describes how the principles of the DBJ-1 can be extended to a portable roll-up antenna. Since it is the second version of this antenna, it will be referred to as the DBJ-2. Principles of the DBJ-1

The DBJ-2 package includes the pre tuned antenna, ready to unroll and install. The package includes: - Roll-Up J-Pole, terminated with a BNC-M connector. - 6 foot RG58 jumper, with BNC-M and BNC-F connectors. This combination of connectors should attach this antenna to virtually any handheld transceiver. There is no assembly necessary.

The DBJ-2: A Portable VHF-UHF Roll-Up J-pole Antenna for ARES Edison Fong, WB6IQN WB6IQN reviews the theory of the dual band 2 meter / 70 cm J-pole antenna and then makes detailed measurements of a practical, easy to replicate, “roll-up” portable antenna. radials. The DBJ-1 is easy to construct using inexpensive materials from your local hard-

The most common request from users is for a portable “roll-up” version of this antenna for backpacking or emergency use. To address this request, I will describe how the principles of the DBJ-1 can be extended to a portable roll-up antenna. Since it is the second version of this antenna, I call it the DBJ-2.

This document describes the design and operation of a portable dual-band J-pole antenna called the DBJ-2. It summarizes: 1) The DBJ-2 builds upon an earlier dual-band J-pole design (DBJ-1) by making it portable and roll-up using PVC pipes and lightweight materials. 2) A J-pole works by matching the impedance between a low-impedance feedline and ...

The DBJ-2 roll-up dual band J-pole antenna is just what I was looking for to use in my “go bag”. Dr. Fong and his students individually build, tune and test each antenna before shipment.

2025年3月25日 · 设计思想是一段1/4波长的同轴，作为U段开路阻隔， 但对V段导通。 具体资料看下面。 调整注意顺序，首先调整U段，两个地方，一个是U段振子，调整到频点，另外一个是J-Pole接入部分的长短，调整到SWR最小。 U段好了之后，接1/4波长同轴，频点和SWR应该不变。 然后再接V段， 这时调整V段频点，U段应该不受影响。 调整麻烦一点，不过两段是分别调，不相互干扰，总是可以调出来，问题在于U段带宽太大，只能顾一头，最后根据本地中继调了一个 …

Bands: 2 m and 70 cm; Maximum input power: 50 W; Impedance: 50 Ohm; Gain: 2.1 dBi; SWR: less than 1.7:1 for VHF and less than 1.5:1 for UHF; Primary source: https://edsantennas.weebly.com; Videos: How does a J-pole antenna work? AD#36; How to build a J-pole with twinlead: Ask Dave #42; Ham Radio Antenna - DBJ-2 …

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2024年7月6日 · Ed’s DBJ-2 is a portable VHF-UHF roll-up J-pole antenna constructed out of 300 Ω twin lead. It’s very flexible and can easily roll up into a 6 inch coil. When extended, it’s 92 inches long. The antenna itself is 54 inches and the soldered on feedline is another 38 inches.