No guys, and has survived since october 97. Bends in the breeze a
little
but the whip at the top has almost no wind load.
Materials:
6061-T6 24' long 3" dia .125 wall
6061-T6 24' long 2.5 dia .125 wall
Commercial 18' telescoping aluminum whip.
1/4 x 20 round head stainless screws. x9
1/4 x 20 hex head screws. x9
Drill and tap 2.5" dia tubing at 120 degrees around circumference to
make
three "spacer rings" out of the round head screws (9 holes). The rings
start at the bottom and are spaced vertically about 18" apart.
Screw in the 1/4 x 20 round heads. They act as a spacer, to make up the
difference between the 2.5 and 3" tubing.
Offset by 90 degrees from the round heads and above by about 6 inches,
drill and tap 3 more sets of holes (9 holes). These must match holes
drilled near the top of the 3" dia section. Slide the 2.5" into the 3"
tubing and secure with the 9 hex heads.
Antenna is now about 44' long. Make an aluminum cap to fit inside the
2.5 dia tube at the top. The cap should extend into the 2.5 dia tube at
the top by about 2 inches. Drill a hole in it so the whip fits snug. I
used two set screws in the side of the cap to hold the whip in the cap.
I
used 3 set screws threaded into the side of the cap to hold it to the
top of the 2.5 tubing. Tubing with whip is about 60' long.
Set a 6 x6 x8" PT post 4' into the ground and set in concrete.
Make two big u bolts out of threaded rod and use 3" PVC pipe as
insulators between the ant and the U bolts.
Have a tuner at the base but 80 needs no tuner and has great bandwidth.
about 300 KHz.
Have about 16 copper radials out. Most about 50' some about 80'. The
area
is wet out way past 10 wavelengths. Horizon is good in most directions
but doesn't seem to matter much
I rarely need to call twice in any pile on 80/75 (with the PA at
1500W).
It seems loud to the locals also. Best antenna on 80 I have seen for
the
size/effort/cost.
Bob N2DVQ
Dave Bowker wrote:
> Does anyone on the reflector have a "tried and proven"
> mechanical/structural design for a full-sized, SELF-SUPPORTING 80M
> vertical element?
>
> 73, Dave, K1FK
> Fort Kent, ME
>
> --
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