Wisconsin Parts Database Instructions and Discussion Team/Group > WISCONSIN
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> New cb radio antenna k-40, 57" trunk or roof mount K40
New cb radio antenna k-40, 57" trunk or roof mount K40
K40 PArts ListHow to Roof Mount the K40
1. Remove the base Washer (K310)
2. Loosen set-screw on locking ring.
4. Slide off collar and remove bracket.
5. Drill a 7/8" hole through roof of vehicle.
6. Insert Base Assembly with locking ring thru the hole, and replace collar, snap ring and base washer.
7. Tighten locking ring set screw from inside the vehicle.
K40 Tuning How to Tune and Adjust the K40 Trunk, Magnet or Roof Mount
1. Connect SWR meter between antenna and radio.
2. Measure SWR first on Channel 1 and then measure SWR on Channel 40. If the SWR is higher on Channel 1 than channel 40, pull the whip out 1/8" until the SWR is about /or is the same on Channel 1 and Channel 40.
If the SWR is lower on Channel 1 than lower channel 40, pull the whip out and cut off 1/8" from the bottom of the whip. Insert the whip back in the base and recheck the SWR on channel 1 and Channel 40. Continue until the SWR is about /or is the same on Channel 1 and Channel 40.
It is important that the car or truck doors are shut while making SWR measurements. Also the vehicle should be at least 30 ft. from any metal wire or structures.
