Testing Your Antenna

Often the antenna is not the source of the problem, but is the first item to receive the doubt and blame. The following simple tests, using either an ohm meter or continuity tester, can be performed quickly, efficiently and remove any doubt about the condition of the antenna.

NOTE: For the following tests, disconnect antenna from radio.

 

I. The Wilson 1000 and 5000 Roof Top, Trunk Lip or Magnetic Mount:


A. Testing the Antenna Coil:

  1. Remove antenna coil from the mount.
  2. Touch one lead (negative or positive) of meter or tester to the center pin at the bottom of the antenna coil.
  3. Touch the other lead of meter to either the threads on the bottom of the coil, or the chrome mast at top of antenna.
  4. In either position, if the meter shows a shorted condition (needle swings to the far right), or reads continuity, the coil is in proper working order.

 

B. The Antenna Coax Cable:

  1. With the antenna coil removed, touch one lead of meter or tester to the center pin of the PL-259 connector.
  2. Touch the other lead to the center hole located on the top of the SO-239 mount.
  3. If this shows a shorted condition (or reads continuity), the center portion of the coax is in proper working order.
  4. Touch one lead of meter to outer shell of the PL-259 connector.
  5. Touch other lead of meter to the threads on SO-239 mount.
  6. If this shows a shorted condition (or reads continuity), the shield portion of the coax is in proper working order.
  7. Touch one lead (negative or positive) of meter or tester to the center pin of the PL-259 coax connector.
  8. Touch the other lead of meter to either the threads on the SO-239 mount or the outer shell of the PL-259 connector.
  9. If this shows no reading (or reads no continuity), the coax is not shorted out and is in proper working order.


C. The Antenna Coax Connector:

  1. With the antenna coil removed, touch one lead of meter or tester to the center pin of the PL-259 coax connector.
  2. Touch the other lead of meter to threads on the SO-239 mount or the outer shell of the coax cable.
  3. This connection should show no reading or continuity. While these two points are connected through the meter, wiggle the connector and observe the meter or continuity tester.
  4. If there is no change in indication, the connector portion of the antenna is in proper working order. If the needle swings to the right, the connector is bad and should be replaced.

 

II. The Wilson 500 & Little Wil


The antenna coil is not removable on these antennas, and therefore may be tested only in the following manner:

  1. Touch one lead of meter or tester to the center pin of the PL-259 coax connector.
  2. Touch the other lead of meter to the chrome mast on the top of the antenna coil.
  3. If this shows a shorted condition (or reads continuity), the coil and center portion of the coax is in proper working order.
  4. Touch one lead of meter or tester to the center pin of the PL-259 coax connector.
  5. Touch the other lead of meter to the outer shell of the PL-259 connector.
  6. With the Wilson 500, this will show a shorted condition (or reads continuity). On the Little Wil, there will be no reading.
  7. While these two points are connected through the meter, wiggle the connector and observe the meter or continuity tester.
  8. If there is no change in indication, the connector portion of the antenna is in proper working order. If the needle swings to the left, the connector is bad and should be replaced.

 

III. The Wilson Trucker Antennas:

 

  1. Touch one lead (negative or positive) of meter or tester to the stainless steel shaft (below the antenna coil).
  2. Touch the other lead of meter to the chrome mast on the antenna coil.
  3. If this shows a shorted condition (or reads continuity), the coil portion of the antenna in proper working order.

 

IV. The Wilson FGT & Flexible Fiberglass:

 

  1. Remove the rubber cap at the top of the antenna.
  2. Touch one lead (negative or positive) of meter or tester to the threaded portion at the bottom of the fiberglass antenna.
  3. Touch the other lead of meter to the brass whip tip at the top of the antenna.
  4. This should produce a shorted condition (or reads continuity), if the antenna is in proper working order.
  5. Touch one lead (negative or positive) of meter or tester to the threaded portion at the bottom or the brass whip tip of the fiberglass antenna.
  6. Touch the other lead of meter to the lug attached to the matching lead wire.
  7. Either position should read a shorted condition (or reads continuity), if the antenna is in proper working order.

 

After Testing Antenna


If, after verifying that the antenna has tested properly, the problem still persists, it is from another source. The most common problem is one of poor or inadequate grounding. This may be from either the vehicle, antenna mount, radio, or amplifier. Check the following items and potential sources:

  1. Recheck the ground on the antenna installation
  2. Check the ground on the radio - not the power ground. You may need to add an additional ground wire from the chassis of the radio to actual metal ground.
  3. Check the ground on any amplifier.

Check the center hole of the SO-239 Mount on the antenna. It can be the cause of fluctuating SWR and poor connections. There are some poorly manufactured mounts on the market that is the source of a lot of antenna problems.