It's probably an internal factory number. The only match I could get for the EHEC bit came up with "81 patients with diarrhea and vomiting", so those transformers have clearly seen some use on live Top 20 hits.

Nice one from when we were still young...LOL...

1973 - HP 3580A

The Model 3580A is a spectrum analyzer optimized for frequencies between 5Hz and 50kHz.

The major contribution of this instrument is digital storage of the display information. The display is refreshed at high speed on a conventional CRT from a digital memory. This eliminates the analog storage and slow sweep rates that have been a problem for even the best CRTs.
A second contribution is the reduction of sweep time through the use of a technique called "adaptive sweep". This technique takes advantage of the fact that the spectrum of interest is usually above a noise or threshold level. When the signal is below the selected threshold it is possible to speed up the sweep. When signals are encountered that are above the threshold, the sweep slows down to reproduce the full response. It is possible to achieve as much as an order of magnitude improvement in sweep speed with this feature.
A third contribution is a resolution bandwidth of 1 Hz, the best available on any sweeping spectrum analyzer. This allows the resolution of closely spaced spectral components. It also simplifies noise analysis where readings are traditionally referred to a bandwidth of 1 Hz.
The combination of these features plus others result in an instrument uniquely optimized for low frequency spectrum analysis.
:

LOL- thanks for manual. I tested the unit out last night, everything is working order and well maintained. It looks like it going to exactly what I need for quick audio tests.

Wha? Where does your friend work? Kinetic? I foresee a slew of Frankensteinish endeavors to come this summer.

Likely yes.....;)

Very cool!