Do a web search on Potato Cannons.  They can be inexpensively  made from PVC
pipe and fueled with propane from a hand torch.  They will throw a 2" diameter
hunk of potato several hundred feet.  They are reasonably safe, easy to make and
one hell of a lot of fun.  Generally quite accurate too.  Proven
technology.......

Rye K9LCJ



gii3kev wrote:

There are numerous ways to get a wire over a tree and its interesting to
hear so many viewpoints. I dont have any problems with a catapult and
fishing line to get over 60 - 80 ft trees, in fact the line not only
goes over the tree but often goes way beyond the tree by 50 ft, and not
difficult ot spot the line and weight. A catapult and fishing line are
easy to obtain, whereas a strong 100- 200 lb bow is hard to find and no
doubt expensive for the odd job, hardly cost effective.
A crossbow at 300 lbs would be the answer with the appropriate heavy
ended arrow, this would take a line well over the big oregon pine at 200
ft high, but you have to be strong otherwise you would be incapable of
pulling the bow string to load the arrow. The cannon approach is the
best option and let the gunpowder do all the work, the biggest effort
for the user is digging out the cannon ball at the other end.
There seems to be plenty of feedback about methods of getting ropes over
trees but little technical knowledge about large loops, feed methods and
performance, apart from contributions from the USA. Plenty of back end
DC engineers, digital and psk but RF engineers thin on the ground.
de Mal/G3KEV