Agilent FieldFox 9912A option hack?

[nexus]

Hey all,

Had a question to pose to the general community. These handheld microwave analyzers come with all hardware inside, but are heavily crippled through the typical license paywalls.

Older Agilent handhelds are vxWorks based as far as I can tell. There also are serial port connections on some boards that allow you to open a shell and get some options happening.

Has anyone made a pass at a FieldFox before? Base units do cable (distance to fault) and one-port analysis only. Spectrum analysis and two-port vna is all option based in software.

Any anecdotes would be appreciated! The best inside-pics I could get were from another post where a fellow blogger replaced his RTC batt: https://www.eevblog.com/forum/repair/agilent-fieldfox-n9912a-6-ghz-rtc-battery-swapquick-repair/

[nexus]

Roger. I suppose that means I need to buy one first.

Someone on here went and nabbed the $3500 one on ebay shorty after I started this topic..

[coromonadalix]

EEVblog is now .... well known   

[TheSteve]

The FieldFox runs WinCE.

Some other basics:

If they are Agilent branded, or Keysight branded with a white label then they run an older/slower CPU board. If they have a red Keysight badge they use a newer much faster processor board. The faster processor board models have more features such as an RTSA.

The N9912A(SA, very basic VNA) and N9923A(full 2 port VNA, no SA) are of an older design, the other models all run upgraded and better RF hardware.

[nexus]

I wish basic VNAs were more attainable the way good entry level SAs have started to become. You can pick up a second hand RSA306 for 1.5K if you shop around and wait on ebay. A used TTR503 fetches an eyewatering 7k+.

Just having difficulty deciding whether its even worth trying to buy a VNA under $5K that has the following attributes:

2 port (min. S11, S21)
>= 6GHz analog bandwidth
> 90dB dynamic range across entire bandwidth

plus: not a massive boat anchor

[TheSteve]

The boat anchor part is a good challenge - my 8753E 6 GHz was very nice, and not that heavy compared to a lot of gear. Still it was a decent size. Now I get by with a very nice Fieldfox

[nexus]

So Mr. Fox, any way to get that performance without robbing a bank? Not like showing up in a mask would be suspicious now though...

[TheSteve]

Mine was blessed with licenses from Keysight.

[tgetec]

Anyone installed 30-day Trial Options? What if the RTC is no longer powered?
Since it is not possible to modify the system time by more then 6hours backwards per day, it looks to me that the trial licenses are validated against the RTC date.

I read the RTC time is resetting on every power down here:
https://www.eevblog.com/forum/repair/agilent-fieldfox-n9912a-6-ghz-rtc-battery-swapquick-repair/

[felixsys]

I removed the RTC battery but strangely the device continues to normal clock operation and doesn't reset the data/time.
of course I removed also the battery pack.
If someone knows where I can find the RTC IC.. I would like to remove it to test it

[Alexander0]

Hello,
how are you doing? were you able to drop RTC time?