BG4QBF rt，十多天了终于搞出来了，发帖纪念（） 9月13号新考的A证，呼号没记错的话是16号下来的，随后一直在镇江、南京区域活跃。我注册的设备是新买的泉盛UV-K6和家里旧的特易通TH-UV88，原装天线总不得劲，给K6搭配了QS-771能50km打上南京省中继，但还是感觉差点什么。自己一直比较喜欢动手，网上又有很多自制天线教程，我便有了自制八木的想法。 9月27号拿到了nanovna（做天线最好还是配一个），并且打算做个双段天线（然而事实证明新手还是先搓单段入坑），后面两天研究了下莫克森-八木天线和KG0ZZ的uv八木，最后选择KG0ZZ那种设计，因为可用带宽大一点。 然而，我犯了几个大错误，导致制作失败，包括但不限于：选用4mm不锈钢当振子（切不动，无法修剪），螺丝固定振子（不可拆卸，不可调整间距），松垮垮的固定（有源振子摇摇欲坠）。相关过程照片删掉了，留一个最后的失败品照片看看。 （国庆好忙，我从archive.org扒下来KG0ZZ的制作教程和视频，翻译工作至今没有完成） 最后我想通了，拿家里面（装修剩下的？）的2mm铜丝开始搓单U段的七单元八木。我的尺寸参数是按照之前uv双段天线的u段部分来的，那么第一步是先剪振子。 剪出来是弯的，可以放在平的桌面上滚动找到弯曲点，手动掰直。 振子合照 找到中线 上捆扎带。主梁是不锈钢丝寄过来时用的固定物，砂纸打磨防扎手 然后是要焊馈线，如图剥出的长度其实还是偏短。 焊好后得到非常不错的偶极天线（雾） 总装带去测试，驻波偏高，遂剥去绝缘、调整间距和修剪振子（幸亏没用胶粘死）。实战有效果但不多，据反馈有点断续。 那这个时候呢我是已经发现我的驻波图形呈w形，435附近这块驻波能上到2.5然而前后都是低谷。一开始以为是有源振子剪短了，新做了一个有源振子换上，还是不行，又做了一个，依然不行。 后来我去请教Qwen（人工智能），它告诉我可能是阻抗失配。我打开史密斯一看确实，但手头没有电容，只得尝试发夹匹配 （其实ai还告诉我，你的有源振子有点短，但你过长的反射单元又弥补了这一点……只能说修剪天线时要注意比例） 之前的驻波图像 加上发夹匹配 非常巧我一次匹配就成功了，驻波比也成功拉下来了。435处最低，能达到1.03，再带出去试试 效果不错，镇江江海之门参加南京省中继点名第七，直线55km左右。 以上就是我的大致制作流程，由于自己没啥经验就不留图纸误导大家了（主要是我在外面天线不在身边）。调驻波比积累了些经验，下次试试莫克森-八木（） 这里是qbg永远慢我一步的BG4QBF，祝你永不qbg（）
BI9BUM The antenna is good, but the coil could be replaced with stainless steel wire or phosphor copper wire (as I saw in Blue Book, I still don't know what it is, but it should be harder than phosphor copper wire). Then, replace wood with steel and glue with welding, and you can start production.
BG4QBF BI9BUM Stainless steel wire – absolutely must use fine gauge… My 4mm stainless steel wire can only be used with a corner grinder; this is a painful lesson. ( )
StarChen BG4QBF Well, I also bought some 4mm stainless steel rods at the time, but I couldn't figure out what to do with them. In the end, I just bought a metal saw and that solved the problem.😂
BD1CAM Could you please tell me what the U-shape size is for the "downward facing" connector that matches the cable? I've found that this type is easier to work with than the gamma-type, and I'd like to use it, but I haven't been able to find specific dimensions.
BG4QBF BD1CAM The dimensions of the materials vary, and the size of the 2mm copper wire I bent is approximately 5cm and 2cm. I recommend leaving them longer initially and using zip ties to secure them before checking the results. Then, trim as needed, and finally, solder them.
BG2GNF BG4QBF Does "U-matching" involve directly connecting the two ends of two active transducers with a cable of a specific length?
BG4QBF BG2GNF That's correct; by adjusting the impedance in this way, I have achieved a better match, and the standing wave ratio has decreased.
BA4SUA Later, I consulted with Qwen (artificial intelligence), and it suggested that the issue might be due to impedance mismatch. When I checked the Smith chart, I confirmed this, but I didn't have any capacitors on hand, so I had to try using a bnc adapter to match. Could you please explain how to connect a capacitor, feedline, and oscillator to achieve impedance matching?
BG4QBF BA4SUA That's where Gamma comes in; there are online tutorials for making a feed box, which requires an additional small box and metal rods. The key is to learn how to properly solder the wires.
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