GP拉杆天线，中间振子线圈，40米波段，用nanovna看驻波波比，谷底在7.05MHz，swr约1.4，接ft991a短波机，FM或LSB模式通联时，短波机内置swr测量驻波比巨大，直接爆表，求教大佬怎么解决。

假负载呢？假负载先测一下

用的同一根馈线和同样的转接头么？如果不是，从馈线或转接头上入手找原因。

天分用之前是不是没校准啊

我也是，nanovna和大红点的数据不太对应，但不至于爆表。

是同一根馈线，因为是M头，接短波机和自动天调不需要转接头，接NanoVNA用了M头转SMA头，NanoVNA显示约1.4，自动天调显示9.99，算是爆表了，FT991A直接报高驻波，自动调谐失败。我在怀疑地网不给力，一发射就垮掉了

天分校准过，参考M哥视频

我有一根馈线和FT-710的M口配合不是很好，旋紧一半还能感觉到齿咬合不是很紧密，如果不注意的话就会出现刚接好线驻波正常、过一会就驻波飞起的情况。

nanovna是这样的，不带功率测的根本没有参考价值

@"BG5CJI"#p50125 先说说你地网。。我怀疑你用网分测量时候你成地网了

The Nanovna measured a standing wave ratio (SWR) of 1.4, and the shortwave receiver has an integrated SWR meter.

BG5CJI

GP whip antenna, center-loaded loop, 40-meter band, using Nanovna to measure standing wave ratio (SWR), the minimum SWR is at 7.05 MHz, with an approximate value of 1.4:1. When connected to an FT991A shortwave radio and operating in FM or LSB mode, the built-in SWR meter on the shortwave radio shows a very high standing wave ratio, causing it to overload. I would like to ask experienced users for advice on how to resolve this issue.

BG2EFX

BG5CJI Let's start by talking about your internet connection.
I suspect that when you used a network to measure, you were connected to a local network.

BG5NKC

What about a dummy load? First, let's test the dummy load.

Liridice

Are you using the same feed line and the same connector? If not, investigate the issue by starting with either the feed line or the connector.

BG4IDK

Did I forget to calibrate it before using it?

tudoubocai

I also find that the data from Nanovna and Big Red Dot don't quite align, but it doesn't reach alarming levels.

BG5CJI

It's the same feed line, because it's an M-type connector. It doesn't require a transition adapter when connecting to a shortwave receiver and an automatic antenna tuner. However, when using a NanoVNA with an M-type to SMA adapter, the NanoVNA shows approximately 1.4, while the automatic antenna tuner shows 9.99, which indicates a significant reflection. The FT991A directly reports a high standing wave, and the automatic tuning fails.
I'm having trouble with my internet connection; it keeps dropping out whenever I try to use it.

BG5CJI

Talent assessment passed; refer to M's video.

BH3PTS

Could it be due to poor contact at the connection?

Liridice

I have a coaxial cable and the M connector for the FT-710 that don't seem to fit well together. When I tighten it halfway, I can still feel that the teeth aren't engaging tightly enough. If I'm not careful, I might experience a situation where the SWR is normal right after connecting the cable, but then quickly rises.

BH4GQD

Nanovna is like this: data without power measurements has no practical value at all.

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