User's Manual
Carlson Wireless USA revision 2.12 Page 10
(4) Rough alignment. This is usually easier then it would seem. Since it
is a prerequisite that you have line of sight between the two points, here
are several ideas that have worked for installers:
(1) If you can see the other unit, simply aim the units towards each other.
(2) During midday, use a mirror or compact disk to create a reflection ap-
proximately towards the other site while someone watches for the flash.
(3) Plot out the path on a topo map and set the antennas using a com-
pass.
How close in alignment do they need to be? +/- 10 degrees will be
adequate for most paths using the 14 dB gain antenna. Certain paths that
have a low fade margin may require a more accurate setting.
Final alignment. This is usually done by connecting a standard cordless
phone to the FXS or FXO end, and then give a best guess to the direc-
tion, establish a connection and rotating the antennas both right and left
noting the points where the signal disappears, (assuming that it does) and
then centering them between those cutoff points.
Photo showing assembly of mount and adjustment screws
Carlson Wireless USA revision 2.12 Page 7
(4) Mounting structure.
Warning! Use extreme caution to avoid contact with any high volt-
age power lines when constructing antenna structures!
The enclosure is designed to mount on a steel vertical mast, with an ac-
tual outside diameter of 1.3 to 2.5 inches ( 3 to 6 cm ). This mast must
locate the radiating element at least 6.6 feet (2 m) from any persons, not
move significantly in any anticipated wind and must be connected with a
bare copper #8 AWG wire to a copper clad ground rod driven at least 6.6
feet (2 m) into moist earth.
(3) Availability of telephone service and power.
The I-WLL-Trailblazer system consists of two units. One is designed to
connect to the standard phone lines provided by a local telephone com-
pany office (FXO side) and the other connects to the telephone instru-
ments such as; DTMF (touch tone) telephones, fax machines, and com-
puter modems (FXS side) via individually twisted pair phone/data cable.
The system is very flexible about voltage requirements. 12 to 48 Volts DC
with the current being inversely proportional to the voltage, the power use
being approximately 2 Watts for the FXO side, in any state, and 2 to 4
Watts for the FXS side depending on usage state. We recommend over-
sizing the supply by 1.5 to 2 times. Depending on the length, most instal-
lations can use 4 twisted pair, #22 AWG feed cable. This will drop about 1
volt per 100 feet of length. To allow for most voltage drop situations we
recommend a 15 volt, 1 A power supplies.
We minimize the interference from these devices through intelligent chan-
nel selection and external directional antennas.
Intelligent Channel Selection
Our system needs about 10 MHz of clear bandwidth to operate properly.
If the system experiences undesirable interference levels the next call will
be chosen on a different channel. If the system experiences minimal inter-
ference levels then that channel will remain as a favorite. This is similar to
what we have seen in some of the more sophisticated cordless tele-
phones.
A very directional antenna
For professionally trained dealers we have we have a much tighter beam-
width antenna utilizing a parabolic grid design. This antenna provides
very high side and rear signal rejection and only adds a small percentage
of cost of the system.