[Elecraft] MAST HOLE FOAM FILLERS

[Bill]

A PVC mast 3' into the ground will easily break off - use 2" galvanized 
pipe and allow several feet above the grass level. This will allow you 
to connect the 50' mast to same. Best to make a swivel mount several 
feet off the grass level to allow for putting it up and down. You must 
guy this tower every 10 feet or it will do the dance in the wind. For a 
light weight installation that is well guyed you can use post setting 
mix. You should use a tube and make a mushroom at the bottom to keep 
frost heaving at bay.

Guying is very important - you will gain most of your wind resistance 
strength from it. It will not survive even modest winds without guying.

I do something similar with a 25' piece of 2" aluminum pipe fastened at 
the grass level to an 8' T-post driven in 4'. The tower is guyed at 12' 
and the top. Guys go to T-posts and are tied off above 4' to provide for 
easy mowing. T-posts must be the heavy cast types - rolled are just junk 
and will easily fold under any load.

My NVIS wire antennas (75 and 40 meters) have survived in excess of 70 
MPH winds with no problems at all. My system has been up for about 10 
years without any failures.

Just remember, 50' is about four times more of a problem than my 25'. 
Also, aluminum pipe, although more expensive, will be much more solid 
than any plastic tube.

Bill W2BLC