Topband: tree losses

[Richard Fry]

Rudy Severns wrote:
>Tom's correct, the issue is not "resonance" but rather what, if anything, 
>happens when you have a so-so conductor/insulator (a tree) in the 
>near-field and/or further out. Do the losses matter?
________________

Here are several data points on this subject.

Recording the relative readings on the dBµ and S/N displays of a Tecsun 
PL-310 tuned to a 790 kHz directional station about 52 miles east of me, 
radiating about 1 kW in my direction:

        Location                                     dBµ                S/N 
(dB)
   (Tecsun 4-1/2 ft AGL)
Area clear for 50 ft around                    32                       15
Pin oak tree, 3' diameter trunk,             42                       24
  east side against trunk
Ditto, but west side of trunk                  34                      14
Gnd Wire of 50' utility pole                    48                      24
   (Tecsun 9 ft AGL)
Gnd Wire of 50' utility pole                    50                      24

The field improvement when the rx is held against the east side of the trunk 
is completely gone when the receiver is moved to the east about 15 feet.  So 
the effects are quite localized.

These locations were all within 100' of each other.