, the Wire Antenna Element is
usually laying against the surface of the House's Interior Walls
and therefore may not be as theoretical as expected.

TIP - Try the Loop Antenna with both Antenna Inputs the LO-Z 50
Ohms and the HI-Z 500 Ohms on Several Shortwave Bands :
120M - 90M - 75M - 60M - 49M - 41M - 31M - 25M - 22M
- 19M - 16M - 13M - 11M

YMMV - On some the LO-Z may be the best connection and
on others the HI-Z may be the best connection.

BALUN - As you stated a simple Matching Transformer may
provide the necessary Broad Banded 'match' to be able to use
a single In-Door Loop Antenna Input for All Bands.

TWIN LEAD DOUBLE LOOP - Another 'Trick' is to make the
Loop a Double Loop using 300 Ohm TV type Twin Lead wired
in Series with a piece of the same 300 Ohm TV type Twin Lead
from the Ceiling Loop to the Radio/Receiver. In this instance
the HI-Z 500 Ohm Terminals usually work the best and it goes
without saying that the Double Loop is Twice as Long as a
Single Loop ) This does not seem to work as well with
the narrower and closer together common Speaker Wire.

FWIW - Some Claim that the Double Ceiling Loop Antenna
provides more signal and less noise then a Single Ceiling
Loop Antenna. I have yet to do a side-by-side of the One
or the Two around the same Ceiling at the same time.
Note - I would thing that it would take at least 6" or may
be closer to a Foot between the Single and Double Loops
to give each one a reasonable independent test in the same
room.

Some Food-for-Thought and an Invitation to Experiment
with In-Door Horizontal [Flat] Ceiling Loop Antennas.
[ Surprise Yourself :]


iane ~ RHF