Review on K40 K 30 Automotive Accessories by Casey Mann

K30 is a good antenna. Implement something smaller than a full size 102" 1/4 shaft steel pin, that's a compromise. The shorter the length, the lower the performance. The quality of the load coil in the base is crucial. I had a 102 inch peg on a Jeep Wrangler, a K40 on a suburban roof and a Wilson 1000 on my car. These are all good antennas. k30 on the roof of my chevy silverado and i'm happy with it. Get an SWR meter and test it. I had to trim the length a bit to get the SWR below 2.0 on channels 1 and 40. That is normal. The shorter the antenna, the more difficult it becomes to get the SWR to a reasonable value. below 2.5] ----- I wouldn't go shorter than k30. A bad antenna is a very short unnamed antenna with a center load. Stick to brand names, the longer the better.