My 40M beam works only intermittently. Typically under normal
conditions, the received signals are weak and the SWR is very high.
If I rotate the antenna, it "comes alive" in some directions and works
fine for a while, then dies again. In all cases, if I transmit into it
with a KW is comes alive and works fine for a while (few minutes) and
then dies again. A single dit will fix it. 100W does not do it.

I replaced the coax which runs around the rotator and it made no
difference. I just recently learned that a local friend also has an
intermittent antenna which can be restored by transmitting a KW into it.

Is this a common problem? is there a generic solution? Any hints
would be appreciated. Note that it is not too easy when up on the tower
to jiggle things while someone on the ground tries to watch the SWR and
shout back and forth. We tried that when we replaced the coax.

Thanks!

Bob W8ERD