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World of Ham Radio 1997
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1997-02-01
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42 lines
If I wanted to put up a J-pole antenna permanently, what is a good way
to support it? Is this design tolerant of nearby metal (like masts,
twin lead supports, etc)? Could I do the below and not mess the antenna up?
_____
!______________/ \
! _____/ support grabbing onto plastic with wires
! removed about a foot above wire ends
!
!
! | | do not short this end.
! | | (when trimming for vswr, cut both sides)
! | |
metal mast | |
! | |
! 3/4 | | Technically-speaking, this is a 1/2
! wave | | wave end-fed antenna with a 1/4 wave
! | | matching section.
! | |
! | 1/4" gap
!<- 3 to 5"---->| | (trim for vswr _below_ gap)
! | | 1/4
! _| |_wave
!_____________/ | | \
coax ctr conductor=>* *<= coax shield
! 1 1/4"-| |
! -*- solder the twin leads together at bottom
!
another support grabbing ribbon at the point where the coax connects
!
I strongly suspect that the above will have problems, especially the metal
mast being only a few inches away from the antenna. The top support is
grabbing onto the ribbon with the wires trimmed away about a foot above
the top ends of the antenna wires. This should keep that support from
severely messing up the top. Maybe use a good stiff plastic mast
instead of metal? PVC? I would guess that I can use a twin lead support
to hold the antenna where the coax connects, and get away with it. Even
tape the coax to it.
What say, antenna experts?