Mokhoa oa ho Haha DIY 2 Meter J-pole Antenna

Haeba u batla antenna e theko e tlase, hape e bonolo ea ho aha antenna, antenna ea J-pole e ntle haholo! Hoo e ka bang nako ea lihora, hammoho le lihlahisoa tsa boleng ba $ 15, u ka ba le antenna ea j-pole e sebetsang hantle haholo.

The j-pole antenna is generally an end fed half wave dipole that utilizes a 1/4 wave shorted matching stub as a resistance transformer. The j-pole antenna will yield somewhat less than 3 DB of gain omnidirectionally.

The product I chose to construct the j-pole antenna was 3/4 inch copper pipe used for plumbing. Here are the plans to develop a 2 meter J-pole antenna:

The above measurements for the J-pole remain in inches. Measurements on overall length, as well as stub length are from the centerline of the splitting up pipe (horizontal) to the top of the antenna. The Link at measurement is 2 1/4 inches from the top of the horizontal participant to the point of link. The range between the main component of the j-pole centerline as well as the tuning stub centerline is 2 ″. I cut a size of RG-8X foam coax to a length of 67 ″ for the feedline, and coil up 4 turns (as small as you can get it) just listed below the straight part of the matching section. This will certainly de-couple the feedline from the j-pole antenna, as well as aid supply some lightning security. Link the center conductor of the coax to the primary aspect, and the guard to the tuning stub of the j-pole.

In all of the above dimensions, they are to be thought about starting points for building a j-pole. I momentarily affix the coax using 1 inch hose clamps, as well as readjust the coax connection first to the lowest SWR. From there, I adjust the length of the main aspect of the J-pole. After that I start over by re-adjusting the coax link.