8753C/87054A 6 GHz故障排除

刚刚购买了87054A测试装置，用于我的8753C。
在3 GHz范围内一切都很好，但是当我转到6 GHz时，我得到一个“小心：可能的错误锁定”消息。
我已经完成了以下故障排除：1。当在3 GHz范围内设置2 GHz的CW频率时，我在连接到端口1或R输出（通过功率分配器）的specrum分析仪上获得了良好的单响应。
然而，进入6 GHz范围并设置任何CW频率（例如，2或4 GHz），我看到信号在整个地方跳舞。
它肯定没有锁定，似乎从DC-ish到3 GHz。
我没有看到3 GHz以上输出的迹象。
2. 8753C的射频输出电平似乎合理;
使用通过功率分配器插入RF OUT到RF IN路径的功率计我看到的信号在它们应该的位置的dB左右，我可以产生超过+20 dBm的输出。
3.我尝试在+10 dBm处施加2 GHz（尽可能多的曲柄）从单独的信号发生器到测试装置的RF IN端口，然后在两者中查看R输出（通过功率分配器）
3 GHz和6 GHz范围。
我认为这可能是赠品：在两个范围内，R端口的输出频率为2 GHz -12 dBm，但4 GHz输出低于-60 dBm。
因此，在切换频率范围时，输出信号没有区别，就好像没有使用倍频器一样。
我也做了一些其他的测试，但这三个似乎表明双倍的转换可能不起作用，永远不会被切换。
接收器期望信号的频率是它实际看到的频率的2倍，因此不满意并且不会锁定。
我现在最关心的是试图确定问题是否在测试集中，因为经销商给了我保修，我可能能够解决这个问题。
但我没有其他分析器或测试装置可以交换，因此我想尽可能多地做以避免发回未被破坏的东西。
（顺便说一句，我已经交换了射频和控制互连电缆，这没有任何区别。）我的诊断是否有意义？
我是否应该进行任何其他测试以最终确定进出其中一个方框？
谢谢，约翰



     以下为原文

  Just acquired an 87054A test set to use with my 8753C.  Everything is just fine in 3 GHz range, but when I go to 6 GHz, I get a "CAUtiON: POSSIBLE FALSE LOCK" message.

I have done the following troubleshooting:

1.  When setting a CW frequency of say 2 GHz in the 3 GHz range, I get a nice single response on a specrum analyzer connected to Port 1 or the R output (through a power divider).  However, going to 6 GHz range and setting any CW frequency (e.g., either 2 or 4 GHz) I see the signal dancing all over the place.  It's definitely not locked and seems to be sweeping from DC-ish through 3 GHz.  I don't see any sign of output above 3 GHz.

2.  RF output level from the 8753C seems to be reasonable; using a power meter inserted via power divider on the RF OUT to RF IN path I'm seeing signals that are within a dB or so of where they should be, and I can generate more than +20 dBm output.

3.  I've tried applying 2 GHz at +10 dBm (as much as I can crank) from a separate signal generator to the RF IN port of the test set and then looking at the R output (through a power divider) in both 3 GHz and 6 GHz ranges.  I think this may be the giveaway: in both ranges, the R port has a 2 GHz output at about -12 dBm but the 4 GHz output is lower than -60 dBm.  So there's no difference in the output signal when switching frequency ranges, as if the doubler isn't being engaged.

I've done some other tests as well but those three seem to indicate that the switch around the doubler probably isn't working and is never being switched in line.  The receiver is expecting a signal at 2X the frequency it actually sees, and therefore is unhappy and doesn't lock.

My biggest concern right now is trying to determine whether the problem is in the test set, since the dealer gave me a warranty and I may be able to make this *his* problem.  But I don't have other analyzers or test sets to swap around, and therefore I want to do as much as I can to avoid sending back something that isn't broken.  (By the way, I've swapped RF and control interconnect cables and that didn't make any difference.)

Does my diagnostic make sense?  Are there any other tests I should perform to definitively rule in or out one of the boxes?   

Thanks,

John