已经短波FT891半个多月了（采用MA01），现在主要遇到2个问题 1、usb连接电脑发射，原来是超过5w，JTDX就提示找不到设备。现在加了磁环能设置14w，发射时候PO有点不稳定0-14波动。如果单纯安卓音频线FT8CN连接就不会。 2、明明测好驻波近1.2。然后馈线接到FT891上采用FM模式测试驻波远高于2，发射不了。主要还是偶发，每次更换完线圈重新拿天分去测。毕竟我现在也FT8通联了十几个。想想还是入手个天调，以后可能会新增其他天线，现在频繁更换线圈，测驻波有点麻烦，而且垂直和鱼竿两种模式驻波不一样，加个天调应该能稍微改善一下。谢谢大家提供参考建议。

可以问你几个问题么？你的天线离发射机距离多远？是在馈线上加的磁环么？磁环指的是塑料外壳带卡扣安装在馈线上，还是馈线缠绕在环状铁氧体上？听你的描述，好像应该先解决地网不佳导致馈线上有共模电流的问题。如果需要自动天调的话，可以考虑mAT-30。老HAM都吐槽做工和LDG差得远，但胜在性价比高，能像FC-40一样和FT-891联动。

@"Liridice"#p89194 磁环，我是加在连接电脑的数据线上。天线距离电脑一米远，墙和窗户间隔，我如果不用数据线连电脑。换成单音频线连手机不会有这问题。地网在14MHz以上，垂直架设时候都是1.2以下的。只有鱼竿式的时候高一些。

@"BG2EFX"#p89208 LDG什么型号，搜到都好贵。我还不如买FC50试试呢。每次换线圈麻烦，而且14.074换到14.270其他频率驻波可能又高了。嗯，是我肯定以后换天线，现在说真的，短波之后学会了不少东西。

@"BG5EQA"#p89210 FC属于白给~ Z-11 pro II、AT-100ProII都可以~

@"BG5EQA"#p89210 你这些坑我几乎都踩过。数据线加磁环用处不大，如果你暂时改善不了天线的位置，就在GP馈电点加一个扼流圈或者1:1的unun，这样可以防止馈线参与发射，减少沿着馈线进入室内的共模电流，你遇到的掉cat和驻波变化问题也能明显改善。最大的问题还是天线离发射机太近了，万一自激了可能要烧台子。原配FC天调是肯定不行的，驻波超过3就拉不下来了。中心频率有点偏又懒得调整的时候可以用天调，如果想用天调把MA-01拉到全频段可用还是算了吧。

我也是891，DIY的GP，8根地网，使用扩展坞连接一根USB线和typec转音频，加了自己用FT240-43磁环做的扼流环，100W的FT8没有一点问题，而且你最好做个接地，一开始我也会掉USB，加了扼流环就没这个烦恼了，而且天调本质上还是骗发射机，我宁愿自己用天分调

@"BG5JKZ"#p89248 那我就去买个扼流环试试，地网用那种16的排线可以吗？我用的5米的拆成了8组。但是效果也不是很好，是不是要3.5米，还是单根16排线上2根，不懂他们说自己做地网，用0.5平和这些排线有没有区别。

@"BG5EQA"#p89261 可以，我就是16P排线拆开，4P一组，8根地网，5.6米拉杆，天分从10米到20米波段全部都能调到1.1以下的驻波

一个全尺寸GP或者全尺寸的正V，利用天分仪自己调整谐振，就不需要用天分了，除非你的环境无法将驻波拉下来（譬如阳台钓鱼，或地网环境不佳）

@"bh1cqz"#p89380 就是鱼竿，太长危险。办公室四楼风也大有时候风吹着看着天分在摆动，家里13楼风更大，平时都风声不断。所以才选了ma01。现阶段就是学习野架，把坑提前都踩踩。

Are there any more affordable options for Tianji?

BG5EQA

I've been using the FT891 for about a month and a half (using MA01), and I'm now encountering two main problems.
1. When connected to the computer via USB, it was originally transmitting at over 5W, which caused JTDX to report that no device was found. After adding a magnetic loop, I can set it to transmit at 14W, but the power output fluctuates slightly (0-14W) during transmission. This doesn't happen when using a standard Android audio cable and connecting via FT8CN.
2. Despite measuring a standing wave of approximately 1.2, the signal was not transmitting properly when connected to the FT891 using FM mode, as the measured standing wave was significantly higher than 2. This appears to be an intermittent issue that occurs after replacing the coil. I currently have over ten FT-8 radios working.

I was thinking about getting a tuner, as I might add other antennas in the future. Currently, frequently changing the coils and measuring the SWR (Standing Wave Ratio) is a bit of a hassle. Also, the SWR differs depending on whether I'm using the vertical or fishing rod mode. A tuner should help improve this somewhat. Thanks for your helpful suggestions.

Liridice

Could I ask you a few questions? How far away is your antenna from the transmitter? Is it a magnetic loop that's been added to the feed line? Does the magnetic loop refer to a plastic case with clips attached to the feed line, or does the feed line wrap around a ring of ferrite material? Based on your description, it seems like we should first address the problem of poor ground conditions causing common-mode current in the feed line.
If you need automatic antenna tuning, the mAT-30 is worth considering. Many HAM radio operators have complained that the construction quality and performance of LDG antennas are far inferior to those of HAM, but the mAT-30 offers a good balance between price and performance, allowing it to work seamlessly with FT-891, just like the FC-40.

BG5EQA

Liridice The magnetic ring is connected to the data cable that connects to the computer. The antenna is one meter away from the computer, with a wall and window separating them. If I don't use the data cable to connect to the computer, but instead use a single audio cable to connect to my phone, this problem won't occur. Grounding frequencies above 14MHz are typically below 1.2 meters when vertically mounted. They tend to be higher when using a fishing rod style antenna.

BG2EFX

听劝买LDG~
如果你用MA-01 别指望ATU能帮你消停换线圈

BG5EQA

BG2EFX What LDG model are you looking for? They seem to be quite expensive. I might try the FC50 instead. It's a hassle to change the coils, and switching between frequencies like 14.074 MHz and 14.270 MHz could potentially increase the standing wave ratio. Well, I definitely plan to upgrade the antenna in the future. But honestly, after working with shortwave radio, I've learned quite a bit.

BG2EFX

BG5EQA
FC belongs to Bai Ge.
Both the Z-11 Pro II and the AT-100 Pro II are suitable.

Liridice

BG5EQA
I've encountered most of the issues you described. The combination of a data cable and an inductor doesn't seem to offer much benefit. If you can't improve the antenna's position temporarily, adding a choke or a 1:1 unun at the GP power point can prevent the feed line from participating in transmission, reducing common-mode current entering the room along the feed line. This should also noticeably improve the issues you're experiencing with signal drop and standing wave variations. The biggest problem is that the antenna is too close to the transmitter; if it resonates, it could damage the equipment.
Using the original FC tuner is definitely not an option, as it won't work if the resonance exceeds 3. If you want to use the tuner to bring the MA-01 to full frequency range, just forget about it.

BI1XNN

BG2EFX
I was wondering why I could only find AT 100M PRO on Taobao, but not AT 100 PRO II. Are they the same product, or is there no distributor for AT 100 PRO II in China?

BG5JKZ

I'm also a 891, a DIY GP with 8 ground wires. I use an extension dock to connect one USB cable and a Type-C to audio adapter, plus I made my own inductor using an FT240-43 magnetic ring. The 100W FT8 doesn't have any problems at all, and you should also make a good ground connection. Initially, I would lose the USB connection as well, but after adding the inductor, I no longer have this problem. Furthermore, the "skywave" technique is essentially deceiving the transmitter, so I prefer to use a traditional antenna tuner myself.

BG5EQA

BG5JKZ So, I'm going to buy a grounding ring to try. Can I use the 16-pole cable you mentioned for the ground? I have 5 meters of cable that I've divided into 8 groups. However, it wasn't very effective. Should I use 3.5 meters instead, or two pieces of 16-pole cable? I don't understand why they said that if you make your own ground wire using 0.5mm and these cables, there is a difference.

BG5JKZ

BG5EQA Yes, I am using a 16-position patch panel, with 4 positions per group, 8 ground wires, and a 5.6-meter pull cable. The frequency range from 10 meters to 20 meters can all be adjusted to have a standing wave below 1.1.

bh1cqz

A full-size GP or full-size vertical antenna, when tuned using a tuner, doesn't require a separate tuner unless your environment prevents you from bringing the standing wave down (e.g., fishing on a balcony or in a poor ground condition).

BG5EQA

bh1cqz It's the fishing rod, it's too long and dangerous. The wind on the fourth floor of the office is also quite strong, sometimes the wind blows and I can see the line moving in the air. The wind is even stronger at my home on the 13th floor, so there's always a constant whistling sound. That's why I chose the ma01. Right now, I'm just learning how to use it for casting, trying to avoid making mistakes early on.

bh1cqz

BG5EQA If possible, try to install a directional antenna or directly use a 750 MHz antenna. If that's not feasible, use the MA-01 or a small sausage antenna. These are functional, but their performance is limited.
When deployed in the field, the choice of GP, Positive V, End-to-End, and DP depends on what works best for your specific needs. The primary focus should be on maximizing efficiency.

xyzyx

One issue that the original poster encountered; we might even be able to coordinate efforts.😂
https://forum.hamcq.cn/d/7684/31

BG2EFX

BI1XNN The local representative for HAM is located domestically.

BI9ALM

Gimbal solution

BG5EQA

bh1cqz

BG5EQA That's pretty good! What's the furthest place SSB can communicate with?

BG5EQA

bh1cqz 5W, to Brazil using FT8. While I bought an antenna, SSB hasn't started yet, but I found that it was too close and affected the mouse, keyboard, and computer at 10W. The safest option is 5W for communication. Currently, setting up the antenna takes about 30 seconds. However, I need to adjust the ground connection each time. There may be some settings that need to be modified for SSB and FT8.

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