Chris Campbell wrote:
"I am trying to get a radio clock to sync up with WWVB (60 KHz out of
Colorado).

A course in antennas is nice but loop antennas are covered in the "ARRL
Antenna Book". In my 19th edition, loop antennas are covered starting on
pages 5-1 and 14-2. See Fig 3 on page 14-3.

At 60 KHz, any practical loop is physically small in terms of
wavelength. The far field pattern of a small circular loop is the same
as that of a small square loop of the same enclosed area (Kraus edition
3, page 197). Area equals the square`s side length squared, and that is
equal to pi times the radius squared for the circular loop.

Current is all in the same direction in the small loop, so there`s a
null perpendicular to the plane of the loop and radiation is in the
plane of the loop. If the loop is placed in the vertical position,
radiation is vertically polarized as required for all ground wave
propagation.

Far field strength associated with a small loop is directly proportional
to the enclosed area in terms of wavelength (Formula 8 on page 199 of
Kraus).

Every receiving antenna is also a transmitting antenna. The most power
that may be tapped from the antenna is 50%, and a matched load is
required to extract 50%. Any mismatch increases the % of re-radiation.
At a 100% mismatch, i.e., a shorted dipole or an untapped resonant loop,
100% of the energy captured must be re-radiated.

So, set up a large resonant loop to capture all the 60 KHz energy you
can. Position the 60 KHz receiver (clock) to couple the most desired
energy and the least undesired energy possible into the receiver.

A high-Q loop, except for radiation resistance, is desirable. Litz` wire
uses copper better than solid wire does at 60 KHz.

Best regards, Richard Harrison, KB5WZI