[TowerTalk] Refurbing a Cushcraft 40-2CD

[James Wolf]

If you are considering reworking a 40-2CD, there are a couple things I would
recommend since I have been through this sometime ago. 
Inspection showed that every loading coil had corrosion on the screw
connecting the coil wire ends to the elements.  I cut away the shrink tubing
over the end of the loading coils and replaced the screw with a Stainless
Steel screw and put new heat shrink over the whole assembly and sealed the
ends of the heat shrink with Silicone Glue before shrinking it.  I'm not a
mechanical engineer, but possibly a better solution would be to run a bolt
through the element; then again, maybe not.  It has been up for over 25
years now without any intermittent issues. There may be a better solution to
sealing the heat shrink as such as the self-sealing heat shrink.
What seems to have happened is that the original heat shrink didn't seal
well enough, so moisture was able to get into the coil. 

Another thing I did was strengthen the elements with inside tubing.  The
elements especially seem weak close to the boom.  Even my reinforced
elements have had a slight bend in them for some time due to middle America
winds.

Dave Leeson, W6NL did an article on strengthening the 40-2CD,
http://k7vc.com/402cd.html
Another article is "Simplified Strengthening of the Cushcraft 40-2CD" by
N4KG in the Mar/Apr issue in of NCJ, 1994.

Also, put locktight on the nuts holding the capacity hats to the elements.

I also made a new mounting bracket that will allow the antenna to tilt up or
down so one can get to the element attachment points to remove an element
for repair.

NOTE: If lightning hits an element, the loading coil will disappear.  No
cure for this, but the tilt mounting bracket will become your best friend.

Good Luck.

Jim - KR9U