After a several month search for the diagram
of the McKay Dymec 100D active antenna I found
a friend had just completed the AMRAD active
antenna discribed in the September 2001 issue
of QST.
Is is a very good antenna.
In a side by side test last night, the AMRAD
stomped the 100D badly.
The AMRAD had no intermod and was much quiter.
I found this link to address some aspects not
covered in QST.
http://www.amrad.org/projects/lf/actant/index.htm
The antenna can be optimised for LF or for ~50KHz
to over 30MHz. Gain does decreas a little with
increasing frequency, but at 27.035, the highest
frequency we could find a repeatable singal,
the AMRAD was still much better then the
100D.
Terry