[Antennas] Multiband elevated radials

[Richard Brunner]

Re:
> Anyone with information on constructing multiband radials for 40 thru 10?
> I see Butternut describes one using 300 ohm twinlead to cover 40, 20, 15
> and 10.

If your antenna is above ground you can use a counterpoise.  I use one with 
a Butternut vertical.  Note that the 300 Ohm one in their instruction sheets 
is badly designed, and didn't work for me, also 300 Ohm line is delicate and 
has no integrity when you start cutting conductors.  See, "How To Build An 
Effective All-Band Counterpoise," in July 1998 CQ, pages 20,21,24. (by me) 
I used 450 Ohm ladderline, two lengths from the antenna, each length 30' 
9.5", with one wire cut 15' 5" from the antenna.  This gives 40M and 15M 
resonance overall, and 20M on the cut section.  Additionally, at the end the 
long wire is fed through the end insulator and connected to the second wire, 
which is cut 8' 2" from the insulator, forming a 10M stub.  This stub 
isolates the end 8 feet of the antenna on 10M, allowing 3/4 wave resonance 
on 10M.  The isolated length of wire is left in place and does no harm. 
These dimensions gave resonance at 7.1, 14.12, 21.23, and 28.47 Mhz.  This 
is also the basis for a jim-dandy four-band dipole.

Richard Brunner, AA1P