Forums › SP Series Discussions › Strange spurs in SP145 without input signal
- This topic has 1 reply, 2 voices, and was last updated 12 months ago by
Justin Crooks.
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MehdiParticipantHello. I did a simple test to compare SP145’s noise floor to BB60D, and observed a strange behaviour in SP145. Please check the screenshots.
Is this related to the fact that SP145 doesn’t have a preselector filter bank?
Settings are equal:
30MHZ-6GHZ
10KHZ RBW and 3KHZ VBW
Trace mode Average (100 times averaging)
Ref level -30dBm
Attenuation 0dB
Input port terminated with a high quality 50 ohm load.
Both tested on the same version of Spike on the same laptop in the same environment.Bests
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Justin CrooksModerator- This reply was modified 12 months ago by
Justin Crooks.
Mehdi,
Signals present when the input is terminated are “residual responses” or sometimes “residual spurious”.
The specification for the BB60D is -120 dBm. This is one of the strengths of the BB60D.
The specification for the SP145 is -103 dBm, similar to the BB60C.
This is not directly related to the preselector, and is more closely related to filtering and isolation differences in the architectures.- This reply was modified 12 months ago by
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