[R-390] Spectrum Analyzer

[2002tii]

Glenn wrote:

>I am looking at possibly buying a 3585 A or B model. My 
>understanding is the B model has a little better dynamic range. I 
>have looked on the web and can't find information on the differences.
>Would any of the users of this list know any differences, off line 
>or not? Perhaps the B model uses better FET's in the front end. The 
>A model seems to be very available and the B model a little harder 
>to find. I am wondering

They are both great machines if you don't need to go above 40 
MHz.  The primary differences are the display and control functions 
and other microprocessor circuitry.  For example, the A has its 
reticle grid on the CRT, while the B generates it with the electron 
gun.  They have a different set of GPIB commands, as 
well.  Functionally, they are peas in a pod.  I have never noticed 
any difference in DR, but there may be one.  Certainly, I have never 
needed anything better in that regard than an A.  The B models were 
not made for nearly as long as the A's, which accounts for the 
present difference in availability.

>if one were to buy the A model, could it be upgraded to the B by 
>changing out a few parts??

No.  In fact, some A modules will not work in other A's of different 
eras.  For this reason, one has to be careful when acquiring spares.

Best regards,

Don