I just got my hands on this great receiver from AOR which covers 10 kHz to 2.6 GHz. The AR-5000 is one of the best receivers made by AOR. It is old but still one of the best scanners out there. This model is the +3 version which has some extra features. Synchronous AM, Automatic Frequency Control and Noise blanker.
On the back of the receiver there are two antenna inputs and a mysterious connector (jack-plug) which I haven't investigated yet.
With the AR-5000 came the Spectrum Display Unit or the SDU5000. But since I will use my second SDR-14 with the receiver I will not be using the SDU5000.
I have added the manuals for both units below.