Okay guys ... this is one of those articles you should read in its entirety before doing anything! I think we'll start with this because too many people damage their antennas by doing the wrong thing. You should not, under any circumstances, twist the tip when trying to remove it. Twisting could break an internal solder joint or alter the winding coil design. Rule 1, you MUST have the antenna tip installed when taking SWR measurements on fiberglass antennas UNLESS you plan to use the antenna without a tip during normal use. Why? If you add the tip after you tune the antenna ( "cause it's easier than putting it on and off"), the antenna will become electrically longer. The reason why this happens has to do with added capacitance. The antenna wants to releases the electromagnetic field into the air space and the added material of the tip restricts that function, thus altering the characteristics of the antenna. Accordingly, if you are going to leave the tip on during normal use ... the SWR measurements MUST be taken with the tip on. So, take the initial SWR readings, pull the tip, make the adjustment, replace the tip and take new readings. The tip is an optional piece but it's use must be considered during the tuning process.
Dealing with the antenna tip On physically short antennas, we hold the antenna between our feet and hook a couple of our fingernails from two hands under the base of the tip and pull upward. On longer antennas, we have another person hold the antenna horizontally and use the finger-tip pull method to remove the tip. Alternatively, locate a flat edged object and snag the bottom edge of the tip on that edge and pull the antenna towards you. Examples include the edge of a bumper, angle-iron, edge of a bench, etc.. The key is to break the vacuum-like seal that is created when the tip was installed. On very old antennas it may be necessary to carefully slit the edge of the tip length-wise with a knife to get it off ... not always, but sometimes.
Thinking Ahead Once you have the antenna tuned, you might consider pulling it off one last time and wiping it clean to allow it to stay put during normal use. Many off-road users like to wipe it clean and then use a shot of hair spray as a deterrent for it coming off when the antenna contacts occasional tree branches. |
Updated 2023.12.07