The internals of the DE31 antenna are discussed (and shown) he
http://www.drmrx.org/forum/archive/i...hp/t-1210.html



N9NEO wrote:

Yes, I would think that you would want the variable capacitor close to
the loop too. I think what we have here with the loop is just an
inductor...

Damned if I know what is in the unit by the radio. I suspect a
variable capacitor and a jfet like a mpf-102. I don't think a
varactor diode kind of setuup will tune such a broad range. I will
take my unit apart one day soon and report back to group if anyone
interested.

regards,
NEO