dave wrote:
"Hi, I have read in one of the old ARRL books about a hula loop antenna
that only stands about 3 inches high on 10 meters but works like a full
size dipole."

There is a related horizontal Hula-Hoop antenna, Fig. 3.35 on page 43 of
"Short Wave Listener`s Handbook", a CQ "Technical Series" book by John
Schultz, W2EEY. This is probably from a reprint of a "CQ" article.

The antenna looks like a short-circuited 1/4-wave stub, turned up with
its conductors into a vertical plane, then coiled into a nearly complete
loop.

So, the small loop should tend to have nulls perpendicular to the planes
containing the parallel coils made by the stub. Response should be good
in the planes of the wires making the two loops. But, the article
doesn`t say.

Best regards, Richard Harrison, KB5WZI