使用E8361A和E8361C来测量高达50dB的步进衰减器只在高衰减>40dB时才会出现尖峰

你在S11也看到了同样的问题吗？
在过去，一些固件版本存在第一点问题（并且您使用的旧版分析器使用较旧的固件）。
如果您将起始频率更改为略高于10 MHz（例如40 MHz）的值，峰值是否仍显示在第一个点上？



     以下为原文

  do you also see the same problem in S11?  

In the past some firmware revisions have had 1st point problems (and you are using an older analyzer with older firmware).  if you change the start frequency to something slightly higher than 10 MHz (40 MHz for example) does the spike still show up on the first point?

嗨daras，我没有看到S11和S22的尖峰。
我们没有观察到这个问题如果启动频率是333MHz。
以前测试开始频率是333MHz，现在我们改变它以覆盖10MHz的低频启动。
我将尝试45MHz，因为E-cal和不确定性是10MHz-45MHz的最差。
如果我能看到尖峰发生在45MHz，我会更新固件。
谢谢你的建议。



     以下为原文

  Hi daras,

I do not see the spike on S11 and S22. We  did not observe this issues If the start frequency is 333MHz. Previously the test start frequency is 333MHz and now we change it to cover low frequency start from 10MHz. 

I will try 45MHz since the E-cal and uncertainty is the worst from 10MHz-45MHz. If i can see the spike happen at 45MHz I will update the firmware. 

Thanks for your suggestion.

如果尖峰是来自信号源的实际信号，你应该在R1和B中看到它，你也应该在S11中看到它（在你的情况下是S22，因为它是相同的信号源）。
更新到您的盒子可用的最新固件（对于C型号为A.09.42.22）并查看问题是否仍然存在。



     以下为原文

  If the spike was an actual signal from the source, you should have seen it both in R1 and B and you should have also seen it in S11 (and S22 in your case since it is the same source).  Update to the latest firmware available for your box (for the C model that is A.09.42.22) and see if the problem persists.

我们将E8361A升级到CPU 1.1GHz的A.07.50.48之后仍然存在问题。
我仍然可以看到10MHz的尖峰大约1.8-2dB。
我还检查复选框在低频率下降低IF BW，应用平均因子= 5并尝试打开平滑。
以上所有方法都无法改善10MHz的尖峰。
如果您仍然知道如何改进它，请告诉我。
谢谢。



     以下为原文

  The problem still there after we upgrade E8361A to A.07.50.48 for CPU 1.1GHz. I still can see the spike at 10MHz about 1.8-2dB.

I also check the checkbox reduce IF BW at Low frequencies, apply Averaging factor=5 and also try to turn on the smoothing.

All method above not able to improve the spike at 10MHz.

If you still have any idea how to improve it please let me know. 

Thanks.