8590A显示抖动

我有一段时间没有使用模拟频谱分析仪，也不知道这是不是问题。
当从反射锁定的RF信号发生器显示稳定的载波时，显示的峰值来回跳跃一点。
例如，当测量1.5 GHz载波时，它会随机地来回移动+/- 50或100 kHz左右。
输入RF电平似乎没有区别，但我一直使用-20到-60 dBm。
如果我使用峰值标记，它会达到峰值，但峰值稍微移动，可能会或可能不会返回。
标记信号跟踪使峰值居中，但显示轻微的频率变化。
显示的载波频率完全符合规格，自校准工作没有任何障碍。
该组的其他成员使用此频谱分析仪的时间比我长得多，我希望得到建议或意见。
谢谢



     以下为原文

  I have not used an analog spectrum analyzer for quite some time and don't know if this is a problem or not.

When displaying a stable carrier from a ref locked RF signal generator, the displayed peak jumps back and forth a little. For example, when measuring a 1.5 GHz carrier it moves back and forth randomly +/- 50 or 100 kHz or so. The input RF level seems to make no difference but I have been using -20 to -60 dBm.

If I use Peak Marker, it goes to peak but then the peak moves slightly and may or may not return. The marker signal tracking keeps the peak centered but shows the slight frequency changes.

The displayed frequency of the carrier is well within specs and self-calibration works without any hitches.

Other members of this group have been using this spectrum analyzer much longer than I and I am hoping for advice or comments.

Thanks