Assembly Instructions: Bencher Skylark
Tools Required:
Pop Rivet Tool
Tape Measure
Hex Wrenches
Screwdriver
Several Disposable Rags
Two Saw Horses
Several boxes or bowls to hold fasteners and small parts
Sharpie Marker Pen or the Equivalent
Acid Brush or stiff quarter-inch brush
Assembly Note: Jet Lube SS-30 is an effective antiseizing agent. A small amount of it should be put on the threads of all screws and bolts
prior to putting lock washers and nuts on. This is especially so for the U-bolts and the
boom to mast hardware. This will allow easy removal at a later date should it be
necessary to do so.
The small brush specified in the tools required list is the easiest way to apply the Jet Lube
both on element assembly and on bolt and screw threads.
Boom Assembly
Refer to the boom drawings and be sure you understand it. There are three inner sleeves
of 48” X 1 7/8” diameter, and 4 outer sleeves, 2” X 48”. Each of the 7 boom pieces has
holes precision drilled, and all holes should line up perfectly.
Note that the 4 pieces of 2” lengths have letters, A, B and C, marked in black. The letters
refer to the junction points, so there is Junction “A”, Junction “B” and Junction “C”.
The inner tubes also have marked letters, in red.
Take a 2” OD tube with the black letter “A” stenciled on end – place the piece on a flat
surface so that the “A” is upright and to the right end of the tube as you face it. Take the
1-7/8” tube with a red “A” stenciled on it, hold it so the red “A” is right side up, and slide
the left end of that tube into the end of the 2” tube marked with a black “A”. Notice the
hole left of the red “A”; slide the inner tube so that the hole lines up with the hole in the
outer sleeve. Pass a 2 ¾” bolt through the hole, and put a nut on it a few turns to hold the
assembly captive.
Find the 2” outer sleeve with a black “A” stenciled on one end, and a black “B” stenciled
on the other end. Slide the “A” end down over the 1-7/8 sleeve from the first section.
Rotate until the holes line up, and pass a 2 - 3/4” bolt through and add a nut for a few
turns.
Take the 1-7/8” tube marked with a red “B”, holding it so the “B” is upright. Slide the left
end of that tube into the right end of the existing assembly. Note that there are two sets of
holes. Pass a 2 ¾” bolt through one set and add a few turns of a nut.
Take the 2” tube marked with a black “B” on one end and a black “C” marked on the
other. Slide the “B” end over the right end of the boom assembly, and line up the holes;
pass a bolt though and put a nut on a few turns.
The remaining section of 1 7/8” tubing should be marked with a red “C”. Hold the tubing
so that the “C” is upright. Slide the left end of the tube into the assembly, line up the
holes and put a temporary bolt through as before.
The last piece of 2” tubing is marked “C”. With the “C” upright, slide the left end of the
tube onto the assembly and use a temporary bolt and nut.
This completes the initial assembly of the boom.
There are seven aluminum element platforms. These are mounted at the seven element
stations. In many cases, there is already a temporary bolt through the boom where the
element platform will mount. When mounting these platforms it is necessary to remove
the temporary bolt first. The platform station numbers are based one the distance from the
reflector end of the boom in inches, starting at the “A” end of the boom. Stations are
mounted so that the flat plate area is down. The first station is the 17 meter reflector,
which is about 19” in from the end of the boom. Remove the temporary bolt and nut, slip
an element platform over the boom tube, as shown in the picture, slide a 2 ¾” bolt
through, add a lock washer and nut and tighten.
In the same manner, mount the other six element platforms. Use a tape measure to
confirm the station element locations. Besides the first platform mounted at 19”,
platforms should be mounted at 46”, 90”, 94.5”, 159.75”, 177 inches and 183”. Make
sure that the stations are correct. Note that the first station may not be exactly 19” in from
the end; this is OK. However, to measure the rest of the stations, place the 19” mark of
your tape measure exactly centered on the hole of the first station. All other stations
should be exactly correct.
Element Assembly
The integrity of this antenna depends on the stainless steel aviation grade pop rivets
supplied. It is beyond the scope of this manual to cover how to pop rivet. Though the
process is neat and simple, you do want to be sure you get it done right! If there is any
question, get assistance from someone who has experience. Also, the internet has several
different instructional aids. A short video on pop riveting is at:
http://www.askthebuilder.com/Pop_Rivet_Tool_Video.shtml
Do note that sometimes in pop riveting it is necessary to pull up on the rivet by squeezing
the riveter handle, then releasing pressure on the handle, pushing the rivet tool down
further and then squeezing the handle again. If you have never done pop riveting before it
would be time well spent to try three or four rivets on a couple pieces of sheet metal.
In assembling the elements, you will be using the Jet Lube SS-30 anti-seize,
which is a copper bearing grease paste. This insures a good electrical connection between
element segments. Some people believe that copper bearing grease paste is a problem
because of galvanic action. However, galvanic action requires dissimilar metals AND
water or another liquid electrolyte. The grease in Jet Lube SS-30 prevents water from
getting involved, so there is no galvanic reaction.
In any case, note that if Jet Lube SS-30 gets on your clothes, it is virtually impossible to
remove the stain. For this reason, we strongly recommend you wear clothing for which
permanent stains will not be an issue. Also, you will want rags for wiping away excess
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