David wrote:
http://www.techlib.com/files/rushconv.pdf

Pick your 1MHz band, and tune away. You'll need to tweek a bit if
you want to be very far from 15 MHz.

--
David Hatch
KR7DH

Andy comments:

Excellent, David !!! Thanks for the circuit. Note that it can
easily be modified to get WWV also...... I suspect one could
use a CA3028 if one wanted to build it with a single IC, for some
reason...

Yet another simple converter can be made using a NE602.
I don't have a circuit handy, but it can easily be designed from the
data sheet.
Andy W4OAH

PS I'm going to check out 15.42 Mhz --- I hadn't messed with it
before.....