I bought a 5203 because I want to use it to measure frequency, power, bandwidth.
With the bandwidth I have a problem. I tried it with spectrum mode at:
Spectrum Range 125Mhz
Spectrum Bins 16384
Window Function Blackman
Display Mode Average
Logarithmic Unit dBm 50 Ohm
First I searched a radio station and found it at 98.5 MHz with peak at -57,19dBm.
From the peak I go down with the second level ruler to -3dB of the peak.
With the two frequency rulers I go to the crossingpoints left and right of the signal
and I get a bandwidth of 17,23kHz. I think a stereo broadcast should be wider than
17,23kHz. If I'm right the chanal bandwidth is a max. of 150kHz.
Now I'm very confused because I tried to change the spectrum bins up to 65536, this should
be 1,9kHz Bin width, before it was 7kHz, so I hoped to get a better result. What I get
is something complete other then in the first try. Now I measure a peak of -65,3dBm that
is a really to big different. At -3dB under the peak I measure a bandwidth of 6kHz.
Of course there will be different between measuring with 16384 or 65536 Bins but I never
will know what I measure because on every changing the Spectrum Bins I will get an other
With the radio station it is only an example, I tried also with other signals like the
output of amateur radios on different frequencys.
How can I get a result of measuring which is a exakt measuring which I can trust?