Topband: 160m/80m duoband vertical question

[Herb Schoenbohm]

Jim,  I have a 80 meter vertical base fed wire "T" with the top loading 
provided by a center fed 30 foot horizontal wire to bring the base 
impedance up a bit.  I also support a 40 meter single wire vertical from 
the same top catenary by fan slopping slightly the 40 meter vertical 
wire to the top with a dacron rope to reach the top configuration.  It 
works very well and is a super DX antenna on these bands with about 30 
60 foot radials laying on the ground.  I don't see any reason why a 
similar configuration would not work on 160/80 meters.


Herb Schoenbohm, KV4FZ




On 11/5/2013 10:27 AM, Jim Garland wrote:
> My 160m vertical is 79ft high (wire running up a 26m Spiderbeam fiberglass
> pole), with a capacity hat. Is it workable to put an 80m 1/4 wave wire on
> the same mast join both antennas at the base, in the same way people make
> multiband fan dipoles? The idea would be that when operationg on 80m, the
> 160m antenna would present a high Z, and vice-versa when operating on 160m.
> I don't have a feeling for how much interaction there would be between the
> two wires, separated by only a couple of inches. Another option would be to
> electrically isolate the wires and select one or the other with a relay.  If
> possible, I'd like to avoid matching networks and complicated switching
> arrangements, because the antenna is 700 ft from my station. Any advice is
> most welcome.
>
> 73,
>
> Jim W8ZR
>
> _________________
> Topband Reflector