[time-nuts] 35601A as stand-in for 11848A ?

[Bruce Griffiths]

John Miles wrote:
> HP's approach with the 11729 was to put about 0 dBm on the RF port (from the
> 'reference', typically but not necessarily an 8662A) and apply the test
> signal at about +11 dBm to the LO port, via an AGC-limited amplifier.  The
> IF output is terminated by the 50-ohm LNA input port.
>
>   
Thats why its phase noise floor is relatively high.
Saturating both mixer ports and using a capacitive IF port termination
should achieve a lower phase noise floor.
The tradeoff is that careful calibration of the mixer phase sensitivity
frequency response needs to be done.
However the offset frequency limit for such techniques is about 50KHz or so.

Bruce