I am looking to build a LF antenna for a home built WWVB receiver and
have found a number of antenna designs. The ones that might be best
look like shielded loop antennas. Here is a pretty good page showing
construction of one.

http://w5jgv.com/rxloop/index.htm

I will be looking to get as large a signal out of the antenna as
possible without using a preamp. From what I can tell, I will want to
use as many turns as possible, limited by the upper frequency of the
antenna. I assume this is because as the cable gets longer the self
resonant frequency drops.

Am I headed down the right path? The only other antenna I have found
for LF work is a ferrite core coil antenna, but my impression is that
they don't pick up as large a signal. That is somewhat mitigated by the
fact that nearly every crystal radio that isn't connected to a long wire
is connected to a ferrite core. These are powered by the received
signal itself, so it must pick up some decent signal. Then again, I
think they mostly pick up local stations without a very optimal antenna,
no?

I'm interested in any sources of info that might help me in my planning.

Rick