4. Antenna elements are fastened without drilling the
5. Avoid screw, nuts and clamp in fastening of antenna elements.
6. T- joint is mechanically strong the antenna element.
7. Weight of one antenna element in length of 1 meter
made from of a silumin tube in 10-mm
OD with the T- joint was only 70 grams
8. Antenna made by step by step stringing of the T-
joints with already installed there antenna elements.
How to use T- joint at antenna? Picture1 and 2 show
the way. However, some advices are below. Take T-joint that has
ID closest to a diameter of antenna traverse. If the T-joint has
Less the diameter of antenna traverse you need gnaw
through to obtain needed ID. Leave wall thickness not less the
Do ID on to 0.5- 1 –millimeters less the OD of the
traverse and do longitudinal cut in the lower part of the T- joint.
At the case before installation of the T- joint to the traverse
a small thing (like wooden or metal bar) should be inserted into
the cutting. See Picture 3.
When the T- joint is sitting at the right place at the traverse
just remove the bar and the T- joint would be fastened well to
It is possible hard fastened the T- joint to the traverse
by 1-2 small screw. Another way for hard fastening – put some
glue in to pipe-bend. The pipe- bend was closed by a plastic washer
and epoxy. ( See Picture 3.)
Holes for antenna elements should have ID on to 0.2-
0.5 – millimeters less the OD of the antenna element. The holes
should be drilled with drilling machine. T-joint at drilling should
be placed on to horizontal table of the drilling machine. Antenna
elements go through the holes with pressure but then hard fastened
at the T-joint.
Active dipole vibrator made from two halves may be
fastened to T- joint with help of a plate made from a good and
mechanically hard insulated stuff. It may be thick PC, thick plexiglass.
The plate is fastened to cut side tap. See picture 4.
However, it is possible to insert two half vibrator
into a thick rod from an insulated stuff, then the rod with the
active vibrator is fastened into the T- joint above mentioned
ways (See picture
T- joint was tested to strength
after being three hours at minus 28 degrees Celsius. Attempt to
break the T- joint pooling of the antenna element (fastened inside
the T – joint) is failed. Antenna element was broken (4-mm OD
silumin) , T-joint- no. It was tried to break the T- joint with
help of a hammer. Hammer left only slight dent on the T- joint
but no any crack.
Using prepared T-joints (with drilled holes for antenna
element and traverse) it takes from me only several hours to assemble
7- elements VHF antenna. Hope, it will work long time for me.
See picture 5.