LPY2
•
5
STANDARD HOOK-UP
Normal applications are well suited by the default performance of the unit
without the need for cumbersome reflective elements. The standard wiring
configuration is simply to use the Logi as the complete antenna and merely add
a means of connection for your radio. The easiest method to interface your
antenna and radio is through the use of a coaxial cable with a pre-mounted
connector. Standard RG-58 and a BNC connector are often used by ‘scanner
buffs’ to quickly and easily monitor the airwaves. Other types of coaxial cable
such as RG-142, .141 and .085 semi-rigid will also provide you with a good low
loss connection as well as excellent high frequency characteristics.
Let’s take a look at the circuit board for a moment to
become more familiar with its layout. The bottom side
is the ‘ground’ connection and is labeled with the
designers call sign “WA5VJB”. Notice that the via (the
small plated through hole) near the narrow front of the
board is not directly connected to the center trace on
the bottom side. It is directly connect on the top side
however.
1. Scrape off the protective solder mask coating on the bottom side center
ground trace with a razor. Only remove the mask along the center trace,
not the perpendicular elements. Be careful not to accidentally cut them
while removing the mask. This is where you’ll attach the ground shield of
your coax.
2. Tin the center ground trace you just scraped with a thin layer of solder.
This will make mounting the ground conductor easier in a moment.
3. Measure back 4 3/4” from the open end of your coax and remove the
outer protective sheath (if applicable) to expose the ground conductor.
4. Using a small pair of wire cutters (or a razor for the semi-rigid coax
variety), clip away a 1/2” of the ground braid from the same open end to
expose the inner dielectric layer.
5. You now need to trim away the end 7/16” of the inner dielectric layer
giving access to the center conductor. Position your razor for the cut and
roll the coax on the table top to slice through the entire circumference
(Don’t mark-up the wife’s table!!). The end goal is to leave about 1/16” of
the dielectric between the ground conductor and the
center conductor.
6. Carefully tin (solder the braid wire together to
keep it from fraying) the first 1/4” of the ground braid.
Be careful not to melt the dielectric with too much
heat.
Via
Bottom
Top
7/16"
4 1/4"
1/16"
