RadioBanter - View Single Post

December 21st 04, 10:10 PM

On 21 Dec 2004 13:42:56 -0800, wrote:

It is a repeater 80 miles away I would like to hit. I would also to try
long range simplex if possible.

Hi OM,

I've touched on the requirements for you and the repeater. You will
be successful in direct, root proportion to heights for simplex.

The difference between a J-Pole or Ground Plane, or vertical Dipole,
or Discone, or sleeve Dipole.... and so on, will be marginal. The
difference between a simple vertical (as were all those in that list)
and an vertical array has gain for the same power. However, the
difference between that same array compared to any antenna turned 90°
to it can have -20 to -30dB (those are minuses) difference IF you
choose the wrong orientation WRT the listener. This is called crossed
polarization and can be a killer (you wanted to put this up once, and
if that once happens to be cross polarized to the majority of the
traffic you want to engage in - kiss them good bye).

You should be advised that FM is usually vertical, and SSB is usually
horizontal. See any problems with trying to make one antenna work
everywhere?

The other problem is the transmision line will have to be long,
probably35 feet or more. Is this a problem?

Of course. You simply have to investigate by what degree. RG-174
would be like plugging your ears and mouth, other bigger and more
expensive lines would not. Fortunately this is very simple to resolve
as line is characterized in the loss per hundred feet (if you only use
35 feet, you need only reckon 35% of that quoted loss).

73's
Richard Clark, KB7QHC