Dan Cisson wrote:
>
> K7LXC@aol.com wrote:
> >
> > In a message dated 96-09-16 00:28:24 EDT, you write:
> >
> > >I may be getting confused, but if this was the 20M yagi on 48' boom, I
> > >think that's more than an "average antenna," and I'm personally not
> > >surprised that one person (unless you're 200 pounds plus) might not be
> > >able to move it.
> >
> > Hi, Rich --
> >
> > In my book, a 48' boom 20M antenna is not an average antenna. Might be
> > standard for a medium to big gun but bigger than normal. And the 20M Telrex
> > you mentioned is even BIGGER.
> >
> > >I have done a lot of single handed work here with the Telrex 6-el 20 (46'
> > >boom, 175-200 pounds I guess), 8-el 15 (similar size and weight) and
> > >homebrew 3-el 40, which I put up single handed but first the boom then
> > >each element by itself. I find the maximum pull on a rope is like
> > >ringing a church bell, pulling straight down on the rope, using all your
> > >body weight to pull down. It's just possible to raise an antenna of this
> > >class this way with one person. The hardest part is when you have to
> > >hold its weight with just one hand while you use the other hand to tie
> > >off the rope. I don't recommend it; it's at the limits of one person's
> > >capabilities (or beyond).
> >
> > A device that will enable you to do this is used in mountain climbing
> > circles and is called an ascender. It's used for ascending a fixed rope. It
> > clamps on a rope, slides in one direction and locks in the other. In an
> > antenna rigging situation, you install it upsidedown so that you can pull
> > the
> > rope down but it locks as soon as you let go of it. There are several
> > manufacturers including Gibbs (I use this one), Jumar, etc. Check with REI,
> > Northface, etc. for what they carry. Figure $30-50 for one.
> > >
> > 73, Steve K7LXC
> >
> > TOWER TECH -- professional tower supplies and services for amateurs
> >
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>
> WELL,HERE WE GO, ME PUTTING MY 2 CENTS WORTH IN. THE REAL SERIOUS
> DX'ers HAVE A SAYING, "IF IT STAYS UP, ITS NOT BIG ENOUGH". I
> CONCUR WITH THAT STATEMENT. THE 48 FT. BOOM WAS NO PROBLEM FOR ME
> TO GET TO THE TOP OF BILLS TOWER. THEY ARE A LOT OF EASY INNOVATIONS
> ONE CAN APPLY THAT MAKES PUTTING UP HUGE ANTENNAS RATHER EASY.
> HOWEVER, IT CAN BE TIME CONSUMING,FOR LIKE BILL, I MOSTLY HAVE
> TO DO ALL MY TOWER WORK ALONE, OR WITH ONE OF MY KIDS DOING THE
> KNOT TIEING.AT THIS PRESENT, I HAVE A SIX ELEMENT ON A 72 FT. BOOM,
> SUPPORTED BY 127' OF ROHN 25. 6 YEARS AGO, I HAD A 10 ELEMENT
> ON A 128 FT BOOM, SUPPORTED BY 116 FT OF ROHN 80 SERIES,A 4-FT WIDE
> TOWER. I COULD HAVE EASILY MADE THAT ANTENNA 150 LONG!!! THE BOOM
> CONSISTED OF 70 FT OF ROHN 25, WITH 29 FT OF COMMON 2" ALUMINUM
> BOOM GOING OUT EACH END OF THE TOWER BOOM. I BUILT THE ANTENNA
> ON TOP OF THE TOWER,ON PIVOTING HINGE PLATES. THESE PLATES ARE THE
> REAL SECRET TO PUTTING UP A LARGE ANTENNA. THESE PLATES WERE 60"
> WIDE, 15" TALL AND 1/2" THICK. BOTH PLATES FACE EACH OTHER, AND ONE
> PLATE ATTACHES TO THE MAST, ONE TO THE BOOM.ABOUT 4" FROM EACH END
> AND IN THE MIDDLE OF THE PLATES, I DRILLED A 1" HOLE THROUGH BOTH
> PLATES FOR A 1" STUD TO GO THROUGH THE PLATES. THIS WILL ALLOW THE
> PLATES TO PIVOT EITHER LEFT, OR RIGHT, DEPENDING ON WHICH STUD YOU
> PULL OUT. THE OTHER KEY THING ABOUT THIS IS, THE PLATES MUST BE THICK
> ENOUGH TO TOLLERATE FLEXING WHEN YOU HINGE OVER A FULLY BUILT ANTENNA.
> THIS CAN BE DONE WITH ALMOST ANY ANTENNA, AND ALLOWS YOU TO BUILD
> A LARGE ANTENNA ON TOP OF THE TOWER.ONE THING TO REMEMBER, THE PIVOT
> HOLES MUST HAVE THE SAME DISTANCE BETWEEN THEM AS THE TOWER WIDTH,
> OR THE ANTENNA WILL NOT HINGE OVER, HITTING THE TOWER BEFORE GETTING
> VERTICAL. ONCE IT HINGES OVER VERTICAL, YOU HAVE 1/2 OF THE ANTENNA
> NEXT TO THE TOWER. THE FINAL CRITICAL POINT IS, THE UPPER PART OF
> THE SUPPORTING TOWER MUST FREE- STAND WITH NO GUY WIRES IN THE WAY
> OF THE ANTENNA HINGING OVER. I ALMOST HAD A BIG PRIBLEM WITH THIS
> ON THE 72 FT BOOM I HAVE UP NOW. ROHN 25 DOES NOT SAFELY FREE STAND
> WITH 40FT UNGUYED, FOR 1/2 OF THE BOOM LENGTH IS 36 FT, THEREFORE
> WHEN I HINGE OVER THIS ANTENNA, 36 FT COMES IN NEXT TO THE TOWER!!!
> REALLY, I SHOULD HAVE PUT UP NO LESS THAN ROHN 45. I HOPE ALL THIS
> HELPS SOMEONE, OR ALOT OF PEOPLE REALIZE THEY CAN PUT UP MOST ANY
> THING THEY WANT AS LONG AS THE SUPPORTING TOWER HOLDS UP
> 73 DAN N4GNR dann4gnr@hartcom.net
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