[Milsurplus] UPX-7 airborna IFF interrogator

[FERMI Ugo (FGA)]

Hi radar buffs,

I'm looking for info concerning a rather odd IFF apparatus: the AN/ UPX-7 airborne IFF interrogator.
According to the www.tpub.com<http://www.tpub.com> website, it was an interrogator set used to provide checking facilities for the ubiquitous Radar Identification Set AN/APX-6.
The main part of it was the RT-198/UPX-7 interrogator, which looks nearly identical to the RT-82/APX-6 transpondor.
I suspect that the RT-198 was actually an RT-82 modified in such a way to use its circuitry for generating standard double-pulse interrogations, rather than generating replies.
Who knows about it?  Any schematic dwg on hand?
I would buy a copy of technical manual, if any available.

Best 73's from Torino, Italy
Ugo, IW1FQG