Topband: Power Coupling in the USA

Steve Ireland sire@iinet.net.au
Mon, 06 May 2002 11:59:24 +0800


At 07:02 PM 5/05/2002 -0000, you wrote:
NI6T said
>Steve:
>
>The major reasons for using verticals at low-lattitude DXpedition locations
>are, as you are certainly aware:
>
>* the almost-certain impossibility of finding or providing sufficiently high
>supports for a horizontal antenna, especially on islands having, at best,
>nothing higher than coconut palms leaning in a downwind direction
>* the relative ease of deployment of a vertical
>* in the case of island destinations, the proximity to the sea
>
>Bob, NM7M, mentioned a few days ago my intent to have had both an IV and a
>vertical had I gone to T31. Unfortunately, our attempt was airplane-based
>and, when that approach proved impossible, a boat-borne operation went there
>instead. I still hope to run that experiment someday.
>
>Given my druthers, I would elect to have a variety of antennas for topband,
>as I would here. But pragmatism lobbies, usually, for a vertical, only.
>
>Garry, NI6T

Hi Gary,

Great to hear from you and hope all is well.

I agree with you entirely, especially as island-based DXpeditions are
usually near the sea, with the very low far-field losses that proximity to
the sea brings and the ease of erection of a vertical antenna.  A
inverted-L BCS also gives the DXpedition the best of both vertical and
horizontal polarisation - at a huge variety of angles.

Having a variety of antenna polarisation is the thing - and variety of
radiation angles - to work DX all the time.  There is no way I would
sacrifice my Marconi-T vertical - it is a useful antenna under some
conditions.

My concern is when a DXpedition goes to a location at low latitudes when
they are well away from the sea and sitting on a lot of rock.  Under these
circumstances, a low dipole or inverted-L could well be much better DX
antenna than a vertical.  My first contact with the Caribbean from VK6 - a
very difficult path - was with VP5/WA2VYA, who was running an IC706
barefoot to a low dipole...

Vy 73,

Steve, VK6VZ