Thanks for the numbers, Gregg. I managed to find the program as a ZIP file
all over the Internet but everyone I downloaded wouldn't install.

The antenna you calculated is big, way too big to go in the attic. It was a
cool idea though. Imagine giving people of a tour of my house. "...And up
here we have the WWVB reradiating magnetic loop antenna with a resonant
frequency of 60 KHz and a bandwidth of 56.2 Hz." I can hear them now,
"Geez, Vic, you are a major geek."

Anyway, a 2M wide antenna is a bit big so I need to find another way.
Active antennas won't do either. One clock sits on my desk in my office and
the other one hangs on the wall. Antennas on those will have a very low
wife acceptance factor.

Can I build a repeater? The receiving antenna in these clocks is small.
Maybe a small low power transimitter with the same size antenna? Can I buy
a repeater? Can I buy a transmitter?

Thanks for all your help on this,

Vic