ftp.agilent.com/

Hi, everyone. I have a 8753D VNA with firmware revision prior to 6.12 (it is 5.40 Mar 27, 1996).

While trying to perform a TRL* calibration, I read on the manuals that there are 3 classes for the TRL cal. But, these classes do not appear in my 8753D. There are only 12 classes instead of 15.

After downloading VNA cal kit manager, i found out that:
"The 8753D network analyzer (with firmware revision prior to 6.12) does not use the three TRL classes in implementing its TRL* calibration. Instead, it re-uses the ten reflection and transmission classes from the full two-port cal in its own unique way. It is recommended that you refer to the Agilent 8753D operating manual for instructions on how to define a TRL* cal kit and perform the calibration.
Hopefully, no one is still using this old firmware. Later revisions have added the three TRL classes."

So, I tried hard to find an older manual for 8753d, but without success..

I would really appreciate if someone could upload or give a link for an old version (probably earlier than Mar 27, 1996) of the 8753d user guide. Or, if someone could give me info about the definition of the classes for TRL* cal.

Also, the TRL/LRM OPTIONS softkey is missing from the "Modify Calibration Kit Menu", which has options for setting the reference plane to be determined either from THRU or REFLECT. So, my 8753d uses the THRU to determine the location of the reference plane, or not?

Thank you very much in advance for any info you can provide.
Papamichail Michail

Michail
apart of all your questions, why not upgrade the firmware to the latest one? Normally they are available in agilent web pages.
Mazz

@Mazz,

Downladable firmwares are available from the "E" versions only, and with special CPU unit upgrade for the "D" version.
For earlier versions the firmware is is in oldfashioned EPROMS, which should be phisically changed to newer ones.

Yes, unfortunatelly this is the truth as g579 says ..

Thank you both for your replies.

Any other reply (or the precious for me user guide) is also welcome

Michail

1st of all, I write to You that I have no experience on 8753D (TRL) , also I'm not able to answer all Your question, in particular, the how the ref plane is set.

But I try to help You anyway

- look at ftp://ftp.agilent.com/pub/callpub2/rfmw/nwa/8753D/

- The following agilent site provide manuals of 8753D of Years '96 and '97
http://www.home.agilent.com/agilent/...t=80039.k.1&ki[0]=8753d&cc=US&lc=eng&sm=g

- The classes shown by VNA Cal Kit Manager are 12 instead the classical 3 TRL classes, but looking whit attention You may recognize that the 1st word of the description IS the name of the standard; i.e. in the 2nd line You read "Line Forward Match" : it means LINE.
Following the order proposed by Cal Kit Manager , in my opinion, You should edit on the following order:
1 R
2 L
3 L
4 R
5 L
6 L
7 T
8 T
9 T
10 T
11 I don't know
12 I don't know

Hope this is a small help. Bye

Sergio,
I would really like to thank you about the info you provided!
Doing a search in agilent ftp site I found the following file
ftp://ftp.agilent.com/pub/callpub2/r...str%20WAMI.pdf
which is exactly what i wanted. It has detailed info about TRL* calibration in old 8753D VNAs, including info for the reference planes. There were also some details-restrictions I was missing, but now I am aware of.

The fist 10 classes indeed have to be filled in the order you suggested.

So, PROBLEM SOLVED,
anyone who has a similar VNA and wants to perform TRL* calibration has to study the pdf in the link.

Thank you very much again!
Bye

I hope the measurement problem is really solved.... Yes, because, I had a poor experience with my 8722D TRL* since the upgrade to TRL.
I really never got any advantage from TRL*.
In almost all measurement the residual ripple was higher than the SOLT calibrated.
I suggest to you SOLT calibration instead TRL* where possible.
Bye