[time-nuts] HP 8566A, 8568B and 3585A Noise floor.

Tom Holmes tholmes at woh.rr.com
Thu Jul 4 18:34:50 UTC 2013


Marki...

The noise floor spec to compare is the Displayed Average Noise Level (DANL).
This will usually be measured at the narrowest Resolution Bandwidth (RBW)
and Video Bandwidth (VBW) available. And possibly some trace averaging
thrown in and either the Average or Sampling Detector since this is a noise
measurement. 

Some analyzers go to 1 HZ RBW, some only 100 Hz, so beware of
apples/oranges.

-80 dBc is a measurement relative to a CW signal, which implies a phase
noise spec, as I found a specification of  -80 dBc/Hz @ 10 kHz offset on
their web site. The best Spec Ans available today are specified at around
-129 dBc/Hz@ 10 kHz offset (Agilent's PXA). 

Rigol's best claimed DANL is -135 dBm for the DSA800 series, and -148 dBm
for the DSA1000 series. I suspect they get that from having an internal
preamp. With the preamp off the number is more likely around -135 dBm. High
end units today can achieve very close to -174 dBm DANL, at the cost of a
new Corvette.

I found a spec for noise sidebands at 10 kHz offset for the 8566B at -108
dBc. But that isn't dBc/Hz, which would be lower when adjusted for the RBW
setting.

Tom Holmes, N8ZM
Tipp City, OH
EM79


> -----Original Message-----
> From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
> Behalf Of Mark C. Stephens
> Sent: Thursday, July 04, 2013 3:56 AM
> To: time-nuts at febo.com
> Subject: [time-nuts] HP 8566A, 8568B and 3585A Noise floor.
> 
> I just had a discussion about older spectrum analyser versus the new Rigol
type
> SA.
> 
> They are saying the Rigol is -80dBc.
> 
> Unfortunately I don't know what the specs of mine are.
> Could someone help me out with some noise floor figures for the following?
> 
> 
> *         HP 8566A
> 
> *         HP 8568B
> 
> *         HP 3585A
> 
> Many thanks,
> -marki
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com To unsubscribe, go to
> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.




More information about the Time-nuts_lists.febo.com mailing list