自动调谐无法在MXA上检测到低于10Mhz的信号

嗨，我正在使用33522A产生325Hz的正弦波，-5dBM输入MXA。
见附件。
我自动调谐以检测我的现场频率，但MXA无法检测到任何频率。
我将频率设置为10Mhz并自动调谐，MXA可以检测到此信号。
后来我将起始频率设置为300Hz，停止频率为1MHz。
MXA也无法在325Hz检测到我的信号。
参见附图，标记为325.2Hz。
我的应用是测量325Hz和高达5次谐波的基频。
但现在，MXA无法检测到如此低的信号。
可能是因为我的设备问题？
或低频测量有限制吗？
希望你能帮忙。
Screen_101.png77.5 KB



     以下为原文

  Hi,

I'm using 33522A to generate a sine wave at 325Hz, -5dBM to input onto a MXA.

See attached.

I autotune to detect my spot frequency, but the MXA is unable to detect any.

I set the frequency at 10Mhz and autotune, MXA can detect this signal.

Later i set up my start frequency at 300Hz, stop frequency 1MHz.  

MXA is also not able to detect my signal at 325Hz. See attached pic with marker at 325.2Hz.

My application is to measure the fundamental frequency at 325Hz and up to 5th hARMonics.

But now, MXA is unable to detect such low signal.

Can it be due to my equipment issue? or is there a limitation at low frequency measurement?

Hope you can help.   
附件

• IMG_0131[1]2.1 MB
• Screen_101.png77.5 KB