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

[Bruce Griffiths]

Said
SAIDJACK at aol.com wrote:
> Hi guys,
>  
> does anyone have any experience with "home-brew" quadrature-PLL PN  
> measurements? Renting/buying a E5052A or TSC5120A does get to  be expensive.. 
>  
> I am using different mixers (Mini Circuits ZFM-150 and ZFM-4) and the noise  
> floor coming out of these seems much higher than I expected. Any  suggestions 
> on mixers anyone? How about the low pass filter and amplifier?
>   
The Mininicuits phase detectors may be better, at least they are
specified for phase detector operation and have specified (and
relatively high ) RF - LO isolation.
Selecting a mixer where the RF and LO transformer primaries can have
separate low frequency grounds may be useful.
>  
> I built an LC 8th-order 1.5MHz lowpass, and I wonder if the reflected  energy 
> (at 10MHz, 20MHz, etc) is causing noise and  intermodulation in the diodes 
> etc.
>   
Does the filter have an inductive or capacitive input?
> Thanks for any hints,
> bye,
> Said
>   
Bruce