I'm looking for a single antenna solution for my IC-R3 receiver. Could
a discone antenna cover 500KHz to 440 MHz with usable signal? (This is
receive only.) Would a ramdom length wire be my best bet?



Here is my spur of the moment opinion... think of the frequency you
want to monitor and thing of the antenna. Then realize that to get a
reasonable signal you need an antenna that is substantially large in terms
of the wavelength of the signals you want to capture.

If you want to monitor HF, MF, and even lower frequencies, a standard
VHF discone such as the diamond D-J130 is such a tiny fraction of the
wavelength of HF signals that there is very little HF signal captured by
it.

You need wire, and plenty of it, if you want low frequencies!


Ed K7AAT