HP33120A输出幅度不正确

我会检查33120A上的输出终端设置，并确保它设置为50欧姆。
如果你去菜单，系统，学期：你可以检查你是否设置为50欧姆或Hi Z.除此之外，我不知道该怎么做，我肯定会仔细检查你的电缆阻抗。
也许其他人遇到过这个并有想法？



     以下为原文

  I would check the output termination setting on the 33120A and make sure it is set to 50ohms.  If you go to menu, system, out term: you can check if you have it set for 50 ohms or Hi Z.  Other than that I'm not sure what to do here, I would definately double check the impedance of your cabling.  Maybe others have ran into this and have ideas?

谢谢你的回复。
我设置为50欧姆，并使用50欧姆阻抗同轴电缆。
结果仍然不正确。



     以下为原文

  Thank you for replying.
I setted to 50 ohms and also use a 50 ohms impedance coaxial cable. The result is still incorrect.

如果33120A设置为50欧姆的输出负载，则使用50欧姆电缆并且示波器具有50欧姆输入阻抗，则示波器应具有与函数发生器相同的读数。
在这种情况下，我看不出如何在示波器上输出100 mVpp并获得近700 mVpp。
听起来好像示波器具有高输入阻抗（当它被设置为50欧姆的输出负载时，它会读取33120A电压的两倍），然后示波器读取Vrms。
（100 mVpp * 2）= 71 mVrms。
如果在示波器上使用10：1探头设置，则显示为707 mVrms。需要尝试的一些事项：检查示波器上的探头设置。
您获得更高读数的事实让我想知道您是否将其设置为10：1而不是1：1设置函数发生器上的输出负载以匹配示波器的输入阻抗。
大多数示波器都是高阻抗，尽管少数示波器可以选择50欧姆。
如果函数发生器设置为50欧姆负载但由高阻抗示波器终止，则示波器的读数将是显示电压的两倍。检查以确保函数发生器和示波器都设置为mVpp。
我希望这有帮助！



     以下为原文

  If the 33120A is set for an output load of 50 Ohms, you are using 50 Ohm cabling and the oscilloscope has a 50 Ohm input impedance, then the oscilloscope should have the same reading as the function generator.  In this scenario, I do not see how you can be outputting 100 mVpp and getting nearly 700 mVpp on the oscilloscope. 

It sounds as though the oscillocope has a high input impedance (causing it to read twice the voltage of the 33120A when it is set for an output load of 50 Ohms) and then the oscilloscope is reading Vrms. (100 mVpp * 2) = 71 mVrms.  If you are using a 10:1 probe setting on the oscilloscope, this will be displayed as 707 mVrms.

A few things to try:

• Check the probe setting on the oscilloscope.  The fact that you are getting a much higher reading makes me wonder if you have it set to 10:1 rather than 1:1
  
• Set the output load on the function generator to match the input impedance of the oscilloscope.  Most oscilloscopes are high impedance, although a few have an option for 50 Ohms.  If the function generator is set to a 50 Ohm load but is terminated by a high impedance oscilloscope, the reading at the oscilloscope will be twice the displayed voltage.
  
• Check to make sure both the function generator and the oscilloscope are set to mVpp. 
  

I hope this helps!