At 07:53 PM 8/26/96 -0500, no9z@prairienet.org (Lynn D. Osterbur) wrote:
>
>
>I am looking for any opinions on the 3 section laddermast sold by
>a company near Chicago. I think its IIX . THey make several accessories
>for towers like side arms and so on.
>
> I was just curious about what that mast can accomodate in the way of
>stacked antennnas. Any info appreciated. tks Lynn
>
>
I have had a WD9IIX laddermast up for 9+ years and am pleased. The mast
has had some big antennas stacked on it and gone thru tornadoes and
Hurricane Opal (80MPH winds).
I currently have a 2 el 12 meter X-Beam with W9PNE wire backs at 70', a
KT34XA at 77', a 2el Cushcraft 40 at 86.5' and a 2 meter Isopole clamped to
the top 3 feet. The tower is an old Tristao similar to the TX472 but built
for guying. It is 71' and I crank it up to 69.4'
Twice tornadoes have passed nearby and actually picked up the mast and ALL
the antennas (rotor and all) and turned them 45 degrees (Tristao does not
anchor the rotor plate to the side bars). I have had to re-weld the side
bar once, but the laddermast keeps on ticking.
I also have the 3 foot standoff for wire antennas or 2 meter antennas and
this is not so good. IIX uses hose clamps (3) and the whole mechanism does
move in the wind.
The laddermast is expensive, but worth it.
Dave K4JRB
BTW: Before you antenna purists call me on the X-Beam (G6XN hates im)...I
have the wire backs W9PNE used in the Antenna Anthology and it is the only
antenna I could mount at this place that did not wreck the KT34XA. I
started out with a beautiful W2PV 4 el (remember the QST article) then K4DLI
and I found that the 3el version was so close thru modeling that we put that
up. It looked great on the 10' South River tower in the back yard, but went
crazy on the tower. Only 20 was not affected. The X-Beam detuned down
40Khz and the XA detuned up 120Khz on 10 and 30 Khz on 15, but the patterns
stayed nearly the same as separate. With 260 countries on 12, I can safely
say its works! I made it from the cross bar of the old G4ZU Birdcage...and
I have a second cross bar...lets see 20 feet is a half wave on 12 meters for
stacking.................
|