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N8975A Thot and Tcold function

Question asked by unknown on Nov 4, 2013
Latest reply on Nov 13, 2013 by unknown
I found the attached pdf from old thread on hot/Cold Load & N8975A and one of the paragraph mention that :

'22. PHOT should show the noise source excess noise. You can substitute any source of noise (unknown or known) to measure its excess noise in dB (relative to kTB). So long as the noise source you used during the calibration process was at the same temperature as the unknown noise source, the excess noise measured is now measured against a calibrated reference. '

I am trying to measure ENR of my noise source (unknown noise source) using N8975A My question as follows:

1) So i can actually cal N8975A with the standard Agilent noise source at rm temp and by looking at the Phot it actually measure ENR of my unknown noise source?

2) what if the unknown noise source is place at a hot plate of 80 degree C (323.15k), and the calibration using the known noise source was done and rm temp 303k, Can i measure the ENR of the unknown source correctly? do i have to do any calculation to remove the temp different between calibration n actual measurement?

Thanks

Best Regards
Jas  

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