[GreenKeys] Mystery - Hoffman diversity FSK converter

[Jim Haynes]

On Sat, 23 Jan 2016, Nick England wrote:

> Looks like a pair of CV-483/URA-17 squeezed into one unit.
> Does anyone remember seeing such a thing advertised or in use?
> What does HMPD mean?
> 
A guess: Hoffman Military Products Division

So looks like a prototype they made hoping to sell to the military and I
guess it never sold.  Or at least not in large enough quantities that
we ever saw any of them.