[time-nuts] 35601A as stand-in for 11848A ?
bruce.griffiths at xtra.co.nz
Sat Jan 5 18:16:03 EST 2008
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
Does the filter have an inductive or capacitive input?
> Thanks for any hints,
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