Electronics > RF, Microwave, Ham Radio

HP 8510C error message

(1/3) > >>

MRIKen:
I recently acquired a complete 8510C network analyzer system (8510C, 8515A S-parameter test set, 83631A Source)
I get two error messages, "No IF Found" and "Caution: Source 1 Failure".  The messages flash between these 2.
The other thing that is odd, if the start frequency is above 8GHz the messages go away and everything seems to work fine.

I have done some searching and can not find anything about why this is happening.

jjoonathan:
Can you show us log amplitude vs frequency?

There are two ways to measure it, both informative in their own way: internally, using the 8510C's a1 parameter measurement (incident signal, port 1), and externally, using a spectrum analyzer attached to port 1 (S11 mode, correction off, so it doesn't hop between ports).

MRIKen:
One thing I did try is S12 and S21 response.  With the cables connected it is basically random noise below about 8 GHz, from 8-26 GHz the response is what one would expect to see.

jjoonathan:
S parameters are ratios. While it's true that we can look at the noise and hypothesize that amplitudes are low in the a (incident) and b (reflected) measurements, the 8510C also allows you to plot the a and b measurements directly. Plotting a will likely show that it is low up to 8GHz. It looks more like 13GHz to me, but amplitude will tell.

The next question is why. Is the source failing to produce a suitable signal below 13GHz? Or are the samplers failing to convert it down to IF? The 83631 has a frequency band that ends at 13.5GHz so I suspect the issue lies there, but the nature of the issue will need to be determined by tuning the source to various frequencies (using either the VNA in zero-span mode or the 8360 Front Panel Emulator) and inspecting its output with a spectrum analyzer.

MRIKen:
I do not have a spectrum analyzer yet, but I can use my scope and look at it to a bit over 1 GHz.  But I will need to get an SMA cable/adapter so I can check the output. 

It is odd that the 'noise' ends at different freq when I change the start freq. 

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod