To Wil, Rik, Rich, Alan and all, many thanks.  Geri's note on birch leaves
leads me to relay my experience with my aerial.  I have been waiting all
Summer for the tree surgeon to lop my Liquidambars, which were up to
20m.  After the gales damaged one of my homemade masts and brought
down all my aerials the tree surgeon turned up and the trees were duly topped.
I have rebuilt both mast and 136 aerial as before.  The feedpoint resistance
has reduced from 144ohm to around 50ohm.  With a transmitter output
of 250v peak to peak or about 156W, which ignoring loss in the 50m of
coax, implies a feedpoint resistance of about 40ohm with the 2A aerial
current I was measuring.  Over three times improvement.  The before
photograph is on my web site.  I hope to post an "after" picture.

With regard to the kind invitations for qsos I simply have to tidy up the
system where my Rx is upstairs and the Tx is in the cellar two floors
down and two flights of stairs in between.  The "over" delay is only suitable
for QRS.

73, Brian
73 Brian     CT1DRP     IN51QD     41 09 58N  08 39 11W
http://homepage.esoterica.pt/~brian