用网分和功率驻波表对夹边天线进行测试，结果差异较大，功率驻波表显示1.1左右，网分显示驻波比2.1左右（435M的忘拍照片了，但数值是2.1） [upl-image-preview uuid=aa82c5ee-6fe4-4d38-b8d4-cd8916737a92 url=https://storage.hamcq.cn/2025-10-15/1760542914-773929-20251015233826-20-73.jpg alt={TEXT?}] [upl-image-preview uuid=8b5e87fc-c0bf-489a-b996-2dfb0d827275 url=https://storage.hamcq.cn/2025-10-15/1760542914-914080-20251015233900-21-73.jpg alt={TEXT?}]

网分的数值除了内外硬件、测试对象外，还跟固件里的优化算法有关，没有专用的驻波表准。为了保证底线，如果两个不同仪器测出的数值差别很大，请永远相信数值较差的那个 🤪

@"BG2MKU"#p82450 UV段手台，需要考虑握持影响，也就是你手握住或者松开，接收发射是有区别的。要想完美复刻握持时的状态，可以买个手台外壳，把天线接上，模拟手持电台的状态，再去测试就会更准一些。更见到的方法是天线装手台上，避开热门频率，小功率发射，根据手台显示的驻波来慢慢调整天线，使其达到理想值。

网分和驻波表就像万用表电阻档和电压档的区别，前者提供弱激励测量响应，后者只测量响应

@"y010204025"#p82460 但是我这个是车载夹边天线啊，我就是用手台测试一下。

@"Felix"#p82461 所以还是功率驻波表比较准？

@"BG2MKU"#p82464 手拿设备和放着也会有差

网分和功率驻波表测的不是一个东西...

在UV段确实是有这个问题，但一般情况下差异不会太大，网分调试短波天线基本上都是挺准的，调完接电台发射，驻波都很完美

以驻波表为准。连续调整频率测驻波，判断下谐振频率和曲线。看图二，小网分常见的问题，在正常的谐振曲线上，又叠加了一个什么乱七八糟的波形，导致在谐振曲线不是平滑的。

@"BG2MKU"#p82464 是的我觉得驻波表比较准。说是拿万用表做类比，高频更复杂一些，涉及源端与负载端的阻抗匹配。网分源端是标准的50欧姆，但电台不一定正好50欧姆。另外就是楼上说的天线接地、附近金属体等环境也可能造成差异

What are the reasons for differences in the results of network division and power standing wave ratio (PWR) tests?

BG2MKU

When testing the antenna with a network analyzer and power meter, there was a significant difference in the results. The power meter showed a VSWR of approximately 1.1, while the network analyzer showed a VSWR of approximately 2.1 (the photo of the 435 MHz signal was lost, but the value is 2.1).

y010204025

BG2MKU UV band handheld, which requires consideration of the grip's impact – whether you hold or release, receiving and transmitting will differ. To perfectly replicate the state when holding, you can purchase a handgrip shell, attach the antenna, and simulate the handheld radio state for testing. A more common method is to mount the antenna on the handgrip, avoiding popular frequencies, low-power transmission, and adjusting the antenna based on the readings displayed on the handgrip to achieve an ideal value.

ba7iqe

BG2MKU The center frequency of your antenna appears to be around 430 kHz, and 435 kHz is likely around 1.5 kHz. The frequency above 435 kHz increases rapidly. My own small network measurements are generally consistent with the Diamond's VSWR meter.

BG8LGP

In addition to the internal and external hardware, test objects, and the optimization algorithms within the firmware, the values of the network segments are also related to the presence or absence of a dedicated standing wave ratio (SWR) meter.
To ensure accuracy, if two different instruments produce significantly different readings, always trust the reading from the instrument that shows a lower value. 🤪

BG2MKU

y010204025 However, this is a car-mounted side-by-side antenna, and I'm just using it to test with my handheld radio.

Felix

Network analyzers and standing wave ratio (SWR) meters are similar to a multimeter's resistance and voltage ranges, but the former provides a weak signal measurement response, while the latter only measures the response.

BG2MKU

Felix So, are power probes still a reliable option?

Watermelon

BG2MKU Holding the device versus placing it down can make a difference.

Felix

BG2MKU
Yes, I agree that the oscilloscope seems to be quite accurate. The comparison with a multimeter is helpful, but high frequencies are more complex and involve impedance matching between the source and load. The network source end is standard 50 ohms, but the radio may not be exactly 50 ohms. Additionally, as someone mentioned above, grounding the antenna and nearby metal objects can also cause differences.

Sunset

The measurements obtained from network division and power standing wave ratio (PWR) meters are not measuring the same thing...

dxs660

There is indeed a problem in the UV band, but generally, the differences are not too significant. The SWR (Standing Wave Ratio) measurements for shortwave antennas are usually quite accurate, and after adjusting the antenna, the transmission and reception performance are both excellent.

BI1KPO

Use the standing wave pattern as a reference. Continuously adjust the frequency to measure the standing wave, and determine the fundamental resonant frequency and curve.
Refer to Figure 2, which shows common problems with small networks. In a normal resonance curve, an irregular waveform is superimposed, causing the resonance curve to be non-smooth.

BI4MPY

Due to differences in the power levels used during testing, some antennas exhibit a larger standing wave ratio at low power but a smaller one at high power.

BG2MKU

Later, I repeated the measurement using a different vehicle. Due to limitations in the testing environment, it was conducted at a local test site. Based on the initial results, it seems that there is a correlation between power and error. It's possible that the error will be larger when the input power is relatively low. I plan to conduct further tests in an open area once I have more time.
The power standing wave ratio (PSWR) data is as follows (all measurements taken with handheld transceivers transmitting at 435 MHz, below 5 Watts, in open areas, and with vehicle-mounted transceivers transmitting from a ground station, above 5 Watts).

Forward power	Reflected power	Based in Bobbi
1.69	0.00	1.08
2.09	0.00	1.08
2.10	0.00	1.09
2.19	0.00	1.09
2.20	0.00	1.10
2.23	0.00	1.11
7.14	0.3	1.51
14.13	0.78	1.65
33.11	2.31	1.71
38.37	2.66	1.74
38.66	2.66	1.74
38.81	2.66	1.74

BG7MGW

BG2MKU So, why do I get such a high standing wave ratio when measuring the very small power output of the network? Is it possible that the network is not properly calibrated? Should I recalibrate and then retest?

zorro145

A network analyzer simply measures the static performance parameters of an antenna itself, while a VSWR meter measures the parameters of the antenna when it is operating (with power). In general, the VSWR meter is more accurate.
However, a network analyzer can also detect the center frequency of the antenna, which is another important parameter.

BG2MKU

BG7MGW I think it's a matter of different measurement principles. The network I calibrated should be fine, but if there are problems, they should be with the adapter. Should I connect the antenna after calibrating with the adapter?

BG7MGW

BG2MKU Let's see if there are any variables that could be affecting the results of both tests. If so, let's reduce those variables and then repeat the tests.

闽ICP备2021006864号-7

闽公网安备35020602002794号互联网举报中心

用户协议隐私政策社区规范积分规则中继规则转载须知
更新日志联系我们常见问题友情链接运营报告赞助

浩奇科技（厦门）有限公司

是无线电，把我们联系在一起