4
IMPROVING SWR
There are several ways to improve the SWR of your radio/antenna
combination.
Try these first.
·
Be sure you are using the type of cable recommended for your
equipment. If the manufacturer recommends a 50ohm cable, do not
substitute another type that has different impedance.
·
Confirm that you mounted your antenna according to the
manufacturer’s instructions. The angle and the base arrangement can
affect the SWR reading.
·
Adjust the length of your antenna according to the instructions provided
by the manufacturer. A change of as little as 1/16 inch can make a
measurable difference.
·
See your radio’s and antenna’s owner’s manuals.
MEASURING FIELD STRENGTH
Your meter can measure the low levels of radio frequency (RF) generated by
a radio transmitter. You can use these measurements to map the transmitting
direction and coverage pattern of your antenna, or to compare your radio and
antenna’s efficiency before and after an adjustment.
You do not need to connect the meter to the antenna or the radio to measure
field strength.
It takes two people to measure field strength. For an accurate measurement,
you will need to map the site around your antenna. Then, while someone
presses the radio transmit key, you will need to walk around the site around
your antenna with the meter, marking the readings you see.
Hints:
In addition to the meter, we recommend you use the following items to help
you measure field strength:
·
Several photocopies of the template
·
36 objects such as rocks or weighted pieces of paper
·
25 feet of rope or strong cord
·
Calculator
·
Pencil
·
Compass
• Make sure there is at least 25 feet of open space in all directions around
your antenna. 10
PREPARING THE ANTENNA SITE
Before you use the meter to measure field strength, you should mark the site
around the antenna in a pattern that will help you make the measurement. An
easy way to do this is to map the area around your antenna using a template
like this one.