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INTRODUCING OPAR-
The One Person Antenna Raiser
by John Reisenauer,
Jr., KL7JR
Updated with new
Aluminum Version 11-2010
(Updated with newer compact version
01-08-09)
See end of article
Like to
operate portable? Do you have trouble finding help for antenna raising at
your QTH? This may just be the answer for you.
You can drive a
vehicle on the base for portable operations or mount permanently at your
QTH by bolting base to concrete inserts. Slip the mast in the base of OPAR
(short pipe section tilts), mount your antenna and hoist up all alone.
Mast easily secures in place with moveable locking bolt and large spanner
nut. Guying methods should also be employed for heavier antennas. I've
used OPAR to lift small beams, verticals, rigid dipoles and various wire
antennas to heights of 20-30 feet with minimal effort all by
myself!
OPAR shown above set up ready to
accept antenna mast.
Simply insert mast end in to OPAR pipe stub,
install antenna and raise.
OPAR shown above with antenna raised and
mast locked in place.
Although OPAR is designed for "one-person operation"
using small to medium sized antennas, it's always good safety practice to
have help on hand. OPAR as pictured is considered "medium-duty" use.
Several variations (use your imagination for your own particular use!)
exist (ie-length of vertical or horizontal members, etc.) depending on
your specific use. A flexible design is what makes OPAR more "user
friendly" compared to the commercially made models. For larger antennas or
operating in the Arctic, I'd recommend adding a second vertical brace
higher up on the vertical section and adding at least another 12 inches or
more to the overall height (36 to 48 inches plus). If you are not an
experienced welder, it's best to have a professional welder do the welding
(the number of "good welds" is directly proportional to the length of time
the antenna and mast stays in the air!). My OPAR cost about $340 to make
locally. Raising a tri-bander alone is not easy especially for the
inexperienced Ham, but it is possible if done correctly. Remember to have
help on hand if at all possible. I wished I had OPAR many years ago! Good
luck with your antenna projects.
MATERIALS LIST (medium duty
OPAR)
- vertical support 36 inches tall by 9 inches wide w/support
braces every 6 to 8 inches.
- horizontal support (drive-on) same as
above.
- 1 inch OD square tube steel used (approx. 20 feet total
required) for strength vs. round stock.
- 1/2 inch x 3 inch long
bolt with welded spanner nut
- mast hinge is ?" pipe by 6 inches
long inside two ?' pipe sections.
- 3/8 inch by 2" wide plate used
to secure mast to top of vertical support.
Some
economical mast materials used by KL7JR:
1. Light-duty use: Chain link fence
"top rail" pipe or EMTconduit for smaller light weight
antennas.
2. Medium to Heavy-duty
use: IMC threaded conduit or galvanized
threaded water pipe (1 ?" size works great).
Suggested use of masting and antenna types: (with updates as
of 03-18-10)
The
tallest mast I used was 25 feet, unguyed with an A99 Solarcon vertical or
Shakespeare 2010 vertical, or various wired
antennas (dipoles, G5RV's etc.).
Anything over 25 ft
becomes unmanageable and must be guyed.
I've used small beams
up to 20 feet without guys. On lighter wire antennas I used light weight
conduit (EMT or IMC threaded 1 1/4") or chain link fence top rail pipe 1"
diameter.
For the verticals or
beams, 1 1/4" IMC or galvanized water pipe worked great. The antennas go
up fast and easy, but you must do it fast to gain momentum, or the antenna
becomes very heavy midway the push up and then you'll struggle with it.
Below is a picture
with the 2010 vertical at 24 feet, and withstood some strong Yukon windstorms in Nov. and
Dec. for several days!
Photo by KL7JR
No...that's
not a TV antenna mounted on the mast...it is on the building in the
background!
Below you'll
see the lighter
version of OPAR that I haven't tried yet, but the original is a workhorse
and right now sits in the back of my truck ready for the weekend.
Oh, I add a 2nd down brace from the top of the raiser
that clips to the mast to the bottom of the raiser for heavier antennas
like I used.
The photo below shows the
additional brace I added (later) from the top to the bottom of OPAR
to accommodate heavier antennas. Also see closeup
photo.
Check out that "backup"
satellite dish above the door on the building!
I kid you not, and I
highly recommend you do a couple trial "hoists" without an antenna to get
the swing of things, this baby is slick! You don't have to be
parallel with the vehicle either when you drive on the base.
Sometimes I've had to go up at an angle less than and more than 90
degrees. Round pipe would also work. Square tubing was on
hand. You can also play with the height and width of the
support depending on what you want to hoist up.
I based my
design on heavy pipe and heavy antennas. I've been using my OPAR for
about 10 years now and it's been a life saver for me hoisting up antennas
by myself.
New Updated Compact LIGHTER
Version!
I've been kicking
this simple design above around for some time. It's smaller and
lighter than my original
OPAR (one person
antenna raiser) at the begining of this article, and only cost $50 (2009
prices), for a welding shop to make for me.
Quarter-inch plate
and 1/4"x4"x3" angle. Modify it to your own design as you
wish!
Update
11-2010
Well I just wouldn?t let it be. I
just had to make a lighter version but hopefully just as sturdy. Allow me
to introduce my latest brainchild, hi hi!
 
Latest Aluminum version.
Front view on left, backside
view on right in photos above.
The older and heaver designs in
the earlier (top) part of this article were Yukon tested (the
purple one is the original design and the black is the lighter version and
the aluminum is the 3rd design you see above.....phew! After
using the lighter version on 4 setups ovar a 3 week period, I know I had
to try to go lighter yet....( I ain't getting any younger! )
The Aluminum OPAR -
Redefining a proven design!
Although the latest design of OPAR worked
well for me on my 2010 VY1RST/VE8RST trip, I wanted an even lighter
antenna raiser. Would an aluminum version work in the harsh arctic or just
end up a brittle mass of scrap metal when 40 below zero?
This
design uses 4"x 4" aluminum angle (2 at 30 inches tall) and a 1/4
inch aluminum plate
(8"x 20"). The bolts are 7/16 inch and I will
probably replace with eye bolts which are easier to grab with gloves on.
Construction is similar to the lighter version OPAR but the weight is
now cut down to a mere 16 pounds! Four inch angle should handle large
heavy antennas such as a tri bander, and 2.5 inch or 3 inch angle would
easily handle smaller lighter antennas. I have $200 invested (aluminum
costs more in material and welding labor than steel) in this beauty and I
am confident it will work fine in the arctic.
CQ DX here we come!
ENJOY!
DISCLAIMER
Feel free to copy or modify this design at your own risk. Neither USI,
NCDXA nor KL7JR claim any responsibility.
73 de Yukon John,
KL7JR
KL7JR@Yahoo.com
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