hp 8595E YTF problem (high band loss)

[Tardz]

Hi,

I have a problem with my 8595E, the 2.9-6.5 GHz band has too much insertion loss, around 15dB flat. The low band works correctly.
I know that this seems to be a common problem, and the question is: is it the RF switch or the filter.
If the problem is the RF switch, there is nothing to do, but if it is the adjustments, is it possible to correct it.
I have attached the image of the open YTF, we can see that no sphere is centered, is this normal for a YTF... the bw for a frequency configured at 5GHz is 29 MHz, Q=172 and insertion loss of 31.7dB.
Normally the signal should have had a loss of 16.5±2.5dB, from the input to the high band output of the YTF.
This measurement is made after a PRESET of the 8595E, FREQ=5GHz, SPAN=0...and the test is done on a 6GHz 8753ES VNA (the input attenuator of the 8595E is therefore at 10dB).

Has anyone had this kind of problem managed to resolve it?

Regards
Yves

[lugaw]

Someone tried fixing YTF like yours that have the spheres moved and it seems to have worked.

https://www.simonsdialogs.com/2018/12/hp-5086-7803-yig-tuned-filter-and-switch-sytf-details-and-adjustment/

[Tardz]

Thanks for the information, it will be very useful to me.