The Watkins-Johnson HF-1000 (and NSA version, WJ-8711) are mentioned in this article

On January 11, 2012 the National Security Agency (NSA) released a pre-1995 article entitled “Receiver Dynamics” from its classified internal magazine, Cryptologic Quarterly. It contains an excellent, well-written explanation of the specifications of shortwave receivers used by some of NSA’s K4 divisions.

Download the article here (PDF).

Thanks to Ed in the SWLfest list for the tip!