Hi All,

 

The vertical 5m section of my inverted L runs up into the branches of a silver birch tree.  The wire goes over a large bough at 5m or so and then comes out of the branches for some 22m down to a 4m high pole attached to the garage.

 

Has anyone a guesstimation of the losses in signal caused by running the wire through the tree?

 

Using vertload and tophat2 I calculate the antenna to be around 0.25% efficient but this assumes it is in free space.  Can anyone suggest a figure for the additional loss due to tree heating!

 

The vertical element is actually sloping at about 20 degree from the tree down to the loading coil.  The length is nearer 6metres but the vertical height over ground at the bough is about 5m.

 

(Santa may be bringing me a set of swaged poles with which to build mark 2, well away from the silver birch!)

 

With best regards

 

 

Jim

 

 

Dr. James Cowburn G7NKS